CN109131336A

CN109131336A - Obtain the method and system of coefficient of road adhesion

Info

Publication number: CN109131336A
Application number: CN201710453890.5A
Authority: CN
Inventors: 周勇有; 张永生; 刘祖齐; 刘晓康; 王荣蓉
Original assignee: Nanjing Rong Jun Technology Development Co Ltd; Huawei Technologies Co Ltd
Current assignee: Nanjing Rong Jun Technology Development Co Ltd; Huawei Technologies Co Ltd
Priority date: 2017-06-15
Filing date: 2017-06-15
Publication date: 2019-01-04
Anticipated expiration: 2037-06-15
Also published as: CN109131336B

Abstract

This application provides a kind of method and systems for obtaining coefficient of road adhesion, the lateral speed of the first mass center is calculated by integration method, the multiple lateral speeds of second mass center for being directed to multiple coefficient of road adhesion are calculated by model method, in turn, coefficient of road adhesion is solved according to the lateral speed of the first mass center and the lateral speed of multiple second mass centers.This method comprises: obtaining the mass center longitudinal acceleration of the vehicle, mass center side acceleration, mass center yaw velocity, front wheel angle and mass center longitudinal velocity；The corresponding lateral speed of second mass center of each preset coefficient of road adhesion in the lateral speed of the first mass center and multiple preset coefficient of road adhesion is calculated according to the parameter of acquisition；In turn, target coefficient of road adhesion is calculated according to the corresponding lateral speed of second mass center of preset coefficient of road adhesion each in the lateral speed of the first mass center and multiple preset coefficient of road adhesion.

Description

Obtain the method and system of coefficient of road adhesion

Technical field

This application involves automotive fields, and more particularly, to a kind of method and system for obtaining coefficient of road adhesion.

Background technique

Many vehicle control systems, especially active safety system, control algolithm need to meet road adaptive characteristic, At this point, coefficient of road adhesion μ and vehicle centroid side velocity V_yThere is weight to vehicle control system, especially active safety system Big influence.

Therefore, how to estimate that coefficient of road adhesion μ further calculates vehicle centroid side according to coefficient of road adhesion μ To speed V_yIt is a urgent problem to be solved.

Summary of the invention

The application provides a kind of method and system for obtaining coefficient of road adhesion, can pass through common some vehicle-mounted sensings Device parameter collected estimates that it is lateral further to calculate vehicle centroid according to coefficient of road adhesion μ by coefficient of road adhesion μ Speed V_y。

In a first aspect, the embodiment of the present application provides a kind of method for obtaining coefficient of road adhesion, it is applied to vehicle, packet It includes:

Obtain mass center longitudinal acceleration, mass center side acceleration, mass center yaw velocity, front wheel angle and the matter of the vehicle Heart longitudinal velocity；

According to the mass center yaw velocity, the mass center longitudinal velocity and the mass center side acceleration, the first mass center side is calculated To speed；

According to the mass center longitudinal acceleration, the mass center side acceleration, the mass center yaw velocity, the front wheel angle, it is somebody's turn to do Mass center longitudinal velocity and multiple preset coefficient of road adhesion calculate each pre- in multiple preset coefficient of road adhesion If the corresponding lateral speed of second mass center of coefficient of road adhesion；

Obtain at least one lateral speed of third mass center；Wherein, which is and the first mass center side The second mass center lateral speed close to speed, this approaches and is used to indicate the lateral speed of third mass center and the first mass center side It is less than first threshold to the absolute value of the difference of speed；

According to the corresponding preset road surface of the lateral speed of third mass center each at least one lateral speed of third mass center Attachment coefficient calculates target coefficient of road adhesion.

Therefore, the embodiment of the present application acquisition coefficient of road adhesion method in, according to from accelerometer, gyroscope, ABS system, grating etc. can support the mass center longitudinal acceleration obtained in the inexpensive sensor of volume production, mass center lateral at present The parameters such as acceleration, mass center yaw velocity, front wheel angle and mass center longitudinal velocity calculate target coefficient of road adhesion, effectively Vehicle security is improved, balances integral vehicle cost, while being easily achieved again.

It optionally,, should after the lateral speed of the first mass center is calculated in a kind of implementation of first aspect Method further include:

The lateral speed of first mass center is filtered.

Optionally, lateral according to the mass center longitudinal acceleration, the mass center at this in a kind of implementation of first aspect Acceleration, the mass center yaw velocity, the front wheel angle, the mass center longitudinal velocity and multiple preset coefficient of road adhesion, Calculate the corresponding lateral speed of second mass center of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion it Afterwards, this method further include:

The lateral speed of second mass center is filtered.

Therefore, in the method for the acquisition coefficient of road adhesion of the embodiment of the present application, by the lateral speed of the first mass center The lateral speed of the second mass center corresponding with preset coefficient of road adhesion each in multiple preset coefficient of road adhesion is filtered Wave processing, eliminates each preset coefficient of road adhesion pair in the lateral speed of the first mass center and multiple preset coefficient of road adhesion Score accumulation error present in the solution procedure for the lateral speed of the second mass center answered improves the calculating of target coefficient of road adhesion Precision, thus, improve dynamics Controlling precision and vehicle driving safety.

Optionally, in a kind of implementation of first aspect, this is filtered the lateral speed of the first mass center, Include:

According to formulaPlace is filtered to the lateral speed of the first mass center Reason,

Wherein,It is the lateral speed of the first mass center obtained after filtering processing,It is the first mass center side To speed, τ is time constant, and s is Laplace operator.

Optionally, in a kind of implementation of first aspect, this is filtered the lateral speed of the second mass center, Include:

According to formulaThe lateral speed of second mass center is filtered Wave processing,

Wherein,When be preset coefficient of road adhesion being i after filtering processing obtained the second mass center Lateral speed,The lateral speed of the second mass center when be preset coefficient of road adhesion being i, τ is time constant, and s is to draw General Laplacian operater.

Optionally, in a kind of implementation of first aspect, in the lateral speed of the first mass center and multiple preset The corresponding lateral speed of second mass center of each preset coefficient of road adhesion is by filtering processing in coefficient of road adhesion, and obtains When taking the lateral speed of two third mass centers, the calculating target coefficient of road adhesion, comprising:

According to formulaCalculate the target road Face attachment coefficient

Wherein,It is target coefficient of road adhesion,It is lateral by the first mass center obtained later is filtered Speed,It is one in two lateral speeds of third mass center,It is another in two lateral speeds of third mass center One,It isCorresponding coefficient of road adhesion,It isCorresponding coefficient of road adhesion.

It optionally,, should after the target coefficient of road adhesion is calculated in a kind of implementation of first aspect Method further include:

The 4th lateral speed of mass center is calculated according to the target coefficient of road adhesion；

According to the 4th lateral speed of mass center and the lateral speed of the first mass center, the lateral speed of target centroid is calculated.

Optionally, in a kind of implementation of first aspect, this is according to the 4th lateral speed of mass center and first matter The lateral speed of the heart calculates the lateral speed of target centroid, comprising:

High-pass filtering is carried out to the lateral speed of first mass center, obtains the filtered lateral speed of first mass center；

Low-pass filtering is carried out to the lateral speed of the 4th mass center, obtains the lateral speed of filtered 4th mass center；

According to the lateral speed of filtered 4th mass center and the filtered lateral speed of first mass center, the mesh is calculated Mark the lateral speed of mass center.

Therefore, in the method for the acquisition coefficient of road adhesion of the embodiment of the present application, by the lateral speed of the first mass center High-pass filtering is carried out, and low-pass filtering is carried out to the lateral speed of the 4th mass center, makes full use of first that integration method solves The low frequency characteristic for the 4th lateral speed of mass center that the high frequency characteristics and modelling of the lateral speed of mass center solve improves target matter The computational accuracy of the lateral speed of the heart, thus, improve dynamics Controlling precision and vehicle driving safety.

Optionally, in a kind of implementation of first aspect, the lateral speed of the calculating target centroid, comprising:

According to formulaThe lateral speed of the target centroid is calculated,

Wherein,It is the lateral speed of target centroid,It is the filtered lateral speed of first mass center,It is the lateral speed of filtered 4th mass center, τ is time constant, and s is Laplace operator.

Optionally, in a kind of implementation of first aspect, this laterally adds according to the mass center longitudinal acceleration, the mass center Speed, the mass center yaw velocity, the front wheel angle, the mass center longitudinal velocity and multiple preset coefficient of road adhesion, meter Calculate the corresponding lateral speed of second mass center of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion, packet It includes:

According to the mass center side acceleration, the mass center longitudinal velocity and the mass center yaw velocity, calculate multiple default Coefficient of road adhesion in the lateral speed of each preset corresponding 5th mass center of coefficient of road adhesion；

According to the mass center longitudinal velocity, the mass center yaw velocity corresponding with each preset coefficient of road adhesion The lateral speed of five mass centers calculates the corresponding vehicle of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion Multiple wheels slip angle of tire；

According to the height of the mass center of the mass center longitudinal acceleration, the mass center side acceleration and the vehicle to ground, calculate The load of multiple wheels of the vehicle；

According to the load of multiple wheel, the tire cornering stiffness of multiple wheel is calculated；

According to each preset road surface in multiple preset coefficient of road adhesion, multiple preset coefficient of road adhesion Slip angle of tire, the load of multiple wheel, the Wheel slip of multiple wheel of the corresponding multiple wheel of attachment coefficient are rigid It is corresponding to calculate each preset coefficient of road adhesion in multiple preset coefficient of road adhesion for the tire model of degree and the vehicle Multiple wheel tire force；

It is corresponding according to preset coefficient of road adhesion each in the front wheel angle and multiple preset coefficient of road adhesion Multiple wheel tire force, it is corresponding to calculate each preset coefficient of road adhesion in multiple preset coefficient of road adhesion Mass center side acceleration；

According to each pre- in the mass center longitudinal velocity, the mass center yaw velocity and multiple preset coefficient of road adhesion If the corresponding mass center side acceleration of coefficient of road adhesion, calculate each preset in multiple preset coefficient of road adhesion The corresponding lateral speed of second mass center of coefficient of road adhesion.

Optionally, each in multiple coefficient of road adhesion is calculated in a kind of implementation of first aspect After the corresponding mass center side acceleration of preset coefficient of road adhesion, this method further include:

Laterally added according to the corresponding mass center of preset coefficient of road adhesion each in multiple preset coefficient of road adhesion Speed, the mass center longitudinal velocity and the mass center yaw velocity are calculated and are each preset in multiple preset coefficient of road adhesion The lateral speed of corresponding 5th mass center of coefficient of road adhesion.

Optionally, in a kind of implementation of first aspect, this is according to the mass center side acceleration, the longitudinal speed of the mass center It is corresponding to calculate each preset coefficient of road adhesion in multiple preset coefficient of road adhesion for degree and the mass center yaw velocity The 5th lateral speed of mass center, comprising:

According to formulaCalculate each preset road in multiple preset coefficient of road adhesion The lateral speed of corresponding 5th mass center of face attachment coefficient,

Wherein,Be preset coefficient of road adhesion be i when the 5th lateral speed of mass center, V_xIt is mass center longitudinal velocity, γ is mass center yaw velocity, a_yIt is mass center side acceleration.

Optionally, in a kind of implementation of first aspect, this is according to the mass center longitudinal velocity, the mass center yaw angle speed Degree adheres to system with the lateral speed of each preset corresponding 5th mass center of coefficient of road adhesion, the multiple preset road surface of calculating The slip angle of tire of multiple wheels of the corresponding vehicle of each preset coefficient of road adhesion in number, comprising:

According to formulaIt calculates multiple default Coefficient of road adhesion in the corresponding vehicle of each preset coefficient of road adhesion multiple wheels slip angle of tire,

Wherein,It is the slip angle of tire of the near front wheel of the vehicle,It is the slip angle of tire of the off-front wheel of the vehicle,It is the slip angle of tire of the left rear wheel of the vehicle,It is the slip angle of tire of the off hind wheel of the vehicle, δ_fIt is front wheel angle, It is the lateral speed of preset corresponding 5th mass center of coefficient of road adhesion of some in multiple preset coefficient of road adhesion, V_xIt is Mass center longitudinal velocity, γ are mass center yaw velocity, l_fIt is the mass center of the vehicle to the distance of front axle, l_rIt is the mass center of the vehicle To the distance of rear axle, l_sIt is the half of the vehicle width of the vehicle.

Optionally, in a kind of implementation of first aspect, this laterally adds according to the mass center longitudinal acceleration, the mass center The mass center of speed and the vehicle calculates the load of multiple wheels of the vehicle to the height on ground, comprising:

According to formula The load of multiple wheel is calculated,

Wherein, F_zflIt is the load of the near front wheel of the vehicle, F_zfrIt is the load of the off-front wheel of the vehicle, F_zrlIt is the vehicle Left rear wheel load, F_zrrIt is the load of the off hind wheel of the vehicle, a_xIt is mass center longitudinal acceleration, a_yIt is that mass center laterally accelerates Degree, h_cIt is the centroid distance ground level of the vehicle, m is the vehicle mass of the vehicle, and g is acceleration of gravity, l_fIt is the vehicle Distance of the mass center to front axle, l_rIt is the mass center of the vehicle to the distance of rear axle, l_sIt is the half of the vehicle width of the vehicle.

Optionally, in a kind of implementation of first aspect, which calculates multiple vehicle The tire cornering stiffness of wheel, comprising:

According to formulaThe tire cornering stiffness of multiple wheel is calculated,

Wherein, C_αijIt is the tire cornering stiffness of some wheel, F_zijIt is the load of some wheel, a₁、a₂、a₃It is normal Number；

Work as F_zijIt is the load F of the near front wheel_zflWhen, C_αijIt is the tire cornering stiffness C of the near front wheel_αfl；Work as F_zijIt is off-front wheel Load F_zfrWhen, C_αijIt is the tire cornering stiffness C of off-front wheel_αfr；Work as F_zijIt is the load F of left rear wheel_zrlWhen, C_αijIt is left rear wheel Tire cornering stiffness C_αrl；Work as F_zijIt is the load F of off hind wheel_zrrWhen, C_αijIt is the tire cornering stiffness C of off hind wheel_αrr。

Optionally, in a kind of implementation of first aspect, when the tire model is Brush Model, this is more according to this Each preset coefficient of road adhesion is corresponding in a preset coefficient of road adhesion, multiple preset coefficient of road adhesion should The slip angle of tire of multiple wheels, the load of multiple wheel, the tire cornering stiffness of multiple wheel and the tire of the vehicle Model calculates the wheel of the corresponding multiple wheel of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion Tire power, comprising:

According to formula The tire force of the corresponding multiple wheel of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion is calculated,

Wherein,It is the tire force of a certain wheel, C_αijIt is the tire cornering stiffness of some wheel, F_zijIt is some The load of wheel,It is the slip angle of tire of a certain wheel, μ is some preset road in multiple preset coefficient of road adhesion Face attachment coefficient；

Work as F_zijIt is the load F of the near front wheel_zfl, C_αijIt is the tire cornering stiffness C of the near front wheel_αfl,It is the tire of the near front wheel Side drift angleWhen,It is the tire force of the near front wheelWork as F_zijIt is the load F of off-front wheel_zfr, C_αijIt is the tyre side of off-front wheel Inclined rigidity C_αfr,It is the slip angle of tire of off-front wheelWhen,It is the tire force of off-front wheelWork as F_zijIt is the load of left rear wheel Lotus F_zrl, C_αijIt is the tire cornering stiffness C of left rear wheel_αrl,It is the slip angle of tire of left rear wheelWhen,It is the wheel of left rear wheel Tire powerWork as F_zijIt is the load F of off hind wheel_zrr, C_αijIt is the tire cornering stiffness C of off hind wheel_αrr,It is the tire of off hind wheel Side drift angleWhen,It is the tire force of off hind wheel

Optionally, in a kind of implementation of first aspect, this is according to the front wheel angle and multiple preset road surface The tire force of the corresponding multiple wheel of each preset coefficient of road adhesion, calculates multiple preset road surface in attachment coefficient The corresponding mass center side acceleration of each preset coefficient of road adhesion in attachment coefficient, comprising:

According to formulaCalculate multiple preset road surface The corresponding mass center side acceleration of each preset coefficient of road adhesion in attachment coefficient,

Wherein,It is that some preset coefficient of road adhesion is corresponding in multiple preset coefficient of road adhesion laterally to add Speed,It is the resultant force of the tire force of some preset coefficient of road adhesion in multiple preset coefficient of road adhesion,It is The tire force of the near front wheel of some preset coefficient of road adhesion in multiple preset coefficient of road adhesion,It is multiple pre- If coefficient of road adhesion in some preset coefficient of road adhesion off-front wheel tire force,It is multiple preset roads The tire force of the left rear wheel of the preset coefficient of road adhesion of some in the attachment coefficient of face,It is multiple preset road surface attachments The tire force of the off hind wheel of the preset coefficient of road adhesion of some in coefficient, δ_fIt is front wheel angle, m is the quality of vehicle.

Optionally, in a kind of implementation of first aspect, this is according to the mass center longitudinal velocity, the mass center yaw angle speed Degree and the corresponding mass center side acceleration of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion, calculating The corresponding lateral speed of second mass center of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion, comprising:

According to formulaIt calculates each preset in multiple preset coefficient of road adhesion The corresponding lateral speed of second mass center of coefficient of road adhesion,

Wherein,Be preset coefficient of road adhesion be i when the lateral speed of the second mass center,It is preset road Side acceleration when face attachment coefficient is i, V_xIt is mass center longitudinal velocity, γ is mass center yaw velocity.

Wherein,Be preset coefficient of road adhesion be i when the 5th lateral speed of mass center, V_xIt is mass center longitudinal velocity, γ is mass center yaw velocity,Be preset coefficient of road adhesion be i when mass center side acceleration.

Optionally, in a kind of implementation of first aspect, this is according to the mass center yaw velocity, the longitudinal speed of the mass center Degree and the mass center side acceleration calculate the lateral speed of the first mass center, comprising:

According to formulaThe lateral speed of the first mass center is calculated,

Wherein,It is the lateral speed of the first mass center, V_xIt is mass center longitudinal velocity, γ is mass center yaw velocity, a_yIt is Mass center side acceleration.

Second aspect, the embodiment of the present application provide a kind of system for obtaining coefficient of road adhesion, can execute first party The module or unit of method in any optional implementation of face or first aspect.

The third aspect provides a kind of system for obtaining coefficient of road adhesion, including memory and processor, the memory On be stored with and can serve to indicate that the program code for executing above-mentioned first aspect or its any optional implementation, when the code It is performed, which may be implemented each operation that equipment executes in the method for first aspect.

Fourth aspect provides a kind of computer storage medium, is stored with program code in the computer storage medium, should Program code is used to indicate computer and executes side in any possible implementation of above-mentioned first aspect or first aspect The instruction of method.

5th aspect, provides a kind of computer program product including instruction, when run on a computer, so that Computer executes method described in above-mentioned various aspects.

Detailed description of the invention

Fig. 1 is a kind of a kind of functional block diagram of example vehicle provided by the present application.

Fig. 2 is the schematic flow chart according to the method provided by the present application for obtaining coefficient of road adhesion.

Fig. 3 is the schematic block diagram that the system of coefficient of road adhesion is obtained according to the offer of the application.

Fig. 4 is the schematic block diagram according to the second speed calculator of the embodiment of the present application.

Fig. 5 is another schematic block diagram according to the system of the acquisition coefficient of road adhesion of the embodiment of the present application.

Specific embodiment

Below in conjunction with attached drawing, the technical solution in the application is described.

Fig. 1 is a kind of a kind of functional block diagram of example vehicle 100 provided by the present application.It is coupled to vehicle 100 or is included in Component in vehicle 100 may include propulsion system 110, sensing system 120, control system 130, peripheral equipment 140, power supply 101, computing device 103 and user interface 105.Computing device 103 may include processor 102 and memory 104.Computing device 103 can be a part of the controller of vehicle 100 or controller.Memory 104 may include the finger that processor 102 can be run It enables, and can store map datum.The component of vehicle 100 can be configured to with it is interconnected amongst one another and/or be coupled to each system The mode of other components interconnection of system works.For example, power supply 101 can provide electric power to all components of vehicle 100.Computing device 103 can be configured to receive data and right from propulsion system 110, sensing system 120, control system 130 and peripheral equipment 140 They are controlled.Computing device 103 can be configured to generate the display of image on user interface 105 and from user interface 105 receive input.

In other examples, vehicle 100 may include more, less or different system, and each system may include more More, less or different component.In addition, the system and component shown can be combined or be divided by any number of mode.

Propulsion system 110 can be used for vehicle 100 and provide dynamic movement.As shown, propulsion system 110 includes wheel/wheel Tire 111, transmission device (transmission) 112, energy source 113 and engine/engine 114.

The tire/wheel 111 of vehicle 100 can be configured to various forms, including single block, bicycle/motorcycle, tricycle Or car/truck four-wheel form.Other tire/wheel forms be also it is possible, such as including six or more wheels Those vehicles.The tire/wheel 111 of vehicle 100 can be configured to rotate relative to other 111 differentials of tire/wheel.One In a little examples, tire/wheel 111 may include at least one wheel and and driving surface for being fixedly attached to transmission device 112 At least one tire at the edge for being coupled to wheel of contact.Tire/wheel 111 may include any combination of metal and rubber, Or the combination of other materials.

Transmission device 112 can be used for machine power to be transmitted to tire/wheel 111 from engine/engine 114.For this purpose, Transmission device 112 may include gearbox, clutch, differential mechanism, drive shaft and/or other elements.It include driving in transmission device 112 In the example of moving axis, drive shaft includes one or more axis for being coupled to tire/wheel 111.

Energy source 113 can be the source of all or part of energy energized to engine/engine 114.That is, drawing Hold up/engine 114 can be used for for energy source 113 is converted to mechanical energy.The example of energy source 113 includes gasoline, diesel oil, other Fuel, propane, other fuel based on compressed gas, ethyl alcohol, solar panel, battery and other electric power based on petroleum come Source.(one or more) energy source 113 can additionally or alternatively include fuel tank, battery, capacitor and/or flywheel Any combination.In some instances, other systems of energy source 113 or vehicle 100 provide energy.

Engine/engine 114 can be or including any of internal combustion engine, motor, steam engine and Stirling engine etc. Combination.Other engines and engine are also possible.In some instances, propulsion system 110 may include a plurality of types of engines And/or engine.For example, pneumoelectric mixing car may include petrol engine and motor.Other examples are possible.

Propulsion system 110 can additionally or alternatively include the component other than those of shown.

Sensing system 120 may include several sensors for sensing the information about 100 local environment of vehicle.Such as Shown in figure, the sensor of sensing system includes accelerometer 121, gyroscope 122, front wheel angle sensor 123, ABS control Device 124, radar range finding (RADAR) unit 125, global positioning system 126.Sensing system 120 can also include some additional Sensor, for example, Inertial Measurement Unit (Inertial Measurement Unit, IMU), radio detection unit, laser Ranging (LIDAR) unit, camera and the actuator for position and/or direction for modification sensor, in another example, sensor System 120 may also comprise the sensor of the built-in system of monitoring vehicle 100 (for example, O₂Monitor, fuel ga(u)ge, oil temperature, Etc.).Sensing system 120 can also include other sensors.

Accelerometer 121 can be used for acquiring mass center longitudinal acceleration a_xWith mass center side acceleration a_y。

Gyroscope 122 can be used for measuring mass center yaw velocity γ.

Front wheel angle sensor 123 can be used for measuring front wheel angle δ_f。

Abs controller 124 can be used for obtaining mass center longitudinal velocity V_x。

RADAR unit 125 can be counted as object detecting system, be used to come using radio wave the spy of detection object Property, distance, height, the direction or speed of such as object.RADAR unit 125 can be configured to transmission radio wave or microwave arteries and veins Punching, can rebound from any object in the route of wave.The part energy of wave can be back to receiver (for example, dish by object Shape antenna or antenna), which is also possible to a part of RADAR unit 125.RADAR unit 125 is also configured to pair The signal (rebounding from object) received executes Digital Signal Processing, and can be configured to identification object.It is other to be similar to The system of RADAR has been used in the other parts of electromagnetic spectrum.Another example is LIDAR (light detection and rangings), can be used Visible light from laser, rather than radio wave.

Global positioning system 126 can be the positioning system based on GPS module, be also possible to based on Beidou satellite navigation system The positioning system of system can also be the positioning system based on GALILEO positioning system, can also be other positioning systems.The whole world Positioning system 126 can be any sensor in the geographical location for estimating vehicle 100.For this purpose, global positioning system 126 can It can include transceiver, be based on satellite location data, estimate position of the vehicle 100 relative to the earth.In this example, computing device 103 can be used for estimating in conjunction with map datum using global positioning system 126 vehicle on the road that vehicle 100 can travel on it The position on road boundary.

Control system 130 can be configured to the operation of control vehicle 100 and its component.For this purpose, control system 130 may include Control unit 131, steering unit 132, throttle 133, coefficient of road adhesion solver 134, lateral speed solver 135, navigation Controller 136.

Brake unit 131 can be configured as any combination for the mechanism for making vehicle 100 slow down.For example, brake unit 131 can be used friction to slow down tire/wheel 111.As another example, brake unit 131 can be configured to regenerated (regenerative) and by the kinetic energy of tire/wheel 111 electric current is converted to.Brake unit 131 can also take other forms.

Steering unit 132 can be configured as any combination of the direction of advance of adjustment vehicle 100 or the mechanism in direction.

Throttle 133 can be configured as the service speed of control engine/engine 114 and acceleration simultaneously controls vehicle in turn Any combination of the mechanism of 100 velocity and acceleration.

Coefficient of road adhesion solver 134 can be used for solving coefficient of road adhesion μ.

Lateral speed solver 135 can be used for solving lateral vehicle velocity V_y。

Navigation controller 136 can be any system for the drive route for being configured to determine that vehicle 100.Navigation controller 136 can extraly be configured as dynamically updating drive route while vehicle 100 is in operation.In some examples In, navigation controller 136 can be configured in conjunction with the data for coming global positioning system 126 and one or more predetermined maps so as to Drive route is determined for vehicle 100.

Control system 130 can additionally or alternatively include the component other than those of shown.

Peripheral equipment 140 can be configured to that vehicle 100 is allowed to interact with external sensor, other vehicles and/or user.For This, peripheral equipment 140 may include such as loudspeaker 141, microphone 142, touch screen 143 and wireless communication system 144.

Loudspeaker 141 can be configured to export audio to the user of vehicle 100.Similarly, microphone 142 can be configured to Audio (for example, voice command or other audio inputs) is received from the user of vehicle 100.

Touch screen 143 can be used by the user to the input order of vehicle 100.For this purpose, touch screen 143 can be configured to via electricity At least one of the position and movement of finger for holding sensing, resistance sensing or surface acoustic wave process etc. to sense user. Touch screen 143 can sense it is parallel with touch screen surface or on the direction of touch screen surface in the same plane, with Finger on the vertical direction of touch screen surface or in both directions is mobile, and may also be able to sensing and be applied to touch The level of the pressure of screen surfaces.Touch screen 143 can be semi-transparent by one or more translucent or transparent insulating layers and one or more Bright or transparency conducting layer is formed.Touch screen 143 can also take other forms.

Wireless communication system 144 can be configured as directly or via communication network being wirelessly coupled to one or more Any system of other vehicles, sensor or other entities.For this purpose, wireless communication system 144 may include for directly or by The antenna and chipset of air interface and other vehicles, sensor or other entity communications.Chipset or entire wireless communication system System 144 can be arranged to be communicated according to the wireless communication (for example, agreement) of one or more of the other type, and the wireless communication is all Communication protocol, cellular technology as described in bluetooth, IEEE 802.11 (including 802.11 revised edition of any IEEE) are (such as GSM, CDMA, Universal Mobile Communication System (Universal Mobile Telecommunications System, UMTS), EV-DO, WiMAX or long term evolution (Long Term Evolution, LTE)), purple honeybee, dedicated short-range communication (Dedicated Short Range Communications, DSRC) and radio frequency identification (Radio Frequency Identification, RFID) communication, etc..Wireless communication system 144 can also take other forms.

Peripheral equipment 140 can additionally or alternatively include the component other than those of shown.

Power supply 101 can be configured to provide electric power to some or all components of vehicle 100.For this purpose, power supply 101 may include Such as rechargable lithium ion or lead-acid battery.In some instances, one or more battery group can be configured to provide electric power. Other power materials and configuration are also possible.In some instances, power supply 101 and energy source 113 can be realized together, such as some In all-electric car like that.

It may include one or more general processors and/or one or more including the processor 102 in computing device 103 A application specific processor (for example, image processor, digital signal processor etc.).It include more than one processor with regard to processor 102 For, this processor can work independently or work in combination.Computing device 103, which can be realized, to be based on receiving by user interface 105 Input control vehicle 100 function.

Memory 104 may include one or more volatile storage components and/or one or more non-volatile deposits in turn Storing up component, such as light, magnetic and/or organic memory device, and memory 104 can be completely or partially integrated with processor 102.It deposits Reservoir 104 may include can be by the instruction (for example, programmed logic) that processor 102 is run, to run various vehicle functions, including this Any one of function or method of described in the text.

The component of vehicle 100 can be configured to interconnect with other components in its respective internal system and/or outside Mode work.For this purpose, the component and system of vehicle 100 can be by system bus, network and/or other connection mechanisms communicatedly It links together.

Fig. 2 is the schematic flow chart according to a kind of method 200 of acquisition coefficient of road adhesion of the embodiment of the present application.It should Method 200 can be executed by vehicle 100 as shown in Figure 1, for example, can be by four-wheel car (the near front wheel, off-front wheel, left rear wheel And off hind wheel) execute, the embodiment of the present application is particularly limited not to this.This method 200 includes:

210, obtain the mass center longitudinal acceleration, mass center side acceleration, mass center yaw velocity, front wheel angle of the vehicle With mass center longitudinal velocity.

It is alternatively possible to acquire mass center longitudinal acceleration a by accelerometer_xWith mass center side acceleration a_y, unit is m/s²。

It is alternatively possible to measure mass center yaw velocity γ, unit rad/s by gyroscope.

It is alternatively possible to pass through front wheel angle sensor measurement front wheel angle δ_f, unit rad.

It is alternatively possible to obtain vehicle centroid longitudinal velocity V by abs controller_x, unit m/s.

It is alternatively possible to obtain the vehicle in real time by accelerometer, gyroscope, front wheel angle sensor and abs controller Mass center longitudinal acceleration, mass center side acceleration, mass center yaw velocity, front wheel angle and mass center longitudinal velocity.

It is alternatively possible to obtain the mass center longitudinal acceleration of the vehicle, mass center side acceleration, mass center by storing equipment Yaw velocity, front wheel angle and mass center longitudinal velocity, at this point, the storage equipment is stored with through accelerometer, gyroscope, preceding Take turns mass center longitudinal acceleration, mass center side acceleration, the mass center yaw angle of the vehicle that rotary angle transmitter and abs controller obtain Speed, front wheel angle and mass center longitudinal velocity.

It should be understood that the sensors such as accelerometer, gyroscope, front wheel angle sensor and abs controller are general purpose transducer, These sensors are equipped on general some automobiles.

220, according to the mass center yaw velocity, the mass center longitudinal velocity and the mass center side acceleration, calculate the first matter The lateral speed of the heart.

It is alternatively possible to the lateral speed of the first mass center is calculated according to formula 1,

Wherein,It is the lateral speed of the first mass center, V_xIt is mass center longitudinal velocity, γ is mass center yaw velocity, a_yIt is matter Heart side acceleration.

Optionally, as shown in formula 1, the lateral speed of the first mass center can be solved by integration method.

230, according to the mass center longitudinal acceleration, the mass center side acceleration, the mass center yaw velocity, the preceding rotation Angle, the mass center longitudinal velocity and multiple preset coefficient of road adhesion calculate every in multiple preset coefficient of road adhesion The corresponding lateral speed of second mass center of a preset coefficient of road adhesion.

It is alternatively possible to which it is attached to calculate each preset road surface in multiple preset coefficient of road adhesion in the following way The corresponding lateral speed of second mass center of coefficient:

It should be understood that the value range of coefficient of road adhesion is 0-1.

Optionally, multiple preset coefficient of road adhesion can be obtained by dividing equally the coefficient of road adhesion of gamut, For example, the coefficient of road adhesion of gamut can be divided into 10 preset coefficient of road adhesion, respectively 0.1,0.2, 0.3、0.4、0.5、0.6、0.7、0.8、0.9、1.0。

It should be understood that it is more to divide equally obtained coefficient of road adhesion, the 230 obtained lateral vehicle of the second mass center through the above steps The solving precision of speed is higher, and correspondingly, solving complexity is also higher.

It should be understood that each corresponding lateral speed of second mass center of preset coefficient of road adhesion.

It should also be understood that the height on the mass center of vehicle to ground is a known parameters, can be obtained according to vehicle dimension measurement It takes.

It should also be understood that the tire model of vehicle is a known parameters, the tire model of each car can be directly acquired.

Adhere to it is alternatively possible to calculate each preset road surface in multiple preset coefficient of road adhesion according to formula 2 The lateral speed of corresponding 5th mass center of coefficient,

It should be understood that the lateral vehicle of corresponding 5th mass center of preset coefficient of road adhesion each of is calculated by formula 2 Speed is identical.

It is alternatively possible to by mass center side acceleration a_yIt is preset as 0.

Adhere to it is alternatively possible to calculate each preset road surface in multiple preset coefficient of road adhesion according to formula 3 The slip angle of tire of multiple wheels of the corresponding vehicle of coefficient,

Optionally, as shown in formula 3, after four wheels of four-wheel car can be the near front wheel, off-front wheel, left rear wheel and the right side Wheel.

It should be understood that l_f、l_rAnd l_sFor known parameters, it can be measured and be obtained according to vehicle dimension.

It is alternatively possible to the load of multiple wheels of the vehicle is calculated according to formula 4,

It should be understood that m is known parameters, it can be measured and be obtained according to vehicle dimension.

It is alternatively possible to the tire cornering stiffness of multiple wheel is calculated according to formula 5,

Optionally, a₁、a₂、a₃It can be demarcated by test.

Adhere to it is alternatively possible to calculate each preset road surface in multiple preset coefficient of road adhesion according to formula 6 The tire force of the corresponding multiple wheel of coefficient,

Adhere to it is alternatively possible to calculate each preset road surface in multiple preset coefficient of road adhesion according to formula 7 The corresponding mass center side acceleration of coefficient,

Adhere to it is alternatively possible to calculate each preset road surface in multiple preset coefficient of road adhesion according to formula 8 The corresponding lateral speed of second mass center of coefficient,

Optionally, each preset coefficient of road adhesion is corresponding in multiple preset coefficient of road adhesion is calculated Mass center side acceleration after, this method further include:

Optionally, each preset coefficient of road adhesion is corresponding in multiple preset coefficient of road adhesion is calculated Mass center side acceleration after, each preset road in multiple preset coefficient of road adhesion can be calculated by formula 9 The lateral speed of corresponding 5th mass center of face attachment coefficient,

It should be understood that each preset road surface attachment in multiple preset coefficient of road adhesion is calculated by formula 9 After the lateral speed of corresponding 5th mass center of coefficient, solved by formula 3-8 each in multiple preset coefficient of road adhesion The corresponding lateral speed of second mass center of preset coefficient of road adhesion.

Optionally, by formula 7, that each preset road surface in multiple preset coefficient of road adhesion is calculated is attached After the corresponding mass center side acceleration of coefficient, formula 9 can be directly substituted into calculate multiple preset road surface attachment system Then the lateral speed of each preset corresponding 5th mass center of coefficient of road adhesion in number is solved multiple pre- by formula 3-8 If coefficient of road adhesion in the corresponding lateral speed of second mass center of each preset coefficient of road adhesion, in this way, being performed a plurality of times Aforesaid operations, to improve corresponding second mass center of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion The computational accuracy of lateral speed.

240, obtain at least one lateral speed of third mass center；Wherein, which is and first matter The close lateral speed of the second mass center of the lateral speed of the heart, this approaches and is used to indicate the lateral speed of third mass center and first matter The absolute value of the difference of the lateral speed of the heart is less than first threshold.

Optionally, which can be a preset value, for example, 0.2 or 0.5, which can be according to reality Border needs to be adjusted.

It is alternatively possible to directly choose multiple and the first mass center side in the multiple lateral speeds of second mass center being calculated To speed close to the lateral speed of the second mass center, for example, choosing two the second matter closest to the lateral speed of the first mass center every time The lateral speed of the heart.

250, it is corresponding preset according to each lateral speed of third mass center at least one lateral speed of third mass center Coefficient of road adhesion calculates target coefficient of road adhesion.

Optionally, in the lateral speed of one third mass center of acquisition, the corresponding preset road of the lateral speed of third mass center Face attachment coefficient is exactly the target coefficient of road adhesion.

Optionally, in the lateral speed of two third mass centers of acquisition, target road surface attachment can be calculated according to formula 10 Coefficient,

Wherein,It is target coefficient of road adhesion,It is the lateral speed of the first mass center,It is two third mass centers One in lateral speed,It is another in two lateral speeds of third mass center,It isCorresponding road surface Attachment coefficient,It isCorresponding coefficient of road adhesion.

Optionally, after the lateral speed of the first mass center is calculated in step 220, this method 200 further include:

The lateral speed of first mass center is filtered.

Optionally, this is filtered the lateral speed of the first mass center, comprising:

The lateral speed of first mass center is filtered according to formula 11,

Optionally, each preset road surface in multiple preset coefficient of road adhesion is calculated in step 230 to adhere to After the corresponding lateral speed of second mass center of coefficient, this method 200 further include:

The lateral speed of second mass center is filtered.

Optionally, this is filtered the lateral speed of the second mass center, comprising:

The lateral speed of second mass center is filtered according to formula 12,

Optionally, each preset road surface in the lateral speed of the first mass center and multiple preset coefficient of road adhesion The lateral speed of corresponding second mass center of attachment coefficient is by filtering processing, should and when obtaining the lateral speed of two third mass centers Calculate target coefficient of road adhesion, comprising:

The target coefficient of road adhesion is calculated according to formula 13

It should be understood that in formula 13, two lateral speeds of third mass center be from obtained after filtering processing this is more It is selected in the corresponding lateral speed of second mass center of each preset coefficient of road adhesion in a preset coefficient of road adhesion.

It is alternatively possible to by the frequency-domain analysis methods such as bandpass filtering, Fast Fourier Transform (FFT), wavelet transformation to this first Corresponding second mass center of each preset coefficient of road adhesion in the lateral speed of mass center and multiple preset coefficient of road adhesion Lateral speed removes incredible low frequency part and high frequency section by filtering processing, in turn, eliminates sensor biasing and road The accumulation of error low frequency caused by injustice, while eliminating the accumulation of error high frequency caused by noise.

Optionally, after the target coefficient of road adhesion is calculated, this method 200 further include:

Optionally, it is lateral to calculate target centroid according to the 4th lateral speed of mass center and the lateral speed of the first mass center for this Speed, comprising:

It should be understood that the high frequency section precision for the lateral speed of the first mass center being calculated by integration method is higher, pass through mould The low frequency part precision for the 4th lateral speed of mass center that type method is calculated is higher.

It optionally, can be first lateral to first mass center before carrying out high-pass filtering to the lateral speed of first mass center Speed be filtered shown in such as formula 11.

It is alternatively possible to the lateral speed of the target centroid is calculated according to formula 14,

Wherein,It is the lateral speed of target centroid,It is the filtered lateral speed of first mass center, It is the lateral speed of filtered 4th mass center, τ is time constant, and s is Laplace operator.

Therefore, the embodiment of the present application acquisition coefficient of road adhesion method in, according to from accelerometer, gyroscope, Mass center longitudinal acceleration, the matter of the vehicle obtained in the current inexpensive sensor that can have supported volume production such as ABS system, grating The parameters such as heart side acceleration, mass center yaw velocity, front wheel angle and mass center longitudinal velocity calculate target road surface attachment system Number effectively increases vehicle security, balances integral vehicle cost, while being easily achieved again.

Further, by each preset road in the lateral speed of the first mass center and multiple preset coefficient of road adhesion The attachment coefficient corresponding lateral speed of second mass center in face is filtered, and eliminates the lateral speed of the first mass center and multiple preset In coefficient of road adhesion present in the solution procedure of the corresponding lateral speed of second mass center of each preset coefficient of road adhesion Score accumulation error improves the computational accuracy of target centroid lateral speed and target coefficient of road adhesion, thus, improve dynamics Control precision and vehicle driving safety.

Further, by carrying out high-pass filtering to the lateral speed of the first mass center, and to the 4th lateral speed of mass center Low-pass filtering is carried out, the high frequency characteristics and modelling for the lateral speed of the first mass center for making full use of integration method to solve solve The low frequency characteristic of the 4th lateral speed of mass center arrived improves the computational accuracy of the lateral speed of target centroid, thus, improve dynamics Control precision and vehicle driving safety.

Fig. 3 is the schematic block diagram according to the system 300 of the acquisition coefficient of road adhesion of the embodiment of the present application.The acquisition road The system 300 of face attachment coefficient is applied to vehicle, as shown in figure 3, the system 300 of the acquisition coefficient of road adhesion includes:

Signal picker 310, the first speed calculator 320, the second speed calculator 330 and coefficient of road adhesion solver 340, wherein

The signal picker 310, the mass center longitudinal acceleration, mass center side acceleration, mass center for obtaining the vehicle are horizontal Pivot angle speed, front wheel angle and mass center longitudinal velocity；

The first speed calculator 320, it is vertical for obtaining the mass center yaw velocity, the mass center from the signal acquisition unit It is lateral to speed and the mass center side acceleration, and according to the mass center yaw velocity, the mass center longitudinal velocity and the mass center The lateral speed of the first mass center of acceleration calculation；

The second speed calculator 330, for obtaining the mass center longitudinal acceleration, the mass center side from the signal acquisition unit To acceleration, the mass center yaw velocity, the front wheel angle and the mass center longitudinal velocity, according to the mass center longitudinal acceleration, it is somebody's turn to do Mass center side acceleration, the mass center yaw velocity, the front wheel angle, the mass center longitudinal velocity and multiple preset road surfaces Attachment coefficient calculates each preset coefficient of road adhesion corresponding second mass center side in multiple preset coefficient of road adhesion To speed；

The coefficient of road adhesion solver 340, for obtaining the first mass center side to speed from the first speed calculator, It is corresponding that each preset coefficient of road adhesion in multiple preset coefficient of road adhesion is obtained from the second speed calculator The lateral speed of second mass center, and obtain at least one lateral speed of third mass center；Wherein, the lateral speed of third mass center be with The close lateral speed of the second mass center of the lateral speed of first mass center, this close to be used to indicate the lateral speed of third mass center with The absolute value of the difference of the lateral speed of first mass center is less than first threshold；

The coefficient of road adhesion solver 340 is also used to according at least one lateral speed of third mass center each The corresponding preset coefficient of road adhesion of the lateral speed of three mass centers calculates target coefficient of road adhesion.

Optionally, in the first speed calculator 320 according to the mass center yaw velocity, the mass center longitudinal velocity and the matter Heart side acceleration, after calculating the lateral speed of the first mass center, the system 300 further include:

Frequency-domain analyser 350, for being filtered to the lateral speed of the first mass center.

Optionally, it is calculated in multiple preset coefficient of road adhesion in the second speed calculator 330 each pre- If the corresponding lateral speed of second mass center of coefficient of road adhesion after, the system 300 further include:

Frequency-domain analyser 350, for each preset coefficient of road adhesion in multiple preset coefficient of road adhesion The corresponding lateral speed of second mass center is filtered.

Optionally, after the target coefficient of road adhesion is calculated in the coefficient of road adhesion solver 340, the system 300 further include:

Lateral speed solver 360, for obtaining the first mass center side from the first speed calculator to speed, from this The target coefficient of road adhesion is obtained in coefficient of road adhesion solver, and the 4th mass center is calculated according to the target coefficient of road adhesion Lateral speed, and according to the 4th lateral speed of mass center and the lateral speed of the first mass center, calculate the lateral speed of target centroid.

Optionally, the lateral speed solver 360, is also used to:

Optionally, as shown in figure 4, the second speed calculator 330, comprising:

Slip angle of tire computing unit 331, tyre load computing unit 332, tire cornering stiffness computing unit 333, wheel Tire power computing unit 334, side acceleration computing unit 335 and lateral speed computing unit 336, wherein

The lateral speed computing unit 336, for according to the mass center side acceleration, the mass center longitudinal velocity and the mass center Yaw velocity calculates corresponding 5th mass center of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion Lateral speed；

The slip angle of tire computing unit 331, for according to the mass center longitudinal velocity, the mass center yaw velocity and this is every The lateral speed of a corresponding 5th mass center of preset coefficient of road adhesion calculates each in multiple preset coefficient of road adhesion The slip angle of tire of multiple wheels of the corresponding vehicle of preset coefficient of road adhesion；

The tyre load computing unit 332, for according to the mass center longitudinal acceleration, the mass center side acceleration and the vehicle Mass center to the height on ground, calculate the load of multiple wheels of the vehicle；

The tire cornering stiffness computing unit 333 calculates the wheel of multiple wheel for the load according to multiple wheel Tire cornering stiffness；

The tire force computing unit 334, for according to multiple preset coefficient of road adhesion, multiple preset road surface The load of the slip angle of tire of the corresponding multiple wheel of each preset coefficient of road adhesion, multiple wheel in attachment coefficient Lotus, the tire cornering stiffness of multiple wheel and the vehicle tire model, calculate in multiple preset coefficient of road adhesion The tire force of the corresponding multiple wheel of each preset coefficient of road adhesion；

The side acceleration computing unit 335, for according to the front wheel angle and multiple preset coefficient of road adhesion In the corresponding multiple wheel of each preset coefficient of road adhesion tire force, calculate multiple preset coefficient of road adhesion In the corresponding mass center side acceleration of each preset coefficient of road adhesion；

The lateral speed computing unit 336 is also used to according to the mass center longitudinal velocity, the mass center yaw velocity and this is more The corresponding mass center side acceleration of each preset coefficient of road adhesion, calculates multiple pre- in a preset coefficient of road adhesion If coefficient of road adhesion in the corresponding lateral speed of second mass center of each preset coefficient of road adhesion.

Optionally, it is calculated in multiple preset coefficient of road adhesion often in the side acceleration computing unit 335 After the corresponding mass center side acceleration of a preset coefficient of road adhesion, which is also used to basis The corresponding mass center side acceleration of each preset coefficient of road adhesion, the mass center are vertical in multiple preset coefficient of road adhesion To speed and the mass center yaw velocity, each preset coefficient of road adhesion in multiple preset coefficient of road adhesion is calculated The lateral speed of corresponding 5th mass center.

It should be understood that according to the above-mentioned of the modules in the system 300 of the acquisition coefficient of road adhesion of the embodiment of the present application With other operation and/or functions respectively in order to realize the embodiment of the present application method 200 corresponding process, for sake of simplicity, herein It repeats no more.

Fig. 5 shows the schematic block diagram of the system 400 provided by the embodiments of the present application for obtaining coefficient of road adhesion, this sets Standby 400 include:

Memory 410, for storing program code；

Processor 420, for executing the program code in memory 410, when the program code executes, the processor 420 are used for:

Obtain mass center longitudinal acceleration, mass center side acceleration, mass center yaw velocity, front wheel angle and the matter of the vehicle Heart longitudinal velocity；According to the mass center yaw velocity, the mass center longitudinal velocity and the mass center side acceleration, the first mass center is calculated Lateral speed；According to the mass center longitudinal acceleration, the mass center side acceleration, the mass center yaw velocity, the front wheel angle, it is somebody's turn to do Mass center longitudinal velocity and multiple preset coefficient of road adhesion calculate each pre- in multiple preset coefficient of road adhesion If the corresponding lateral speed of second mass center of coefficient of road adhesion；Obtain at least one lateral speed of third mass center；Wherein, this The lateral speed of three mass centers is the second mass center lateral speed close with the lateral speed of the first mass center, this approaches and is used to indicate this The absolute value of the difference of the lateral speed of third mass center and the lateral speed of the first mass center is less than first threshold；According to this at least one The corresponding preset coefficient of road adhesion of each lateral speed of third mass center in the lateral speed of third mass center, it is attached to calculate target road surface Coefficient.

It should be understood that in the embodiment of the present application, which can be central processing unit (Central Processing Unit, CPU), the processor 420 can also be other general processors, digital signal processor (DSP), specially With integrated circuit (ASIC), ready-made programmable gate array (FPGA) either other programmable logic device, discrete gate or crystal Pipe logical device, discrete hardware components etc..General processor can be microprocessor or the processor be also possible to it is any often The processor etc. of rule.

The memory 410 may include read-only memory and random access memory, and to processor 420 provide instruction and Data.The a part of of memory 410 can also include nonvolatile RAM.For example, memory 410 can also be deposited Store up the information of device type.

Optionally, it is calculated at this according to the mass center yaw velocity, the mass center longitudinal velocity and the mass center side acceleration After the lateral speed of first mass center, which is used for:

The lateral speed of first mass center is filtered.

Optionally, this according to the mass center longitudinal acceleration, the mass center side acceleration, the mass center yaw velocity, should Front wheel angle, the mass center longitudinal velocity and multiple preset coefficient of road adhesion calculate multiple preset road surface attachment system In number after the corresponding lateral speed of second mass center of each preset coefficient of road adhesion, which is used for:

The lateral speed of second mass center is filtered.

Optionally, after the target coefficient of road adhesion is calculated, which is used for:

Optionally, which is used for:

Optionally, the corresponding mass center of each preset coefficient of road adhesion in multiple coefficient of road adhesion is calculated After side acceleration, which is used for:

It should be understood that according to the processor 420 in the system 400 of the acquisition coefficient of road adhesion of the embodiment of the present application and storing Above and other operation and/or function of device 410 respectively in order to realize the embodiment of the present application method 200 corresponding process, be Succinct, details are not described herein.

The embodiment of the present application provides a kind of computer readable storage medium, for storing instruction, when the instruction is calculating When running on machine, which can be used for executing the method 200 of the acquisition coefficient of road adhesion of above-mentioned the embodiment of the present application.It should Readable medium can be ROM or RAM, and the embodiment of the present application is without limitation.

It should be understood that the terms "and/or" and " at least one of A or B ", only a kind of description affiliated partner Incidence relation, indicate may exist three kinds of relationships, for example, A and/or B, can indicate: individualism A exists simultaneously A and B, These three situations of individualism B.In addition, character "/" herein, typicallys represent the relationship that forward-backward correlation object is a kind of "or".

It should be understood that the serial number size of above-mentioned each process is not meant to execute sequence in each embodiment of the application It is successive, the execution of each process sequence should be determined by its function and internal logic, the implementation without coping with the embodiment of the present application Journey constitutes any restriction.

Those of ordinary skill in the art may be aware that list described in conjunction with the examples disclosed in the embodiments of the present disclosure Member and algorithm steps can be realized with the combination of electronic hardware or computer software and electronic hardware.These functions are actually It is implemented in hardware or software, the specific application and design constraint depending on technical solution.Professional technician Each specific application can be used different methods to achieve the described function, but this realization is it is not considered that exceed Scope of the present application.

It is apparent to those skilled in the art that for convenience and simplicity of description, the system of foregoing description, The specific work process of device and unit, can refer to corresponding processes in the foregoing method embodiment, and details are not described herein.

In several embodiments provided herein, it should be understood that disclosed systems, devices and methods, it can be with It realizes by another way.For example, the apparatus embodiments described above are merely exemplary, for example, the unit is drawn Point, only a kind of logical function partition, there may be another division manner in actual implementation, such as multiple units or components can To combine or be desirably integrated into another system, or some features can be ignored or not executed.Another point, it is shown or beg for The mutual coupling, direct-coupling or communication connection of opinion can be through some interfaces, the INDIRECT COUPLING of device or unit Or communication connection, it can be electrical property, mechanical or other forms.

Unit may or may not be physically separated as illustrated by the separation member for this, show as unit Component may or may not be physical unit, it can it is in one place, or may be distributed over multiple nets On network unit.It can select some or all of unit therein according to the actual needs to realize the mesh of this embodiment scheme 's.

It, can also be in addition, each functional unit in each embodiment of the application can integrate in one processing unit It is that each unit physically exists alone, can also be integrated in one unit with two or more units.

If the function is realized in the form of SFU software functional unit and when sold or used as an independent product, Ke Yicun Storage is in a computer readable storage medium.Based on this understanding, the technical solution of the application is substantially right in other words The part of part or the technical solution that the prior art contributes can be embodied in the form of software products, the calculating Machine software product is stored in a storage medium, including some instructions are used so that a computer equipment (can be individual Computer, server or network equipment etc.) execute each embodiment this method of the application all or part of the steps.And it is preceding The storage medium stated includes: USB flash disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory The various media that can store program code such as (Random Access Memory, RAM), magnetic or disk.

The above, the only specific embodiment of the application, but the protection scope of the application is not limited thereto, it is any Those familiar with the art within the technical scope of the present application, can easily think of the change or the replacement, and should all contain Lid is within the scope of protection of this application.Therefore, the protection scope of the application should be based on the protection scope of the described claims.

Claims

1. a kind of method for obtaining coefficient of road adhesion, is applied to vehicle characterized by comprising

Obtain mass center longitudinal acceleration, mass center side acceleration, mass center yaw velocity, front wheel angle and the mass center of the vehicle Longitudinal velocity；

According to the mass center yaw velocity, the mass center longitudinal velocity and the mass center side acceleration, the first mass center is calculated Lateral speed；

According to the mass center longitudinal acceleration, the mass center side acceleration, the mass center yaw velocity, the preceding rotation Angle, the mass center longitudinal velocity and multiple preset coefficient of road adhesion calculate the multiple preset coefficient of road adhesion In the corresponding lateral speed of second mass center of each preset coefficient of road adhesion；

Obtain at least one lateral speed of third mass center；Wherein, the lateral speed of third mass center is and first mass center side The second mass center lateral speed close to speed, it is described close to being used to indicate the lateral speed of third mass center and described the The absolute value of the difference of the lateral speed of one mass center is less than first threshold；

It is attached according to the corresponding preset road surface of the lateral speed of third mass center each at least one described lateral speed of third mass center Coefficient, calculate target coefficient of road adhesion.

2. the method according to claim 1, wherein described according to the mass center yaw velocity, the matter Heart longitudinal velocity and the mass center side acceleration, after calculating the lateral speed of the first mass center, the method also includes:

The lateral speed of first mass center is filtered.

3. method according to claim 1 or 2, which is characterized in that it is described according to the mass center longitudinal acceleration, it is described Mass center side acceleration, the mass center yaw velocity, the front wheel angle, the mass center longitudinal velocity and multiple default Coefficient of road adhesion, calculate each preset coefficient of road adhesion in the multiple preset coefficient of road adhesion corresponding the After the lateral speed of two mass centers, the method also includes:

The lateral speed of second mass center is filtered.

4. method according to any one of claims 1 to 3, which is characterized in that adhere to the target road surface is calculated After coefficient, the method also includes:

According to the lateral speed of the 4th mass center and the lateral speed of the first mass center, the lateral speed of target centroid is calculated.

5. according to the method described in claim 4, it is characterized in that, described according to the lateral speed of the 4th mass center and described The lateral speed of one mass center calculates the lateral speed of target centroid, comprising:

According to the filtered lateral speed of 4th mass center and the filtered lateral speed of first mass center, institute is calculated State the lateral speed of target centroid.

6. according to claim 1 to the method any in 5, which is characterized in that it is described according to the mass center longitudinal acceleration, The mass center side acceleration, the mass center yaw velocity, the front wheel angle, the mass center longitudinal velocity and multiple It is corresponding to calculate each preset coefficient of road adhesion in the multiple preset coefficient of road adhesion for preset coefficient of road adhesion The lateral speed of the second mass center, comprising:

According to the mass center side acceleration, the mass center longitudinal velocity and the mass center yaw velocity, calculate the multiple The lateral speed of each preset corresponding 5th mass center of coefficient of road adhesion in preset coefficient of road adhesion；

It is corresponding according to the mass center longitudinal velocity, the mass center yaw velocity and each preset coefficient of road adhesion It is corresponding to calculate each preset coefficient of road adhesion in the multiple preset coefficient of road adhesion for the 5th lateral speed of mass center The slip angle of tire of multiple wheels of the vehicle；

According to the height of the mass center of the mass center longitudinal acceleration, the mass center side acceleration and the vehicle to ground, meter Calculate the load of multiple wheels of the vehicle；

According to the load of the multiple wheel, the tire cornering stiffness of the multiple wheel is calculated；

According to each preset road surface in the multiple preset coefficient of road adhesion, the multiple preset coefficient of road adhesion The slip angle of tire of the corresponding the multiple wheel of attachment coefficient, the load of the multiple wheel, the multiple wheel tire It is attached to calculate each preset road surface in the multiple preset coefficient of road adhesion for the tire model of cornering stiffness and the vehicle The tire force of the corresponding the multiple wheel of coefficient；

It is corresponding according to preset coefficient of road adhesion each in the front wheel angle and the multiple preset coefficient of road adhesion The multiple wheel tire force, calculate each preset coefficient of road adhesion in the multiple preset coefficient of road adhesion Corresponding mass center side acceleration；

According to each in the mass center longitudinal velocity, the mass center yaw velocity and the multiple preset coefficient of road adhesion The corresponding mass center side acceleration of preset coefficient of road adhesion calculates each pre- in the multiple preset coefficient of road adhesion If the corresponding lateral speed of second mass center of coefficient of road adhesion.

7. according to the method described in claim 6, it is characterized in that, each in the multiple coefficient of road adhesion is calculated After the corresponding mass center side acceleration of preset coefficient of road adhesion, the method also includes:

Laterally accelerated according to the corresponding mass center of preset coefficient of road adhesion each in the multiple preset coefficient of road adhesion Degree, the mass center longitudinal velocity and the mass center yaw velocity calculate each in the multiple preset coefficient of road adhesion The lateral speed of preset corresponding 5th mass center of coefficient of road adhesion.

8. a kind of system for obtaining coefficient of road adhesion, is applied to vehicle characterized by comprising

Signal picker, the first speed calculator, the second speed calculator and coefficient of road adhesion solver, wherein

The signal picker, for obtaining the mass center longitudinal acceleration, mass center side acceleration, mass center yaw angle of the vehicle Speed, front wheel angle and mass center longitudinal velocity；

The first speed calculator, for obtaining the mass center yaw velocity, the mass center from the signal acquisition unit Longitudinal velocity and the mass center side acceleration, and according to the mass center yaw velocity, the mass center longitudinal velocity and institute It states mass center side acceleration and calculates the lateral speed of the first mass center；

The second speed calculator, for obtaining the mass center longitudinal acceleration, the mass center from the signal acquisition unit Side acceleration, the mass center yaw velocity, the front wheel angle and the mass center longitudinal velocity, it is longitudinal according to the mass center Acceleration, the mass center side acceleration, the mass center yaw velocity, the front wheel angle, the mass center longitudinal velocity, with And multiple preset coefficient of road adhesion, calculate each preset road surface attachment system in the multiple preset coefficient of road adhesion The corresponding lateral speed of second mass center of number；

The coefficient of road adhesion solver, for obtaining first mass center side to speed from the first speed calculator, Each preset coefficient of road adhesion pair in the multiple preset coefficient of road adhesion is obtained from the second speed calculator The lateral speed of the second mass center answered, and obtain at least one lateral speed of third mass center；Wherein, the lateral vehicle of third mass center Speed is the second mass center lateral speed close with the lateral speed of the first mass center, and described approach is used to indicate the third The absolute value of the difference of the lateral speed of mass center and the lateral speed of the first mass center is less than first threshold；

The coefficient of road adhesion solver is also used to according to each third matter at least one described lateral speed of third mass center The corresponding preset coefficient of road adhesion of the lateral speed of the heart calculates target coefficient of road adhesion.

9. system according to claim 8, which is characterized in that in the first speed calculator according to the mass center sideway Angular speed, the mass center longitudinal velocity and the mass center side acceleration, after calculating the lateral speed of the first mass center, the system Further include:

Frequency-domain analyser, for being filtered to the lateral speed of the first mass center.

10. system according to claim 8 or claim 9, which is characterized in that be calculated in the second speed calculator described It is described in multiple preset coefficient of road adhesion after the corresponding lateral speed of second mass center of each preset coefficient of road adhesion System further include:

Frequency-domain analyser, for corresponding to each preset coefficient of road adhesion in the multiple preset coefficient of road adhesion The lateral speed of second mass center is filtered.

11. according to the system any in claim 8 to 10, which is characterized in that in the coefficient of road adhesion solver It is calculated after the target coefficient of road adhesion, the system also includes:

Lateral speed solver, for obtaining first mass center side from the first speed calculator to speed, from described The target coefficient of road adhesion is obtained in coefficient of road adhesion solver, calculates the 4th according to the target coefficient of road adhesion The lateral speed of mass center, and according to the lateral speed of the 4th mass center and the lateral speed of the first mass center, calculate target centroid Lateral speed.

12. system according to claim 11, which is characterized in that the lateral speed solver is also used to:

13. according to the system any in claim 8 to 12, which is characterized in that the second speed calculator, comprising:

Slip angle of tire computing unit, tyre load computing unit, tire cornering stiffness computing unit, tire force computing unit, Side acceleration computing unit and lateral speed computing unit, wherein

The lateral speed computing unit, for according to the mass center side acceleration, the mass center longitudinal velocity and the matter Heart yaw velocity calculates each preset coefficient of road adhesion the corresponding 5th in the multiple preset coefficient of road adhesion The lateral speed of mass center；

The slip angle of tire computing unit, for according to the mass center longitudinal velocity, the mass center yaw velocity and described The lateral speed of each corresponding 5th mass center of preset coefficient of road adhesion calculates in the multiple preset coefficient of road adhesion The slip angle of tire of multiple wheels of the corresponding vehicle of each preset coefficient of road adhesion；

The tyre load computing unit, for according to the mass center longitudinal acceleration, the mass center side acceleration and described The mass center of vehicle calculates the load of multiple wheels of the vehicle to the height on ground；

The tire cornering stiffness computing unit calculates the wheel of the multiple wheel for the load according to the multiple wheel Tire cornering stiffness；

The tire force computing unit, for according to the multiple preset coefficient of road adhesion, the multiple preset road surface The slip angle of tire of the corresponding the multiple wheel of each preset coefficient of road adhesion in attachment coefficient, the multiple wheel It is attached to calculate the multiple preset road surface for the tire model of load, the tire cornering stiffness of the multiple wheel and the vehicle The tire force of the corresponding the multiple wheel of each preset coefficient of road adhesion in coefficient；

The side acceleration computing unit, for according in the front wheel angle and the multiple preset coefficient of road adhesion The tire force of the corresponding the multiple wheel of each preset coefficient of road adhesion calculates the multiple preset road surface attachment system The corresponding mass center side acceleration of each preset coefficient of road adhesion in number；

The lateral speed computing unit is also used to according to the mass center longitudinal velocity, the mass center yaw velocity and described The corresponding mass center side acceleration of each preset coefficient of road adhesion, calculates described more in multiple preset coefficient of road adhesion The corresponding lateral speed of second mass center of each preset coefficient of road adhesion in a preset coefficient of road adhesion.

14. system according to claim 13, which is characterized in that institute is calculated in the side acceleration computing unit It is described after stating the corresponding mass center side acceleration of each preset coefficient of road adhesion in multiple preset coefficient of road adhesion Lateral speed computing unit, is also used to according to preset coefficient of road adhesion each in the multiple preset coefficient of road adhesion Corresponding mass center side acceleration, the mass center longitudinal velocity and the mass center yaw velocity calculate the multiple preset The lateral speed of each preset corresponding 5th mass center of coefficient of road adhesion in coefficient of road adhesion.

15. a kind of computer readable storage medium, including instruction, when described instruction is run on computers, the computer Execute the method as described in any in claim 1 to 7.