CN117048359A - Vehicle stability control method and device on low-attachment road surface and new energy automobile - Google Patents

Vehicle stability control method and device on low-attachment road surface and new energy automobile Download PDF

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Publication number
CN117048359A
CN117048359A CN202311087070.0A CN202311087070A CN117048359A CN 117048359 A CN117048359 A CN 117048359A CN 202311087070 A CN202311087070 A CN 202311087070A CN 117048359 A CN117048359 A CN 117048359A
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China
Prior art keywords
wheel acceleration
slip
attenuation coefficient
rate
slip rate
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CN202311087070.0A
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Chinese (zh)
Inventor
李良浩
谭开波
唐如意
黄大飞
刘小飞
崔环宇
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Chongqing Seres New Energy Automobile Design Institute Co Ltd
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Chongqing Seres New Energy Automobile Design Institute Co Ltd
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Priority to CN202311087070.0A priority Critical patent/CN117048359A/en
Publication of CN117048359A publication Critical patent/CN117048359A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
    • B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
    • B60W30/02—Control of vehicle driving stability
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
    • B60W30/18—Propelling the vehicle
    • B60W30/18172—Preventing, or responsive to skidding of wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/10—Vehicle control parameters
    • B60L2240/14—Acceleration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/40—Drive Train control parameters
    • B60L2240/42—Drive Train control parameters related to electric machines
    • B60L2240/423—Torque
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/10—Longitudinal speed
    • B60W2520/105—Longitudinal acceleration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2710/00—Output or target parameters relating to a particular sub-units
    • B60W2710/08—Electric propulsion units
    • B60W2710/083—Torque
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Power Engineering (AREA)
  • Regulating Braking Force (AREA)

Abstract

The application provides a vehicle stability control method and device on a low-attachment road surface and a new energy automobile. The method comprises the following steps: judging whether the wheel acceleration antiskid zone bit is activated or not based on the wheel acceleration and the wheel acceleration change rate; when the wheel acceleration antiskid zone bit is activated, determining a wheel acceleration antiskid target attenuation coefficient; judging whether the slip rate anti-slip flag bit is activated or not based on the slip rate of the wheels and a slip rate threshold value; when the slip rate anti-slip flag bit is activated, determining a slip rate anti-slip target attenuation coefficient; when the wheel acceleration antiskid zone bit or the slip rate antiskid zone bit is activated, the attenuation coefficient change gradient is utilized to process the requested attenuation coefficient of the current period; and calculating the shaft end request torque based on the shaft end target torque and the gradient processed request attenuation coefficient, and transmitting the shaft end request torque to the driving motor to execute torque control. The application improves the stability and the trafficability of the vehicle on the low-accessory road surface and enhances the driving experience of the user.

Description

Vehicle stability control method and device on low-attachment road surface and new energy automobile
Technical Field
The application relates to the technical field of new energy automobiles, in particular to a method and a device for controlling the stability of a vehicle on a low-attachment road surface and a new energy automobile.
Background
With the increasing update and progress of new energy automobile technology, how to improve the driving comfort and performance of new energy automobiles on the premise of ensuring safety has been an important subject for industry. In particular, in various complex road conditions, how to ensure the stability of the vehicle is critical to the safety and driving experience of the driver. In practice, the vehicle may encounter low adhesion roadways, such as slippery, icy or sand roads, and these road conditions may result in a reduced coefficient of friction between the vehicle tires and the roadway, thereby affecting the stability and safety of the vehicle.
Conventional solutions rely mainly on hardware techniques, such as increasing the friction coefficient between the tyre and the road surface by using tyres with a high friction coefficient, changing winter tyres in rainy and snowy days or using snow chains. However, these conventional methods have not been ideal for the new energy vehicle because the power system, weight distribution and control strategy of the new energy vehicle are different from those of the conventional vehicle, so that the conventional solution may not be suitable or have limited effect on the new energy vehicle. Therefore, there is a need to provide a stability control scheme for a new energy automobile on a low-adhesion road surface, so as to solve the problems of poor stability, reduced driving safety and poor driving experience of the automobile when the automobile runs on the low-adhesion road surface.
Disclosure of Invention
In view of the above, the embodiment of the application provides a method and a device for controlling the stability of a vehicle on a low-adhesion road surface and a new energy automobile, so as to solve the problems of poor stability, reduced driving safety and poor driving experience of the automobile in the prior art when the automobile runs on the low-adhesion road surface.
In a first aspect of an embodiment of the present application, there is provided a vehicle stability control method on a low-traction surface, including: determining the corresponding wheel acceleration and the wheel acceleration change rate of each wheel, and judging whether the wheel acceleration anti-skid marker bit is activated or not based on the wheel acceleration and the wheel acceleration change rate; when the wheel acceleration anti-skid flag bit is activated, determining a wheel acceleration anti-skid target attenuation coefficient based on the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate; determining the slip rate corresponding to each wheel, and judging whether the slip rate anti-slip flag bit is activated or not based on the slip rate and a preset slip rate threshold value; when the slip rate anti-slip flag bit is activated, determining a slip rate anti-slip target attenuation coefficient based on the slip rate absolute value and the slip rate change rate absolute value; when the wheel acceleration antiskid zone bit or the slip rate antiskid zone bit is activated, determining an attenuation coefficient change gradient, and processing a request attenuation coefficient of the current period by using the attenuation coefficient change gradient to obtain a request attenuation coefficient after gradient processing; based on the axle end target torque of the current period and the gradient processed request attenuation coefficient, calculating the axle end request torque, and transmitting the axle end request torque to the driving motor to execute torque control so as to control the low attachment stability of the vehicle.
In a second aspect of the embodiment of the present application, there is provided a vehicle stability control device on a low-traction surface, including: the first judging module is configured to determine the corresponding wheel acceleration and the corresponding wheel acceleration change rate of each wheel, and judge whether the wheel acceleration anti-skid flag bit is activated or not based on the wheel acceleration and the wheel acceleration change rate; the first determining module is configured to determine a wheel acceleration anti-skid target attenuation coefficient based on the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate when the wheel acceleration anti-skid flag bit is activated; the second judging module is configured to determine the slip rate corresponding to each wheel, and judge whether the slip rate anti-slip flag bit is activated or not based on the slip rate and a preset slip rate threshold value; a second determination module configured to determine a slip rate antiskid target attenuation coefficient based on the slip rate absolute value and the slip rate change rate absolute value when the slip rate antiskid flag bit is activated; the processing module is configured to determine an attenuation coefficient change gradient when the wheel acceleration anti-skid flag bit or the slip rate anti-skid flag bit is activated, and process the requested attenuation coefficient of the current period by using the attenuation coefficient change gradient to obtain a request attenuation coefficient after gradient processing; and the control module is configured to calculate the axle end request torque based on the axle end target torque of the current period and the gradient processed request attenuation coefficient, and transmit the axle end request torque to the driving motor to execute torque control so as to perform low-stability control on the vehicle.
In a third aspect of the embodiment of the application, a new energy automobile is provided, which comprises an entire automobile controller, a motor controller, a driving motor and a transmission system; the whole vehicle controller is used for realizing the vehicle stability control method on the low-attachment road surface so as to send the axle end request torque to the motor controller; the motor controller is used for controlling the torque of the driving motor through the transmission system according to the shaft end request torque.
The above at least one technical scheme adopted by the embodiment of the application can achieve the following beneficial effects:
determining the wheel acceleration and the wheel acceleration change rate corresponding to each wheel, and judging whether the wheel acceleration anti-skid marker bit is activated or not based on the wheel acceleration and the wheel acceleration change rate; when the wheel acceleration anti-skid flag bit is activated, determining a wheel acceleration anti-skid target attenuation coefficient based on the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate; determining the slip rate corresponding to each wheel, and judging whether the slip rate anti-slip flag bit is activated or not based on the slip rate and a preset slip rate threshold value; when the slip rate anti-slip flag bit is activated, determining a slip rate anti-slip target attenuation coefficient based on the slip rate absolute value and the slip rate change rate absolute value; when the wheel acceleration antiskid zone bit or the slip rate antiskid zone bit is activated, determining an attenuation coefficient change gradient, and processing a request attenuation coefficient of the current period by using the attenuation coefficient change gradient to obtain a request attenuation coefficient after gradient processing; based on the axle end target torque of the current period and the gradient processed request attenuation coefficient, calculating the axle end request torque, and transmitting the axle end request torque to the driving motor to execute torque control so as to control the low attachment stability of the vehicle. The application can accurately identify the low-attachment working condition, and realize the attenuation of the shaft end request torque through the gradient processed request attenuation coefficient, thereby improving the stability and the trafficability of the vehicle on the low-attachment road surface and enhancing the driving experience of users.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic flow chart of a method for controlling vehicle stability on a low-overhead road surface according to an embodiment of the present application;
fig. 2 is a schematic structural diagram of a vehicle stability control device on a low-overhead road surface according to an embodiment of the present application;
fig. 3 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
It should be understood that the various steps recited in the method embodiments of the present application may be performed in a different order and/or performed in parallel. Furthermore, method embodiments may include additional steps and/or omit performing the illustrated steps. The scope of the application is not limited in this respect.
The term "including" and variations thereof as used herein are intended to be open-ended, i.e., including, but not limited to. The term "based on" is based at least in part on. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments. Related definitions of other terms will be given in the description below. It should be noted that the terms "first," "second," and the like herein are merely used for distinguishing between different devices, modules, or units and not for limiting the order or interdependence of the functions performed by such devices, modules, or units.
It should be noted that references to "one", "a plurality" and "a plurality" in this disclosure are intended to be illustrative rather than limiting, and those skilled in the art will appreciate that "one or more" is intended to be construed as "one or more" unless the context clearly indicates otherwise.
The new energy automobile in the embodiment of the application refers to an automobile which adopts novel energy (non-traditional petroleum and diesel energy) and has advanced technology. The automobiles adopt a novel power system, so that the automobile emission can be effectively reduced, the influence on the environment is reduced, and the energy utilization efficiency is improved. The new energy automobiles of the embodiment of the application include, but are not limited to, the following types of automobiles: electric Vehicles (EVs), pure electric vehicles (BEVs), fuel Cell Electric Vehicles (FCEVs), plug-in hybrid electric vehicles (PHEVs), hybrid Electric Vehicles (HEVs), and the like.
The following describes in detail a method and apparatus for controlling the stability of a vehicle on a low-grade road according to an embodiment of the present application with reference to the accompanying drawings.
Fig. 1 is a schematic flow chart of a method for controlling vehicle stability on a low-overhead road surface according to an embodiment of the present application. The vehicle stability control method on the low-grade road surface of fig. 1 may be performed by the whole vehicle controller of the new energy vehicle. As shown in fig. 1, the method for controlling the stability of the vehicle on the low-traction surface specifically includes:
s101, determining the corresponding wheel acceleration and the wheel acceleration change rate of each wheel, and judging whether the wheel acceleration anti-skid marker bit is activated or not based on the wheel acceleration and the wheel acceleration change rate;
S102, when a wheel acceleration anti-skid flag bit is activated, determining a wheel acceleration anti-skid target attenuation coefficient based on the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate;
s103, determining the slip rate corresponding to each wheel, and judging whether the slip rate anti-slip flag bit is activated or not based on the slip rate and a preset slip rate threshold value;
s104, when the slip rate anti-slip flag bit is activated, determining a slip rate anti-slip target attenuation coefficient based on the slip rate absolute value and the slip rate change rate absolute value;
s105, when the wheel acceleration antiskid zone bit or the slip rate antiskid zone bit is activated, determining an attenuation coefficient change gradient, and processing a request attenuation coefficient of the current period by using the attenuation coefficient change gradient to obtain a request attenuation coefficient after gradient processing;
and S106, calculating the axle end request torque based on the axle end target torque of the current period and the gradient processed request attenuation coefficient, and transmitting the axle end request torque to the driving motor to execute torque control so as to perform low-stability control on the vehicle.
In the embodiment of the application, during the running process of the vehicle, the parameters of the whole vehicle and each wheel are monitored in real time by utilizing the VCU (Vehicle Control Unit) to obtain real-time motion parameters. Real-time kinematic parameters of a vehicle include, but are not limited to, the following: wheel speed, vehicle speed, shaft end target torque, etc. of each wheel.
Further, in the embodiment of the application, the wheel acceleration and the wheel acceleration change rate are calculated based on the wheel speeds of all the wheels obtained by real-time monitoring, and in practical application, the wheel acceleration is the result of derivative calculation based on the wheel speeds, and the wheel acceleration change rate is the result of further derivative calculation based on the wheel accelerations. In one example, the calculation formulas corresponding to the wheel acceleration and the wheel acceleration change rate respectively are:
where V represents the wheel speed of the wheel, a represents the wheel acceleration, and μ represents the wheel acceleration change rate.
In some embodiments, determining whether the wheel acceleration anti-skid flag is activated based on the wheel acceleration and the wheel acceleration rate of change comprises:
comparing the corresponding wheel acceleration and the wheel acceleration change rate of each wheel respectively, and selecting the maximum wheel acceleration and the maximum wheel acceleration change rate;
when the maximum wheel acceleration is larger than the first wheel acceleration threshold value and the maximum wheel acceleration change rate is larger than the first wheel acceleration change rate threshold value, judging that the wheel acceleration anti-skid flag bit is activated;
and when the maximum wheel acceleration is smaller than the second wheel acceleration threshold value within the preset time period and the maximum wheel acceleration change rate is smaller than the second wheel acceleration change rate threshold value, judging that the wheel acceleration anti-skid flag bit is not activated.
Specifically, the control system of the new energy automobile monitors the wheel speeds of all wheels in real time through the sensing equipment, and calculates the wheel acceleration according to the wheel speeds. Further, by continuously monitoring the wheel acceleration, the system can calculate the rate of change of the wheel acceleration. To ensure that which wheel is likely to be at risk of slipping is accurately identified, the system compares the wheel acceleration and the wheel acceleration rate of change of each wheel, and selects the largest wheel acceleration and wheel acceleration rate of change.
Further, the system calculates the maximum value of the wheel acceleration and the wheel acceleration change rate of the left and right wheels. The purpose of this is to ensure that in any case the risk of slipping is accurately captured. Then, the system judges whether the wheel acceleration anti-skid flag bit should be activated according to a preset threshold value. These thresholds are formulated based on test scenarios under different adhesion coefficients, with the aim of ensuring that the system is able to adequately identify the risk of tire instability. In order to enable the system to quickly respond to the risk of slipping and to activate the corresponding function in time, the activation threshold is set relatively sensitive. Conversely, to ensure that the function can continue to function if necessary, the exit threshold is set relatively conservative.
In one example, when the maximum wheel acceleration is greater than the first wheel acceleration threshold and the maximum wheel acceleration rate of change is greater than the first wheel acceleration rate of change threshold, the system may determine that the wheel acceleration anti-skid flag has been activated. At this point, the vehicle may be at risk of slipping and the system needs to take appropriate action to ensure the stability of the vehicle. Namely, activating the wheel acceleration antiskid zone bit when the following conditions are met: a > threshold A1, and μ > threshold B1, where a represents the maximum wheel acceleration, μ represents the maximum wheel acceleration rate of change, threshold A1 represents the first wheel acceleration threshold, and threshold B1 represents the first wheel acceleration rate of change threshold.
In another example, when the system continuously monitors that the maximum wheel acceleration is less than the second wheel acceleration threshold and the maximum wheel acceleration rate of change is less than the second wheel acceleration rate of change threshold for a predetermined period of time, the system may determine that the wheel acceleration anti-skid flag bit has been exited. At this point, the vehicle has recovered to be stable, and the system may stop the low-stability control operation on the vehicle. Namely, the wheel acceleration anti-skid flag bit is withdrawn when the following conditions are satisfied: a < threshold C1 and holding Tms, and μ < threshold D1 and holding Tms, where a represents the maximum wheel acceleration, μ represents the maximum wheel acceleration change rate, threshold C1 represents the second wheel acceleration threshold, and threshold D1 represents the second wheel acceleration change rate threshold.
Through the technical scheme provided by the embodiment, whether the vehicle is likely to slide or not is judged by monitoring the acceleration of the wheels and the change rate of the acceleration, when the vehicle is judged to slide, the wheel acceleration anti-slip marker bit is activated, and when the vehicle stops sliding, the wheel acceleration anti-slip marker bit is withdrawn, so that the low-attachment working condition is accurately identified, and the torque of the vehicle is adjusted accordingly to ensure the stability.
In some embodiments, determining the wheel acceleration slip target attenuation coefficient based on the wheel acceleration absolute value and the wheel acceleration rate of change absolute value includes:
inquiring a preset first attenuation coefficient mapping relation by using the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate to obtain a wheel acceleration anti-skid target attenuation coefficient; the first damping coefficient mapping relation is used for representing a preset value of the wheel acceleration anti-skid target damping coefficient changing along with the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate.
Specifically, when the wheel acceleration antiskid zone bit is in an activated state, a preset wheel acceleration antiskid damping coefficient table (namely, a table form of a first damping coefficient mapping relation) is inquired by utilizing the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate to obtain a wheel acceleration antiskid target damping coefficient.
In an example, the embodiment of the application can save the first damping coefficient mapping relationship in a two-dimensional table, wherein a horizontal axis in the two-dimensional table (i.e. a wheel acceleration anti-slip damping coefficient table) represents the absolute value of the wheel acceleration change rate, a vertical axis represents the absolute value of the wheel acceleration, and a table look-up value is the wheel acceleration anti-slip target damping coefficient.
The process of determining the wheel acceleration antiskid target attenuation coefficient by looking up the values in the two-dimensional table according to the embodiment of the present application is described below in connection with the wheel acceleration antiskid attenuation coefficient table related to the actual application scene according to the embodiment of the present application, as shown in table 1, table 1 is the wheel acceleration antiskid attenuation coefficient table configured in the actual application scene according to the embodiment of the present application.
TABLE 1 wheel acceleration anti-slip damping coefficient table
0 10 30
0 1 0.9 0.8
10 0.7 0.6 0.5
30 0.5 0.4 0.3
When the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate are known, the unique wheel acceleration slip target damping coefficient can be determined by referring to the above table 1 with the absolute value of the wheel acceleration change rate as the abscissa (corresponding to the horizontal axis of table 1) and the absolute value of the wheel acceleration as the ordinate (corresponding to the vertical axis of table 1). Therefore, the value of the wheel acceleration slip target damping coefficient is determined by the wheel acceleration absolute value and the wheel acceleration change rate absolute value of the current period together.
In some embodiments, the method further comprises:
acquiring historical actual measurement data of a vehicle, setting corresponding wheel acceleration anti-skid target attenuation coefficients for the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate according to the historical wheel acceleration and the historical wheel acceleration change rate in the historical actual measurement data by utilizing a preset configuration rule of the wheel acceleration anti-skid target attenuation coefficients, and establishing a first attenuation coefficient mapping relation between the wheel acceleration anti-skid target attenuation coefficients and the absolute value of the wheel acceleration change rate;
the configuration rules of the wheel acceleration anti-skid target attenuation coefficient comprise rules set by taking the larger the absolute value of the wheel acceleration and the absolute value of the change rate of the wheel acceleration as targets.
Specifically, the control system obtains historical measured data of the vehicle, including historical wheel acceleration and historical wheel acceleration rate of change. Based on the historical data, the system analyzes the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate by utilizing a predefined configuration rule of the wheel acceleration anti-skid target attenuation coefficient, and sets a corresponding wheel acceleration anti-skid target attenuation coefficient for the absolute value. Further, a first damping coefficient mapping relationship between the wheel acceleration slip target damping coefficient and the absolute value of the wheel acceleration change rate is established.
In practical application, the first attenuation coefficient mapping relationship is based on a core principle: when the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate are larger (indicating that the tire is unstable is more serious), in order to cope with this more effectively, the system needs to take more intense measures to restore the stability of the vehicle. Therefore, the wheel acceleration slip target damping coefficient will be set smaller, so that the torque output of the vehicle will be more damped, helping to reduce slip and quickly restore stability.
To achieve the above object, the control system uses a predetermined rule for configuring the wheel acceleration slip-resistant target damping coefficient, the basic idea of the rule is that: the larger the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate, the smaller the wheel acceleration slip target damping coefficient. This arrangement ensures that the system can take more powerful measures to restore the stability of the vehicle in the face of more severe slip or instability conditions.
In some embodiments, determining whether the slip rate anti-slip flag is activated based on the slip rate and a preset slip rate threshold includes:
comparing the slip rates corresponding to the wheels, selecting the maximum slip rate, judging that the slip rate anti-slip flag bit is activated when the maximum slip rate is larger than a slip rate threshold value, and judging that the slip rate anti-slip flag bit is not activated when the maximum slip rate is smaller than the slip rate threshold value.
Specifically, the vehicle low-traction stability control method of the present application further considers slip-ratio-based slip prevention control. The control system monitors the slip rate of each wheel in real time. The slip ratio is an index reflecting the degree of slip of the wheel with respect to the road surface, and the larger the value thereof, the more serious the relative slip between the tire and the road surface. In order to accurately determine which wheel has the greatest slip ratio, the system compares the slip ratios of the wheels and selects the greatest value.
In one example, the embodiment of the present application will calculate the slip rate of each wheel based on the wheel speed of each wheel and the vehicle speed, the calculation process is as follows:
wherein, delta represents slip ratio, V represents vehicle speed, V w Representing the wheel speeds of the individual wheels.
Further, in order to simplify the calculation and improve the response speed, the system only takes the maximum value of the left and right wheel slip rate for analysis. The purpose of this is to ensure that the system is able to quickly and accurately respond to any possible risk of slipping. The system can judge whether the slip rate anti-slip flag bit is activated according to a preset slip rate threshold value. These thresholds are formulated based on test scenarios under different adhesion coefficients, and are intended to ensure that the system can accurately identify that the vehicle is likely to be at risk of slipping when the slip rate reaches or exceeds a certain threshold. In order to enable the system to respond quickly and activate the corresponding function in time, the activation threshold for slip rate is set relatively low so that when slip rate reaches or slightly exceeds this value, the system will determine that the wheel is in slip and activate the anti-slip flag. Conversely, in order to ensure that the function can continue to function if necessary, the exit threshold for the slip rate is set relatively high.
In one example, when the maximum slip rate is greater than a preset slip rate threshold (i.e., delta > slip rate threshold), the system may determine that the slip rate anti-slip flag has been activated. At this time, it is determined that at least one wheel is likely to be in front of the slip risk, and the system needs to take corresponding measures to restore the stability of the vehicle.
In another example, when the maximum slip rate is less than the slip rate threshold (i.e., delta < slip rate threshold), the system may determine that the slip rate slip flag has been exited, indicating that the vehicle has recovered stability, and the system may stop continuing the low stability control operation on the vehicle.
Through the technical scheme provided by the embodiment, the stability control method based on the slip rate is provided for the new energy automobile, various slip risks can be responded more accurately and rapidly, and proper measures are taken to ensure the stability and driving safety of the automobile.
In some embodiments, determining the slip rate antiskid target attenuation coefficient based on the slip rate absolute value and the slip rate change rate absolute value includes:
inquiring a preset second attenuation coefficient mapping relation by utilizing the sliding rate absolute value and the sliding rate change rate absolute value to obtain a sliding rate anti-sliding target attenuation coefficient; the second attenuation coefficient mapping relation is used for representing a preset value of the sliding rate anti-slip target attenuation coefficient along with the absolute value of the sliding rate and the absolute value of the sliding rate change rate.
Specifically, when the slip rate anti-slip flag bit is in an activated state, a preset slip rate anti-slip target attenuation coefficient table (namely, a table form of a second attenuation coefficient mapping relation) is inquired by using the absolute value of the slip rate and the absolute value of the change rate of the slip rate, so that the slip rate anti-slip target attenuation coefficient is obtained.
In an example, the embodiment of the present application may save the second attenuation coefficient mapping relationship in a two-dimensional table, where a horizontal axis in the two-dimensional table (i.e., the slip rate antiskid target attenuation coefficient table) represents an absolute value of a slip rate, a vertical axis represents an absolute value of a slip rate change rate, and a table look-up value is a slip rate antiskid target attenuation coefficient.
The process of determining the slip rate anti-slip target attenuation coefficient by looking up the values in the two-dimensional table according to the embodiment of the present application is described below in connection with the slip rate anti-slip target attenuation coefficient table related to the actual application scenario according to the embodiment of the present application, as shown in table 2, table 2 is the slip rate anti-slip target attenuation coefficient table configured in the actual application scenario according to the embodiment of the present application.
TABLE 2 slip Rate anti-slip target attenuation coefficient Table
0 10 30
0 0.8 0.7 0.6
10 0.7 0.6 0.5
30 0.5 0.4 0.3
When the slip ratio absolute value and the slip ratio change rate absolute value are known, the slip ratio change rate absolute value is taken as an abscissa (corresponding to the horizontal axis of table 2), and the slip ratio absolute value is taken as an ordinate (corresponding to the vertical axis of table 2), and the unique slip ratio slip prevention target attenuation coefficient can be determined by referring to table 2. Therefore, the value of the slip ratio slip prevention target damping coefficient is determined by the slip ratio absolute value of the current period and the slip ratio change rate absolute value.
In some embodiments, the method further comprises:
acquiring historical actual measurement data of the vehicle, setting corresponding slip rate anti-slip target attenuation coefficients for the absolute value of the slip rate and the absolute value of the slip rate change rate according to the historical slip rate and the historical slip rate change rate in the historical actual measurement data by utilizing a configuration rule of a preset slip rate anti-slip target attenuation coefficient, and establishing a second attenuation coefficient mapping relation between the slip rate anti-slip target attenuation coefficients and the absolute value of the slip rate change rate;
the configuration rules of the slip rate anti-slip target attenuation coefficient comprise rules set by taking the slip rate absolute value and the greater the slip rate change rate absolute value as targets, wherein the smaller the slip rate anti-slip target attenuation coefficient is.
Specifically, the control system may obtain historical measured data of the vehicle from the on-board database. These data record the historical slip rate and the historical slip rate change rate of the vehicle during past travel. Based on these historical data, the control system analyzes the absolute value of the slip rate and the absolute value of the slip rate change rate using a configuration rule of a predetermined slip rate slip-resistant target attenuation coefficient, thereby setting a corresponding slip rate slip-resistant target attenuation coefficient therefor. Then, the system establishes a second attenuation coefficient mapping relationship between the slip rate antiskid target attenuation coefficient and the absolute value of the slip rate change rate.
In practical applications, the second attenuation coefficient mapping relationship follows a core principle: when the absolute value of the slip ratio and the absolute value of the slip ratio change rate are larger, this means that the tire is unstable more seriously. In order to more effectively cope with this situation, the system needs to take more intense measures to restore the stability of the vehicle. Therefore, the slip ratio slip target damping coefficient is set smaller, thereby making the torque output of the vehicle more damped, helping to reduce slip and quickly restore stability.
Therefore, to achieve the above objective, the rule of configuration of slip-ratio slip-target attenuation coefficient is based on the following principle: the larger the slip rate absolute value and the slip rate change rate absolute value are, the smaller the slip rate anti-slip target attenuation coefficient is. This arrangement ensures that the system can take more powerful measures to restore the stability of the vehicle in the face of more severe slip or instability conditions.
In some embodiments, prior to determining the attenuation coefficient change gradient, the method further comprises:
when the wheel acceleration anti-skid flag bit is in an activated state or the wheel acceleration anti-skid flag bit and the slip rate anti-skid flag bit are both in an activated state, using a wheel acceleration anti-skid target attenuation coefficient as a target attenuation coefficient;
When the wheel acceleration antiskid zone bit is in an inactive state, the slip rate antiskid target attenuation coefficient is used as a target attenuation coefficient.
Specifically, to select an appropriate target attenuation coefficient, a more adaptive stability control strategy is provided for the vehicle. Before determining the gradient of the change of the attenuation coefficient, the system firstly checks the activation states of the wheel acceleration anti-skid flag bit and the slip rate anti-skid flag bit. The activation status of these two flags may provide the system with critical information about the current stability status of the vehicle.
In one example, if the wheel acceleration anti-skid flag is active, the system uses the wheel acceleration anti-skid target damping coefficient as the target damping coefficient regardless of whether the slip rate anti-skid flag is active. This is because the wheel acceleration is generally more directly and accurately reflective of the real-time state of the wheel, and therefore the system prioritizes the information of the wheel acceleration when the wheel acceleration anti-skid flag is activated.
In another example, if the wheel acceleration anti-skid flag is in an inactive state and the slip rate anti-skid flag is in an active state, the system may use the slip rate anti-skid target damping coefficient as the target damping coefficient. This is because in the event that the wheel acceleration anti-skid flag is not activated, the slip rate may provide the system with useful information regarding the overall stability of the vehicle.
In some embodiments, determining the attenuation coefficient change gradient includes:
inquiring a preset attenuation coefficient change gradient mapping relation by utilizing the speed of the vehicle in the current period and the shaft end target torque to obtain an attenuation coefficient change gradient; the attenuation coefficient change gradient mapping relation is used for representing a preset value of the attenuation coefficient change gradient along with the change of the vehicle speed and the shaft end target torque;
the attenuation coefficient change gradient mapping relation is established based on the attenuation coefficient change gradient, the vehicle speed and the shaft end target torque; the configuration rules of the attenuation coefficient variation gradient include rules for controlling the requested attenuation coefficient of the current period to be reduced to be set by a target when the wheel acceleration slip prevention flag or the slip rate slip prevention flag is activated.
Specifically, the system first collects data of the vehicle speed and the shaft end target torque of the vehicle in the current period. These two parameters are key factors in determining the gradient of the variation of the attenuation coefficient, as they are closely related to the dynamic performance and stability of the vehicle. The system will then query the two parameters using a predetermined decay factor gradient map. This map is a two-dimensional table with the axle end target torque as the abscissa and the vehicle speed as the ordinate. By looking up this table, the system can obtain a preset value for the gradient of the attenuation coefficient variation under the current conditions. The purpose of this mapping relationship is to ensure that the system can select the most appropriate gradient of the attenuation coefficient variation under different driving conditions, thereby achieving the best stability control effect.
Further, if the wheel acceleration antiskid flag or slip rate antiskid flag is activated, the strategy of the system becomes more conservative. In this case, the system will control the requested attenuation coefficient for the current period to drop only. This is because the stability of the vehicle is compromised when the wheels are in a slip condition, and thus the system needs to take steps to reduce the torque output of the vehicle to help restore stability. When the tire is stabilized, the damping coefficient is allowed to slowly rise, so that the torque output of the vehicle gradually returns to a normal level.
In some embodiments, after deriving the gradient processed requested attenuation coefficient, the method further comprises:
when the wheel acceleration anti-skid flag bit and/or the slip rate anti-skid flag bit are activated or are out of an activated state, carrying out filtering treatment on the gradient treated request attenuation coefficient by utilizing a preset filtering coefficient, a filtering output value of a previous period and the request attenuation coefficient of a current period to obtain a filtered request attenuation coefficient corresponding to the current period; and when the difference between the request attenuation coefficient and the target attenuation coefficient after the filtering process is smaller than a preset difference threshold value, exiting the filtering process.
In particular, in order to make the damping coefficient change smoother, a more comfortable and stable driving experience is provided. After determining the requested attenuation coefficient after the gradient processing, the system will further perform filtering processing. The purpose of this operation is to eliminate abrupt changes in the damping coefficient due to activation or withdrawal of the wheel acceleration slip flag and/or slip rate slip flag. To achieve this, the system uses a preset filter coefficient, which is determined based on the dynamic performance and stability requirements of the vehicle.
In one example, when the filtering process begins, the system considers the filtered output value of the previous cycle and the requested attenuation coefficient of the current cycle. By combining the two parameters and the preset filter coefficient, the system can obtain the request attenuation coefficient after the filter processing corresponding to the current period. In this way, the system can ensure that the variation of the attenuation coefficient is smooth and continuous, thereby avoiding abrupt changes in the attenuation coefficient due to functional activation or withdrawal. In practical application, the following formula can be adopted to calculate the output value after the current filtering:
y(t)＝K·u(t)+(1-K)·y(t-1)
wherein K represents a filter coefficient, u (t) represents a current sampling value, y (t-1) represents a previous period filter output value, and y (t) represents an output value after current filtering.
Further, the embodiment of the application also sets a preset difference threshold. When the difference between the requested attenuation coefficient and the target attenuation coefficient after the filtering process is less than this threshold, the system may consider that the attenuation coefficient has approached the target value, and thus no further filtering process is required. This design ensures that the system responds quickly after reaching the target state, thereby providing more flexible and efficient stability control.
After the operations of the above embodiments are performed, the embodiments of the present application calculate the shaft-end requested torque based on the shaft-end target torque and the filtered requested damping coefficient. For example, the shaft end request torque may be calculated using the following formula:
T req ＝T raw ×Factor
wherein T is req Representing the torque requested at the shaft end, T raw Representing the shaft end target torque, and Factor representing the requested attenuation coefficient after the filtering process.
According to the technical scheme provided by the embodiment of the application, the low-adhesion working condition is identified and responded by skillfully utilizing the wheel acceleration, the wheel acceleration change rate, the slip rate and the slip rate change rate. Through real-time monitoring and analysis of the parameters, the system can timely identify whether the wheels are in a sliding state, so that a more timely and accurate stability control strategy is provided for a driver. The system can effectively control the maximum driving and braking torque of the vehicle through damping adjustment of the axle end torque, so that the stability of the vehicle on a low-attachment road surface is ensured. Therefore, the trafficability of the vehicle on the low-traction road surface can be improved, the driving safety can be greatly improved, and more comfortable and stable driving experience is provided for a driver. In addition, the technical scheme adopts various advanced processing technologies, such as gradient processing and filtering processing, so as to ensure that the change of the attenuation coefficient is smooth and continuous. These designs can avoid abrupt changes in the damping coefficient due to functional activation or withdrawal, thereby providing a more continuous and smooth driving experience. In general, the application provides an efficient, intelligent and practical low-attachment stability control scheme for the new energy automobile. By combining real-time vehicle parameters, preset mapping relation and advanced processing technology, the scheme can provide more stable, safe and comfortable driving experience for a driver, so that the performance and safety of the new energy automobile on a low-attachment road surface are obviously improved.
The following are examples of the apparatus of the present application that may be used to perform the method embodiments of the present application. For details not disclosed in the embodiments of the apparatus of the present application, please refer to the embodiments of the method of the present application.
Fig. 2 is a schematic structural diagram of a vehicle stability control device on a low-traction road surface according to an embodiment of the present application. As shown in fig. 2, the vehicle stability control device on a low-overhead road surface includes:
a first judging module 201 configured to determine a wheel acceleration and a wheel acceleration change rate corresponding to each wheel, and judge whether the wheel acceleration anti-skid flag bit is activated based on the wheel acceleration and the wheel acceleration change rate;
a first determination module 202 configured to determine a wheel acceleration anti-skid target attenuation coefficient based on the wheel acceleration absolute value and the wheel acceleration change rate absolute value when the wheel acceleration anti-skid flag bit is activated;
a second judging module 203 configured to determine a slip rate corresponding to each wheel, and judge whether the slip rate anti-slip flag bit is activated based on the slip rate and a preset slip rate threshold;
a second determination module 204 configured to determine a slip rate antiskid target attenuation coefficient based on the slip rate absolute value and the slip rate change rate absolute value when the slip rate antiskid flag bit is activated;
The processing module 205 is configured to determine an attenuation coefficient change gradient when the wheel acceleration anti-skid flag bit or the slip rate anti-skid flag bit is activated, and process the requested attenuation coefficient of the current period by using the attenuation coefficient change gradient to obtain a requested attenuation coefficient after gradient processing;
the control module 206 is configured to calculate an axle end request torque based on the axle end target torque of the current period and the gradient processed request attenuation coefficient, and transmit the axle end request torque to the driving motor to perform torque control so as to perform low-stability control on the vehicle.
In some embodiments, the first determining module 201 of fig. 2 compares the wheel acceleration and the wheel acceleration change rate corresponding to each wheel, and selects the maximum wheel acceleration and the maximum wheel acceleration change rate; when the maximum wheel acceleration is larger than the first wheel acceleration threshold value and the maximum wheel acceleration change rate is larger than the first wheel acceleration change rate threshold value, judging that the wheel acceleration anti-skid flag bit is activated; and when the maximum wheel acceleration is smaller than the second wheel acceleration threshold value within the preset time period and the maximum wheel acceleration change rate is smaller than the second wheel acceleration change rate threshold value, judging that the wheel acceleration anti-skid flag bit is not activated.
In some embodiments, the first determining module 202 of fig. 2 queries the predetermined first damping coefficient mapping relationship using the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate to obtain the wheel acceleration slip target damping coefficient; the first damping coefficient mapping relation is used for representing a preset value of the wheel acceleration anti-skid target damping coefficient changing along with the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate.
In some embodiments, the first determining module 202 of fig. 2 obtains historical measured data of the vehicle, sets corresponding wheel acceleration anti-slip target attenuation coefficients for the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate according to the historical wheel acceleration and the historical wheel acceleration change rate in the historical measured data, and establishes a first attenuation coefficient mapping relationship between the wheel acceleration anti-slip target attenuation coefficients and the absolute value of the wheel acceleration change rate; the configuration rules of the wheel acceleration anti-skid target attenuation coefficient comprise rules set by taking the larger the absolute value of the wheel acceleration and the absolute value of the change rate of the wheel acceleration as targets.
In some embodiments, the second determining module 203 of fig. 2 compares the slip rates corresponding to the wheels, selects the maximum slip rate, determines that the slip rate anti-slip flag is activated when the maximum slip rate is greater than the slip rate threshold, and determines that the slip rate anti-slip flag is not activated when the maximum slip rate is less than the slip rate threshold.
In some embodiments, the second determining module 204 of fig. 2 queries the predetermined second attenuation coefficient mapping relationship using the slip rate absolute value and the slip rate change rate absolute value to obtain the slip rate antiskid target attenuation coefficient; the second attenuation coefficient mapping relation is used for representing a preset value of the sliding rate anti-slip target attenuation coefficient along with the absolute value of the sliding rate and the absolute value of the sliding rate change rate.
In some embodiments, the second determining module 204 of fig. 2 obtains historical measured data of the vehicle, sets corresponding slip rate anti-slip target attenuation coefficients for the slip rate absolute value and the slip rate change rate absolute value according to the historical slip rate and the historical slip rate change rate in the historical measured data by using a configuration rule of a predetermined slip rate anti-slip target attenuation coefficient, and establishes a second attenuation coefficient mapping relationship between the slip rate anti-slip target attenuation coefficients and the slip rate absolute value and the slip rate change rate absolute value; the configuration rules of the slip rate anti-slip target attenuation coefficient comprise rules set by taking the slip rate absolute value and the greater the slip rate change rate absolute value as targets, wherein the smaller the slip rate anti-slip target attenuation coefficient is.
In some embodiments, the processing module 205 of fig. 2 uses the wheel acceleration antiskid target attenuation coefficient as the target attenuation coefficient when the wheel acceleration antiskid flag is in an active state, or both the wheel acceleration antiskid flag and the slip rate antiskid flag are in an active state, prior to determining the attenuation coefficient variation gradient; when the wheel acceleration antiskid zone bit is in an inactive state, the slip rate antiskid target attenuation coefficient is used as a target attenuation coefficient.
In some embodiments, the processing module 205 of fig. 2 queries a predetermined attenuation coefficient variation gradient mapping relationship to obtain an attenuation coefficient variation gradient by using the vehicle speed and the shaft end target torque of the vehicle in the current period; the attenuation coefficient change gradient mapping relation is used for representing a preset value of the attenuation coefficient change gradient along with the change of the vehicle speed and the shaft end target torque; the attenuation coefficient change gradient mapping relation is established based on the attenuation coefficient change gradient, the vehicle speed and the shaft end target torque; the configuration rules of the attenuation coefficient variation gradient include rules for controlling the requested attenuation coefficient of the current period to be reduced to be set by a target when the wheel acceleration slip prevention flag or the slip rate slip prevention flag is activated.
In some embodiments, after obtaining the gradient processed request attenuation coefficient, when the wheel acceleration anti-skid flag bit and/or the slip rate anti-skid flag bit are activated or are out of the activated state, the processing module 205 of fig. 2 performs filtering processing on the gradient processed request attenuation coefficient by using a preset filtering coefficient, a filtering output value of a previous period and the request attenuation coefficient of a current period to obtain the filtered request attenuation coefficient corresponding to the current period; and when the difference between the request attenuation coefficient and the target attenuation coefficient after the filtering process is smaller than a preset difference threshold value, exiting the filtering process.
It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present application.
The embodiment of the application also provides a new energy automobile, which comprises an entire automobile controller, a motor controller, a driving motor and a transmission system; the whole vehicle controller is used for realizing the steps of the sliding torque control method under the working condition of the deceleration strip so as to send the final sliding torque to the motor controller; the motor controller is used for controlling the torque of the driving motor through the transmission system according to the final sliding torque.
Fig. 3 is a schematic structural diagram of an electronic device 3 according to an embodiment of the present application. As shown in fig. 3, the electronic apparatus 3 of this embodiment includes: a processor 301, a memory 302 and a computer program 303 stored in the memory 302 and executable on the processor 301. The steps of the various method embodiments described above are implemented when the processor 301 executes the computer program 303. Alternatively, the processor 301, when executing the computer program 303, performs the functions of the modules/units in the above-described apparatus embodiments.
Illustratively, the computer program 303 may be partitioned into one or more modules/units, which are stored in the memory 302 and executed by the processor 301 to complete the present application. One or more of the modules/units may be a series of computer program instruction segments capable of performing a specific function for describing the execution of the computer program 303 in the electronic device 3.
The electronic device 3 may be an electronic device such as a desktop computer, a notebook computer, a palm computer, or a cloud server. The electronic device 3 may include, but is not limited to, a processor 301 and a memory 302. It will be appreciated by those skilled in the art that fig. 3 is merely an example of the electronic device 3 and does not constitute a limitation of the electronic device 3, and may include more or fewer components than shown, or may combine certain components, or different components, e.g., the electronic device may also include an input-output device, a network access device, a bus, etc.
The processor 301 may be a central processing unit (Central Processing Unit, CPU) or other general purpose processor, digital signal processor (Digital Signal Processor, DSP), application specific integrated circuit (Application Specific Integrated Circuit, ASIC), field programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 302 may be an internal storage unit of the electronic device 3, for example, a hard disk or a memory of the electronic device 3. The memory 302 may also be an external storage device of the electronic device 3, for example, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card) or the like, which are provided on the electronic device 3. Further, the memory 302 may also include both an internal storage unit and an external storage device of the electronic device 3. The memory 302 is used to store computer programs and other programs and data required by the electronic device. The memory 302 may also be used to temporarily store data that has been output or is to be output.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, the specific names of the functional units and modules are only for distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided by the present application, it should be understood that the disclosed apparatus/computer device and method may be implemented in other manners. For example, the apparatus/computer device embodiments described above are merely illustrative, e.g., the division of modules or elements is merely a logical functional division, and there may be additional divisions of actual implementations, multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated modules/units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the present application may implement all or part of the flow of the method of the above embodiment, or may be implemented by a computer program to instruct related hardware, and the computer program may be stored in a computer readable storage medium, where the computer program, when executed by a processor, may implement the steps of each of the method embodiments described above. The computer program may comprise computer program code, which may be in source code form, object code form, executable file or in some intermediate form, etc. The computer readable medium may include: any entity or device capable of carrying computer program code, a recording medium, a U disk, a removable hard disk, a magnetic disk, an optical disk, a computer Memory, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), an electrical carrier signal, a telecommunications signal, a software distribution medium, and so forth. It should be noted that the content of the computer readable medium can be appropriately increased or decreased according to the requirements of the jurisdiction's jurisdiction and the patent practice, for example, in some jurisdictions, the computer readable medium does not include electrical carrier signals and telecommunication signals according to the jurisdiction and the patent practice.
The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims (12)

1. A vehicle stability control method on a low-overhead road surface, comprising:
determining the corresponding wheel acceleration and the wheel acceleration change rate of each wheel, and judging whether the wheel acceleration anti-skid marker bit is activated or not based on the wheel acceleration and the wheel acceleration change rate;
when the wheel acceleration anti-skid flag bit is activated, determining a wheel acceleration anti-skid target attenuation coefficient based on the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate;
determining the slip rate corresponding to each wheel, and judging whether the slip rate anti-slip zone bit is activated or not based on the slip rate and a preset slip rate threshold value;
When the slip rate anti-slip flag bit is activated, determining a slip rate anti-slip target attenuation coefficient based on the slip rate absolute value and the slip rate change rate absolute value;
when the wheel acceleration antiskid zone bit or the slip rate antiskid zone bit is activated, determining an attenuation coefficient change gradient, and processing a request attenuation coefficient of a current period by using the attenuation coefficient change gradient to obtain a request attenuation coefficient after gradient processing;
and calculating the shaft end request torque based on the shaft end target torque of the current period and the gradient processed request attenuation coefficient, and transmitting the shaft end request torque to a driving motor to execute torque control so as to perform low-stability control on the vehicle.
2. The method of claim 1, wherein the determining whether a wheel acceleration anti-skid flag is activated based on the wheel acceleration and the wheel acceleration rate of change comprises:
comparing the corresponding wheel acceleration and the wheel acceleration change rate of each wheel respectively, and selecting the maximum wheel acceleration and the maximum wheel acceleration change rate;
when the maximum wheel acceleration is larger than a first wheel acceleration threshold value and the maximum wheel acceleration change rate is larger than the first wheel acceleration change rate threshold value, judging that the wheel acceleration anti-skid flag bit is activated;
And when the maximum wheel acceleration is smaller than the second wheel acceleration threshold value and the maximum wheel acceleration change rate is smaller than the second wheel acceleration change rate threshold value within the preset time period, judging that the wheel acceleration anti-skid flag bit is not activated.
3. The method of claim 1, wherein determining the wheel acceleration slip target damping coefficient based on the wheel acceleration absolute value and the wheel acceleration rate of change absolute value comprises:
inquiring a preset first attenuation coefficient mapping relation by utilizing the absolute value of the wheel acceleration and the absolute value of the change rate of the wheel acceleration to obtain an attenuation coefficient of the wheel acceleration anti-skid target; the first attenuation coefficient mapping relation is used for representing a preset value of the wheel acceleration anti-skid target attenuation coefficient along with the change of the absolute value of the wheel acceleration and the absolute value of the change rate of the wheel acceleration.
4. A method according to claim 3, characterized in that the method further comprises:
acquiring historical actual measurement data of a vehicle, setting corresponding wheel acceleration anti-slip target attenuation coefficients for the absolute value of the wheel acceleration and the absolute value of the wheel acceleration change rate according to the historical wheel acceleration and the historical wheel acceleration change rate in the historical actual measurement data by utilizing a preset configuration rule of the wheel acceleration anti-slip target attenuation coefficients, and establishing a first attenuation coefficient mapping relation between the wheel acceleration anti-slip target attenuation coefficients and the absolute value of the wheel acceleration change rate;
The configuration rules of the wheel acceleration anti-skid target attenuation coefficient comprise rules set by taking the larger the absolute value of the wheel acceleration and the absolute value of the change rate of the wheel acceleration as targets, and the smaller the wheel acceleration anti-skid target attenuation coefficient is.
5. The method of claim 1, wherein the determining whether the slip rate anti-slip flag is activated based on the slip rate and a preset slip rate threshold comprises:
comparing the slip rates corresponding to the wheels, selecting the maximum slip rate, judging that the slip rate anti-slip flag bit is activated when the maximum slip rate is larger than the slip rate threshold value, and judging that the slip rate anti-slip flag bit is not activated when the maximum slip rate is smaller than the slip rate threshold value.
6. The method of claim 1, wherein determining the slip rate anti-slip target attenuation coefficient based on the slip rate absolute value and the slip rate change rate absolute value comprises:
inquiring a preset second attenuation coefficient mapping relation by utilizing the sliding rate absolute value and the sliding rate change rate absolute value to obtain the sliding rate anti-skid target attenuation coefficient; the second attenuation coefficient mapping relation is used for representing a preset value of the sliding rate anti-slip target attenuation coefficient along with the absolute value of the sliding rate and the absolute value of the sliding rate change rate.
7. The method of claim 6, wherein the method further comprises:
acquiring historical actual measurement data of a vehicle, setting corresponding slip rate anti-slip target attenuation coefficients for an absolute value of slip rate and an absolute value of slip rate change rate according to a historical slip rate and a historical slip rate change rate in the historical actual measurement data by utilizing a configuration rule of a preset slip rate anti-slip target attenuation coefficient, and establishing a second attenuation coefficient mapping relation between the slip rate anti-slip target attenuation coefficients and the absolute value of slip rate change rate;
the configuration rules of the slip rate anti-slip target attenuation coefficient comprise rules set by taking the slip rate absolute value and the slip rate change rate absolute value as targets, wherein the slip rate anti-slip target attenuation coefficient is smaller.
8. The method of claim 1, wherein prior to said determining the attenuation coefficient change gradient, the method further comprises:
when the wheel acceleration antiskid zone bit is in an activated state or both the wheel acceleration antiskid zone bit and the slip rate antiskid zone bit are in an activated state, using the wheel acceleration antiskid target attenuation coefficient as a target attenuation coefficient;
And when the wheel acceleration antiskid zone bit is in an unactivated state, using the slip rate antiskid target attenuation coefficient as a target attenuation coefficient.
9. The method of claim 1, wherein the determining the attenuation coefficient variation gradient comprises:
inquiring a preset attenuation coefficient change gradient mapping relation by utilizing the speed of the vehicle in the current period and the shaft end target torque to obtain the attenuation coefficient change gradient; the attenuation coefficient change gradient mapping relation is used for representing a preset value of the attenuation coefficient change gradient along with the change of the vehicle speed and the shaft end target torque;
the attenuation coefficient change gradient mapping relation is established based on the attenuation coefficient change gradient, the vehicle speed and the shaft end target torque; the configuration rules of the attenuation coefficient change gradient comprise rules which are set by controlling the attenuation coefficient of the current period to be reduced to a target when the wheel acceleration anti-skid flag bit or the slip rate anti-skid flag bit is activated.
10. The method of claim 1, wherein after the deriving the gradient processed requested attenuation coefficient, the method further comprises:
when the wheel acceleration anti-skid flag bit and/or the slip rate anti-skid flag bit are activated or are out of an activated state, filtering the gradient processed request attenuation coefficient by using a preset filtering coefficient, a filtering output value of a previous period and the current period request attenuation coefficient to obtain a filtered request attenuation coefficient corresponding to the current period; and when the difference between the request attenuation coefficient and the target attenuation coefficient after the filtering process is smaller than a preset difference threshold value, exiting the filtering process.
11. A vehicle stability control device on a low-overhead road surface, comprising:
the first judging module is configured to determine the corresponding wheel acceleration and the corresponding wheel acceleration change rate of each wheel, and judge whether the wheel acceleration anti-skid flag bit is activated or not based on the wheel acceleration and the wheel acceleration change rate;
a first determination module configured to determine a wheel acceleration anti-skid target attenuation coefficient based on an absolute value of the wheel acceleration and an absolute value of a rate of change of the wheel acceleration when the wheel acceleration anti-skid flag bit is activated;
The second judging module is configured to determine the slip rate corresponding to each wheel, and judge whether the slip rate anti-slip flag bit is activated or not based on the slip rate and a preset slip rate threshold value;
a second determination module configured to determine a slip rate antiskid target attenuation coefficient based on an absolute value of a slip rate and an absolute value of a slip rate change rate when the slip rate antiskid flag bit is activated;
the processing module is configured to determine an attenuation coefficient change gradient when the wheel acceleration anti-skid flag bit or the slip rate anti-skid flag bit is activated, and process the request attenuation coefficient of the current period by using the attenuation coefficient change gradient to obtain a request attenuation coefficient after gradient processing;
and the control module is configured to calculate the axle end request torque based on the axle end target torque of the current period and the gradient processed request attenuation coefficient, and transmit the axle end request torque to the driving motor to execute torque control so as to perform low-stability control on the vehicle.
12. The new energy automobile is characterized by comprising a whole automobile controller, a motor controller, a driving motor and a transmission system;
the vehicle controller being configured to implement the method of any one of claims 1 to 10 to send a shaft end request torque to a motor controller;
The motor controller is used for controlling the torque of the driving motor through the transmission system according to the shaft end request torque.
CN202311087070.0A 2023-08-28 2023-08-28 Vehicle stability control method and device on low-attachment road surface and new energy automobile Pending CN117048359A (en)

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CN117048359A true CN117048359A (en) 2023-11-14

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