CN116985768A

CN116985768A - Shaft braking force balance control method and device for electromechanical braking system

Info

Publication number: CN116985768A
Application number: CN202311261505.9A
Authority: CN
Inventors: 刘长运; 王巍; 郑利水; 段珍珍; 宋京阳; 顾红萍
Original assignee: Wanxiang Qianchao Co Ltd; Zhejiang Wanxiang Precision Industry Co Ltd
Current assignee: Wanxiang Qianchao Co Ltd; Zhejiang Wanxiang Precision Industry Co Ltd
Priority date: 2023-09-27
Filing date: 2023-09-27
Publication date: 2023-11-03
Anticipated expiration: 2043-09-27
Also published as: CN116985768B

Abstract

The application provides a method and a device for controlling the balance of the shaft braking force of an electromechanical braking system, which are used for determining the calculated value of the yaw rate generated by a steering wheel according to the steering wheel angle signal of a vehicle; obtaining and according to the real-time yaw rate measured value of the vehicle and the yaw rate calculated value of the vehicle, obtaining a yaw rate deviation value of the vehicle; obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle; according to a braking torque target value of the vehicle, a motor open-loop current value of the vehicle is obtained by using a preset current calculation model; a motor target current value for braking a rear axle of the vehicle is determined based on the motor open loop current value and the motor current deviation value of the vehicle. Compared with the prior art, in the scheme of the application, on the premise of meeting the condition that the vehicle braking is free from deviation, a force sensor is not required to carry out closed-loop control on the braking clamping force, and the system cost is effectively controlled.

Description

Shaft braking force balance control method and device for electromechanical braking system

Technical Field

The application relates to the technical field of automobiles, in particular to a method and a device for controlling the balance of shaft braking force of an electromechanical braking system.

Background

Most of the existing automobile braking modes are that a front axle adopts a double-channel hydraulic integrated control system to realize braking, and a rear axle adopts an electromechanical braking execution module to realize braking. The dual-channel hydraulic integrated control system realizes braking mainly through front axle wheel speed acquisition and front axle hydraulic braking. The working principle of the electromechanical brake execution module is that the clamping force of a brake disc is realized through a motor, a speed reducing mechanism, a ball screw mechanism and a brake caliper, and the braking force acting on the brake disc can be adjusted by applying different currents to the motor, but the motor and other mechanisms cannot be completely consistent in the processing and using processes. Therefore, when the same current is applied to the left and right motors, there is necessarily a difference in the actual braking force on both sides of the rear axle on the vehicle.

The electro-mechanical brake actuation system has no hydraulic brake pressure balancing characteristics as compared to the hydraulic system. Therefore, the electromechanical brake execution module needs to ensure that braking forces on two sides of the rear axle are consistent from control, and the vehicle is prevented from being deviated due to the generation of additional yaw moment.

In the existing method for controlling the braking force balance on two sides of the rear axle, one is to carry out closed-loop control on braking clamping force by adopting a force sensor, and the other is to carry out closed-loop control on motor current only, so that the braking force is ensured through structural performance consistency.

However, the method of performing closed-loop control on the brake clamping force by using the force sensor can increase the BOM cost and the failure mode due to the inconvenience of installing the force sensor, and the method of performing closed-loop control on the motor current only can increase the processing cost due to high requirements on structural processing.

Disclosure of Invention

In view of this, in order to solve the problem that the installation of the force sensor for performing the closed-loop control on the braking clamping force and the closed-loop control on the motor current both cause the increase of the system cost, the first aspect of the embodiment of the present application discloses a method for controlling the braking force balance of the electromechanical braking system shaft, which includes:

determining a yaw rate calculation value generated by a steering wheel according to a steering wheel angle signal of the vehicle; the rear axle brake of the vehicle is realized through an electromechanical brake executing module;

obtaining and according to the real-time yaw rate measured value of the vehicle and the yaw rate calculated value of the vehicle, obtaining a yaw rate deviation value of the vehicle;

obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle;

according to the braking torque target value of the vehicle, a preset current calculation model is utilized to obtain an open-loop current value of a motor of the vehicle;

And determining a motor target current value for braking a rear axle of the vehicle according to the motor open-loop current value and the motor current deviation value of the vehicle.

A second aspect of the embodiments of the present application discloses a device for controlling the balance of braking force of an electromechanical braking system, the device comprising:

the first numerical value determining module is used for determining a yaw rate calculated value generated by a steering wheel according to a steering wheel angle signal of the vehicle; the rear axle brake of the vehicle is realized through an electromechanical brake executing module;

a first deviation value determining module, configured to obtain and obtain a yaw rate deviation value of the vehicle according to a real-time yaw rate measurement value of the vehicle and the yaw rate calculation value of the vehicle;

a second deviation value determining module for obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle;

the second value determining module is used for obtaining an open-loop current value of a motor of the vehicle by using a preset current calculation model according to a braking torque target value of the vehicle;

and a third value determining module for determining a motor target current value for braking a rear axle of the vehicle according to the motor open-loop current value and the motor current deviation value of the vehicle.

According to the embodiment of the application, a yaw rate calculated value generated by a steering wheel is determined according to a steering wheel angle signal of a vehicle; the rear axle brake of the vehicle is realized through an electromechanical brake executing module; obtaining and according to the real-time yaw rate measured value of the vehicle and the yaw rate calculated value of the vehicle, obtaining a yaw rate deviation value of the vehicle; obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle; according to a braking torque target value of the vehicle, a motor open-loop current value of the vehicle is obtained by using a preset current calculation model; a motor target current value for braking a rear axle of the vehicle is determined based on the motor open loop current value and the motor current deviation value of the vehicle. Compared with the prior art, in the scheme of the embodiment, on the premise that the condition that the vehicle brake is free from deviation and the braking force balance control accuracy of the electronic mechanical brake execution module on two sides of the rear axle is improved, a force sensor is not required to be used for carrying out closed-loop control on the braking clamping force, and the system cost is effectively controlled.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments 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 the balance of axle braking force of an electromechanical brake system according to an embodiment of the present application;

FIG. 2 is a schematic flow chart of a method for controlling the balance of axle braking force of an electromechanical brake system according to example II of the present application;

FIG. 3 is a schematic flow chart of a method for controlling the balance of axle braking force of an electromechanical brake system according to example III of the present application;

FIG. 4 is a flow chart of a method for controlling the balance of axle braking force of an electromechanical brake system according to example IV of the present application;

FIG. 5 is a schematic flow chart of a method for controlling the balance of axle braking force of an electromechanical brake system according to example five of the present application;

FIG. 6 is a flow chart of a method for controlling the balance of axle braking force of an electromechanical brake system according to example six of the present application;

FIG. 7 is a flow chart of a method for controlling the balance of axle braking force of an electromechanical brake system according to example seven of the present application;

fig. 8 is a schematic block diagram of a shaft braking force balance control device for an electromechanical brake system according to an example eight of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It should be noted that the terms "first," "second," "third," and "fourth," etc. in the description and claims of the present application are used for distinguishing between different objects and not for describing a particular sequential order. The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, apparatus, article, or device that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or device.

Example one

As shown in fig. 1, fig. 1 is a schematic flowchart of an electromechanical brake system axle braking force balance control method according to an embodiment of the present application, the electromechanical brake system axle braking force balance control method includes:

step S101, determining a yaw rate calculation value generated by the steering wheel according to a steering wheel angle signal of the vehicle.

In this embodiment, the rear axle braking of the vehicle is realized by the electromechanical brake execution module.

In this embodiment, the steering wheel angle signal of the vehicle is acquired by the sensor, and may be used to determine whether the vehicle is in one of a straight traveling state, a small-angle steering state, and a large-angle steering state.

In this embodiment, the yaw rate calculated value generated by the steering wheel may be obtained by calculating using the collected steering wheel angle signal of the vehicle through a preset calculation method or model. The specific calculation mode is not limited, and reasonable selection can be performed according to actual application requirements.

Alternatively, in view of the fact that in actual practice, there is no need to perform the axle braking force balance control process when the driver performs the large angle steering control of the vehicle using the steering wheel, step S101 may include:

s101a, determining a yaw rate calculation value generated by a steering wheel according to the steering wheel angle signal of the vehicle when the steering wheel angle signal of the vehicle meets a preset signal condition.

S101b, stopping the shaft braking force balance control process of the electromechanical brake system when the steering wheel angle signal of the vehicle does not satisfy the preset signal condition.

The setting mode of the preset signal condition is not limited, and reasonable selection can be performed according to actual application requirements.

Further, in order to improve the rationality and accuracy of the vehicle axle brake balance control, it may be preferable that the preset signal condition is that the vehicle represented by the steering wheel angle signal of the vehicle is in a straight running state or in a small angle steering state.

Step S102, obtaining and according to the real-time yaw rate measured value of the vehicle and the calculated yaw rate value of the vehicle, obtaining the yaw rate deviation value of the vehicle.

In this embodiment, the yaw-rate real-time measurement value of the vehicle may be obtained by real-time measurement using a measurement device provided on the vehicle. The specific type of the measuring device is not limited, and the measuring device can be reasonably selected according to actual application requirements.

In the present embodiment, the yaw rate deviation value of the vehicle is obtained from the real-time yaw rate measurement value of the vehicle and the yaw rate calculation value of the vehicle, that is, the yaw rate deviation value of the vehicle is calculated by the formulaDetermining;

wherein ,for the yaw-rate deviation value of the vehicle, +.>Calculating a value for the yaw rate of the vehicle, +.>Is an actual measurement of the yaw rate of the vehicle.

Step S103, obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle.

In this embodiment, the motor current deviation value of the vehicle is the difference between the current value of the motor in the left rear electromechanical brake actuation sub-module and the current value of the motor in the right rear electromechanical brake actuation sub-module of the rear axle of the vehicle.

In this embodiment, the obtaining manner of the motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle is not limited, and may be reasonably selected according to the actual application requirement.

Step S104, obtaining an open-loop current value of a motor of the vehicle by using a preset current calculation model according to a braking torque target value of the vehicle.

In this embodiment, the target braking torque value of the vehicle is a braking torque value expected to be achieved when the electromechanical braking system brakes the vehicle. The method for determining the braking torque target value of the vehicle is not limited, and the method can be reasonably selected according to actual application requirements.

In this embodiment, the preset current calculation model is used to calculate and obtain a motor open loop current value of the vehicle according to a braking torque target value of the vehicle, that is, the input of the preset current calculation model is the braking torque target value of the vehicle, and the output is the motor open loop current value of the vehicle. The construction mode of the preset current calculation model is not limited, and reasonable selection can be performed according to actual application requirements.

In this embodiment, when the motor open-loop current value of the vehicle is the current value required by the motor in the electromechanical brake execution module calculated from the braking force of the vehicle from the target value when the rear axle of the vehicle is braked.

Step S105, determining a motor target current value for braking a rear axle of the vehicle according to the motor open loop current value and the motor current deviation value of the vehicle.

In the present embodiment, the motor target current value for braking the rear axle of the vehicle is a current value that needs to be supplied to the motor in order to balance the braking force generated by the left rear electromechanical brake execution submodule and the braking force generated by the right rear electromechanical brake execution submodule when the rear axle of the vehicle is braked.

In this embodiment, the calculation manner of determining the motor target current value for braking the rear axle of the vehicle according to the motor open-loop current value and the motor current deviation value of the vehicle is not limited, and may be reasonably selected according to the actual application requirements.

Alternatively, in order to make the calculation simple, it may be preferable that the motor target current value for braking the rear axle of the vehicle is a value obtained by adding the motor open loop current value and the motor current deviation value of the vehicle, that is, according to the formulaA motor target current value that brakes a rear axle of the vehicle is determined.

wherein ,for a motor target current value for braking a rear axle of a vehicle, < >>Open loop current value for motor of vehicle, +.>Is the motor current offset value of the vehicle.

As can be seen from the above embodiments of the present invention, in the embodiments of the present invention, a yaw rate calculation value generated by a steering wheel is determined according to a steering wheel angle signal of a vehicle; the rear axle brake of the vehicle is realized through an electromechanical brake executing module; obtaining and according to the real-time yaw rate measured value of the vehicle and the yaw rate calculated value of the vehicle, obtaining a yaw rate deviation value of the vehicle; obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle; according to a braking torque target value of the vehicle, a motor open-loop current value of the vehicle is obtained by using a preset current calculation model; a motor target current value for braking a rear axle of the vehicle is determined based on the motor open loop current value and the motor current deviation value of the vehicle. Compared with the prior art, in the scheme of the embodiment, on the premise that the condition that the vehicle brake is free from deviation and the braking force balance control accuracy of the electronic mechanical brake execution module on two sides of the rear axle is improved, a force sensor is not required to be used for carrying out closed-loop control on the braking clamping force, and the system cost is effectively controlled.

Example two

As shown in fig. 2, fig. 2 is a schematic flowchart of an electromechanical brake system axle braking force balance control method disclosed in example two of the present application, the electromechanical brake system axle braking force balance control method comprising:

step S201, when the steering wheel rotation angle signal of the vehicle meets the preset signal condition, determining a yaw rate calculation value generated by the steering wheel according to the mass center longitudinal speed value of the vehicle, the wheel rotation angle value of the vehicle, the wheelbase value of the vehicle and the characteristic vehicle speed value of the vehicle.

In this embodiment, the specific obtaining modes of the centroid longitudinal speed value of the vehicle, the wheel rotation angle value of the vehicle, the wheelbase value of the vehicle and the characteristic vehicle speed value of the vehicle are not limited, and can be reasonably selected according to actual application requirements. For example, the vehicle parameter value can be obtained by direct measurement by using a sensor, can be obtained by calculation according to the measurement result of the sensor and a known formula, and can be directly inquired to obtain the vehicle parameter value.

Alternatively, in order to make the calculated yaw-rate calculation value of the steering wheel more accurate, it is preferable to calculate the yaw-rate according to the formulaDetermining a yaw rate calculation value generated by the steering wheel;

wherein ,calculating a value for the yaw rate generated for the steering wheel, for example >For the value of the longitudinal speed of the centre of mass of the vehicle +.>For the wheel angle value of the vehicle, < >>For the wheelbase value of the vehicle, < > for>Is a characteristic vehicle speed value of the vehicle.

Step S202, obtaining and according to the real-time yaw rate measured value of the vehicle and the calculated yaw rate value of the vehicle, obtaining the yaw rate deviation value of the vehicle.

In this embodiment, the content of step S202 is substantially the same as or similar to that of step S102 in the previous embodiment, and will not be described herein.

Step S203, obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle.

In this embodiment, the content of step S203 is substantially the same as or similar to that of step S103 in the first embodiment, and will not be described herein.

Step S204, according to the braking torque target value of the vehicle, the motor open-loop current value of the vehicle is obtained by using a preset current calculation model.

In this embodiment, the content of step S204 is substantially the same as or similar to that of step S104 in the first embodiment, and will not be described herein.

Step S205, determining a motor target current value for braking a rear axle of the vehicle according to the motor open loop current value and the motor current deviation value of the vehicle.

In this embodiment, the content of step S205 is substantially the same as or similar to that of step S105 in the previous embodiment, and will not be described herein.

As can be seen from the above embodiments of the present application, in the embodiments of the present application, when a steering wheel angle signal of a vehicle satisfies a preset signal condition, a yaw rate calculation value generated by the steering wheel is determined according to a centroid longitudinal speed value of the vehicle, a wheel angle value of the vehicle, a wheelbase value of the vehicle, and a characteristic vehicle speed value of the vehicle. Compared with the previous embodiment, in the scheme of the present embodiment, the calculated yaw rate value generated by the steering wheel is calculated by using the centroid longitudinal speed value of the vehicle, the wheel angle value of the vehicle, the wheelbase value of the vehicle and the characteristic vehicle speed value of the vehicle, so that the calculated yaw rate is more accurate.

Example three

As shown in fig. 3, fig. 3 is a schematic flowchart of an electromechanical brake system axle braking force balance control method according to an example three of the present application, the electromechanical brake system axle braking force balance control method comprising:

step S301, determining a yaw rate calculation value generated by the steering wheel according to a steering wheel angle signal of the vehicle.

In this embodiment, the content of step S301 is substantially the same as or similar to the content of step S101 in the first embodiment or step S201 in the second embodiment, and will not be described herein.

Step S302, obtaining and according to the real-time yaw rate measured value of the vehicle and the calculated yaw rate value of the vehicle, obtaining the yaw rate deviation value of the vehicle.

In this embodiment, the content of step S302 is substantially the same as or similar to the content of step S102 in the first embodiment or step S202 in the second embodiment, and will not be described herein.

Step S303, obtaining a motor current deviation value of the vehicle according to a yaw rate deviation value of the vehicle, a z-axis rotation inertia value of the vehicle, a track value of the vehicle, a brake friction coefficient value of the vehicle and a friction radius value of the vehicle.

In this embodiment, the specific obtaining modes of the yaw rate deviation value of the vehicle, the z-axis rotation inertia value of the vehicle, the track value of the vehicle, the brake friction coefficient value of the vehicle and the friction radius value of the vehicle are not limited, and can be reasonably selected according to actual application requirements. For example, the vehicle parameter value can be obtained by direct measurement by using a sensor, can be obtained by calculation according to the measurement result of the sensor and a known formula, and can be directly inquired to obtain the vehicle parameter value.

Alternatively, in order to make the calculated motor current deviation value more accurate, it may be preferable to follow the formula Obtaining a motor current deviation value of a vehicle;

wherein ,for the motor current deviation value of the vehicle, +.>For the z-axis rotational inertia of the vehicle, +.>For the yaw-rate deviation value of the vehicle, +.>For the track value of the vehicle, < > for>For fitting parameters +.>For the brake friction coefficient of the vehicle, +.>Is the value of the friction radius of the vehicle.

Step S304, according to the braking moment target value of the vehicle, the motor open-loop current value of the vehicle is obtained by using a preset current calculation model.

In this embodiment, the content of step S304 is substantially the same as or similar to the content of step S104 in the first embodiment or step S204 in the second embodiment, and will not be described herein.

Step S305, determining a motor target current value for braking a rear axle of the vehicle according to the motor open loop current value and the motor current deviation value of the vehicle.

In this embodiment, the content of step S305 is substantially the same as or similar to the content of step S105 in the first embodiment or step S205 in the second embodiment, and will not be described herein.

As can be seen from the above embodiments of the present invention, in the embodiments of the present invention, the motor current deviation value of the vehicle is obtained according to the yaw rate deviation value of the vehicle, the z-axis rotation inertia value of the vehicle, the track value of the vehicle, the brake friction coefficient value of the vehicle, and the friction radius value of the vehicle. Compared with the previous embodiment, in the solution of the present embodiment, the motor current deviation value of the vehicle is obtained by calculating according to the yaw rate deviation value of the vehicle, the z-axis rotation inertia value of the vehicle, the track value of the vehicle, the brake friction coefficient value of the vehicle and the friction radius value of the vehicle, so that the calculated motor current deviation value of the vehicle is more accurate.

Example four

As shown in fig. 4, fig. 4 is a schematic flowchart of an electromechanical brake system axle braking force balance control method disclosed in example four of the present application, the electromechanical brake system axle braking force balance control method comprising:

step S401, providing different magnitudes of currents for the motor of the test electronic mechanical brake executing module, and measuring the braking force generated by the test electronic mechanical brake executing module to obtain test data.

In the present embodiment, in order to make the test result better applicable to determining the motor target current value for braking the rear axle of the vehicle, it is preferable that the test electromechanical brake execution module and the electromechanical brake execution module are both identical in structure and in installation position on the vehicle.

In this embodiment, the specific type of the measuring device for measuring the braking force generated by the test electromechanical brake module is not limited, and may be reasonably selected according to the actual application requirements.

In this embodiment, the test data is used to characterize the correspondence between the current value and the braking force measurement value.

Step S402, a current calculation model is obtained according to the test data.

In this embodiment, the obtaining manner of the current calculation model according to the test data is not limited, and may be reasonably selected according to the actual application requirement. For example, the current calculation model may be obtained by curve fitting based on the test data, or may be obtained by machine learning based on the test data.

Alternatively, in order to make the manner of obtaining the current calculation model simple, it may be preferable to obtain the current calculation model by curve fitting based on the test data.

The fitting formula of the current calculation model obtained by curve fitting according to the test data is not limited in type, and can be reasonably selected according to actual application requirements, for example, a Gaussian function, a quadratic function, a logarithmic function and the like.

Alternatively, in order to make the fitted current calculation model more accurate, it may be preferable to use the formula based on the test dataFitting to obtain a current calculation model; wherein (1)>To fit the difference +.>For the i-th preset sampling period, +.>For the nth preset sampling period, +.>For the current value of the ith preset sampling period, < >> and />For fitting parameters +.>Braking force measurement value of the ith preset sampling period;

the preset current calculation model is as follows:

；

wherein ,open loop current value for motor of vehicle, +.>For the braking torque target value of the vehicle,/->In order to fit the parameters of the model,for the brake friction coefficient of the vehicle, +.>Is the value of the friction radius of the vehicle.

The specific value of the preset sampling period is not limited, and can be reasonably selected according to actual application requirements.

Step S403, determining a yaw rate calculation value generated by the steering wheel according to the steering wheel angle signal of the vehicle.

In this embodiment, the content of step S403 is substantially the same as or similar to the content of step S101 in the first embodiment, step S201 in the second embodiment, or step S301 in the third embodiment, and will not be described again here.

Step S404, obtaining and according to the real-time yaw rate measured value of the vehicle and the calculated yaw rate value of the vehicle, obtaining the yaw rate deviation value of the vehicle.

In this embodiment, the content of step S404 is substantially the same as or similar to the content of step S102 in the first embodiment, step S202 in the second embodiment, or step S302 in the third embodiment, and will not be described again.

Step S405, obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle.

In this embodiment, the content of step S405 is substantially the same as or similar to the content of step S103 in the first embodiment, step S203 in the second embodiment, or step S303 in the third embodiment, and will not be described again here.

Step S406, according to the braking torque target value of the vehicle, the motor open-loop current value of the vehicle is obtained by using a preset current calculation model.

In this embodiment, the content of step S406 is substantially the same as or similar to the content of step S104 in the first embodiment, step S204 in the second embodiment, or step S304 in the third embodiment, and will not be described again here.

Step S407, determining a motor target current value for braking a rear axle of the vehicle according to the motor open loop current value and the motor current deviation value of the vehicle.

In this embodiment, the content of step S407 is substantially the same as or similar to the content of step S105 in the first embodiment, step S205 in the second embodiment, or step S305 in the third embodiment, and will not be described again.

As can be seen from the above embodiments of the present invention, in the embodiments of the present invention, different magnitudes of currents are provided to a motor of a test electro-mechanical brake execution module, and a braking force generated by the test electro-mechanical brake execution module is measured to obtain test data; and obtaining a current calculation model according to the test data. Compared with the previous embodiment, in the solution of the present embodiment, the test electromechanical brake execution module having the same structure as the electromechanical brake execution module and the same installation position on the vehicle is used for measurement to obtain test data, and the current calculation model is obtained according to the test data, so that the accuracy of the motor open loop current value of the vehicle calculated by using the constructed current calculation model is higher.

Example five

As shown in fig. 5, fig. 5 is a schematic flowchart of an electromechanical brake system axle braking force balance control method according to an example fifth of the present application, the electromechanical brake system axle braking force balance control method comprising:

step S501, the motor of the test electromechanical brake execution module is powered according to a first current change rule, and braking force generated by the test electromechanical brake execution module is measured to obtain brake increase data.

In this embodiment, the first current variation rule is that the current value gradually increases from a preset minimum value to a preset maximum value. The specific increasing mode of gradually increasing the current value from the preset minimum value to the preset maximum value in the first current change rule is not limited, and the current value can be reasonably selected according to actual application requirements. For example, the increase may be linear or non-linear.

Alternatively, in order to simplify the manner in which the current value is changed, it may be preferable that the first current change rule is that the current value increases linearly from a preset minimum value to a preset maximum value.

The specific values of the preset minimum value and the preset maximum value are not limited, and can be reasonably selected according to actual application requirements.

In this embodiment, the brake increase data is used to characterize the correspondence between the current value and the brake force measurement value.

Step S502, the motor of the test electromechanical brake execution module is powered according to the second current change rule, and braking force generated by the test electromechanical brake execution module is measured to obtain braking rollback data.

In this embodiment, the second current variation rule is that the current value gradually decreases from a preset maximum value to a preset minimum value. The specific reduction mode that the current value in the second current change rule gradually reduces from the preset maximum value to the preset minimum value is not limited, and the current value can be reasonably selected according to actual application requirements. For example, the reduction may be linear or non-linear.

Alternatively, in order to simplify the manner in which the current value is changed, it may be preferable that the second current change rule is that the current value linearly decreases from a preset maximum value to a preset minimum value.

In this embodiment, the brake rollback data is used to characterize the correspondence between the current value and the brake force measurement value.

In this embodiment, the implementation sequence of step S501 and step S502 is not limited, and may be reasonably selected according to the actual application requirement.

Step S503, obtaining a brake increase calculation model according to the brake increase data.

In this embodiment, the brake increase calculation model is used to calculate and obtain the current value according to the braking force value under the working condition of brake force increase. The method for obtaining the brake increase calculation model according to the brake increase data is not limited, and can be reasonably selected according to actual application requirements.

Step S504, a brake rollback calculation model is obtained according to the brake rollback data.

In this embodiment, the braking retraction calculation model is used to calculate and obtain the current value according to the braking force value under the braking force retraction working condition. The method for obtaining the brake rollback calculation model according to the brake rollback data is not limited, and can be reasonably selected according to actual application requirements.

Step S505, determining a yaw rate calculation value generated by the steering wheel according to the steering wheel angle signal of the vehicle.

In this embodiment, the content of step S505 is substantially the same as or similar to the content of step S101 in the first embodiment, step S201 in the second embodiment, or step S301 in the third embodiment, or step S401 in the fourth embodiment, and will not be described in detail herein.

Step S506, obtaining and according to the real-time yaw rate measured value of the vehicle and the calculated yaw rate value of the vehicle, obtaining the yaw rate deviation value of the vehicle.

In this embodiment, the content of step S506 is substantially the same as or similar to the content of step S102 in the first embodiment, step S202 in the second embodiment, step S302 in the third embodiment, or step S402 in the fourth embodiment, and will not be described in detail herein.

Step S507, obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle.

In this embodiment, the content of step S507 is substantially the same as or similar to the content of step S103 in the first embodiment, step S203 in the second embodiment, or step S303 in the third embodiment, or step S403 in the fourth embodiment, and will not be described in detail herein.

Step S508, determining a target model from the brake increase calculation model and the brake rollback calculation model according to the brake torque target value of the vehicle, and obtaining an open-loop current value of a motor of the vehicle by using the target model.

In this embodiment, a corresponding braking force value is calculated according to a braking torque target value of the vehicle, and the braking force value is compared with a first preset braking force value range corresponding to braking increase data in a braking increase model and a second preset braking force value range corresponding to braking retraction data in a braking retraction calculation model respectively. When the braking force value is within a first preset braking force range, the target model is a braking increase calculation model; when the braking force value is within the second preset braking force range, the target model is a braking rollback calculation model.

Step S509 of determining a motor target current value for braking a rear axle of the vehicle based on the motor open-loop current value and the motor current deviation value of the vehicle.

In this embodiment, the content of step S509 is substantially the same as or similar to the content of step S105 in the first embodiment, step S205 in the second embodiment, step S305 in the third embodiment, or step S407 in the fourth embodiment, and will not be described in detail herein.

As can be seen from the above embodiments of the present invention, in the embodiments of the present invention, a motor of a test electromechanical brake execution module is powered according to a first current change rule, and braking force generated by the test electromechanical brake execution module is measured to obtain brake increase data; powering a motor of the test electromechanical brake execution module according to a second current change rule, and measuring braking force generated by the test electromechanical brake execution module to obtain brake rollback data; obtaining a brake increase calculation model according to the brake increase data; according to the braking rollback data, a braking rollback calculation model is obtained; and determining a target model from the brake increase calculation model and the brake rollback calculation model according to the brake moment target value of the vehicle, and obtaining the motor open-loop current value of the vehicle by using the target model. Compared with the previous embodiment, in the scheme of the embodiment, different models are constructed according to the increase or decrease of the motor current, so that the accuracy of the models is improved. And selecting a target model according to the braking torque target value of the vehicle, so that the motor open-loop current value of the vehicle calculated according to the target model and the braking torque target value is more accurate.

Example six

As shown in fig. 6, fig. 6 is a schematic flowchart of an electromechanical brake system shaft braking force balance control method according to an example six of the present application, the electromechanical brake system shaft braking force balance control method including:

step S601, power is supplied to a motor of the test electromechanical brake execution module according to a first current change rule, and braking force generated by the test electromechanical brake execution module is measured to obtain brake increase data.

In this embodiment, the content of step S601 is substantially the same as or similar to that of step S501 in the fifth embodiment, and will not be described herein.

Step S602, the motor of the test electromechanical brake execution module is powered according to the second current change rule, and braking force generated by the test electromechanical brake execution module is measured to obtain braking rollback data.

In this embodiment, the content of step S602 is substantially the same as or similar to that of step S502 in the fifth embodiment, and will not be described herein.

In step S603, the first sub-data, the second sub-data, and the third sub-data are segmented from the brake increase data according to the magnitude of the brake force measurement value.

In this embodiment, the specific splitting manner of splitting the first sub data, the second sub data and the third sub data from the brake increment data is not limited, and may be reasonably selected according to the actual application requirement.

In this embodiment, the first sub-data, the second sub-data, and the third sub-data are all used to represent the correspondence between the current value and the braking force measurement value. The maximum value of the corresponding braking force measurement value in the first sub data is smaller than the minimum value of the corresponding braking force measurement value in the second sub data, and the maximum value of the corresponding braking force measurement value in the second sub data is smaller than the minimum value of the corresponding braking force measurement value in the third sub data.

In step S604, the first sub-model, the second sub-model and the third sub-model are obtained according to the first sub-data, the second sub-data and the third sub-data, respectively.

In this embodiment, the first sub-model is used to calculate and obtain the current value according to the braking force value under the working condition of light braking. The specific obtaining mode of the first sub-model according to the first sub-data is not limited, and reasonable selection can be performed according to actual application requirements.

In this embodiment, the second sub-model is used to calculate and obtain the current value according to the braking force value under the working condition of the middle brake. The specific obtaining mode of the second sub-model according to the second sub-data is not limited, and reasonable selection can be performed according to actual application requirements.

In this embodiment, the third sub-model is used to calculate and obtain the current value according to the braking force value under the working condition of strong braking. The specific obtaining mode of the third sub-model according to the third sub-data is not limited, and reasonable selection can be performed according to actual application requirements.

Step S605, a brake rollback calculation model is obtained according to the brake rollback data.

In this embodiment, the content of step S605 is substantially the same as or similar to that of step S504 in the fifth embodiment, and will not be described herein.

Step S606, determining a yaw rate calculation value generated by the steering wheel according to the steering wheel angle signal of the vehicle.

In this embodiment, the content of step S606 is substantially the same as or similar to the content of step S101 in the first embodiment, step S201 in the second embodiment, or step S301 in the third embodiment, or step S401 in the fourth embodiment, or step S505 in the fifth embodiment, and will not be repeated here.

Step S607, obtaining and based on the real-time yaw rate measurement value of the vehicle and the calculated yaw rate value of the vehicle, obtaining a yaw rate deviation value of the vehicle.

In this embodiment, the content of step S607 is substantially the same as or similar to the content of step S102 in the first embodiment, step S202 in the second embodiment, step S302 in the third embodiment, step S402 in the fourth embodiment, or step S506 in the fifth embodiment, which are not described herein.

Step S608, obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle.

In this embodiment, the content of step S608 is substantially the same as or similar to the content of step S103 in the first embodiment, step S203 in the second embodiment, step S303 in the third embodiment, step S403 in the fourth embodiment, or step S507 in the fifth embodiment, and will not be repeated here.

Step S609, determining a target model from the first sub-model, the second sub-model, the third sub-model and the brake rollback calculation model according to the braking torque target value of the vehicle, and obtaining a motor open-loop current value of the vehicle by using the target model.

In this embodiment, a corresponding braking force value is calculated according to a braking torque target value of the vehicle, and the braking force value is compared with a third braking force value range corresponding to first sub-data in the first sub-model, a fourth braking force value range corresponding to second sub-data in the second sub-model, a fifth braking force value range corresponding to third sub-data in the third sub-model, and a second braking force value range in the braking rollback calculation model, respectively. When the braking force value is within the third braking force value range, the target model is the first sub-model; when the braking force value is within the fourth braking force value range, the target model is the second sub-model; when the braking force value is within the fifth braking force value range, the target model is a third sub-model; when the braking force value is within the second braking force value range, the target model is a braking rollback calculation model.

Step S610, determining a motor target current value for braking a rear axle of the vehicle according to the motor open loop current value and the motor current deviation value of the vehicle.

In this embodiment, the content of step S610 is substantially the same as or similar to the content of step S105 in the first embodiment, step S205 in the second embodiment, step S305 in the third embodiment, step S407 in the fourth embodiment, or step S509 in the fifth embodiment, which are not described herein.

As can be seen from the above embodiments of the present invention, in the embodiments of the present invention, the first sub-data, the second sub-data, and the third sub-data are segmented from the brake increase data according to the magnitude of the brake force measurement value; according to the first sub data, the second sub data and the third sub data, a first sub model, a second sub model and a third sub model are respectively obtained; and determining a target model from the first sub-model, the second sub-model, the third sub-model and the brake rollback calculation model according to the brake torque target value of the vehicle, and obtaining a motor open-loop current value of the vehicle by using the target model. Compared with the embodiment, in the scheme of the embodiment, corresponding models under different braking conditions are constructed according to the magnitude of the braking force value, and the accuracy of the models is improved. And selecting a target model according to the braking torque target value of the vehicle, so that the motor open-loop current value of the vehicle calculated according to the target model and the braking torque target value is more accurate.

Example seven

As shown in fig. 7, fig. 7 is a schematic flowchart of an electromechanical brake system shaft braking force balance control method according to an example seventh of the present application, the electromechanical brake system shaft braking force balance control method including:

step S701, supplying power to the motor of the test electro-mechanical brake execution module according to the first current variation rule, and measuring the braking force generated by the test electro-mechanical brake execution module to obtain brake increase data.

In this embodiment, the content of step S701 is substantially the same as or similar to the content of step S501 in the fifth embodiment or step S601 in the sixth embodiment, and will not be described herein.

Step S702, supplying power to the motor of the test electromechanical brake execution module according to the second current change rule, and measuring the braking force generated by the test electromechanical brake execution module to obtain brake rollback data.

In this embodiment, the content of step S702 is substantially the same as or similar to the content of step S502 in the fifth embodiment or step S602 in the sixth embodiment, and will not be described herein.

Step S703, obtaining a brake increase calculation model according to the brake increase data.

In this embodiment, the content of step S703 is substantially the same as or similar to that of step S503 in the fifth embodiment, and will not be described herein.

In step S704, fourth sub-data, fifth sub-data, and sixth sub-data are cut out from the brake rollback data according to the magnitude of the brake force measurement value.

In this embodiment, the specific splitting manner of splitting the fourth sub-data, the fifth sub-data and the sixth sub-data from the brake rollback data is not limited, and may be reasonably selected according to actual application requirements.

In this embodiment, the fourth sub-data, the fifth sub-data, and the sixth sub-data are used to characterize the correspondence between the current value and the braking force measurement value. The maximum value of the corresponding braking force measurement value in the fourth sub-data is smaller than the minimum value of the corresponding braking force measurement value in the fifth sub-data, and the maximum value of the corresponding braking force measurement value in the fifth sub-data is smaller than the minimum value of the corresponding braking force measurement value in the sixth sub-data.

Step S705, obtaining the fourth sub-model, the fifth sub-model and the sixth sub-model according to the fourth sub-data, the fifth sub-data and the sixth sub-data, respectively.

In this embodiment, the fourth sub-model is used to calculate and obtain the current value according to the braking force value under the working condition of light braking. The specific obtaining mode of the fourth sub-model according to the fourth sub-data is not limited, and reasonable selection can be performed according to actual application requirements.

In this embodiment, the fifth sub-model is used to calculate and obtain the current value according to the braking force value under the working condition of the middle brake. The specific obtaining mode for obtaining the fifth sub-model according to the fifth sub-data is not limited, and the fifth sub-model can be reasonably selected according to actual application requirements.

In this embodiment, the sixth sub-model is used to calculate and obtain the current value according to the braking force value under the forced working condition. The specific obtaining mode of the sixth sub-model according to the sixth sub-data is not limited, and the sixth sub-model can be reasonably selected according to actual application requirements.

Step S706, determining a yaw rate calculation value generated by the steering wheel according to the steering wheel angle signal of the vehicle.

In this embodiment, the content of step S706 is substantially the same as or similar to the content of step S101 in the first embodiment, step S201 in the second embodiment, step S301 in the third embodiment, step S401 in the fourth embodiment, step S505 in the fifth embodiment, or step S606 in the sixth embodiment, which are not described herein.

Step S707 obtains and obtains a yaw rate deviation value of the vehicle from the real-time yaw rate measurement value of the vehicle and the yaw rate calculation value of the vehicle.

In this embodiment, the content of step S702 is substantially the same as or similar to the content of step S102 in the first embodiment, step S202 in the second embodiment, step S302 in the third embodiment, step S402 in the fourth embodiment, step S506 in the fifth embodiment, or step S607 in the sixth embodiment, which are not described herein.

Step S708, obtaining a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle.

In this embodiment, the content of step S708 is substantially the same as or similar to the content of step S103 in the first embodiment, step S203 in the second embodiment, step S303 in the third embodiment, step S403 in the fourth embodiment, step S507 in the fifth embodiment, or step S608 in the sixth embodiment, which are not described in detail herein.

Step S709, determining a target model from the fourth, fifth and sixth sub-data and the brake increase calculation model according to the braking torque target value of the vehicle, and obtaining a motor open loop current value of the vehicle using the target model.

In this embodiment, a corresponding braking force value is calculated from a braking torque target value of the vehicle, and the braking force value is compared with a sixth braking force value range corresponding to fourth sub-data in the fourth sub-model, a seventh braking force value range corresponding to fifth sub-data in the fifth sub-model, an eighth braking force value range corresponding to sixth sub-data in the sixth sub-model, and a first braking force value range in the brake increase calculation model, respectively. When the braking force value is within the sixth braking force value range, the target model is a fourth sub-model; when the braking force value is within the seventh braking force value range, the target model is a fifth sub-model; when the braking force value is within the eighth braking force value range, the target model is a sixth sub-model; when the braking force value is within the first braking force value range, the target model is a braking increase calculation model.

Step S710, determining a motor target current value for braking a rear axle of the vehicle according to the motor open loop current value and the motor current deviation value of the vehicle.

In this embodiment, the content of step S710 is substantially the same as or similar to the content of step S105 in the first embodiment, step S205 in the second embodiment, step S305 in the third embodiment, step S407 in the fourth embodiment, step S509 in the fifth embodiment, or step S610 in the sixth embodiment, which are not described in detail herein.

As can be seen from the above embodiments of the present invention, in the embodiments of the present invention, the fourth sub-data, the fifth sub-data, and the sixth sub-data are cut out from the brake rollback data according to the magnitude of the brake force measurement value; according to the fourth sub data, the fifth sub data and the sixth sub data, the fourth sub model, the fifth sub model and the sixth sub model are respectively obtained; and determining a target model from the fourth sub-data, the fifth sub-data, the sixth sub-data and the brake increase calculation model according to the braking torque target value of the vehicle, and obtaining a motor open-loop current value of the vehicle by using the target model. Compared with the embodiment, in the scheme of the embodiment, corresponding models under different braking conditions are constructed according to the magnitude of the braking force value, and the accuracy of the models is improved. And selecting a target model according to the braking torque target value of the vehicle, so that the motor open-loop current value of the vehicle calculated according to the target model and the braking torque target value is more accurate.

Example eight

As shown in fig. 8, fig. 8 is a schematic block diagram showing a construction of an electromechanical brake system shaft braking force balance control device according to an eighth embodiment of the present application, the pressure adjusting device of the electric vehicle wheel cylinder includes:

a first numerical determination module 801, configured to determine a yaw rate calculation value generated by a steering wheel according to a steering wheel angle signal of a vehicle; the rear axle brake of the vehicle is realized through an electromechanical brake executing module;

a first deviation value determining module 802, configured to obtain and obtain a yaw rate deviation value of the vehicle according to a real-time yaw rate measurement value of the vehicle and a yaw rate calculation value of the vehicle;

a second deviation value determining module 803, configured to obtain a motor current deviation value of the vehicle according to the yaw rate deviation value of the vehicle;

the second value determining module 804 is configured to obtain, according to a braking torque target value of the vehicle, an open-loop current value of a motor of the vehicle by using a preset current calculation model;

a third value determination module 805 for determining a motor target current value for braking a rear axle of the vehicle based on the motor open loop current value and the motor current deviation value of the vehicle.

Optionally, the first numerical determination module 801 is further configured to determine, when the steering wheel angle signal of the vehicle meets a preset signal condition, a yaw rate calculation value generated by the steering wheel according to a centroid longitudinal speed value of the vehicle, a wheel angle value of the vehicle, a wheelbase value of the vehicle, and a characteristic vehicle speed value of the vehicle.

Further, the first numerical determination module 801 is further configured to determine a first numerical value according to a formulaDetermining a yaw rate calculation value generated by the steering wheel;

wherein ,calculating a value for the yaw rate generated for the steering wheel, for example>For the value of the longitudinal speed of the centre of mass of the vehicle +.>For the wheel angle value of the vehicle, < >>For the wheelbase value of the vehicle, < > for>Is a characteristic vehicle speed value of the vehicle.

Optionally, the first deviation value determining module 802 is further configured to obtain a motor current deviation value of the vehicle according to a yaw rate deviation value of the vehicle, a z-axis rotation inertia value of the vehicle, a track value of the vehicle, a brake friction coefficient value of the vehicle, and a friction radius value of the vehicle.

Further, the first deviation value determining module 802 is further configured to determine a deviation value according to a formulaObtaining a motor current deviation value of the vehicle;

wherein ,for the motor current deviation value of the vehicle, +.>For the z-axis rotational inertia of the vehicle, +.>For the yaw-rate deviation value of the vehicle, +.>For the track value of the vehicle, < > for>Is a preset proportional coefficient>For the brake friction coefficient of the vehicle, +.>Is the value of the friction radius of the vehicle.

Optionally, the device further comprises a model building module, wherein the model building module is used for providing different magnitudes of currents for the motor of the test electromechanical brake executing module, and measuring the braking force generated by the test electromechanical brake executing module to obtain test data; the structure of the test electromechanical brake execution module is the same as that of the electromechanical brake execution module and the installation position of the test electromechanical brake execution module on the vehicle; the test data are used for representing the corresponding relation between the current value and the braking force measured value;

And obtaining a current calculation model according to the test data.

Further, the test data includes brake increase data and brake rollback data, each of which is used to characterize a correspondence of a current value and a brake force measurement value; the current calculation model includes a brake increase calculation model and a brake rollback calculation model. The model building model is also used for supplying power to a motor of the test electromechanical brake executing module according to a first current change rule, and measuring braking force generated by the test electromechanical brake executing module to obtain brake increase data; the first current change rule is that a current value gradually increases from a preset minimum value to a preset maximum value;

powering a motor of the test electromechanical brake execution module according to a second current change rule, and measuring braking force generated by the test electromechanical brake execution module to obtain brake rollback data; the second current change rule is that the current value gradually decreases from a preset maximum value to a preset minimum value.

Obtaining a brake increase calculation model according to the brake increase data; the braking increase calculation model is used for calculating and obtaining a current value according to a braking force value under the working condition of braking force increase;

According to the braking rollback data, a braking rollback calculation model is obtained; the braking rollback calculation model is used for calculating and obtaining a current value according to a braking force value under the working condition of braking force rollback.

Correspondingly, the second value determining module 804 is further configured to determine a target model from the brake increase calculation model and the brake rollback calculation model according to the brake torque target value of the vehicle, and obtain a motor open loop current value of the vehicle by using the target model.

Further, the first current change rule is that the current value is linearly increased from a preset minimum value to a preset maximum value; the second current variation rule is that the current value is linearly decreased from a preset maximum value to a preset minimum value.

Further, the model building module is further used for segmenting the first sub-data, the second sub-data and the third sub-data from the brake increase data according to the magnitude of the brake force measured value; the maximum value of the corresponding braking force measured value in the first sub data is smaller than the minimum value of the corresponding braking force measured value in the second sub data, and the maximum value of the corresponding braking force measured value in the second sub data is smaller than the minimum value of the corresponding braking force measured value in the third sub data;

according to the first sub data, the second sub data and the third sub data, a first sub model, a second sub model and a third sub model are respectively obtained; the first sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of light braking; the second sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of middle braking; the third sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of strong braking.

Correspondingly, the second value determining module 804 is further configured to determine a target model from the first sub-model, the second sub-model, the third sub-model, and the brake rollback calculation model according to a brake torque target value of the vehicle, and obtain a motor open loop current value of the vehicle using the target model.

Further, the model building module is further configured to divide fourth sub-data, fifth sub-data and sixth sub-data from the brake rollback data according to the magnitude of the brake force measurement value; the maximum value of the corresponding braking force measured value in the fourth sub data is smaller than the minimum value of the corresponding braking force measured value in the fifth sub data, and the maximum value of the corresponding braking force measured value in the fifth sub data is smaller than the minimum value of the corresponding braking force measured value in the sixth sub data;

according to the fourth sub data, the fifth sub data and the sixth sub data, a fourth sub model, a fifth sub model and a sixth sub model are respectively obtained; the fourth sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of light braking; the fifth sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of middle braking; the sixth sub-model is used for calculating and obtaining a current value according to a braking force value under the forced working condition.

Correspondingly, the second value determining module 804 is further configured to determine a target model from the fourth sub-data, the fifth sub-data, the sixth sub-data, and the brake increase calculation model according to the braking torque target value of the vehicle, and obtain a motor open loop current value of the vehicle using the target model.

Optionally, the model building module is further configured to utilize a formula according to the test dataFitting to obtain a current calculation model;

wherein ,to fit the difference +.>For the ith preset acquisitionSample period (I)>For the nth preset sampling period, +.>For the current value of the ith preset sampling period, < >> and />For fitting parameters +.>Braking force measurement value of the ith preset sampling period;

the preset current calculation model is as follows:

；

The device for controlling the balance of the braking force of the shaft of the electromechanical brake system according to the embodiment can realize the corresponding method for controlling the balance of the braking force of the shaft of the electromechanical brake system in the method embodiments, and has the beneficial effects of the corresponding method embodiments, which are not described in detail herein.

Thus, specific embodiments of the present application have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may be advantageous.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises an element.

It will be apparent to those skilled in the art that embodiments of the present application may be provided as methods, apparatus. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer storage media (including, but not limited to, magnetic disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for the device embodiments, since they are substantially similar to the method embodiments, the description is relatively simple, and reference is made to the description of the method embodiments in part.

The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and variations of the present application will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the application are to be included in the scope of the claims of the present application.

Claims

1. A method for controlling axle braking force balance of an electromechanical brake system, the method comprising:

2. The method of claim 1, wherein determining a calculated yaw rate of the steering wheel based on the steering wheel angle signal of the vehicle comprises:

when the steering wheel angle signal of the vehicle meets a preset signal condition, according to a formulaDetermining a yaw rate calculation generated by the steering wheel;

3. The method according to claim 1, wherein the obtaining a motor current deviation value of the vehicle from the yaw-rate deviation value of the vehicle includes:

according to the formulaObtaining a motor current deviation value of the vehicle;

wherein ,for a vehicleMotor current deviation value of vehicle, /)>For the z-axis rotational inertia of the vehicle, +.>For the yaw-rate deviation value of the vehicle, +.>For the track value of the vehicle, < > for>For fitting parameters +.>For the brake friction coefficient of the vehicle, +.>Is the value of the friction radius of the vehicle.

4. The method according to claim 1, wherein the method further comprises:

Providing different current for the motor of the test electromechanical brake executing module, and measuring the braking force generated by the test electromechanical brake executing module to obtain test data; the test electromechanical brake execution module and the electromechanical brake execution module are identical in structure and installation position on a vehicle; the test data are used for representing the corresponding relation between the current value and the braking force measured value;

and obtaining the current calculation model according to the test data.

5. The method of claim 4, wherein the test data includes brake increase data and brake rollback data each characterizing a correspondence of a current value and a brake force measurement value; the current calculation model comprises a brake increase calculation model and a brake rollback calculation model;

the step of providing different magnitudes of currents for the motor of the test electromechanical brake execution module, and measuring the braking force generated by the test electromechanical brake execution module, the step of obtaining test data includes:

supplying power to a motor of the test electromechanical brake execution module according to a first current change rule, and measuring braking force generated by the test electromechanical brake execution module to obtain brake increase data; the first current change rule is that a current value gradually increases from a preset minimum value to a preset maximum value;

Supplying power to a motor of the test electromechanical brake execution module according to a second current change rule, and measuring braking force generated by the test electromechanical brake execution module to obtain brake rollback data; the second current change rule is that the current value gradually decreases from a preset maximum value to a preset minimum value;

correspondingly, the obtaining the current calculation model according to the test data comprises:

obtaining the brake increase calculation model according to the brake increase data; the braking increase calculation model is used for calculating and obtaining a current value according to a braking force value under the working condition of braking force increase;

according to the brake rollback data, the brake rollback calculation model is obtained; the braking rollback calculation model is used for calculating and obtaining a current value according to a braking force value under the braking force rollback working condition;

correspondingly, the obtaining the motor open loop current value of the vehicle by using a preset current calculation model according to the braking torque target value of the vehicle comprises the following steps:

and determining a target model from the brake increase calculation model and the brake rollback calculation model according to the brake moment target value of the vehicle, and obtaining an open-loop current value of a motor of the vehicle by using the target model.

6. The method of claim 5, wherein the first current variation rule is that a current value increases linearly from a preset minimum value to a preset maximum value; the second current change rule is that the current value is linearly reduced from a preset maximum value to a preset minimum value.

7. The method of claim 5, wherein the brake increase calculation model comprises a first sub-model, a second sub-model, and a third sub-model;

the obtaining the brake increase calculation model according to the brake increase data comprises:

according to the magnitude of the braking force measured value, the first sub-data, the second sub-data and the third sub-data are segmented from the braking increase data; the maximum value of the corresponding braking force measured value in the first sub-data is smaller than the minimum value of the corresponding braking force measured value in the second sub-data, and the maximum value of the corresponding braking force measured value in the second sub-data is smaller than the minimum value of the corresponding braking force measured value in the third sub-data;

according to the first sub data, the second sub data and the third sub data, the first sub model, the second sub model and the third sub model are respectively obtained; the first sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of light braking; the second sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of middle braking; the third sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of strong braking;

Correspondingly, the determining a target model from the brake increase calculation model and the brake rollback calculation model according to the brake torque target value of the vehicle, and obtaining the motor open loop current value of the vehicle by using the target model comprises:

and determining a target model from the first sub-model, the second sub-model, the third sub-model and the braking rollback calculation model according to the braking torque target value of the vehicle, and obtaining an open-loop current value of a motor of the vehicle by using the target model.

8. The method of claim 5, wherein the brake rollback calculation model includes a fourth sub-model, a fifth sub-model, and a sixth sub-model;

the obtaining the brake rollback calculation model according to the brake rollback data comprises the following steps:

cutting fourth sub-data, fifth sub-data and sixth sub-data from the brake rollback data according to the magnitude of the brake force measured value; the maximum value of the corresponding braking force measured value in the fourth sub-data is smaller than the minimum value of the corresponding braking force measured value in the fifth sub-data, and the maximum value of the corresponding braking force measured value in the fifth sub-data is smaller than the minimum value of the corresponding braking force measured value in the sixth sub-data;

According to the fourth sub data, the fifth sub data and the sixth sub data, the fourth sub model, the fifth sub model and the sixth sub model are respectively obtained; the fourth sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of light braking; the fifth sub-model is used for calculating and obtaining a current value according to a braking force value under the working condition of middle braking; the sixth sub-model is used for calculating and obtaining a current value according to a braking force value under the forced working condition;

and determining a target model from the fourth sub-data, the fifth sub-data, the sixth sub-data and the brake increase calculation model according to the braking torque target value of the vehicle, and obtaining an open-loop current value of a motor of the vehicle by using the target model.

9. The method of claim 4, wherein said obtaining said current calculation model from said test data comprises:

Based on the test data, the formula is usedFitting to obtain the current calculation model; wherein (1)>To fit the difference +.>For the i-th preset sampling period, +.>For the nth preset sampling period, +.>For the current value of the ith preset sampling period, < >> and />For fitting parameters +.>Braking force measurement value of the ith preset sampling period;

the preset current calculation model is as follows:

；

wherein ,open loop current value for motor of vehicle, +.>For the braking torque target value of the vehicle,/->For fitting parameters +.>For the brake friction coefficient of the vehicle, +.>Is the value of the friction radius of the vehicle.

10. An electromechanical brake system axle braking force balance control apparatus, the apparatus comprising: