CN109484207B - Braking torque control method and device of driving motor and automobile - Google Patents

Braking torque control method and device of driving motor and automobile Download PDF

Info

Publication number
CN109484207B
CN109484207B CN201811453784.8A CN201811453784A CN109484207B CN 109484207 B CN109484207 B CN 109484207B CN 201811453784 A CN201811453784 A CN 201811453784A CN 109484207 B CN109484207 B CN 109484207B
Authority
CN
China
Prior art keywords
braking
torque
state
braking torque
vehicle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201811453784.8A
Other languages
Chinese (zh)
Other versions
CN109484207A (en
Inventor
李玮
刘超
梁海强
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Electric Vehicle Co Ltd
Original Assignee
Beijing Electric Vehicle Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beijing Electric Vehicle Co Ltd filed Critical Beijing Electric Vehicle Co Ltd
Priority to CN201811453784.8A priority Critical patent/CN109484207B/en
Publication of CN109484207A publication Critical patent/CN109484207A/en
Application granted granted Critical
Publication of CN109484207B publication Critical patent/CN109484207B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • B60L15/2009—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 for braking
    • 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
    • B60L7/00—Electrodynamic brake systems for vehicles in general
    • B60L7/10—Dynamic electric regenerative braking
    • B60L7/18—Controlling the braking effect
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
    • B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
    • 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
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Engineering (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)
  • Regulating Braking Force (AREA)

Abstract

The invention discloses a braking torque control method and device of a driving motor and an automobile, wherein the braking torque control method of the driving motor comprises the following steps: detecting the change states of the braking torques of a hydraulic braking system and a driving motor of the vehicle; when the change state is in a first state, acquiring the current braking state of the vehicle; acquiring a target braking acceleration of the vehicle according to the current braking state; and adjusting the output torque of the driving motor to a target braking torque according to the target braking acceleration, wherein the target braking torque is used for controlling the vehicle to generate the target braking acceleration. According to the embodiment of the invention, by utilizing the advantages of high response speed and high precision of the braking torque of the driving motor, when the vehicle is in the first state, the braking torque of the driving motor is controlled, so that the vehicle is braked more smoothly, and the problems that the vehicle shakes and the braking effect cannot reach the expectation due to the poor braking response capability of a hydraulic braking system are solved.

Description

Braking torque control method and device of driving motor and automobile
Technical Field
The invention relates to the technical field of vehicle braking energy recovery, in particular to a braking energy recovery control method and device and an automobile.
Background
In the face of increasingly severe energy and environmental problems, energy-saving and new energy automobiles are hot spots of current research, people invest a great deal of manpower and material resources to develop related research and development work, and the vigorous development of the energy-saving and new energy automobiles has important significance for realizing global sustainable development and protecting the global environment on which human beings live. In China, energy conservation and new energy automobiles are highly valued and are regarded as one of strategic emerging industries. The development of energy-saving and new energy automobiles, particularly pure electric automobiles with zero pollution and zero emission, has great significance for energy safety and environmental protection in China, and is a trend for future development of the automobile field in China.
Different from a traditional fuel vehicle, the power of the pure electric vehicle is derived from a driving motor, and the driving motor not only has the capability of converting electric energy into mechanical energy to drive the vehicle to move, but also has the capability of converting the mechanical energy into electric energy to charge a vehicle-mounted power battery, namely, the specific energy recovery function (including braking energy recovery and sliding energy recovery, which respectively correspond to different driving conditions) of the pure electric vehicle. The energy recovery of the pure electric vehicle has positive significance for improving the vehicle energy utilization efficiency, and has great influence on prolonging the driving range of the vehicle, so that the improvement of the energy recovery efficiency of the pure electric vehicle is a hotspot of research in the field of the pure electric vehicle.
For pure electric vehicles, the energy recovery mode of the pure electric vehicle is currently undergoing a process of converting the early parallel energy recovery into the current series energy recovery. Compared with parallel energy recovery, the series energy recovery has higher energy recovery efficiency, can fully utilize the negative torque generated in the power generation process of the driving motor to realize the braking of the vehicle, has milestone significance for prolonging the service life of friction parts of a braking system and improving the energy recovery efficiency, has the key point of the series energy recovery control that the relationship between the negative torque output in the power generation process of the driving motor and the braking force generated by a traditional hydraulic part is coordinated, and realizes the braking energy recovery of the vehicle by reasonably distributing and controlling the generation of the braking force.
The method comprises the steps of firstly calculating the current total braking demand torque according to the vehicle state and the opening change of a brake pedal, distributing the braking torques respectively borne by a driving motor and a hydraulic system on the basis, then controlling the driving motor and the hydraulic system to output the corresponding braking torques according to the distributed torque commands, and finally realizing the braking energy recovery function of the vehicle.
The method has the characteristics of clear thought, easy realization and the like, but the control effect of the method needs to be improved under some special working conditions, and the special working conditions are the conditions that the braking force shared by the driving motor and the hydraulic system needs to be quickly adjusted. For a hydraulic system, the control of braking force is realized by controlling the pressure in an oil cylinder, the control system of the hydraulic system is complex, and an execution mechanism has a large number of nonlinear links such as dead zones, inertia and the like, which brings great difficulty to the high-precision control of the output braking force of the hydraulic system, so that the hydraulic system cannot always output corresponding braking force according to a command, especially under the condition that the braking torque command is rapidly changed; in addition, the wear degree of the friction mechanism of the wheel brake caliper also influences the actual braking effect of the hydraulic system. Due to the above characteristics of the hydraulic brake system, the problem of vehicle shaking caused by the irregularity of the total braking force output of the vehicle in the above process and the brake effect can not reach the expected index in special conditions, such as the condition of rapidly adjusting the braking force distribution of the driving motor and the hydraulic brake system.
Disclosure of Invention
In order to solve the technical problems, the invention provides a braking torque control method and device of a driving motor and an automobile, and solves the problems that vehicle shaking and braking effect cannot reach the expectation due to poor braking response capability of a hydraulic braking system.
According to an aspect of the present invention, there is provided a braking torque control method of a driving motor, including:
detecting the change states of the braking torques of a hydraulic braking system and a driving motor of the vehicle;
when the change state is in a first state, acquiring the current braking state of the vehicle;
acquiring a target braking acceleration of the vehicle according to the current braking state;
and adjusting the output torque of the driving motor to a target braking torque according to the target braking acceleration, wherein the target braking torque is used for controlling the vehicle to generate the target braking acceleration.
Wherein the first state comprises one of:
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an increase rate of the braking torque allocated to the driving motor is greater than a second preset value;
a state in which the absolute value of the rate of decrease in the braking torque allocated to the hydraulic brake system is greater than a third preset value, and the absolute value of the rate of decrease in the braking torque allocated to the drive motor is greater than a fourth preset value;
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an absolute value of a decrease rate of the braking torque allocated to the drive motor is greater than a fourth preset value;
an absolute value of a rate of decrease of the braking torque allocated to the hydraulic brake system is greater than a third preset value, and a rate of increase of the braking torque allocated to the drive motor is greater than a second preset value.
Optionally, obtaining the target braking acceleration of the vehicle according to the current braking state includes:
and obtaining the target braking acceleration of the vehicle corresponding to the current braking state according to the current braking state and the mapping relation between the braking state and the target braking acceleration.
Optionally, adjusting the output torque of the driving motor to a target braking torque according to the target braking acceleration includes:
acquiring an acceleration difference value between the target braking acceleration and the actual braking acceleration of the vehicle;
and acquiring the theoretical output braking torque of the driving motor according to the acceleration difference.
Optionally, adjusting the output torque of the driving motor to a target braking torque according to the target braking acceleration, further comprising:
filtering the theoretical output braking torque to obtain the target braking torque, wherein the absolute value of the target braking torque is smaller than a fifth preset value;
adjusting the output torque of the drive motor to the target braking torque.
According to another aspect of the present invention, there is provided a braking torque control apparatus of a driving motor, including:
the detection module is used for detecting the change states of the braking torques of a hydraulic braking system and a driving motor of the vehicle;
the first obtaining module is used for obtaining the current braking state of the vehicle when the change state is in a first state;
the second acquisition module is used for acquiring the target braking acceleration of the vehicle according to the current braking state;
and the control module is used for adjusting the output torque of the driving motor to a target braking torque according to the target braking acceleration, and the target braking torque is used for controlling the vehicle to generate the target braking acceleration.
Wherein the first state comprises one of:
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an increase rate of the braking torque allocated to the driving motor is greater than a second preset value;
a state in which the absolute value of the rate of decrease in the braking torque allocated to the hydraulic brake system is greater than a third preset value, and the absolute value of the rate of decrease in the braking torque allocated to the drive motor is greater than a fourth preset value;
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an absolute value of a decrease rate of the braking torque allocated to the drive motor is greater than a fourth preset value;
an absolute value of a rate of decrease of the braking torque allocated to the hydraulic brake system is greater than a third preset value, and a rate of increase of the braking torque allocated to the drive motor is greater than a second preset value.
Optionally, the second obtaining module includes:
and the first obtaining unit is used for obtaining the target braking acceleration of the vehicle corresponding to the current braking state according to the current braking state and the mapping relation between the braking state and the target braking acceleration.
Optionally, the control module includes:
a second obtaining unit, configured to obtain an acceleration difference between the target braking acceleration and the actual braking acceleration;
and the third acquisition unit is used for acquiring the theoretical output braking torque of the driving motor according to the acceleration difference.
Optionally, the control module further includes:
the processing unit is used for carrying out filtering processing on the theoretical output braking torque to obtain the target braking torque, and the absolute value of the target braking torque is smaller than a fifth preset value;
and the control unit is used for adjusting the output torque of the driving motor to the target braking torque.
According to another aspect of the present invention, there is provided an automobile including the brake torque control apparatus of the driving motor.
The embodiment of the invention has the beneficial effects that:
the embodiment of the invention provides a braking torque control method and device of a driving motor and an automobile. The smoothness of the total braking force output of the vehicle in the first state is effectively guaranteed, and the problems that vehicle shaking and the braking effect cannot reach the expectation due to the poor braking response capability of a hydraulic braking system are solved. The invention has clear thought and simple and convenient realization, and does not relate to the change of the hardware of the original serial brake energy recovery system, thereby having wide popularization value.
Drawings
Fig. 1 is a system architecture diagram to which a braking torque control method of a drive motor according to an embodiment of the present invention is applied;
fig. 2 shows one of flowcharts of a braking torque control method of a drive motor of the embodiment of the invention;
FIG. 3 shows a schematic view of a driver model according to an embodiment of the invention;
fig. 4 shows a second flowchart of a braking torque control method of a driving motor according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of closed loop control of an embodiment of the present invention;
fig. 6 is a block diagram showing a brake torque control device for a drive motor according to an embodiment of the present invention.
Detailed Description
Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
The embodiment of the invention provides a braking torque control method of a driving motor, which is suitable for a vehicle in a first state that the braking force shared by the driving motor and a hydraulic braking system changes rapidly, can ensure smooth output of the total braking force of the vehicle in the first state, and solves the problems of vehicle shaking and unsatisfactory vehicle braking effect in the braking process caused by the factors of part abrasion (brake disc abrasion), poor control accuracy of the braking force of the hydraulic system and the like.
The braking torque control method of the driving motor is suitable for the pure electric vehicle with the system framework shown in figure 1.
As shown in fig. 1, the system architecture includes: a Vehicle Control Unit (VCU), an Accelerator Pedal Sensor (APS), a Brake Pedal Sensor (BPS), a Gear state acquisition Unit (GP), an Electronic Brake Unit (EBU), an electronic Control Unit (ecu), a Motor Controller (MCU), an Antilock Brake System (ABS), a driving Motor (Motor), and a wheel system. In the system framework, the VCU receives signals of the APS, the BPS and the GP, and performs signal interaction with the EBU and the MCU, the Motor is directly connected with wheels through a single-stage reducer, and no gear shifting mechanism is arranged in the middle.
The system architecture is a control system architecture which is mainstream at present and realizes a series energy recovery function, according to the architecture, the VCU calculates braking force required by the vehicle according to the obtained states of an accelerator pedal, a brake pedal, a current gear of the vehicle and other systems, and distributes the braking force, namely, a part of the braking force is realized by controlling the pressure in the hydraulic master cylinder through the EBU, and the other part of the braking force is realized by controlling the driving motor to enter a power generation state through the MCU and controlling the braking torque generated by the driving motor in the power generation state. In the framework, the ABS judges whether to be activated or not according to the wheel speed and slip rate information of the vehicle, and when the ABS is not activated, namely the ABS is not required to intervene in the braking process, the pressure in the hydraulic master cylinder is equal to the pressure in the four wheel cylinders of the vehicle, and the braking force generated by the four wheel cylinders in an ideal state is equal; if the ABS enters an activated state, the ABS respectively controls the pressure in the four wheel cylinders, so that the anti-lock braking function of the vehicle is realized. At present, most of pure electric vehicles cannot control the output torques of four wheels respectively by a driving system (except for hub motors), so that in consideration of driving safety, when an ABS enters an activated state, the braking torque of the driving motor needs to be rapidly reduced to 0, and at this time, the braking force of the vehicle is completely generated by a hydraulic braking system.
The braking torque control method of the driving motor provided by the invention is suitable for the pure electric vehicle with the system framework shown in fig. 1, and considering that most of the current pure electric vehicles with the series connection type energy recovery have the framework, the control method provided by the invention has universal application value.
As shown in fig. 2, the braking torque control method of the driving motor includes:
and 21, detecting the change states of the braking torques of a hydraulic braking system and a driving motor of the vehicle.
Preferably, the step 21 includes:
judging whether the vehicle is in an abnormal state influencing driving safety or not;
and if the vehicle is not in the abnormal state, detecting the change state of the braking torque of a hydraulic braking system and a driving motor of the vehicle.
In this embodiment, the abnormal state affecting driving safety refers to a situation that the driving motor needs to be immediately exited from the braking mode due to driving safety considerations, such as ABS activation, a failure of the driving system, and a failure of the power battery system. If the vehicle is in the abnormal state, there is no need to control the braking torque of the drive motor in the abnormal state, and therefore the detection is terminated. And if the vehicle is not in the abnormal state, detecting the change state of the braking torque of a hydraulic braking system and a driving motor of the vehicle.
And step 22, acquiring the current braking state of the vehicle when the change state is in the first state.
In this embodiment, when the change states of the braking torques of the hydraulic braking system and the driving motor of the vehicle are detected and are in the first state, the current braking state of the vehicle is obtained, where the current braking state includes: a brake pedal opening degree and a brake pedal opening degree change rate.
Wherein the first state comprises one of:
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an increase rate of the braking torque allocated to the driving motor is greater than a second preset value;
a state in which the absolute value of the rate of decrease in the braking torque allocated to the hydraulic brake system is greater than a third preset value, and the absolute value of the rate of decrease in the braking torque allocated to the drive motor is greater than a fourth preset value;
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an absolute value of a decrease rate of the braking torque allocated to the drive motor is greater than a fourth preset value;
an absolute value of a rate of decrease of the braking torque allocated to the hydraulic brake system is greater than a third preset value, and a rate of increase of the braking torque allocated to the drive motor is greater than a second preset value.
In this embodiment, a specific implementation manner of identifying the first state is as follows:
in this embodiment, the braking torque distributed to the hydraulic braking system is obtained by a hydraulic braking system torque command, and the braking torque distributed to the driving motor is obtained by a driving motor torque command. The present embodiment defines the hydraulic brake system torque command as TESaid drive motor torque command is TM。
In this embodiment, the specific identification manner of the state where the increase rate of the braking torque allocated to the hydraulic braking system is greater than the first preset value and the increase rate of the braking torque allocated to the driving motor is greater than the second preset value is to determine TEAnd said TMWhether formula one is satisfied.
The formula I is as follows:
Figure GDA0002435484520000071
and is
Figure GDA0002435484520000072
Wherein, Ke1Is the first preset value, KM1Is the second preset value, TEFor the hydraulic braking system torque command, TM is the drive motor torque command, Ke1＞0，KM1＞0。
If said T isEAnd said TMAnd if the formula one is satisfied, the vehicle is in the first state.
In this embodiment, the absolute value of the rate of reduction of the braking torque allocated to the hydraulic brake system is greater than a third preset value, and the rate of reduction of the braking torque allocated to the drive motor isThe state that the absolute value is greater than the fourth preset value is identified in a specific way of judging the TEAnd said TMWhether formula two is satisfied.
The formula II is as follows:
Figure GDA0002435484520000081
and is
Figure GDA0002435484520000082
wherein-Ke1Is said third predetermined value, -KM1Is the fourth predetermined value, TEIs the hydraulic brake system torque command, TMFor the drive motor torque command, Ke1＞0，KM1＞0。
If said T isEAnd said TMAnd if the formula two is satisfied, the vehicle is in the first state.
In this embodiment, the specific identification manner of the state where the increasing rate of the braking torque allocated to the hydraulic braking system is greater than the first preset value and the absolute value of the decreasing rate of the braking torque allocated to the driving motor is greater than the fourth preset value is to determine TEAnd said TMWhether formula three is satisfied.
The formula III is as follows:
Figure GDA0002435484520000083
and is
Figure GDA0002435484520000084
Wherein, Ke1Is said first preset value, -KM1Is the fourth predetermined value, TEIs the hydraulic brake system torque command, TMFor the drive motor torque command, Ke1＞0，KM1＞0。
If said T isEAnd said TMIf the formula three is satisfied, the vehicle is representedIn the first state.
In this embodiment, the absolute value of the reduction rate of the braking torque allocated to the hydraulic braking system is greater than a third preset value, and the increase rate of the braking torque allocated to the driving motor is greater than a second preset value, and the specific identification manner is to determine the TEAnd said TMWhether formula four is satisfied.
The formula four is as follows:
Figure GDA0002435484520000085
and is
Figure GDA0002435484520000086
wherein-Ke1Is the third predetermined value, KM1Is the second preset value, TEIs the hydraulic brake system torque command, TMFor the drive motor torque command, Ke1＞0，KM1＞0。
If said T isEAnd said TMAnd if the formula four is satisfied, the vehicle is in the first state.
In this embodiment, the TEAnd said TMFor the brake torque distribution command of the VCU, the embodiment only uses the brake torque distribution command, and does not relate to the specific implementation process of torque distribution.
And 23, acquiring the target braking acceleration of the vehicle according to the current braking state.
Specifically, step 23 includes:
and obtaining the target braking acceleration of the vehicle corresponding to the current braking state according to the current braking state and the mapping relation between the braking state and the target braking acceleration.
In the present embodiment, as shown in fig. 3, the target braking acceleration is obtained by establishing a driver model. The specific implementation mode of the driver model is a look-up table, the mapping relation between the vehicle speed and the brake pedal state and the target braking acceleration is determined through early-stage real vehicle calibration, and the mapping relation is stored in a table mode. In the actual application process, the current target braking acceleration is obtained through the driver model according to the current vehicle speed and the brake pedal state of the vehicle. Wherein the brake pedal state includes a brake pedal opening and an opening change rate.
And 24, adjusting the output torque of the driving motor to a target braking torque according to the target braking acceleration, wherein the target braking torque is used for controlling the vehicle to generate the target braking acceleration.
Specifically, as shown in fig. 4, step 24 includes:
step 241, acquiring an acceleration difference value between the target braking acceleration and an actual braking acceleration of the vehicle;
and 242, acquiring theoretical output braking torque of the driving motor according to the acceleration difference.
Step 242 obtains the theoretical output brake torque from equation five.
The formula five is as follows:
Figure GDA0002435484520000091
wherein, Tint(t) is the theoretical output brake torque, KpIs a proportionality coefficient, Kp> 0, Δ a (T) is the acceleration difference, TITo integrate the time constant, TI> 0, t is time.
Preferably, as shown in fig. 4, step 24 further comprises:
step 243, filtering the theoretical output braking torque to obtain the target braking torque, wherein the absolute value of the target braking torque is smaller than a fifth preset value;
and 244, adjusting the output torque of the driving motor to the target braking torque.
Wherein step 243 makes the absolute value of the target braking torque smaller than a fifth preset value through formula six.
Formula six:
Figure GDA0002435484520000101
wherein, Tcmd-1For a second theoretical output brake torque (the second theoretical output brake torque is the theoretical output brake torque obtained by processing the theoretical output brake torque by a formula VI), TinyFor said theoretical output braking torque, TmaxIs the fifth preset value.
In this embodiment, the fifth preset value is determined according to a state of a driving system and a state of the entire vehicle. The absolute value of the target braking torque is smaller than the fifth preset value, so that the target braking torque is prevented from exceeding the maximum value allowed by a driving system or the whole vehicle, and the driving safety is further ensured.
In addition, step 243 filters the theoretical output brake torque by formula seven.
The formula seven:
Figure GDA0002435484520000102
wherein, KfIs a low-pass filter coefficient, S is a transfer function, TcmdFor said target braking torque, Tcmd-1And outputting the braking torque for the second theory.
In this embodiment, the target braking torque can be smoothed by filtering the theoretical output braking torque, so that smoothness of vehicle braking in the braking energy recovery process is ensured.
In this embodiment, the control of the braking torque of the driving motor is closed-loop control, the target braking acceleration obtained in step 23 is used as a control target, and the braking acceleration actually generated in the braking process of the vehicle is kept as consistent as possible with the target braking acceleration by adjusting the braking torque of the driving motor, so as to ensure the smoothness of the vehicle running in the first state.
In the first state, the total braking torque distributed by the VCU to the hydraulic braking system and the driving motor is obtained from the target braking acceleration obtained by the driver model (shown in fig. 3), and at this time, the vehicle should perform the braking operation according to the driver model, but since a series of uncertainties occur in the braking torque performed by the hydraulic braking system in the first state, the embodiment utilizes the characteristic of flexible braking torque output of the driving motor to compensate or counteract the adverse effect on smooth running of the vehicle caused by the uncertainty of the braking force output by the hydraulic braking system in the first state by adjusting the braking torque of the driving motor.
As shown in fig. 5, the closed-loop control is specifically as follows:
obtaining the target braking acceleration a according to the driver model (shown in FIG. 4);
the target braking acceleration a and the actual acceleration a of the vehiclevehicleSubtracting to obtain the acceleration difference value delta a;
the acceleration difference △ a is input into a linear controller (PI), and the theoretical output braking torque T is obtained through the PI (formula five)int；
For the theoretical output braking torque TintProcessing (formula six and formula seven) to obtain the target braking torque Tcmd；
Adjusting the output torque of the drive motor to a target braking torque TcmdBraking the vehicle;
further on said actual acceleration avehicleAnd obtaining the acceleration difference value delta a again, and further braking the vehicle.
In the present embodiment, the theoretical output braking torque TintFor the initial torque command, the braking torque output control for the subsequent driving motor is performed in consideration of the theoretical output braking torque T obtained at that timeintThere is a possibility of excessive or high-frequency vibration, and therefore the direct use thereof for torque control of the driving motor may cause irregularity in the power output of the vehicle, and thus the theoretical output brake torque TintCan not be straightThe brake torque output for controlling the driving motor is connected and needs to be processed; this embodiment is directed to the theoretical output braking torque TintProcessed to obtain a final torque command TcmdWherein the purpose of the processing is, on the one hand, to prevent said theoretical output braking torque TintThe brake torque is too large and exceeds the maximum value allowed by a driving system or the whole vehicle, so that the driving safety is damaged, and on the other hand, the brake torque T is output theoreticallyintFiltering out high frequency vibration in the middle to prevent the theoretical output brake torque TintThe vehicle running smoothness is damaged by the shake. The target braking torque T obtained after processingcmdIs used for driving motor control, and the driving motor is controlled according to the target braking torque TcmdAnd outputting the braking torque, and finally realizing the closed-loop control of the torque, namely compensating or offsetting the adverse effect on the running smoothness of the vehicle caused by the uncertainty of the output braking force of the hydraulic braking system in the first state by adjusting the braking torque of the driving motor.
According to the braking torque control method of the driving motor, provided by the embodiment of the invention, by utilizing the advantages of high braking torque response speed and high precision of the driving motor, when the vehicle is in the first state, the vehicle is braked by regulating the output torque of the driving motor to the target braking torque. The smoothness of the total braking force output of the vehicle in the first state is effectively guaranteed, and the problems that vehicle shaking and the braking effect cannot reach the expectation due to the poor braking response capability of a hydraulic braking system are solved. The invention has clear thought and simple and convenient realization, and does not relate to the change of the hardware of the original serial brake energy recovery system, thereby having wide popularization value.
An embodiment of the present invention also provides a braking torque control apparatus of a driving motor, as shown in fig. 6, including:
the detection module 61 is used for detecting the change states of the braking torques of a hydraulic braking system and a driving motor of the vehicle.
The first obtaining module 62 is configured to obtain a current braking state of the vehicle when the change state is in the first state.
Wherein the first state comprises one of:
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an increase rate of the braking torque allocated to the driving motor is greater than a second preset value;
a state in which the absolute value of the rate of decrease in the braking torque allocated to the hydraulic brake system is greater than a third preset value, and the absolute value of the rate of decrease in the braking torque allocated to the drive motor is greater than a fourth preset value;
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an absolute value of a decrease rate of the braking torque allocated to the drive motor is greater than a fourth preset value;
an absolute value of a rate of decrease of the braking torque allocated to the hydraulic brake system is greater than a third preset value, and a rate of increase of the braking torque allocated to the drive motor is greater than a second preset value.
And a second obtaining module 63, configured to obtain a target braking acceleration of the vehicle according to the current braking state.
Specifically, the second obtaining module includes:
and the first obtaining unit is used for obtaining the target braking acceleration of the vehicle corresponding to the current braking state according to the current braking state and the mapping relation between the braking state and the target braking acceleration.
And a control module 64, configured to adjust the output torque of the driving motor to a target braking torque according to the target braking acceleration, where the target braking torque is used to control the vehicle to generate the target braking acceleration.
Specifically, the control module includes:
a second obtaining unit, configured to obtain an acceleration difference between the target braking acceleration and the actual braking acceleration;
and the third acquisition unit is used for acquiring the theoretical output braking torque of the driving motor according to the acceleration difference.
Preferably, the control module further comprises:
the processing unit is used for carrying out filtering processing on the theoretical output braking torque to obtain the target braking torque, and the absolute value of the target braking torque is smaller than a fifth preset value;
and the control unit is used for adjusting the output torque of the driving motor to the target braking torque.
According to the braking torque control device of the driving motor, provided by the embodiment of the invention, the advantage that the response speed of the braking torque of the driving motor is high and the precision is high is utilized, and when the vehicle is in the first state, the vehicle is braked by adjusting the output torque of the driving motor to the target braking torque. The smoothness of the total braking force output of the vehicle in the first state is effectively guaranteed, and the problems that vehicle shaking and the braking effect cannot reach the expectation due to the poor braking response capability of a hydraulic braking system are solved. The invention has clear thought and simple and convenient realization, and does not relate to the change of the hardware of the original serial brake energy recovery system, thereby having wide popularization value.
The embodiment of the invention also provides an automobile comprising the brake torque control device of the driving motor.
While the preferred embodiments of the present invention have been described, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims (9)

1. A braking torque control method of a drive motor, characterized by comprising:
detecting the change states of the braking torques of a hydraulic braking system and a driving motor of the vehicle;
when the change state is in a first state, acquiring the current braking state of the vehicle;
acquiring a target braking acceleration of the vehicle according to the current braking state;
adjusting the output torque of the driving motor to a target braking torque according to the target braking acceleration, wherein the target braking torque is used for controlling the vehicle to generate the target braking acceleration;
wherein the first state comprises one of:
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an increase rate of the braking torque allocated to the driving motor is greater than a second preset value;
a state in which the absolute value of the rate of decrease in the braking torque allocated to the hydraulic brake system is greater than a third preset value, and the absolute value of the rate of decrease in the braking torque allocated to the drive motor is greater than a fourth preset value;
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an absolute value of a decrease rate of the braking torque allocated to the drive motor is greater than a fourth preset value;
an absolute value of a rate of decrease of the braking torque allocated to the hydraulic brake system is greater than a third preset value, and a rate of increase of the braking torque allocated to the drive motor is greater than a second preset value.
2. The brake torque control method of a drive motor according to claim 1, wherein obtaining a target braking acceleration of the vehicle according to the current braking state includes:
and obtaining the target braking acceleration of the vehicle corresponding to the current braking state according to the current braking state and the mapping relation between the braking state and the target braking acceleration.
3. The brake torque control method of the drive motor according to claim 1, wherein adjusting the output torque of the drive motor to a target brake torque according to the target brake acceleration includes:
acquiring an acceleration difference value between the target braking acceleration and the actual braking acceleration of the vehicle;
and acquiring the theoretical output braking torque of the driving motor according to the acceleration difference.
4. The brake torque control method of the drive motor according to claim 3, wherein adjusting the output torque of the drive motor to a target brake torque according to the target brake acceleration, further comprises:
filtering the theoretical output braking torque to obtain the target braking torque, wherein the absolute value of the target braking torque is smaller than a fifth preset value;
adjusting the output torque of the drive motor to the target braking torque.
5. A braking torque control apparatus of a drive motor, characterized by comprising:
the detection module is used for detecting the change states of the braking torques of a hydraulic braking system and a driving motor of the vehicle;
the first obtaining module is used for obtaining the current braking state of the vehicle when the change state is in a first state;
the second acquisition module is used for acquiring the target braking acceleration of the vehicle according to the current braking state;
the control module is used for adjusting the output torque of the driving motor to a target braking torque according to the target braking acceleration, and the target braking torque is used for controlling the vehicle to generate the target braking acceleration;
wherein the first state comprises one of:
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an increase rate of the braking torque allocated to the driving motor is greater than a second preset value;
a state in which the absolute value of the rate of decrease in the braking torque allocated to the hydraulic brake system is greater than a third preset value, and the absolute value of the rate of decrease in the braking torque allocated to the drive motor is greater than a fourth preset value;
a state in which an increase rate of the braking torque allocated to the hydraulic brake system is greater than a first preset value, and an absolute value of a decrease rate of the braking torque allocated to the drive motor is greater than a fourth preset value;
an absolute value of a rate of decrease of the braking torque allocated to the hydraulic brake system is greater than a third preset value, and a rate of increase of the braking torque allocated to the drive motor is greater than a second preset value.
6. The brake torque control device of a drive motor according to claim 5, wherein the second acquisition module includes:
and the first obtaining unit is used for obtaining the target braking acceleration of the vehicle corresponding to the current braking state according to the current braking state and the mapping relation between the braking state and the target braking acceleration.
7. The brake torque control device of a drive motor according to claim 5, wherein the control module includes:
a second acquisition unit configured to acquire an acceleration difference between the target braking acceleration and an actual braking acceleration of the vehicle;
and the third acquisition unit is used for acquiring the theoretical output braking torque of the driving motor according to the acceleration difference.
8. The brake torque control device of a drive motor according to claim 7, wherein the control module further includes:
the processing unit is used for carrying out filtering processing on the theoretical output braking torque to obtain the target braking torque, and the absolute value of the target braking torque is smaller than a fifth preset value;
and the control unit is used for adjusting the output torque of the driving motor to the target braking torque.
9. An automobile characterized by comprising a brake torque control device of a drive motor according to any one of claims 5 to 8.
CN201811453784.8A 2018-11-30 2018-11-30 Braking torque control method and device of driving motor and automobile Active CN109484207B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811453784.8A CN109484207B (en) 2018-11-30 2018-11-30 Braking torque control method and device of driving motor and automobile

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811453784.8A CN109484207B (en) 2018-11-30 2018-11-30 Braking torque control method and device of driving motor and automobile

Publications (2)

Publication Number Publication Date
CN109484207A CN109484207A (en) 2019-03-19
CN109484207B true CN109484207B (en) 2020-05-19

Family

ID=65698931

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811453784.8A Active CN109484207B (en) 2018-11-30 2018-11-30 Braking torque control method and device of driving motor and automobile

Country Status (1)

Country Link
CN (1) CN109484207B (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112977071B (en) * 2019-12-13 2023-01-10 长城汽车股份有限公司 Control method and device of new energy vehicle and new energy vehicle
CN112009266B (en) * 2020-09-01 2022-02-01 三一专用汽车有限责任公司 Power parameter calibration method and device, vehicle and computer readable storage medium
CN112455429B (en) * 2020-11-30 2022-05-13 广州小鹏自动驾驶科技有限公司 Parking control method and device, vehicle and readable storage medium
CN112706620B (en) * 2020-12-31 2022-08-26 北京金万安汽车电子技术研发有限公司 Motor braking torque control method in energy recovery of new energy vehicle
CN112757909B (en) * 2021-01-12 2023-06-23 恒大新能源汽车投资控股集团有限公司 Vehicle control method and device, electronic equipment and storage medium
CN113002321A (en) * 2021-03-23 2021-06-22 奇瑞新能源汽车股份有限公司 New energy automobile braking method and device, whole automobile controller and new energy automobile
CN113353069B (en) * 2021-07-22 2023-03-24 中国第一汽车股份有限公司 Automatic emergency braking system, and method and system for adjusting automatic emergency braking system
CN115817430A (en) * 2023-01-10 2023-03-21 北京百度网讯科技有限公司 Vehicle braking method, vehicle braking device, electronic equipment, medium and automatic driving vehicle

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102001293A (en) * 2009-09-01 2011-04-06 株式会社万都 Hydraulic control method of regenerative braking system for vehicle
JP2014155342A (en) * 2013-02-08 2014-08-25 Toyota Motor Corp Motor controller
CN104553817A (en) * 2014-12-26 2015-04-29 芜湖市汽车产业技术研究院有限公司 Regeneration braking control method and system
CN106541933A (en) * 2015-09-21 2017-03-29 上海汽车集团股份有限公司 brake energy recovery control method and system
CN107444393A (en) * 2017-07-20 2017-12-08 北京新能源汽车股份有限公司 brake system control method and device

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102540917B1 (en) * 2016-12-15 2023-06-07 현대자동차주식회사 Method for controlling motor torque of electric vehicle

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102001293A (en) * 2009-09-01 2011-04-06 株式会社万都 Hydraulic control method of regenerative braking system for vehicle
JP2014155342A (en) * 2013-02-08 2014-08-25 Toyota Motor Corp Motor controller
CN104553817A (en) * 2014-12-26 2015-04-29 芜湖市汽车产业技术研究院有限公司 Regeneration braking control method and system
CN106541933A (en) * 2015-09-21 2017-03-29 上海汽车集团股份有限公司 brake energy recovery control method and system
CN107444393A (en) * 2017-07-20 2017-12-08 北京新能源汽车股份有限公司 brake system control method and device

Also Published As

Publication number Publication date
CN109484207A (en) 2019-03-19

Similar Documents

Publication Publication Date Title
CN109484207B (en) Braking torque control method and device of driving motor and automobile
US11021158B2 (en) Vehicle dynamics control system in a motor vehicle and electronic vehicle dynamics control unit for a vehicle dynamics control system
US7503631B2 (en) Vehicle braking system and vehicle braking method
CN105228870B (en) Brake apparatus
CN112026771B (en) Composite anti-lock control method based on hub motor/electronic mechanical brake
CN103332184A (en) Electric-hydro complex brake control method for electric vehicle use and controlling device thereof
US11505072B2 (en) Regenerative braking system and method
CN107264338B (en) Anti-sliding control method and system based on rear-drive electric vehicle
CN107791885A (en) The fail safe devices and methods therefor of ECM systems
CN108688474A (en) Braking energy of electric automobiles recycles control algolithm
CN106515423A (en) Regeneration strategy for a vehicle having decoupled front and rear axle drive actuators
CN112549987B (en) Automobile inter-wheel differential steering method based on driving-braking composite control
Zhang et al. Improvement of drivability and fuel economy with a hybrid antiskid braking system in hybrid electric vehicles
CN108944865A (en) The braking system and its braking method of new energy vehicle
JPH08230631A (en) Method and equipment for controlling brake gear of vehicle
CN114454724A (en) Intelligent pure electric vehicle braking energy recovery control method
CN109927701A (en) A kind of pure line traffic control brake system of car of centralized driving formula and its control method
CN117644775A (en) Torque vector control method and device, storage medium and vehicle
Leng et al. Allocation control algorithms design and comparison based on distributed drive electric vehicles
US20190389317A1 (en) Driving torque command generating apparatus and method of eco-friendly vehicle
CN111959476B (en) Intelligent management method for braking mode of hybrid commercial vehicle
CN114734970A (en) Anti-lock braking control system and method based on interval three-mode fuzzy logic braking
CN112977075B (en) Brake control method and device for front wheel drive vehicle and automobile
CN114407870B (en) Control method and device for electric composite braking system, storage medium and commercial vehicle
JP4613163B2 (en) Control device for a motor vehicle driven at least part-time in four wheels

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant