CN117681681A - Torque vector control method and device for distributed hub motor driving system - Google Patents
Torque vector control method and device for distributed hub motor driving system Download PDFInfo
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Abstract
The application provides a torque vector control method and device of a distributed hub motor driving system. After vehicle running information of a distributed hub motor driven vehicle and motor running information of a hub motor are obtained, controlling the torque of each target hub motor to be the average torque of the total driving torque of the vehicle by adopting a two-wheel driving mode when the motor running information meets preset motor fault conditions or the motor running information does not meet the preset motor fault conditions and the motor efficiency is required to be prioritized; and under the condition that the preset motor fault condition is not met and the motor efficiency is not required to be prioritized, if the vehicle is in a steering mode, determining a current functional mode of the vehicle in the steering mode based on the actual vehicle speed in the vehicle running information, and determining the target torque output by each hub motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle. The method improves the steering stability and safety of the vehicle.
Description
Technical Field
The application relates to the technical field of motor control, in particular to a torque vector control method and device of a distributed hub motor driving system.
Background
The distributed hub motor driven vehicle adopts four hub motors for driving, and the hub motors have the advantages of quick response, high transmission efficiency, short transmission chain, easy realization of electric control technology integration and the like, and are an important direction for the development of new energy automobiles in the future.
The distributed driving vehicle is provided with four independent hub motors, compared with the traditional fuel oil vehicle and a vehicle driven by a single motor and double motors, the distributed driving vehicle cancels the mechanical differential device, and can independently control the torque or the rotating speed of four wheels through software, so that the control is more flexible. The torque vector control is an important method in active chassis control, and the key idea is that the unbalanced distribution of the torque is realized by controlling four hub motors through related torque, and the reasonable distribution of the torque rotating speed is realized, so that the body posture of a vehicle is controlled: for example, yaw rate, slip angle, roll angle and the like, can realize the functions of electronic differential speed, stable control, driving anti-skid and the like, and improve the steering stability and the economy of the vehicle.
In the actual engineering application, only a single working condition is considered and analyzed, and the priority and coupling relation of various working conditions are not considered, so that the vehicle steering stability and safety are reduced.
Disclosure of Invention
An object of the embodiment of the application is to provide a torque vector control method and a device of a distributed hub motor driving system, which comprehensively consider various working conditions of a vehicle, reasonably distribute the torque of a hub motor based on specific working conditions and improve the steering stability and safety of the vehicle.
In a first aspect, a torque vector control method of a distributed in-wheel motor drive system is provided, which may include:
acquiring vehicle running information of a distributed hub motor driven vehicle and motor running information of a hub motor;
when the motor operation information is detected to meet a preset motor fault condition, or when the motor operation information is detected to not meet the preset motor fault condition and the motor efficiency is required to be prioritized, a two-wheel driving mode is adopted, and the torque of each target hub motor is controlled to be the average torque of the total driving torque of the vehicle; the preset motor fault condition is a condition that a single motor fault or two different-side motor faults exist; the total driving torque of the vehicle is calculated by a PI controller through a preset target vehicle speed and an actual vehicle speed in the vehicle running information;
And under the condition that the motor running information does not meet the preset motor fault condition and the motor efficiency is not required to be prioritized, if the vehicle is detected to be in a steering mode, determining a current functional mode of the vehicle in the steering mode based on the actual vehicle speed, and determining the target torque output by each hub motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle.
In one possible implementation, when detecting that the motor operation information meets a preset motor fault condition, or when detecting that the motor operation information does not meet the preset motor fault condition and when requiring priority of motor efficiency, adopting a two-wheel driving mode, controlling the torque of the target hub motor to be the average torque of the total driving torque of the vehicle, wherein the method comprises the following steps:
when the motor running information is detected to meet the preset motor fault condition, a two-wheel driving mode is adopted, and the torque of the motor which does not generate faults is controlled to be the average torque of the total driving torque of the vehicle;
and under the condition that the motor running information does not meet the preset motor fault condition and the required motor efficiency is prioritized, adopting a two-wheel driving mode to control the torque of the front axle double motor or the rear axle double motor to be the average torque of the total driving torque of the vehicle.
In one possible implementation, detecting that the vehicle is in a steering mode includes:
if the front axle steering angle in the vehicle running information is larger than a preset positive steering angle threshold value; or the front axle steering angle is smaller than a preset negative steering angle threshold value; or the change rate of the front axle steering angle in the vehicle running information is larger than the preset positive steering angle change rate; or if the change rate of the steering angle of the front axle is smaller than the preset negative steering angle change rate, determining that the vehicle is in a steering mode.
In one possible implementation, determining a current functional mode of the vehicle in the steering mode based on the actual vehicle speed includes:
if the actual vehicle speed is greater than a third vehicle speed threshold value, determining that the vehicle is in a yaw stability control function mode;
if the actual vehicle speed is greater than a second vehicle speed threshold and less than a first vehicle speed threshold, determining that the vehicle is in a yaw stability control transition mode;
if the actual vehicle speed is greater than a first vehicle speed threshold value and less than a second vehicle speed threshold value, determining that the vehicle is in an electronic differential transition mode;
if the actual vehicle speed is smaller than a first vehicle speed threshold value, determining that the vehicle is in an electronic differential function mode;
Wherein the first vehicle speed threshold is less than the second vehicle speed threshold and less than the third vehicle speed threshold.
In one possible implementation, the steering compensation torque is a yaw stability compensation torque or an electronic differential compensation torque;
determining a target torque output by each in-wheel motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle, including:
if the vehicle is in the yaw stability control function mode, determining yaw stability compensation moment based on the actual vehicle speed and the front axle steering angle in the vehicle running information and the vehicle information; calculating the target torque of each hub motor according to the average torque of the total driving torque of the vehicle and the yaw stability compensation torque;
if the vehicle is in a yaw stability control transition mode, determining a yaw moment compensation coefficient based on the actual vehicle speed, the second vehicle speed threshold and the third vehicle speed threshold; calculating the target torque output by each hub motor according to the average torque of the total driving torque of the vehicle, the yaw stability compensation torque and the yaw moment compensation coefficient;
if the vehicle is in the electronic differential function mode, determining electronic differential compensation torque based on the actual vehicle speed, the front axle steering angle, the rear axle steering angle and the vehicle information; the electronic differential compensation torque comprises a compensation torque of a front hub motor and a compensation torque of a rear hub motor; calculating the target torque output by each hub motor according to the average torque of the total driving torque of the vehicle and the electronic differential compensation torque;
If the vehicle is in the electronic differential transition mode, determining an electronic differential compensation torque transition coefficient based on the actual vehicle speed, the first vehicle speed threshold and the second vehicle speed threshold; and calculating the target torque output by each hub motor according to the average torque of the total driving torque of the vehicle, the electronic differential compensation torque and the electronic differential compensation torque transition coefficient.
In one possible implementation, determining the yaw stability compensation moment based on the actual vehicle speed and the front axle steering angle in the vehicle travel information, and the vehicle information, includes:
calculating an ideal yaw rate required by the vehicle based on the actual vehicle speed and the front axle steering angle in the vehicle running information and the vehicle information;
based on the ideal yaw rate and the actual yaw rate in the vehicle running information, using a PI controller to obtain a total additional yaw moment required by the vehicle;
and calculating the total additional yaw moment by adopting a yaw stability compensation algorithm to obtain a yaw stability compensation moment.
In one possible implementation, determining the electronic differential compensation torque based on the actual vehicle speed, the front axle steering angle, the rear axle steering angle, and the vehicle information includes:
Calculating a torque compensation coefficient based on the actual vehicle speed, the front axle steering angle, the rear axle steering angle and the vehicle information;
based on the torque compensation coefficient and the sum T of the average torques of the front axle wheels f Sum of average torque of rear axle wheels T r And determining the compensation moment of the front hub motor and the compensation moment of the rear hub motor.
In one possible implementation, the method further comprises:
if the vehicle is detected not to be in the steering mode, calculating the slip rate of each wheel based on the wheel rotating speed and the actual vehicle speed in the vehicle running information;
and if the slip rate is larger than the slip rate threshold value, determining that the wheel slips, and controlling the output torque of the hub motor of the wheel to be reduced by a preset step length at the moment so as to meet the condition that the slip rate is not larger than the slip rate threshold value.
In a second aspect, a torque vectoring device for a distributed in-wheel motor drive system is provided, the device may include:
the acquisition unit is used for acquiring vehicle running information of the distributed hub motor driven vehicle and motor running information of the hub motor;
the control unit is used for controlling the torque of each target hub motor to be the average torque of the total driving torque of the vehicle by adopting a two-wheel driving mode when detecting that the motor operation information meets the preset motor fault condition or when detecting that the motor operation information does not meet the preset motor fault condition and the motor efficiency is required to be prioritized; the preset motor fault condition is a condition that a single motor fault or two different-side motor faults exist; the total driving torque of the vehicle is calculated by a PI controller through a preset target vehicle speed and the actual vehicle speed in the vehicle running information.
And the determining unit is used for determining a current functional mode of the vehicle in the steering mode based on the actual vehicle speed if the vehicle is detected to be in the steering mode under the condition that the motor running information does not meet the preset motor fault condition and the motor efficiency is not required to be prioritized, and determining the target torque output by each hub motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle.
In a third aspect, a computer-readable storage medium is provided, in which a computer program is stored which, when being executed by a processor, carries out the method steps of any of the first aspects described above.
After vehicle running information of a distributed hub motor driven vehicle and motor running information of a hub motor are obtained, controlling the torque of each target hub motor to be the average torque of the total driving torque of the vehicle by adopting a two-wheel driving mode when the motor running information meets preset motor fault conditions or the motor running information does not meet the preset motor fault conditions and the required motor efficiency is prioritized; the preset motor fault condition is a condition that a single motor fault or two different-side motor faults exist; the total driving torque of the vehicle is calculated by a PI controller through a preset target vehicle speed and an actual vehicle speed. Under the condition that the motor running information does not meet the preset motor fault condition and the motor efficiency is not required to be prioritized, if the vehicle is in a steering mode, determining a current functional mode of the vehicle in the steering mode based on the actual speed in the vehicle running information, and determining the target torque output by each hub motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle. According to the method, multiple working conditions of the vehicle are comprehensively considered, and the torque of the hub motor is reasonably distributed based on the specific working conditions, so that the steering stability and safety of the vehicle are improved.
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In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related 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 torque vector control method of a distributed hub motor driving system according to an embodiment of the present application;
FIG. 2 is a flow chart of another torque vector control method for a distributed in-wheel motor drive system according to an embodiment of the present disclosure;
fig. 3 is a schematic structural diagram of a torque vector control device of a distributed hub motor driving system according to an embodiment of the present application;
fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments of the present application without making any inventive effort, are intended to be within the scope of the present application.
In the prior art, there is a torque vector control method for a distributed hub motor driven vehicle based on the working condition of the vehicle, in the prior art, when the wheels slip, most of the torque vector control method does not consider the requirement of the dynamic property of the vehicle, and also does not consider factors such as the maximum outputtable torque of the hub motor, so that when the torque vector is distributed to the hub motor, the dynamic property of the vehicle is possibly weakened, and an additional yaw moment is generated;
when the existing method analyzes the steering yaw stability, the high-speed working condition and the low-speed working condition are not discussed separately, and when the vehicle runs at a low speed, the additional yaw moment under the steering working condition of the vehicle is identical to the steering direction so as to promote steering and improve operability. When the vehicle runs at a high speed, the additional yaw moment under the steering working condition of the vehicle is opposite to the steering direction, so that the yaw of the vehicle is restrained, and the stability of the vehicle is improved.
The problem to be solved by the application is: when the distributed hub motor driven vehicle runs, the current running working condition of the vehicle is identified, and factors such as wheel slip, motor efficiency, vehicle speed, steering, maximum available torque of the motor and the like are comprehensively considered, so that the output torque of the hub motor is reasonably distributed, and the optimal torque vector system of the distributed hub motor driven vehicle is achieved.
Vehicle operating conditions may be divided into: the method comprises the steps of setting reasonable priorities for the five modes, determining the mode of a current vehicle, and distributing the torque of four hub motors according to the torque vector distribution rule in the current mode.
The method and the device can solve the problems of incomplete functional coverage, disordered logic control and the like under different working conditions of the distributed hub motor vehicle, can be suitable for various complicated driving situations, are beneficial to realizing high-efficiency and reasonable torque vector control, and improve the performance of the vehicle. The torque vector control method can effectively identify the running working condition of the current vehicle, reasonably distribute the torque of the hub motor according to the working condition and improve the vehicle performance.
The preferred embodiments of the present application will be described below with reference to the accompanying drawings of the specification, it being understood that the preferred embodiments described herein are for illustration and explanation only, and are not intended to limit the present application, and embodiments and features of embodiments of the present application may be combined with each other without conflict.
Fig. 1 is a schematic flow chart of a torque vector control method of a distributed hub motor driving system according to an embodiment of the present application. As shown in fig. 1, the method may include:
Step S110, vehicle running information of a distributed hub motor driven vehicle and motor running information of a hub motor are obtained.
In a specific implementation, the VCU obtains motor operation information of the four in-wheel motors from motor controllers of the four in-wheel motors through CAN communication, including: the motor rotation speed under the current vehicle driving, the maximum output torque of the motor, the fault information of the motor and the like.
The information such as accelerator pedal information, vehicle speed, wheel rotation speed, whole wheel base L, wheel base d, tire rolling radius R, front axle steering angle, rear axle steering angle, corresponding steering angle change rate, actual yaw rate and the like can be obtained from the speed sensor and the angle sensor.
Meanwhile, vehicle information may also be obtained, including: whole vehicle mass m, distance L from vehicle mass center to front axle f Distance L from vehicle centroid to rear axle r Cornering stiffness k of front tire f Cornering stiffness k of rear tire r Etc.
Step S120, when the motor operation information is detected to meet the preset motor fault condition, or when the motor operation information is detected not to meet the preset motor fault condition and the motor efficiency is required to be prioritized, a two-wheel driving mode is adopted, and the torque of each target hub motor is controlled to be the average torque of the total driving torque of the vehicle.
When more than three motors fail or two motors on the same side fail, the vehicle does not meet the running condition, and the output torque of the hub motor is 0; when a single motor or two different-side motors are in fault, the two-wheel driving mode is adopted for driving, so the preset motor fault condition is that the single motor or the two different-side motors are in fault.
When the motor needs to meet the efficiency priority, the front axle double motor or the rear axle double motor is used for driving, so that the electric quantity of a battery is saved, and the endurance mileage of the vehicle is improved.
Specifically, when detecting that the motor operation information meets the preset motor fault condition, adopting a two-wheel driving mode to control the torque of the motor which does not have faults to be the average torque of the total driving torque of the vehicle; the total driving torque M of the vehicle is calculated by a PI controller through a preset target vehicle speed and an actual vehicle speed.
And under the condition that the motor running information is detected not to meet the preset motor fault condition and the required motor efficiency is prioritized, adopting a two-wheel driving mode to control the torque of the front axle double motor or the rear axle double motor to be the average torque of the total driving torque of the vehicle, namely M/2.
And step S130, determining a mode of the vehicle under the condition that the motor running information is detected to not meet the preset motor fault condition and the motor efficiency is not required to be prioritized.
If the vehicle is detected to be in the steering mode, the current functional mode of the vehicle in the steering mode is determined based on the actual vehicle speed.
In specific implementation, the motor running information does not meet the preset motor fault condition, and the situation that the motor efficiency is not required to be prioritized is that the hub motors of four wheels of the vehicle work normally, and the current user does not have the situation that the motor efficiency is prioritized.
At this time, the steering angle delta of the front axle is firstly based on f Front axle steering angle change rate w f It is determined whether the vehicle is turned. Specifically, if the front axle steering angle δf in the vehicle running information>Preset positive steering angle threshold delta th The method comprises the steps of carrying out a first treatment on the surface of the Or, the front axle steering angle delta th <Preset negative steering angle threshold-delta th The method comprises the steps of carrying out a first treatment on the surface of the Or, the front axle steering angle change rate w in the vehicle running information f >Preset positive steering angle change rate w th The method comprises the steps of carrying out a first treatment on the surface of the Or, the front axle steering angle change rate w f <Preset negative steering angle change rate-w th It is determined that the vehicle is in the steering mode.
If the vehicle is in the steering mode at the moment, the vehicle can enter an electronic differential mode (comprising an electronic differential transition mode and an electronic differential functional mode) according to the actual vehicle speed at the moment, for example, under the low-speed condition; at high speed, the vehicle enters a yaw stability control mode (comprising a yaw stability control function mode and a yaw stability control transition mode), the steering mode is subjected to function mode distinction, and a transition function area (or a transition function mode) is designed, so that the linear change of compensation torque is realized, and the torque of the hub motor is prevented from suddenly changing.
Specifically, if the actual vehicle speed is greater than the third vehicle speed thresholdV th _ h Determining that the vehicle is in a yaw stability control function mode;
if the actual vehicle speed is greater than the second vehicle speed threshold V th And is smaller than the first vehicle speed threshold V th_l Determining that the vehicle is in a yaw stability control transition mode;
if the actual vehicle speed is greater than the first vehicle speed threshold V th_l And is smaller than the second vehicle speed threshold V th Determining that the vehicle is in an electronic differential transition mode;
if the actual vehicle speed is smaller than the first vehicle speed threshold V th_l Determining that the vehicle is in an electronic differential function mode;
wherein the first vehicle speed threshold V th_l Less than a second vehicle speed threshold V th Less than a third vehicle speed threshold V th _ h 。
Step S140, determining a target torque output by each in-wheel motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle.
The steering compensation torque is yaw stability compensation torque or electronic differential compensation torque.
(1) If the vehicle is in the yaw stability control function mode, determining yaw stability compensation moment based on the actual vehicle speed and the front axle steering angle in the vehicle running information and the vehicle information;
specifically, an ideal yaw rate required by the vehicle is calculated based on the actual vehicle speed and the front axle steering angle in the vehicle running information and the vehicle information;
Wherein, the formula for calculating the ideal yaw rate can be expressed as:
wherein K is a coefficient, L is the wheelbase of the whole vehicle, v x Is practically theVehicle speed delta f The steering angle of the front axle is m is the mass of the whole vehicle, L f For the distance from the centre of mass of the vehicle to the front axle, L r K is the distance from the center of mass of the vehicle to the rear axle f For cornering stiffness, k, of the front tyre r Is the cornering stiffness of the rear tire.
Based on the ideal yaw rate and the actual yaw rate in the vehicle travel information, a PI controller is used to obtain the total additional yaw moment DeltaM required by the vehicle z ；
Adopting yaw stability compensation algorithm to make total additional yaw moment delta M z And calculating to obtain the yaw stability compensation moment.
Wherein, the formula for calculating the yaw stability compensation moment can be expressed as:
wherein R is the rolling radius of the tire, and d is the tread.
Then, calculating the target torque of each hub motor according to the average torque (namely M/4) of the total driving torque of the vehicle and the yaw stability compensation torque;
in the yaw stability control function mode, the formula for calculating the target torques of the 4 in-wheel motors can be expressed as:
wherein T is 1 、T 2 、T 3 、T 4 The final output torque of the front left, front right, rear left and rear right wheels under yaw stability control, respectively.
(2) If the vehicle is in the yaw stability control transition mode, a second vehicle speed threshold V based on the actual vehicle speed th And a third vehicle speed threshold V th _ h Determining a yaw moment compensation coefficient;
the calculation formula of the yaw moment compensation coefficient can be expressed as follows:
in the formula, v x V is the actual speed of the vehicle th For the second vehicle speed threshold, V th _ h Is a third vehicle speed threshold.
Then, the target torque of each in-wheel motor is calculated from the average torque (i.e., M/4) of the total driving torque of the vehicle, the yaw stability compensation torque, and the yaw moment compensation coefficient.
In the yaw stability control transition mode, the formula for calculating the target torques of the 4 in-wheel motors can be expressed as:
(3) If the vehicle is in the electronic differential function mode, determining electronic differential compensation torque based on the actual vehicle speed, the front axle steering angle, the rear axle steering angle and the vehicle information; the electronic differential compensation torque comprises the compensation torque of the front hub motor and the compensation torque of the rear hub motor;
specifically, a torque compensation coefficient is calculated based on the actual vehicle speed, the front axle steering angle, the rear axle steering angle, and the vehicle information;
wherein L is f For the distance from the centre of mass of the vehicle to the front axle, L r K is the distance from the center of mass of the vehicle to the rear axle f 、K r The driving torque ratio of the front axle inner and outer wheels and the driving torque ratio of the rear axle inner and outer wheels are respectively, d is the wheel track of the vehicle, g is the gravitational acceleration, h s Is the height of the centroid, delta r Delta for rear axle steering angle f Is the front axle steering angle.
Based on torque compensation coefficient (i.e. driving torque ratio K of front axle inner and outer wheels f Drive torque ratio K of rear axle inner and outer wheels r ) Sum of front axle wheel average torque T f Sum T of average torque of rear axle wheels r And determining the compensation moment of the front hub motor and the compensation moment of the rear hub motor.
The formula for calculating the compensation torque of the front hub motor and the compensation torque of the rear hub motor can be expressed as:
wherein DeltaT f ,ΔT r The driving torque difference between the front axle inner and outer wheels and the driving torque difference between the rear axle inner and outer wheels are respectively.
Then, the target torque of each in-wheel motor is calculated according to the average torque (i.e., M/4) of the total driving torque of the vehicle and the electronic differential compensation torque.
The formula for calculating the target torque of each in-wheel motor can be expressed as:
(4) If the vehicle is in the electronic differential transition mode, a first vehicle speed threshold V is based on the actual vehicle speed th_l And a second vehicle speed threshold V th Determining an electronic differential compensation torque transition coefficient;
The equation for calculating the electronic differential compensation torque transition coefficient is expressed as:
wherein k' is an electronic differential compensation torque transition coefficient, v x V is the actual speed of the vehicle th For the second vehicle speed threshold, V th _ l Is a first vehicle speed threshold.
And calculating the target torque of each hub motor according to the average torque, the electronic differential compensation torque and the electronic differential compensation torque transition coefficient of the total driving torque of the vehicle.
The formula for calculating the target torque of the 4 in-wheel motors is expressed as:
in some embodiments, if it is detected that the vehicle is not in the steering mode, calculating a slip ratio s of each wheel based on the wheel speed and the actual vehicle speed in the vehicle running information; judging whether the wheel rotates, if so, the slip rate s>Slip ratio threshold s th Determining that the wheel rotates, and performing torque reduction operation on the torque of the wheel hub motor, namely controlling the output torque of the wheel hub motor to be a preset step length T qstep Reducing to satisfy slip ratio s less than or equal to slip ratio threshold s th And increasing the reduced torque to the torque of the same-side non-slip wheel.
Fig. 2 is a flow chart of another torque vector control method of a distributed hub motor driving system according to an embodiment of the present application. As shown in fig. 2, the method may include:
Step 20, acquiring vehicle running information and motor running information;
step 21, judging whether the motor fails;
if yes, executing step 22, wherein the vehicle working condition is a fault mode;
if not, then step 24 is performed:
step 22, judging whether the vehicle can continue running;
if yes, go to step 23;
if not, go to step 24;
step 23, adopting a two-wheel driving mode, wherein the output torque of each hub motor is the average torque of the total driving torque of the vehicle;
step 24, outputting torque of each hub motor to be 0;
step 25, judging whether the efficiency is priority;
if yes, go to step 23;
if not, go to step 26;
step 26, judging whether the vehicle turns or not;
if yes, go to step 27;
if not, go to step 31;
step 27, judging whether the vehicle speed is greater than a vehicle speed threshold value;
if yes, go to step 28;
if not, go to step 29;
step 28, entering a yaw stabilization mode, and executing step 30;
step 29, entering an electronic differential mode, and executing step 30;
step 30, calculating steering compensation torque of a corresponding mode;
step 31, judging whether the wheel slips or not;
if yes, go to step 32;
If not, go to step 33;
step 32, calculating slip compensation;
step 33, calculating the total driving moment of the vehicle;
step 34, determining a target torque output by each in-wheel motor.
The torque vector control method of the distributed hub motor driving system provided by the embodiment of the application has the following advantages:
1. the application range of torque vector control is expanded, multiple running conditions of the vehicle are distinguished, and different control strategies are adopted, so that the torque distribution of the hub motor is more reasonable and effective.
2. Wheel slip reduces wheel torque, helping to reduce tire wear and energy inefficiency.
3. The low-speed steering working condition is that under the electronic differential mode, the steering portability is improved, and meanwhile, the tire abrasion can be reduced.
4. The high-speed steering yaw stability control helps to improve the yaw stability of the vehicle, so that the vehicle can ensure driving safety without ESCs.
5. Under the condition of priority of efficiency, the two-wheel drive is adopted, so that the electric quantity loss of the battery can be reduced, the running efficiency is improved, and the endurance mileage is increased.
6. The torque vector control method is more effective and reliable by performing real vehicle testing on the VCU on the basis of the simulink-carsim joint simulation analysis.
Corresponding to the method, the embodiment of the application also provides a torque vector control device of the distributed hub motor driving system, as shown in fig. 3, which comprises:
an acquisition unit 310 for acquiring vehicle running information of the distributed hub motor-driven vehicle and motor running information of the hub motor;
a control unit 320, configured to control the torque of each target hub motor to be the average torque of the total driving torque of the vehicle by adopting a two-wheel driving mode when it is detected that the motor operation information meets a preset motor failure condition, or when it is detected that the motor operation information does not meet the preset motor failure condition and the motor efficiency is required to be prioritized; the preset motor fault condition is a condition that a single motor fault or two different-side motor faults exist; the total driving torque of the vehicle is calculated by a PI controller through a preset target vehicle speed and the actual vehicle speed.
And a determining unit 330, configured to, when it is detected that the motor running information does not meet a preset motor failure condition and that no priority is required for motor efficiency, determine a current functional mode of the vehicle in the steering mode based on an actual vehicle speed in the vehicle running information if it is detected that the vehicle is in the steering mode, and determine a target torque output by each in-wheel motor based on a steering compensation torque corresponding to the current functional mode and an average torque of the total driving torque of the vehicle.
The functions of each functional unit of the torque vector control device of the distributed hub motor driving system provided by the embodiment of the application may be implemented through the steps of the method, so that the specific working process and beneficial effects of each unit in the torque vector control device of the distributed hub motor driving system provided by the embodiment of the application are not repeated herein.
The embodiment of the present application further provides an electronic device, as shown in fig. 4, including a processor 410, a communication interface 420, a memory 430, and a communication bus 440, where the processor 410, the communication interface 420, and the memory 430 complete communication with each other through the communication bus 440.
A memory 430 for storing a computer program;
the processor 410 is configured to execute the program stored in the memory 430, and implement the following steps:
acquiring vehicle running information of a distributed hub motor driven vehicle and motor running information of a hub motor;
when the motor operation information is detected to meet a preset motor fault condition, or when the motor operation information is detected to not meet the preset motor fault condition and the motor efficiency is required to be prioritized, a two-wheel driving mode is adopted, and the torque of each target hub motor is controlled to be the average torque of the total driving torque of the vehicle; the preset motor fault condition is a condition that a single motor fault or two different-side motor faults exist; the total driving torque of the vehicle is calculated by a PI controller through a preset target vehicle speed and the actual vehicle speed.
And if the motor running information is detected to not meet the preset motor fault condition and the motor efficiency is not required to be prioritized, determining a current functional mode of the vehicle in the steering mode based on the actual vehicle speed in the vehicle running information if the vehicle is detected to be in the steering mode, and determining the target torque output by each hub motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle.
The communication bus mentioned above may be a peripheral component interconnect standard (Peripheral Component Interconnect, PCI) bus or an extended industry standard architecture (Extended Industry Standard Architecture, EISA) bus, or the like. The communication bus may be classified as an address bus, a data bus, a control bus, or the like. For ease of illustration, the figures are shown with only one bold line, but not with only one bus or one type of bus.
The communication interface is used for communication between the electronic device and other devices.
The Memory may include random access Memory (Random Access Memory, RAM) or may include Non-Volatile Memory (NVM), such as at least one disk Memory. Optionally, the memory may also be at least one memory device located remotely from the aforementioned processor.
The processor may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; but also digital signal processors (Digital Signal Processing, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.
Since the implementation manner and the beneficial effects of the solution to the problem of each device of the electronic apparatus in the foregoing embodiment may be implemented by referring to each step in the embodiment shown in fig. 1, the specific working process and the beneficial effects of the electronic apparatus provided in the embodiment of the present application are not repeated herein.
In yet another embodiment provided herein, a computer readable storage medium having instructions stored therein that, when run on a computer, cause the computer to perform the torque vector control method of the distributed in-wheel motor drive system of any of the above embodiments is also provided.
In yet another embodiment provided herein, there is also provided a computer program product containing instructions that, when run on a computer, cause the computer to perform the torque vector control method of the distributed in-wheel motor drive system of any of the above embodiments.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, embodiments of 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, embodiments of the present application may take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.
Embodiments of the present application are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products 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.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted to embrace the preferred embodiments and all such variations and modifications as fall within the scope of the embodiments herein.
It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if such modifications and variations of the embodiments in the present application fall within the scope of the claims and the equivalents thereof in the embodiments of the present application, such modifications and variations are also intended to be included in the embodiments of the present application.
Claims (10)
1. A method of torque vectoring for a distributed in-wheel motor drive system, the method comprising:
acquiring vehicle running information of a distributed hub motor driven vehicle and motor running information of a hub motor;
when the motor operation information is detected to meet a preset motor fault condition, or when the motor operation information is detected to not meet the preset motor fault condition and the motor efficiency is required to be prioritized, a two-wheel driving mode is adopted, and the torque of each target hub motor is controlled to be the average torque of the total driving torque of the vehicle; the preset motor fault condition is a condition that a single motor fault or two different-side motor faults exist; the total driving torque of the vehicle is calculated by a PI controller through a preset target vehicle speed and an actual vehicle speed in the vehicle running information;
And under the condition that the motor running information does not meet the preset motor fault condition and the motor efficiency is not required to be prioritized, if the vehicle is detected to be in a steering mode, determining a current functional mode of the vehicle in the steering mode based on the actual vehicle speed, and determining the target torque output by each hub motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle.
2. The method of claim 1, wherein controlling the torque of the target hub motor to be the average torque of the total driving torque of the vehicle in a two-wheel drive mode when the motor operation information is detected to satisfy a preset motor failure condition or when the motor operation information is detected not to satisfy a preset motor failure condition and when the motor efficiency is required to be prioritized, comprises:
when the motor running information is detected to meet the preset motor fault condition, a two-wheel driving mode is adopted, and the torque of the motor which does not generate faults is controlled to be the average torque of the total driving torque of the vehicle;
and under the condition that the motor running information does not meet the preset motor fault condition and the required motor efficiency is prioritized, adopting a two-wheel driving mode to control the torque of the front axle double motor or the rear axle double motor to be the average torque of the total driving torque of the vehicle.
3. The method of claim 1, wherein detecting that the vehicle is in a steering mode comprises:
if the front axle steering angle in the vehicle running information is larger than a preset positive steering angle threshold value; or the front axle steering angle is smaller than a preset negative steering angle threshold value; or the change rate of the front axle steering angle in the vehicle running information is larger than the preset positive steering angle change rate; or if the change rate of the steering angle of the front axle is smaller than the preset negative steering angle change rate, determining that the vehicle is in a steering mode.
4. A method according to claim 3, wherein determining a current functional mode of the vehicle in the steering mode based on the actual vehicle speed comprises:
if the actual vehicle speed is greater than a third vehicle speed threshold value, determining that the vehicle is in a yaw stability control function mode;
if the actual vehicle speed is greater than a second vehicle speed threshold and less than a first vehicle speed threshold, determining that the vehicle is in a yaw stability control transition mode;
if the actual vehicle speed is greater than a first vehicle speed threshold value and less than a second vehicle speed threshold value, determining that the vehicle is in an electronic differential transition mode;
if the actual vehicle speed is smaller than a first vehicle speed threshold value, determining that the vehicle is in an electronic differential function mode;
Wherein the first vehicle speed threshold is less than the second vehicle speed threshold and less than the third vehicle speed threshold.
5. The method of claim 4, wherein the steering compensation torque is a yaw stability compensation torque or an electronic differential compensation torque;
determining a target torque output by each in-wheel motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle, including:
if the vehicle is in the yaw stability control function mode, determining yaw stability compensation moment based on the actual vehicle speed and the front axle steering angle in the vehicle running information and the vehicle information; calculating the target torque output by each hub motor according to the average torque of the total driving torque of the vehicle and the yaw stability compensation torque;
if the vehicle is in a yaw stability control transition mode, determining a yaw moment compensation coefficient based on the actual vehicle speed, the second vehicle speed threshold and the third vehicle speed threshold; calculating the target torque of each hub motor according to the average torque of the total driving torque of the vehicle, the yaw stability compensation torque and the yaw moment compensation coefficient;
If the vehicle is in the electronic differential function mode, determining electronic differential compensation torque based on the actual vehicle speed, the front axle steering angle, the rear axle steering angle and the vehicle information; the electronic differential compensation torque comprises a compensation torque of a front hub motor and a compensation torque of a rear hub motor; calculating the target torque output by each hub motor according to the average torque of the total driving torque of the vehicle and the electronic differential compensation torque;
if the vehicle is in the electronic differential transition mode, determining an electronic differential compensation torque transition coefficient based on the actual vehicle speed, the first vehicle speed threshold and the second vehicle speed threshold; and calculating the target torque output by each hub motor according to the average torque of the total driving torque of the vehicle, the electronic differential compensation torque and the electronic differential compensation torque transition coefficient.
6. The method of claim 5, wherein determining the yaw stability compensation moment based on the actual vehicle speed and the front axle steering angle in the vehicle travel information, and the vehicle information, comprises:
calculating an ideal yaw rate required by the vehicle based on the actual vehicle speed and the front axle steering angle in the vehicle running information and the vehicle information;
Based on the ideal yaw rate and the actual yaw rate in the vehicle running information, using a PI controller to obtain a total additional yaw moment required by the vehicle;
and calculating the total additional yaw moment by adopting a yaw stability compensation algorithm to obtain a yaw stability compensation moment.
7. The method of claim 5, wherein determining an electronic differential compensation torque based on the actual vehicle speed, front and rear axle steering angles, and vehicle information comprises:
calculating a torque compensation coefficient based on the actual vehicle speed, the front axle steering angle, the rear axle steering angle and the vehicle information;
and determining the compensation moment of the front hub motor and the compensation moment of the rear hub motor based on the torque compensation coefficient, the sum of the average torques of the front axle wheels and the sum of the average torques of the rear axle wheels.
8. The method of claim 1, wherein the method further comprises:
if the vehicle is detected not to be in the steering mode, calculating the slip rate of each wheel based on the wheel rotating speed and the actual vehicle speed in the vehicle running information;
and if the slip rate is larger than the slip rate threshold value, determining that the wheel slips, and controlling the output torque of the hub motor of the wheel to be reduced by a preset step length at the moment so as to meet the condition that the slip rate is not larger than the slip rate threshold value.
9. A torque vectoring device for a distributed in-wheel motor drive system, the device comprising:
the acquisition unit is used for acquiring vehicle running information of the distributed hub motor driven vehicle and motor running information of the hub motor;
the control unit is used for controlling the torque of each target hub motor to be the average torque of the total driving torque of the vehicle by adopting a two-wheel driving mode when detecting that the motor operation information meets the preset motor fault condition or when detecting that the motor operation information does not meet the preset motor fault condition and the motor efficiency is required to be prioritized; the preset motor fault condition is a condition that a single motor fault or two different-side motor faults exist; the total driving torque of the vehicle is calculated by a PI controller through a preset target vehicle speed and an actual vehicle speed in the vehicle running information;
and the determining unit is used for determining a current functional mode of the vehicle in the steering mode based on the actual vehicle speed if the vehicle is detected to be in the steering mode under the condition that the motor running information does not meet the preset motor fault condition and the motor efficiency is not required to be prioritized, and determining the target torque output by each hub motor based on the steering compensation torque corresponding to the current functional mode and the average torque of the total driving torque of the vehicle.
10. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein a computer program which, when executed by a processor, implements the method of any of claims 1-8.
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| CN202410030635.XA CN117681681A (en) | 2024-01-09 | 2024-01-09 | Torque vector control method and device for distributed hub motor driving system |
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| CN202410030635.XA CN117681681A (en) | 2024-01-09 | 2024-01-09 | Torque vector control method and device for distributed hub motor driving system |
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