A method for controlling steering driving torque of a distributed drive vehicle

Abstract

This invention belongs to the field of vehicle torque control technology, specifically relating to a distributed drive vehicle in-situ steering torque control method. Based on the longitudinal and lateral velocities and accelerations at the vehicle's center of gravity, and considering the influence of the slip ratio changes of the four wheels on the overall longitudinal and lateral acceleration, the method selects a single wheel with a large change in longitudinal or lateral force with the longitudinal slip ratio for torque adjustment within one adjustment cycle, while maintaining the original output torque of the other wheels. Using this torque distribution strategy, for vehicles with a center of gravity centered horizontally and longitudinally rearward, in-situ steering can be achieved while allowing the center of gravity to move within a small range. This control method, based on real-time online accumulation of vehicle center of gravity and four-wheel information, achieves automatic and flexible adjustment of the system's operating state by locating the wheel to be adjusted and calculating changes in driving torque, adapting to constantly changing conditions and situations, and maintaining a dynamic operating state to cope with different working conditions.

Description

Technical Field

[0001] This invention belongs to the field of vehicle torque control technology, specifically relating to a method for controlling the driving torque of a distributed drive vehicle for in-situ steering, so as to enable the vehicle to turn around its center of gravity in place, while ensuring that the vehicle's center of gravity moves within a small range. Background Technology

[0002] Distributed drive vehicles can achieve on-the-spot steering because the driving torque of each wheel is independent. The opposite directions of the driving torque on the left and right sides of the vehicle provide the basis for on-the-spot steering. For on-the-spot steering, using a uniform distribution strategy with the same absolute value of driving torque for all four wheels will result in a large displacement of the center of gravity during the steering process for vehicles that are not centered, making it difficult to achieve the purpose of on-the-spot steering effectively. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] The technical problem to be solved by the present invention is: to provide a method for controlling the driving torque of a distributed drive vehicle for in-situ steering, in view of the defects of the relevant control methods involved in the background art, so as to realize in-situ steering around the center of gravity of the vehicle with the center of gravity moving within a small range.

[0005] (II) Technical Solution

[0006] To solve the above technical problems, the present invention provides a method for controlling the in-situ steering torque of a distributed drive vehicle, wherein the implementation process of the method is a closed-loop automatic control process.

[0007] The distributed drive vehicle includes four drive hub motors M ij A center of mass velocity sensor SEN v A center of mass acceleration sensor (SEN) a Four hub motor controller MCUs ij A basic controller CM1 and a correction controller CM2; where i = 1, 2; j = 1, 2;

[0008] The four drive hub motors M ij Each is used to directly drive the four wheels to rotate;

[0009] The centroid velocity sensor SEN v Used to measure the longitudinal and lateral velocities at the vehicle's center of gravity;

[0010] The centroid acceleration sensor SEN a Used to measure longitudinal and lateral acceleration at the vehicle's center of gravity;

[0011] The four wheel hub motor controller MCUsij Used to control the four drive hub motors to perform corresponding operations;

[0012] The basic controller CM1 is used to calculate the desired driving torque T required for the four wheels to initiate steering of the vehicle. sij ;

[0013] The correction controller CM2 is used to calculate the new slip ratio required for correction and the correction drive torque T of the four wheels. ij .

[0014] In the closed-loop automatic control process of the distributed drive vehicle stationary steering drive torque control method, the controlled object is the vehicle's center of gravity, and the control quantity is the drive torque.

[0015] The control method includes the following steps:

[0016] Step 1: By setting the basic vehicle model parameters, the basic controller CM1 calculates the desired drive torque T of the four wheels based on the given values. sij The expected driving torque T of each wheel sij The output is sent to the correction controller CM2;

[0017] Step 2: Correct the controller CM2 based on the input desired drive torque T of the four wheels. sij The corrected drive torque T of each wheel ij Output to the corresponding four wheel hub motor controller MCUs ij middle;

[0018] Step 3: Four hub motor controllers (MCUs) ij Based on the corrected drive torque signal T input from the corrected controller CM2 ij The output is sent to the four drive hub motors M corresponding to the wheels. ij middle;

[0019] Step 4: Four drive hub motors M ij According to the hub motor controller MCU ij The input desired drive torque signal T sij By adjusting the driving force applied to the corresponding wheels and adjusting the wheel speed, the steering can be achieved around the center of mass in place.

[0020] In step 1, during the calculation of the basic controller CM1, the vehicle mass, wheelbase, track width, distance from center of gravity to front axle center, tire rolling radius, and sideslip angle are used as basic vehicle parameters. Under the condition that the wheels are turning at a large sideslip angle during a stationary turn, the longitudinal and lateral force relationships of the four wheels are derived. Let the longitudinal and lateral acceleration 'a' at the center of gravity be... x a ySince all values ​​are 0, the driving torque relationship of the four wheels is derived, and the desired driving torque T is finally calculated. sij Output value.

[0021] Among them, the expected drive torque T calculated by the basic controller CM1 sij The output value is T, where the expected driving torque of the front and rear wheels of the vehicle is equal. s11 =T s12 T s21 =T s22 The desired driving torque T of the two front wheels will change over time. sij Gradually increase the expected driving torque T of the two rear wheels sij The driving torque is gradually increased according to the formula.

[0022] Step 4 includes:

[0023] Step 41: Feedback loop in the closed-loop automatic control process: Vehicle center of gravity speed sensor SEN v Vehicle center of gravity acceleration sensor (SEN) a After the vehicle begins to turn around its center of gravity in place, the longitudinal and lateral velocities v at the vehicle's center of gravity are collected in real time. x v y Longitudinal and lateral acceleration a x a y This information is then fed back to the correction controller CM2.

[0024] Step 42: By setting the basic vehicle model parameters, the basic controller CM1 calculates the desired drive torque T after gradually increasing the drive torque of the front wheels. sij The desired driving torque T of each wheel sij The output is sent to the correction controller CM2.

[0025] Step 4 further includes:

[0026] Step 43: The correction controller CM2 adjusts the longitudinal and lateral velocities at the vehicle's center of gravity based on the input data. x v y Longitudinal and lateral acceleration a x a y and the expected driving torque T of each wheel sij Calculate the corrected driving torque T required for the target to be adjusted after adjustment. ij And output to the corresponding hub motor controller MCU of the wheel of the object to be adjusted. ij middle.

[0027] In the calculation process of the correction controller CM2 in step 43, the longitudinal and lateral velocities v at the vehicle's center of gravity are collected in real time. x v y Longitudinal and lateral acceleration a x a y The required target acceleration a is obtained. xaim a yaim According to the target acceleration a xaim a yaim The symbol, combined with the relationship between the longitudinal slip ratio change of the four wheels and the acceleration of the center of gravity of the vehicle, da x / dσ xij da y / dσ yij The positive and negative relationships are used to reduce the four wheels to two wheels to be adjusted; by comparing the target acceleration a xaim and a yaim The longitudinal or lateral force to be adjusted is determined, and the two wheels are dimensionality-reduced to focus on the wheel whose adjustment force varies more significantly with the longitudinal slip ratio. Finally, based on the wheel selected through dimensionality reduction and the adjustment direction, a proportional correction strategy is used to calculate the required corrected driving torque T for a single wheel after adjustment. ij .

[0028] In step 43, the corrected drive torque T calculated by the corrected controller CM2 is... ij The output value corrects the driving torque of only one wheel to be adjusted within one adjustment cycle, while the output torque of the other three wheels that do not need to be adjusted remains unchanged. This process is repeated in real time until the vehicle completes the turning motion around the center of gravity.

[0029] In the closed-loop automatic control process, a feedback loop exists between the important output and input terminals, and the output directly affects the control process. In road conditions where the external environment is variable and difficult to control, this method provides high accuracy in torque control and is less sensitive to external disturbances and changes in system parameters.

[0030] In the closed-loop automatic control process, control is performed based on the information of output changes, which can eliminate deviations caused by external environmental factors to achieve the expected turning effect around the center of gravity in place; the vehicle has a good effect in turning around its center of gravity once in place, which can satisfy the movement of the center of gravity within a small range.

[0031] (III) Beneficial Effects

[0032] Compared with existing technologies, the distributed drive vehicle in-situ steering torque control method of the present invention is a closed-loop automatic control process. It controls the vehicle based on changes in system output, eliminating deviations caused by external environmental factors to achieve the desired in-situ steering effect around the center of gravity. The method exhibits good performance in a complete in-situ steering maneuver around the center of gravity, ensuring the center of gravity moves within a relatively small range. This invention enables vehicles with a non-centered center of gravity to perform in-situ steering around their center of gravity at any angle, while maintaining a relatively small range of movement. During the entire in-situ steering maneuver, the space required for vehicle execution is small, and the resulting positional offset is minimal. The corrector, based on data feedback within an adjustment cycle, corrects the driving torque of only one wheel, reducing the complexity of the control process and increasing flexibility. Attached Figure Description

[0033] Figure 1 This is a force analysis diagram of a vehicle with its center of gravity located at the rear when turning in place;

[0034] Figure 2 This is a diagram of the vehicle's in-place steering control structure around its center of gravity.

[0035] Figure 3 This is a dimensionality reduction logic diagram for adjusting wheel slip ratio;

[0036] Figure 4 This is a schematic diagram illustrating the combined effect of the corrective controller and the basic controller. Detailed Implementation

[0037] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0038] To solve the above technical problems, the present invention provides a method for controlling the in-situ steering torque of a distributed drive vehicle, wherein the implementation process of the method is a closed-loop automatic control process.

[0039] The distributed drive vehicle includes four drive hub motors M ij A center of mass velocity sensor SEN v A center of mass acceleration sensor (SEN) a Four hub motor controller MCUs ij A basic controller CM1 and a correction controller CM2; where i = 1, 2; j = 1, 2;

[0040] The four drive hub motors M ij Each is used to directly drive the four wheels to rotate;

[0041] The centroid velocity sensor SEN vUsed to measure the longitudinal and lateral velocities at the vehicle's center of gravity;

[0042] The centroid acceleration sensor SEN a Used to measure longitudinal and lateral acceleration at the vehicle's center of gravity;

[0043] The four wheel hub motor controller MCUs ij Used to control the four drive hub motors to perform corresponding operations;

[0044] The basic controller CM1 is used to calculate the desired driving torque T required for the four wheels to initiate steering of the vehicle. sij ;

[0045] The correction controller CM2 is used to calculate the new slip ratio required for correction and the correction drive torque T of the four wheels. ij .

[0046] In the closed-loop automatic control process of the distributed drive vehicle stationary steering drive torque control method, the controlled object is the vehicle's center of gravity, and the control quantity is the drive torque.

[0047] The control method includes the following steps:

[0048] Step 1: By setting the basic vehicle model parameters, the basic controller CM1 calculates the desired drive torque T of the four wheels based on the given values. sij The expected driving torque T of each wheel sij The output is sent to the correction controller CM2;

[0049] Step 2: Correct the controller CM2 based on the input desired drive torque T of the four wheels. sij The corrected drive torque T of each wheel ij Output to the corresponding four wheel hub motor controller MCUs ij middle;

[0050] Step 3: Four hub motor controllers (MCUs) ij Based on the corrected drive torque signal T input from the corrected controller CM2 ij The output is sent to the four drive hub motors M corresponding to the wheels. ij middle;

[0051] Step 4: Four drive hub motors M ij According to the hub motor controller MCU ij The input desired drive torque signal T sij By adjusting the driving force applied to the corresponding wheels and adjusting the wheel speed, the steering can be achieved around the center of mass in place.

[0052] In step 1, during the calculation of the basic controller CM1, the vehicle mass, wheelbase, track width, distance from center of gravity to front axle center, tire rolling radius, and sideslip angle are used as basic vehicle parameters. Under the condition that the wheels are turning at a large sideslip angle during a stationary turn, the longitudinal and lateral force relationships of the four wheels are derived. Let the longitudinal and lateral acceleration 'a' at the center of gravity be... x a y Since all values ​​are 0, the driving torque relationship of the four wheels is derived, and the desired driving torque T is finally calculated. sij Output value.

[0053] Among them, the expected drive torque T calculated by the basic controller CM1 sij The output value is T, where the expected driving torque of the front and rear wheels of the vehicle is equal. s11 =T s12 T s21 =T s22 The desired driving torque T of the two front wheels will change over time. sij Gradually increase the expected driving torque T of the two rear wheels sij The driving torque is gradually increased according to the formula.

[0054] Step 4 includes:

[0055] Step 41: Feedback loop in the closed-loop automatic control process: Vehicle center of gravity speed sensor SEN v Vehicle center of gravity acceleration sensor (SEN) a After the vehicle begins to turn around its center of gravity in place, the longitudinal and lateral velocities v at the vehicle's center of gravity are collected in real time. x v y Longitudinal and lateral acceleration a x a y This information is then fed back to the correction controller CM2.

[0056] Step 42: By setting the basic vehicle model parameters, the basic controller CM1 calculates the desired drive torque T after gradually increasing the drive torque of the front wheels. sij The desired driving torque T of each wheel sij The output is sent to the correction controller CM2.

[0057] Step 4 further includes:

[0058] Step 43: The correction controller CM2 adjusts the longitudinal and lateral velocities at the vehicle's center of gravity based on the input data. x v y Longitudinal and lateral acceleration a x a y and the expected driving torque T of each wheelsij Calculate the corrected driving torque T required for the target to be adjusted after adjustment. ij And output to the corresponding hub motor controller MCU of the wheel of the object to be adjusted. ij middle.

[0059] In the calculation process of the correction controller CM2 in step 43, the longitudinal and lateral velocities v at the vehicle's center of gravity are collected in real time. x v y Longitudinal and lateral acceleration a x a y The required target acceleration a is obtained. xaim a yaim According to the target acceleration a xaim a yaim The symbol, combined with the relationship between the longitudinal slip ratio change of the four wheels and the acceleration of the center of gravity of the vehicle, da x / dσ xij da y / dσ yij The positive and negative relationships are used to reduce the four wheels to two wheels to be adjusted; by comparing the target acceleration a xaim and a yaim The longitudinal or lateral force to be adjusted is determined, and the two wheels are dimensionality-reduced to focus on the wheel whose adjustment force varies more significantly with the longitudinal slip ratio. Finally, based on the wheel selected through dimensionality reduction and the adjustment direction, a proportional correction strategy is used to calculate the required corrected driving torque T for a single wheel after adjustment. ij .

[0060] In step 43, the corrected drive torque T calculated by the corrected controller CM2 is... ij The output value corrects the driving torque of only one wheel to be adjusted within one adjustment cycle, while the output torque of the other three wheels that do not need to be adjusted remains unchanged. This process is repeated in real time until the vehicle completes the turning motion around the center of gravity.

[0061] In the closed-loop automatic control process, a feedback loop exists between the important output and input terminals, and the output directly affects the control process. In road conditions where the external environment is variable and difficult to control, this method provides high accuracy in torque control and is less sensitive to external disturbances and changes in system parameters.

[0062] In the closed-loop automatic control process, control is performed based on the information of output changes, which can eliminate deviations caused by external environmental factors to achieve the expected turning effect around the center of gravity in place; the vehicle has a good effect in turning around its center of gravity once in place, which can satisfy the movement of the center of gravity within a small range.

[0063] Example 1

[0064] This embodiment discloses a method for controlling the steering torque of a distributed drive vehicle, wherein the distributed drive vehicle includes four drive hub motors M. ij (i = 1, 2; j = 1, 2), a centroid velocity sensor SEN v A center of mass acceleration sensor SEN a Four hub motor controller MCUs ij (i = 1, 2; j = 1, 2), one basic controller CM1, one correction controller CM2; four drive hub motors M ij Each sensor is used to directly drive the rotation of the four wheels; the center of gravity speed sensor (SEN) v Used to measure the longitudinal and lateral velocities at the vehicle's center of gravity; Center of Gravity Acceleration Sensor (SEN) a Used to measure longitudinal and lateral acceleration at the vehicle's center of gravity; four wheel hub motor controllers (MCUs) ij The controller receives command signals to control the four drive wheel hub motors to perform corresponding operations; the basic controller CM1 calculates the basic desired drive torque T required by the four wheels to initiate steering of the vehicle. sij (i = 1, 2; j = 1, 2), T s11 =T s12 T s21 =T s22 The driving torque of the front and rear wheels is equal; the correction controller CM2 performs dimensionality reduction screening on the wheels that need to be adjusted, and uses a proportional correction strategy to calculate the new slip ratio and driving torque required for correction.

[0065] The process of this distributed drive vehicle in-situ steering torque control method for in-situ vehicle steering around the center of gravity is as follows:

[0066] Step 1: By setting the basic vehicle model parameters, the basic controller CM1 calculates the desired driving torque T for the four wheels. sij The desired driving torque T of each wheel sij The output is sent to the correction controller CM2;

[0067] Step 2: Correct the controller CM2 based on the input desired drive torque T of the four wheels. sij The corrected drive torque T of each wheel sij Output to the corresponding four wheel hub motor controller MCUs ij middle;

[0068] Step 3, four hub motor controller MCUs ij Based on the corrected drive torque signal T input from the corrected controller CM2 sijThe output is sent to the four drive hub motors M corresponding to the wheels. ij middle;

[0069] Step four, four drive hub motors M ij According to the hub motor controller MCU ij The input desired drive torque signal T sij Adjust the driving force applied to the corresponding wheels and adjust the wheel speed;

[0070] Step 5, Vehicle center of gravity speed sensor SEN v Vehicle center of gravity acceleration sensor (SEN) a After the vehicle begins to turn around its center of gravity in place, the longitudinal and lateral velocities v at the vehicle's center of gravity are... x v y Longitudinal and lateral acceleration a x a y Real-time data acquisition is performed and fed back to the correction controller CM2;

[0071] Step six: By setting the basic vehicle model parameters, the basic controller CM1 calculates the desired drive torque T after gradually increasing the drive torque of the front wheels. sij The desired driving torque T of each wheel sij The output is sent to the correction controller CM2;

[0072] Step 7: The correction controller CM2 adjusts the longitudinal and lateral velocities at the vehicle's center of gravity based on the input values ​​v. x v y Longitudinal and lateral acceleration a x a y and the expected driving torque T of each wheel sij Calculate the target acceleration a required after adjustment. xaim a yaim By combining the influence of the longitudinal slip ratio changes of the four wheels on the target acceleration, the four wheels are reduced to a single wheel to be adjusted. A proportional correction strategy is used to calculate the new drive torque required for the single wheel after adjustment, and the result is output to the corresponding hub motor controller MCU of the wheel to be adjusted. ij middle;

[0073] Step 8: Repeat steps 3 to 7, gradually increasing the driving torque of each wheel. Within one adjustment cycle, only the driving torque of one wheel is corrected, while the output torque of the other three wheels remains unchanged, until the vehicle completes the stationary turning action around the center of gravity.

[0074] The distributed drive vehicle in-situ steering torque control method of the present invention has both a basic controller and a correction controller during implementation, which can achieve the purpose of the vehicle turning around its center of gravity in place; the vehicle turns around its center of gravity once in place with good effect, and can meet the requirement that the center of gravity moves within a small range.

[0075] The technical solution of this embodiment will be further described in detail below with reference to the accompanying drawings:

[0076] like Figure 1 As shown, O is the vehicle's center of gravity. ‘ Let be the vehicle's geometric center, 'a' be the wheel slip angle, 'd' be the distance from the vehicle's center of mass to the geometric center, 'b' be the track width, 'l' be the wheelbase, and 'ω' be the angular velocity of the vehicle's rotation about its center of mass; the left front wheel, right front wheel, left rear wheel, and right rear wheel are respectively Tyre 11 Tyre 12 Tyre 21 Tyre 22 The speeds of each wheel are v tyre11 v tyre12 v tyre21 v tyre22 The longitudinal forces of each wheel are F x11 F x12 F x21 F x22 The lateral forces of each wheel are F y11 F y12 F y21 F y22 The ground forces acting on each wheel are F. 11 F 12 F 21 F 22 The driving torque of each wheel is T. 11 T 12 T 21 T 22 The longitudinal and lateral velocities at the center of mass are v0 and v1x v y The longitudinal and lateral accelerations at the center of mass are a and a, respectively. x a y .

[0077] like Figure 2As shown, the distributed drive vehicle's stationary steering torque control structure works as follows: During the vehicle's stationary steering around its center of gravity, the basic controller first calculates the driving torque of the four wheels, initiating the steering action. Then, the correction sensors process the real-time collected and fed-back longitudinal and lateral velocities and accelerations at the center of gravity. Based on the desired starting torque input from the basic controller, the driving torque of the wheels to be adjusted is corrected, indirectly changing the driving force of the wheels and achieving stationary steering around the center of gravity, thus controlling the movement of the center of gravity within a small range.

[0078] The designed basic controller analyzes and calculates the input vehicle and environmental ground information. During a stationary turn around the center of gravity, the wheels rotate under a large sideslip angle, and the longitudinal and lateral accelerations at the center of gravity are zero. This yields the desired output driving torque for the wheels. During the stationary turn, the driving torque of the front wheels is gradually increased, and the desired driving torque for each wheel is calculated in real time. Based on the wheel force analysis during the stationary turn, the following can be derived:

[0079]

[0080] Wherein: F z — Wheel vertical load

[0081] μ — Ground adhesion coefficient

[0082] The vehicle's center of gravity speed sensor and acceleration sensor can collect longitudinal, lateral velocity and acceleration data at the vehicle's center of gravity in real time, and feed this data signal back to the designed correction controller. This data signal will be continuously used to correct the driving torque of the wheel to be adjusted.

[0083] like Figure 3 As shown, the designed correction controller plans its target acceleration based on the longitudinal and lateral velocities and accelerations at the input center of mass, and calculates and adjusts the wheel longitudinal slip ratio, a factor that can affect the vehicle's longitudinal and lateral acceleration. Based on the planned target acceleration direction and the influence of slip ratio changes on the vehicle's longitudinal and lateral acceleration, and adjusting based on the planned absolute value of the target acceleration and longitudinal or lateral force, a second-order dimensionality reduction is used to select wheels with significant changes in longitudinal slip ratio as the adjustment targets for correction. During stationary turning, the following can be derived from the vehicle body force analysis:

[0084]

[0085] After determining the wheels to be adjusted and the direction of adjustment, a proportional correction strategy is used to derive the new drive torque. In one correction cycle, only the longitudinal slip ratio (i.e., the drive torque) of one wheel is adjusted; the output torque of the other wheels that do not require adjustment remains unchanged. The corrected drive torque signals for all four wheels are output to the corresponding hub motor controllers for each wheel. The adjustment method using the proportional correction strategy is as follows:

[0086] T n+1 =T n +dir·k T

[0087] Where: dir — slip ratio adjustment direction (1, -1)

[0088] k T —Torque Adjustment Ratio

[0089] By using a distributed drive vehicle stationary steering torque control method, the driving torque of the four wheels is adjusted during the stationary steering process around the center of gravity, so that the driving torque of each wheel can change according to the adjusted corrected driving torque value of the desired driving torque value, thereby realizing the stationary steering of the vehicle around the center of gravity and controlling the movement of the center of gravity within a small range.

[0090] like Figure 4 As shown, the in-situ steering torque control method for distributed drive vehicles of the present invention is tested and verified using co-simulation with Carsim and Simulink. In the Carsim simulation program, relevant parameters of the example vehicle are set, and in the Simulink simulation program, a control strategy simulation environment for the controller is built for co-simulation, regressing the parameter k. x k y The value is 0.7, and the torque adjustment ratio k is... T The value is set to 0.25. By comparing the simulation results using only the basic controller and the simulation results after adding the correction controller, under the distributed drive vehicle stationary steering torque control method of the present invention, after adding the correction controller to correct the driving torque of the wheel to be adjusted output by the basic controller, the vehicle can complete one revolution around the center of gravity in place. During this process, the movement of the vehicle's center of gravity is less than 10cm, which has a good stationary steering effect.

[0091] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for controlling a steering drive torque of a distributed drive vehicle, characterized by, The implementation process of the distributed drive vehicle in-situ steering drive torque control method is a closed-loop automatic control process. The distributed drive vehicle includes four drive hub motors. A centroid velocity sensor A center of mass acceleration sensor Four hub motor controllers A basic controller A correction controller Where i = 1, 2; j = 1, 2; The four drive wheel hub motors for directly driving the four wheels to rotate, respectively; The center of mass velocity sensor for measuring longitudinal and lateral velocities at the center of mass of a vehicle; The center of mass acceleration sensor for measuring longitudinal and lateral accelerations at the center of mass of a vehicle; The four wheel hub motor controllers for controlling the four drive wheel hub motors to work correspondingly; The basic controller Used to calculate the desired driving torque required to start the vehicle steering at all four wheels. ; The correction controller for calculating a new slip ratio required for correction and correction drive torques of the four wheels ; In the closed-loop automatic control process of the distributed drive vehicle stationary steering drive torque control method, the controlled object is the vehicle's center of gravity, and the control quantity is the drive torque. The control method includes the following steps: Step 1: By setting basic vehicle model parameters, the basic controller calculates the desired drive torque of each wheel for a given value of the vehicle's speed and outputs it to the correction controller ; Step 2: Correcting the controller According to the inputted four-wheel desired drive torques Correcting the drive torque of each wheel Output to the corresponding four-wheel hub motor controllers of the wheels In the controller Step 3: Four in-wheel motor controllers According to the correction controller The input correction drive torque signal , the four drive wheel in-wheel motors corresponding to the wheel; Step 4: Four drive hub motors According to the hub motor controller The input desired drive torque signal By adjusting the driving force applied to the corresponding wheels and adjusting the wheel speed, the steering can be achieved around the center of mass in place.

2. The distributed drive vehicle spin-on-the-spot drive torque control method of claim 1, wherein, In step 1, the basic controller In the calculation process, the basic vehicle parameters are vehicle mass, wheelbase, track width, distance from center of gravity to front axle center, tire rolling radius, and sideslip angle. During a stationary turn, under conditions of large sideslip angle, the longitudinal and lateral force relationships of the four wheels are derived. The longitudinal and lateral accelerations at the center of gravity are then considered. , Since all values ​​are 0, the driving torque relationship of the four wheels is derived, and the desired driving torque is finally calculated. Output value.

3. The distributed drive vehicle spin-on-the-spot drive torque control method of claim 2, wherein, For the basic controller Calculated desired driving torque The output value is the same as the expected driving torque of the front and rear wheels of the vehicle. , The desired driving torque of the two front wheels will change over time. Gradually increase the desired driving torque of the two rear wheels The driving torque is gradually increased according to the formula.

4. The distributed drive vehicle spin-on-the-spot drive torque control method of claim 1, wherein, Step 4 includes: Step 41: Feedback link in the closed-loop automatic control process: vehicle mass center speed sensor , vehicle mass center acceleration sensor After the vehicle is driven to start the around-mass-center turning on the spot, the longitudinal and lateral speeds 、 , longitudinal and lateral accelerations 、 , which are acquired in real time at the vehicle mass center, are fed back to the correction controller . Step 42: The basic controller is set by setting the basic vehicle model parameters The expected drive torque of the front wheels is calculated by gradually increasing the drive torque of the front wheels The expected drive torque of each wheel is calculated Output to the correction controller In the above-described control, 5. The distributed drive vehicle spin-on-the-spot drive torque control method of claim 4 wherein, Step 4 also includes: Step 43: correction controller According to the input longitudinal and lateral velocities at the vehicle center of mass , , longitudinal and lateral accelerations , and the desired drive torque of each wheel , the target adjusted required correction drive torque to be adjusted is calculated and output to the corresponding in-wheel motor controller of the wheel to be adjusted .

6. The method for controlling the steering torque of a distributed drive vehicle in place as described in claim 5, characterized in that, The correction controller in step 43 During the calculation process, the longitudinal and lateral velocities at the vehicle's center of gravity are collected in real time. , Longitudinal and lateral acceleration , The required target acceleration is obtained. , According to the target acceleration , The symbol, combined with the relationship between the longitudinal slip ratio change of the four wheels and the acceleration at the center of mass. , The positive and negative relationships are used to reduce the four wheels to two wheels that need adjustment; by comparing the target acceleration... and The longitudinal or lateral force to be adjusted is determined, and the two wheels are dimensionality-reduced to focus on the wheel whose adjustment force varies more significantly with the longitudinal slip ratio. Finally, based on the selected wheel and adjustment direction, a proportional correction strategy is used to calculate the required corrected drive torque for each wheel after adjustment. .

7. The method for controlling the steering torque of a distributed drive vehicle in place as described in claim 5, characterized in that, In the step 43, the correction controller The calculated correction drive torque The output value, only the drive torque of one to-be-adjusted object wheel is corrected in one adjustment period, and the output torque of the other three wheels which do not need to be adjusted remains unchanged, and thus the real-time correction is iterated until the vehicle completes the around-center-of-mass turning motion.

8. The distributed drive vehicle spin-on-spot drive torque control method of claim 1, wherein, In the closed-loop automatic control process, there is a feedback loop between the important output and input terminals, and the output quantity has a direct impact on the control process.

9. The method of all-wheel-drive vehicle cornering drive torque control according to claim 1, characterized by, In the closed-loop automatic control process, control is performed based on the information of output changes, which can eliminate deviations caused by external environmental factors and achieve the expected in-situ turning effect around the center of mass.

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