A multi-axle distributed electric drive wheeled vehicle

Abstract

The present application relates to a kind of multi-axle distributed electric drive wheeled vehicle, belong to electric drive vehicle technical field, solve the existing vehicle in vertical obstacle passing, in situ to the problem of poor effect of slow and poor that the wheel slip intervention exists under the large torque low-speed operating condition.The vehicle of the present application comprises: drive anti-skid control system and multiple drive axles, each drive axle includes two wheels and two drive motors, drive anti-skid control system includes: calculation module, obtains the slip ratio difference of each wheel;PI control module, output motor torque command value to drive motor;Fuzzy control module, based on slip ratio difference, PI control module is determined using fuzzy control rule proportion coefficient and integral coefficient;Anti-skid trigger module, make PI control module output motor torque command value.Implementation improves the driving smoothness, stability and controllability effect of vehicle in vertical obstacle passing, in situ steering and other large torque low-speed operating condition.

Description

Technical Field

[0001] This invention belongs to the field of electric drive vehicle technology, and particularly relates to a multi-axle distributed electric drive wheeled vehicle. Background Technology

[0002] Existing multi-axle distributed electric drive wheeled vehicles typically have multiple drive axles, allowing the vehicle to utilize significant driving force, particularly excelling in obstacle climbing. The torque of each wheel in this type of vehicle is independently controllable, greatly enhancing vehicle power and off-road capability. For example, with sufficient motor torque matching, it can traverse vertical obstacles up to 0.8 meters and achieve on-the-spot turning. When performing vertical obstacle traversal and on-the-spot turning, the demands on the drive system are characterized by: high wheel torque demand, low vehicle speed demand, large changes in vehicle posture, and significant changes in wheel load. During these vertical obstacle traversal and on-the-spot turning operations, due to sudden changes in terrain and vehicle posture, the tire traction decreases dramatically, and the tires may even detach from the ground, resulting in a sudden drop in wheel load. Simultaneously, because the driving torque of the wheels is extremely high at this time, the wheel speed increases instantaneously under high torque.

[0003] If the drive motor of a wheel suddenly unloads under high torque output, it may cause faults such as overspeed or overcurrent. Once a fault occurs, the drive motor will lose its torque output capability until the low voltage is cut off to reset the fault. If the wheel speed increases instantaneously, the wheel slip ratio will increase instantly, further reducing the coefficient of friction and thus reducing the torque provided by the wheel to the vehicle. This may cause the vehicle to generate undesirable yaw moment, resulting in loss of vehicle control. In addition, high-speed wheel rotation will cause "burnout," and the resulting rubber debris will further reduce the coefficient of friction, further reducing the driving torque that the tire can provide.

[0004] Therefore, when a vehicle is performing low-speed, high-torque tasks such as passing vertical obstacles or turning on the spot, wheel slippage or spinning may cause the vehicle to run unevenly or become stuck, making it unable to complete the task or even causing the vehicle to lose control.

[0005] Existing vehicle anti-slip drive systems suffer from slow torque reduction and poor effectiveness in low-speed, high-torque driving conditions such as vertical obstacles and stationary turning. Summary of the Invention

[0006] Based on the above analysis, the present invention aims to provide a multi-axle distributed electric drive wheeled vehicle with a drive anti-skid control system to solve the problem that existing vehicles have slow torque reduction and poor effect in wheel slip intervention under high torque and low speed conditions such as passing vertical obstacles and stationary maneuvers.

[0007] This invention provides a multi-axle distributed electric drive wheeled vehicle, having multiple drive axles, each drive axle including two wheels and two drive motors, each wheel being driven by one of the drive motors. The vehicle also includes a drive anti-skid control system, wherein the drive anti-skid control system includes:

[0008] The calculation module calculates the real-time slip ratio of each wheel based on the real-time wheel rotation speed and real-time vehicle speed, and calculates the difference between the target slip ratio and the real-time slip ratio to obtain the slip ratio difference of each wheel.

[0009] The PI control module outputs a motor torque command value F to the drive motor to perform PI control on the output drive torque, thereby reducing the real-time slip rate of the wheel corresponding to the drive motor.

[0010] The fuzzy control module determines the proportional coefficient K of the PI control module based on the slip ratio difference using fuzzy control rules. P and integral coefficient K I ;as well as

[0011] The anti-slip trigger module, when the wheel slip ratio difference is less than the slip ratio difference threshold and the real-time vehicle speed is greater than the vehicle speed threshold, causes the PI control module to output a motor torque command value F to the drive motor of the wheel to perform anti-slip control on the wheel.

[0012] Based on the further improvements to the vehicle, when the slip ratio difference is greater than or equal to the slip ratio difference threshold, or when the real-time vehicle speed is less than the vehicle speed threshold, the anti-slip trigger module causes the PI control module to stop outputting the motor torque command value F to the drive motor of that wheel, so as to stop the drive anti-slip control of that wheel.

[0013] Based on the further improvements to the vehicle described above, the PI control module calculates the motor torque command value F according to the following formula:

[0014] F = F0 + ΔF;

[0015] ΔF=K P e(t)+K I ∫e(t)dt

[0016] In the formula, F0 is the initial motor torque command value, e(t) is the slip ratio difference, t is time, and K P K is the proportionality coefficient. I is the integral coefficient.

[0017] Based on the further improvements to the aforementioned vehicle, the fuzzy control module includes: a positive torque fast fuzzy control submodule.

[0018] When the motor torque command value F is greater than the preset positive torque lower limit value F k At that time, the positive torsion fast fuzzy control submodule uses the positive torsion fast fuzzy control rule to determine the proportional coefficient K. P and integral coefficient K I This reduces the motor torque command value F until it is less than or equal to a preset positive torque lower limit value F. k Or when the anti-slip control of the wheel is stopped.

[0019] Based on the further improvements to the aforementioned vehicle, in the positive torque fast fuzzy control rule, the proportional coefficient K is determined based on the slip ratio difference and the rate of change of the slip ratio difference. P and integral coefficient K I When the rate of change of the slip ratio difference remains constant, the proportionality coefficient K P and integral coefficient K I It increases as the slip ratio difference decreases.

[0020] Based on the further improvements to the aforementioned vehicle, the fuzzy control module also includes: a negative torque pre-fuzzy control submodule.

[0021] When the motor torque command value F is less than or equal to the preset positive torque lower limit value F k At that time, the negative torque pre-fuzzy control submodule outputs the proportional coefficient K using the negative torque pre-fuzzy control rule. P and integral coefficient K I This is done to reduce the motor torque command value F to a negative value, and when the slip ratio difference is close to the target value but has not reached the target value, the motor torque command value F is adjusted to a positive value until the motor torque command value F is greater than the positive torque lower limit value F. k Or when the anti-slip control of the wheel is stopped.

[0022] Based on the further improvements to the aforementioned vehicle, in the negative torque pre-fuzzy control rule, the proportional coefficient K is determined based on the slip ratio difference and the rate of change of the slip ratio difference. P and integral coefficient K I ;

[0023] When the rate of change of the slip ratio difference remains constant, and when the slip ratio difference is less than a negative first preset value, the proportionality coefficient K... P and integral coefficient K I All are positive values ​​and decrease as the slip ratio difference increases; as the slip ratio difference approaches zero from a first preset value, the proportionality coefficient K... P and integral coefficient K I As the slip ratio difference increases, the coefficient decreases from a positive value to a negative value; when the slip ratio difference is zero, the proportionality coefficient K... Pand integral coefficient K I The value is positive; when the slip ratio difference is positive, the proportionality coefficient K is positive. P and integral coefficient K I It is a positive value and decreases as the slip ratio difference increases.

[0024] Based on the further improvements to the vehicle described above, the fuzzy control module calculates the proportional coefficient K of the PI control using the following formula. P and integral coefficient K I :

[0025] K P =K' P +ΔK P

[0026] K I =K' I +ΔK I ;

[0027] Among them, K' P K' I The initial proportional and integral coefficients for PI control; ΔK P ΔK I The proportional coefficient correction value and integral coefficient correction value are determined by fuzzy control rules based on the slip ratio difference of the wheel.

[0028] Based on the further improvements to the vehicle described above, the wheels are respectively connected to the vehicle floor via suspension, the drive motors are all mounted on the vehicle floor, and the drive motors are respectively connected to their corresponding wheels via drive half shafts to drive the wheels to rotate.

[0029] Based on further improvements to the aforementioned vehicle, the vehicle may include two, three, or four drive axles.

[0030] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0031] 1. In this invention, the anti-slip drive system of the vehicle is improved. Specifically, the vehicle slippage situation under driving conditions is accurately identified by the slip ratio difference and vehicle speed. At the same time, the proportional coefficient and integral coefficient of PI control are adjusted by fuzzy control rules, which can realize rapid and stable control of wheel drive torque, so that the wheel slip ratio drops rapidly and stabilizes within a reasonable range. This improves the smoothness, stability and controllability of the vehicle under high torque and low speed driving conditions such as vertical obstacle crossing and stationary driving. It avoids problems such as the vehicle running unevenly or getting stuck due to wheel slippage or spinning, which may prevent the completion of task actions or even loss of vehicle control.

[0032] 2. When the anti-slip drive control system of the present invention performs anti-slip control on the wheel, it adopts a dual fuzzy control rule to adjust the proportional coefficient and integral coefficient of the PI control. Specifically, when the motor torque command value F is greater than the lower limit value of the positive torque F... k At that time, the proportional coefficient and integral coefficient are determined by the positive torque rapid fuzzy control rule, so that the torque decreases rapidly at vehicle speed; when the motor torque command value F is less than or equal to the positive torque lower limit value F k When the proportional and integral coefficients are determined by a positive torque fast fuzzy control rule, a larger negative torque value is pulled back to a positive torque value. In other words, in this embodiment of the invention, when performing drive anti-slip control on the wheel, a dual fuzzy control rule is used to adjust the proportional and integral coefficients of the PI control. Specifically, when the motor torque command value F is greater than the positive torque lower limit value F... k At that time, the proportional coefficient and integral coefficient are determined by the positive torque rapid fuzzy control rule, so that the torque decreases rapidly at vehicle speed; when the motor torque command value F is less than or equal to the positive torque lower limit value F k At that time, the proportional coefficient and integral coefficient are determined by the negative torque fast fuzzy control rule. First, the torque is pulled down to a larger negative torque. When the slip ratio difference is close to the target but has not reached the target, the larger negative torque value is pulled back to correct the positive torque value.

[0033] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0034] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0035] Figure 1 This is a schematic diagram of the drive axle of a multi-axle distributed electric drive wheeled vehicle according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the drive anti-slip control system according to an embodiment of the present invention.

[0037] Figure Labels

[0038] 1. Wheels; 2. Drive motor; 3. Suspension; 4. Drive shaft. Detailed Implementation

[0039] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0040] One embodiment of the present invention discloses a multi-axle distributed electric drive wheeled vehicle, such as... Figure 1 As shown. The vehicle includes: a drive anti-skid control system and multiple drive axles, each drive axle including two wheels 1 and two drive motors 2, each wheel 1 being driven by one drive motor 2. Wherein, as... Figure 2 As shown, the drive anti-slip control system includes: a calculation module, which calculates the real-time slip ratio of each wheel 1 based on the real-time wheel 1 rotation speed and real-time vehicle speed, and calculates the difference between the target slip ratio and the real-time slip ratio to obtain the slip ratio difference of each wheel 1; a PI control module, which outputs a motor torque command value F to the drive motor 2 to perform PI control on the output drive torque, thereby reducing the real-time slip ratio of the wheel 1 corresponding to the drive motor 2; and a fuzzy control module, which determines the proportional coefficient K of the PI control module based on the slip ratio difference using fuzzy control rules. P and integral coefficient K I The anti-slip trigger module, when the slip ratio difference of wheel 1 is less than the slip ratio difference threshold and the real-time vehicle speed is greater than the vehicle speed threshold, causes the PI control module to output a motor torque command value F to the drive motor 2 of wheel 1 to perform drive anti-slip control on wheel 1.

[0041] This invention provides a multi-axle distributed electric drive wheeled vehicle capable of passing vertical obstacles and turning in place.

[0042] Compared with the prior art, the anti-slip drive system of the vehicle in this embodiment of the invention has been improved. Specifically, the vehicle slippage situation under driving conditions is accurately identified by the slip ratio difference and vehicle speed. At the same time, the proportional coefficient and integral coefficient of PI control are adjusted by fuzzy control rules, which can achieve rapid and stable control of the driving torque of wheel 1. This makes the slip ratio of wheel 1 decrease rapidly and stabilize within a reasonable range, thereby improving the smoothness, stability and controllability of the vehicle under high torque and low speed driving conditions such as vertical obstacle crossing and stationary driving. It avoids problems such as the vehicle running unevenly or getting stuck due to wheel 1 slippage or spinning, which may prevent the completion of task actions or even loss of vehicle control.

[0043] Furthermore, fuzzy control is more tolerant of environmental factors and is suitable for changing environments. PI control has strong applicability, independent control parameters, strong robustness, and its control quality is not very sensitive to changes in the controlled object, resulting in high reliability and ease of engineering application.

[0044] In this embodiment of the invention, the real-time slip rate of wheel 1 = (real-time wheel 1 rotation speed - real-time vehicle speed) / real-time vehicle speed. The slip rate difference = target slip rate - real-time slip rate. Wherein, the target slip rate is a preset value.

[0045] In this embodiment of the invention, when the slip ratio difference is less than the slip ratio difference threshold and the real-time vehicle speed is greater than the vehicle speed threshold, wheel 1 is considered to be slipping and anti-skid control needs to be intervened. Otherwise, wheel 1 is considered not to be slipping, or when the vehicle speed is extremely low, the driving intention is considered to be a parking operation, and anti-skid control is not intervened.

[0046] It should be noted that in this embodiment of the invention, the slip ratio difference is the difference between the target slip ratio and the real-time slip ratio, used to reflect how close the real-time slip ratio is to the target slip ratio. Therefore, the slip ratio difference threshold is generally set to a positive or negative value close to zero. Under high torque conditions, when wheel 1 suddenly slips, it generally has a large real-time slip ratio, which exceeds the target slip ratio. In this case, the slip ratio difference is negative, thus less than the slip ratio difference threshold. Simultaneously, in this embodiment of the invention, a vehicle speed threshold is used to determine whether the vehicle is in a driving or stationary state. The vehicle speed threshold is generally a small value to distinguish it from a low-speed driving state.

[0047] Specifically, when the slip ratio difference is greater than or equal to the slip ratio difference threshold, or when the real-time vehicle speed is less than the vehicle speed threshold, the anti-slip trigger module causes the PI control module to stop outputting the motor torque command value F to the drive motor 2 of the wheel 1, so as to stop the drive anti-slip control of the wheel 1.

[0048] Specifically, after the anti-slip control of the wheel 1 is activated, if the slip ratio difference is greater than or equal to the slip ratio difference threshold, it is considered that the wheel 1 has serious slippage. If the real-time vehicle speed is less than the vehicle speed threshold, it is considered that the vehicle speed is extremely low or the wheel 1 suddenly experiences a large external resistance, indicating that the driver intends to brake. Therefore, when the above situations occur, the anti-slip control of the wheel 1 is stopped.

[0049] In one specific embodiment, the wheels 1 are respectively connected to the vehicle floor via suspension 3, and the drive motors 2 are all mounted on the vehicle floor. The drive motors 2 are respectively connected to their corresponding wheels 1 via transmission half shafts 4 to drive the wheels 1 to rotate.

[0050] More specifically, the vehicle includes two, three, or four drive axles. That is, the vehicle can be a two-axle distributed electric drive vehicle, a three-axle distributed electric drive vehicle, or a four-axle distributed electric drive vehicle. Figure 1 The diagram shows the drive axle structure of a three-axle distributed electric drive wheel vehicle.

[0051] In one embodiment, the PI control module calculates the motor torque command value F according to the following formula:

[0052] F = F0 + ΔF;

[0053] ΔF=K P e(t)+K I ∫e(t)dt

[0054] In the formula, F0 is the initial motor torque command value, e(t) is the slip ratio difference, t is time, and K P K is the proportionality coefficient. I is the integral coefficient.

[0055] It should be noted that the initial motor torque command value F0 is generally given by the vehicle's overall control system before driving anti-slip control of wheel 1. When driving anti-slip control of wheel 1 is performed, the drive motor 2 of wheel 1 outputs drive torque according to the corrected motor torque command value F. After driving anti-slip control of wheel 1 is stopped, the drive motor 2 of wheel 1 outputs drive torque according to the initial motor torque command value F0.

[0056] In one embodiment, the fuzzy control module includes: a positive torque fast fuzzy control submodule. When the motor torque command value F is greater than a preset positive torque lower limit value F... k At that time, the positive torsion fast fuzzy control submodule uses the positive torsion fast fuzzy control rule to determine the proportional coefficient K. P and integral coefficient K I This reduces the motor torque command value F until it is less than or equal to a preset positive torque lower limit value F. k Or when the anti-slip control of the wheel 1 is stopped.

[0057] It should be noted that, in this embodiment of the invention, the internal mechanical transmission resistance of the drive motor 2 is taken into account, and the zero torque position is corrected, that is, the motor torque command value F is equal to the lower limit value of the positive torque F. k At that time, the driving torque transmitted to the wheels is zero.

[0058] Specifically, when wheel 1 slips under high torque output conditions such as passing vertical obstacles or turning in place, its speed suddenly increases to a large value, especially when the tire of wheel 1 is close to or has already left the ground. In this embodiment, the positive torque fast fuzzy control submodule determines the proportional coefficient K based on the slip rate difference using positive torque fast fuzzy control rules. P and integral coefficient K I The positive torque fast fuzzy control rule is used to reduce the motor torque command value F, that is, by quickly reducing the drive torque of wheel 1, adjusting the slip ratio of wheel 1, and reducing the speed of wheel 1 to match the vehicle speed.

[0059] Specifically, in the positive torsion fast fuzzy control rule, the proportional coefficient K is determined based on the slip ratio difference and the rate of change of the slip ratio difference. P and integral coefficient K I When the rate of change of the slip ratio difference remains constant, the proportionality coefficient K P and integral coefficient K I It increases as the slip ratio difference decreases.

[0060] In the positive torsion fast fuzzy control rule, the smaller the slip ratio difference, the smaller the proportional coefficient K. P and integral coefficient K I The larger the value, the faster the driving torque of the slipping wheel 1 will be reduced.

[0061] In a preferred embodiment, the fuzzy control module further includes a negative torque pre-fuzzy control submodule. When the motor torque command value F is less than or equal to a preset positive torque lower limit value F... k At that time, the negative torque pre-fuzzy control submodule outputs the proportional coefficient K using the negative torque pre-fuzzy control rule. P and integral coefficient K I This is done to reduce the motor torque command value F to a negative value, and when the slip ratio difference is close to the target value but has not reached the target value, the motor torque command value F is adjusted to a positive value until the motor torque command value F is greater than the positive torque lower limit value F. k Alternatively, stop the anti-slip control of wheel 1.

[0062] Meanwhile, considering that while a larger negative torque can quickly help reduce the speed of wheel 1, if the speed of wheel 1 decreases too quickly, the negative torque may not have enough time to correct to positive torque, and the excessive reduction in wheel 1 speed may lead to stopping or even reversing, increasing safety risks. Therefore, in the negative torque pre-fuzzy control rule, when the slip ratio difference is close to the target but has not reached the target, the motor torque command value F is increased to the positive torque lower limit value F. k The above process corrects the large negative torque value to a positive torque value, thereby eliminating the overshoot problem of the PI control module and allowing the system to quickly enter a stable state.

[0063] In other words, in this embodiment of the invention, when performing anti-slip control on the wheel 1, a dual fuzzy control rule is used to adjust the proportional coefficient and integral coefficient of the PI control. Specifically, when the motor torque command value F is greater than the lower limit value F of the positive torque... k At this time, the proportional and integral coefficients are determined by the positive torque rapid fuzzy control submodule, causing the driving torque of wheel 1 to decrease rapidly. This is achieved when the motor torque command value F is less than or equal to the lower limit of the positive torque F. kAt that time, the proportional coefficient and integral coefficient are determined by the negative torque rapid fuzzy control submodule, and the torque is quickly pulled down to a larger negative torque. At the same time, when approaching the target but not reaching the target, the larger negative torque value is pulled back to correct the positive torque value.

[0064] Specifically, in the negative torque pre-fuzzy control rule, the proportional coefficient K is determined based on the slip ratio difference and the rate of change of the slip ratio difference. P and integral coefficient K I When the rate of change of the slip ratio difference remains constant, and when the slip ratio difference is less than a first preset negative value, the proportionality coefficient K... P and integral coefficient K I All are positive values ​​and decrease as the slip ratio difference increases; as the slip ratio difference approaches zero from a first preset value, the proportionality coefficient K... P and integral coefficient K I As the slip ratio difference increases, the coefficient decreases from a positive value to a negative value; when the slip ratio difference is zero, the proportionality coefficient K... P and integral coefficient K I The value is positive; when the slip ratio difference is positive, the proportionality coefficient K is positive. P and integral coefficient K I It is a positive value and decreases as the slip ratio difference increases.

[0065] In one implementation, the fuzzy control module calculates the proportional coefficient K of the PI control using the following formula. P and integral coefficient K I :

[0066] K P =K' P +ΔK P

[0067] K I =K' I +ΔK I ;

[0068] Among them, K' P K' I The initial proportional and integral coefficients for PI control; ΔK P ΔK I The proportional coefficient correction value and integral coefficient correction value are determined by fuzzy control rules based on the slip ratio difference of wheel 1.

[0069] In this embodiment, the fuzzy control rule first determines the proportional coefficient correction value ΔK based on the slip ratio difference of wheel 1. P and integral coefficient correction value ΔK I Then determine the proportional coefficient K of the PI control module. P and integral coefficient KI .

[0070] Example 1

[0071] This embodiment provides a specific positive torsion fast fuzzy control rule and a negative torsion pre-fuzzy control rule. In fuzzy control, the magnitude of input and output variables is described in linguistic form. In this embodiment, three terms—large, medium, and small—are selected to describe the states of the input and output variables specified by fuzzy control. Adding the two directions (positive and negative) and the zero state, there are a total of seven terms: {negative large, negative medium, negative small, zero, positive small, positive medium, positive large}. Specifically, they are represented by the English letters {NB, NM, NS, ZO, PS, PM, PB}.

[0072] Among them, the proportional coefficient ΔK in the positive torsion fast fuzzy control rule P and integral coefficient ΔK I The correspondence between the change rates of the slip ratio difference e and the slip ratio difference ec is shown in Table 1 and Table 2, respectively.

[0073] Table 1

[0074]

[0075]

[0076] Table 2

[0077]

[0078] Among them, the proportional coefficient ΔK in the negative torsion pre-fuzzy control rule P and integral coefficient ΔK I The correspondence between the change rates of the slip ratio difference e and the slip ratio difference ec is shown in Tables 3 and 4, respectively.

[0079] Table 3

[0080]

[0081] Among them, K P =K' P +ΔK P In Table 3, when ΔK P When it is NB, K P The result is a negative value.

[0082] Table 4

[0083]

[0084]

[0085] Among them, K I =K'I +ΔK I In Table 4, when ΔK I When it is NB, K I The result is a negative value.

[0086] Example 2

[0087] Actual verification was conducted on a 6×6 distributed electric drive vehicle. During bench testing, with the wheels suspended in the air and no ground resistance load, a step signal was applied to a single wheel, suddenly increasing the torque command value by 2000 Nm. The wheel speed instantly increased to 5000 r / min. Using the drive anti-slip control method proposed in this invention, the wheel speed dropped to the designed lower speed value within 5 seconds and remained there, without reverse rotation or severe overshoot. When the vehicle passed a 0.8m vertical obstacle, the anti-slip strategy was fast and effective. During the uphill climb of the first axle, the second axle gradually detached from the ground without significant slippage. When the first axle climbed the wall and the second axle began to climb, the first axle completely detached from the ground, and after slippage, the wheels of the first axle quickly reduced their speed and maintained a slow rotation.

[0088] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0089] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-axle distributed electric drive wheeled vehicle, comprising multiple drive axles, each drive axle including two wheels and two drive motors, each wheel being driven by one of the drive motors, characterized in that, The vehicle also includes a drive anti-skid control system. The drive anti-slip control system includes: The calculation module calculates the real-time slip ratio of each wheel based on the real-time wheel rotation speed and real-time vehicle speed, and calculates the difference between the target slip ratio and the real-time slip ratio to obtain the slip ratio difference of each wheel. The PI control module outputs a motor torque command value F to the drive motor to perform PI control on the output drive torque, thereby reducing the real-time slip rate of the wheel corresponding to the drive motor. The fuzzy control module determines the proportional coefficient of the PI control module based on the slip ratio difference using fuzzy control rules. and integral coefficient The fuzzy control module includes: a positive torque fast fuzzy control submodule, which controls the motor torque command value F when it is greater than a preset positive torque lower limit. At that time, the positive torsion fast fuzzy control submodule uses positive torsion fast fuzzy control rules to determine the proportional coefficient. and integral coefficient This reduces the motor torque command value F until it is less than or equal to a preset lower limit value for positive torque. Or until the anti-slip control of the wheel is stopped; the fuzzy control module also includes: a negative torque pre-fuzzy control submodule, which, when the motor torque command value F is less than or equal to a preset positive torque lower limit value. At that time, the negative torque pre-fuzzy control submodule outputs the proportional coefficient using the negative torque pre-fuzzy control rule. and integral coefficient This is done to reduce the motor torque command value F to a negative value, and when the slip ratio difference is close to the target value but has not yet reached the target value, the motor torque command value F is adjusted to a positive value until the motor torque command value F is greater than the lower limit of the positive torque. Or until the anti-slip control of the wheel is stopped; and The anti-slip trigger module, when the wheel slip ratio difference is less than the slip ratio difference threshold and the real-time vehicle speed is greater than the vehicle speed threshold, causes the PI control module to output a motor torque command value F to the drive motor of the wheel to perform drive anti-slip control on the wheel. When the slip ratio difference is greater than or equal to the slip ratio difference threshold, or when the real-time vehicle speed is less than the vehicle speed threshold, the anti-slip trigger module causes the PI control module to stop outputting the motor torque command value F to the drive motor of that wheel, so as to stop the drive anti-slip control of that wheel.

2. The multi-axle distributed electric drive wheeled vehicle according to claim 1, characterized in that, The PI control module calculates the motor torque command value F according to the following formula: ； In the formula, This is the initial motor torque command value. The difference in slip ratio, where t is time. This is the proportionality coefficient. is the integral coefficient.

3. The multi-axle distributed electric drive wheeled vehicle according to claim 1, characterized in that, In the aforementioned positive torsion fast fuzzy control rule, the proportional coefficient is determined based on the slip ratio difference and the rate of change of the slip ratio difference. and integral coefficient When the rate of change of the slip ratio difference remains constant, the proportionality coefficient and integral coefficient It increases as the slip ratio difference decreases.

4. The multi-axle distributed electric drive wheeled vehicle according to claim 1, characterized in that, In the negative torque pre-fuzzy control rule, the proportional coefficient is determined based on the slip ratio difference and the rate of change of the slip ratio difference. and integral coefficient ; When the rate of change of the slip ratio difference remains constant, and when the slip ratio difference is less than a negative first preset value, the proportional coefficient... and integral coefficient All are positive values ​​and decrease as the slip ratio difference increases; as the slip ratio difference approaches zero from a first preset value, the proportional coefficient... and integral coefficient As the slip ratio difference increases, the coefficient decreases from a positive value to a negative value; when the slip ratio difference is zero, the proportionality coefficient... and integral coefficient The value is positive; when the slip ratio difference is positive, the proportional coefficient is positive. and integral coefficient It is a positive value and decreases as the slip ratio difference increases.

5. The multi-axle distributed electric drive wheeled vehicle according to claim 1, characterized in that, The fuzzy control module calculates the proportional coefficient of PI control using the following formula. and integral coefficient : ； in, , These are the initial proportional and integral coefficients for PI control. , The proportional coefficient correction value and integral coefficient correction value are determined by fuzzy control rules based on the slip ratio difference of the wheel.

6. The multi-axle distributed electric drive wheeled vehicle according to claim 1, characterized in that, The wheels are connected to the vehicle floor via suspension, and the drive motors are all mounted on the vehicle floor. The drive motors are connected to their corresponding wheels via drive half-shafts to drive the wheels to rotate.

7. The multi-axle distributed electric drive wheeled vehicle according to claim 1, characterized in that, The vehicle includes two, three, or four drive axles.

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