A dual-axle drive control method for a vehicle

Abstract

The present invention discloses a dual-axle drive control method for a vehicle, and relates to the field of dual-axle control of vehicles. The method enters a preset mode setting module through a vehicle driving signal, sets the vehicle control mode by using the current driving slope P in the preset mode setting module, and enters a preset fault judgment module, determines whether a corresponding motor is faulty according to a reported signal in the preset fault judgment module, resets the vehicle control mode and the initial value of the torque intermediate variable corresponding to each motor according to the fault state of the motor, and enters a preset mode control module, sets the motor mode and output torque value corresponding to each motor under the control mode by using the accelerator pedal opening A and the initial value of the torque intermediate variable according to the set control mode, and controls the operation of the corresponding motor according to the set motor mode and output torque value, thereby realizing controlling the vehicle to enter different control modes in different scenarios.

Description

Technical Field

[0001] The present invention relates to the field of dual-axis vehicle control, and in particular to a dual-axis driving control method for a vehicle. Background Art

[0002] At present, most three-axle articulated buses use a single motor installed on the second or third axle to drive and control the speed of the vehicle, or use wheel-side motors as drive. The weight of three-axle articulated vehicles is relatively heavy, and single-axle drive and wheel-side drive will cause serious tire wear and vehicle slippage, greatly reducing the life of the tires. At the same time, for different situations such as high power is required during uphill, low power is required during downhill, low power is required when starting on flat roads, and high power is required when the speed increases, the vehicle's adaptability to single-axle drive motors or wheel-side motors is very limited. In addition, when a single-axle motor or wheel-side motor fails, there is no backup or automatic adjustment control solution. Summary of the invention

[0003] In order to solve the problems caused by single-axis drive motors and wheel-side motors and automatically adapt to power requirements under different situations, the present invention proposes a dual-axis drive control method for a vehicle, wherein the vehicle includes, from the front to the rear, a first bridge, a second bridge and a third bridge, wherein the second bridge is equipped with a first motor and the third bridge is equipped with a second motor; the vehicle also includes a controller for obtaining a vehicle driving signal and controlling the motor drive controllers corresponding to the first motor and the second motor according to the vehicle driving signal, so that the vehicle enters a dual-axis control mode or a middle-axis control mode or a rear-axis control mode or a single-dual-axis automatic switching mode; the dual-axis control mode The control mode of the middle axle indicates: controlling the motor drive controller corresponding to the second axle and the third axle to output torque values, and controlling the motor modes of the first motor and the second motor to be working modes; the control mode of the middle axle indicates: controlling the motor drive controller corresponding to the second axle to output torque values, and controlling the motor mode of the first motor to be working modes; the control mode of the rear axle indicates: controlling the motor drive controller corresponding to the third axle to output torque values, and controlling the motor mode of the second motor to be working modes; the single-axle and double-axle automatic switching mode indicates: controlling the control mode of the vehicle to switch between the double-axle control mode, the middle axle control mode and the rear axle control mode; the control method comprises the steps of:

[0004] S1: Real-time acquisition of vehicle driving signals, including: vehicle gear position signal, current vehicle speed V, current driving slope P and accelerator pedal opening A;

[0005] S2: Determine whether the gear position signal is the forward gear. If so, determine whether the current vehicle speed V is equal to 0. If so, proceed to the next step;

[0006] S3: Determine whether the accelerator pedal opening A is equal to 0. If not, enter the preset mode setting module, set the vehicle control mode using the current driving slope P in the preset mode setting module, and enter the preset fault judgment module;

[0007] S4: obtaining the reporting signals of the first motor and the second motor in the preset fault judgment module, judging whether the corresponding motor is faulty according to the reporting signals, resetting the control mode of the vehicle and the initial value of the intermediate torque variable corresponding to each motor according to the fault state of the motor, and entering the preset mode control module;

[0008] S5: In the preset mode control module, according to the set control mode, the motor mode and output torque value corresponding to each motor under the control mode are set using the throttle pedal opening A and the initial value of the torque intermediate variable, the operation of the corresponding motor is controlled according to the set motor mode and output torque value, and return to step S1.

[0009] Furthermore, the preset mode setting module includes:

[0010] S31: Determine whether the current driving slope P is greater than 1. If so, set the vehicle control mode M=1. If not, proceed to the next step. When the value of M is 1, it indicates that the control mode is a dual-axis control mode.

[0011] S32: Determine whether the current driving slope P is less than -2. If so, set the vehicle control mode M=2. If not, proceed to the next step. When the value of M is 2, it indicates that the control mode is the central axis control mode.

[0012] S33: Determine whether the current vehicle speed V is greater than 0 and less than a preset value (5). If so, set the vehicle control mode M=3. If not, proceed to the next step. When the value of M is 3, it indicates that the control mode is the rear axle control mode.

[0013] S34: Set the vehicle control mode M=4, and enter the preset fault judgment module; when the value of M is 4, it means that the control mode is the single-axis and double-axis automatic switching mode.

[0014] Furthermore, the preset fault judgment module includes:

[0015] S41: Obtain the reporting signals of the first motor and the second motor, and determine whether the first motor is faulty according to the reporting signal of the first motor. If so, set the torque intermediate variable N1max1 corresponding to the first motor to 0, the vehicle control mode M to 3, and proceed to the next step; if not, set N1max1 to N1max, where N1max is the preset maximum torque value corresponding to the first motor, and proceed to the next step;

[0016] S42: Determine whether the second motor is faulty based on the reporting signal of the second motor. If so, set the torque intermediate variable N2max1=0 corresponding to the second motor, the vehicle control mode M=2, and enter the preset mode control module; if not, set N2max1=N2max, and enter the preset mode control module; wherein N2max is the preset maximum torque value corresponding to the second motor.

[0017] Furthermore, the preset mode control module includes:

[0018] S51: Determine whether the vehicle mode M is equal to 1. If so, set N1=A*N1max1, S1=1, S2=1, N2=A*N2max1, where: N1 and N2 represent the torque values ​​corresponding to the first motor and the second motor respectively; S1 and S2 represent the motor modes of the first motor and the second motor respectively. When the value is 1, it indicates that the motor mode is the working mode, when the value is 0, it indicates that the motor mode is the standby mode, and when the value is 2, it indicates that the motor mode is the braking mode; control the operation of the corresponding motor according to the set torque value, and return to step S1; if not, go to the next step;

[0019] S52: Determine whether the vehicle mode M is equal to 2. If so, set N2=0, N=N1max1+N2max1, S1=1, S2=0, N1=MIN(A*N, N1max1), control the operation of the corresponding motor according to the set torque value, and return to step S1, where: N is an intermediate variable; if not, go to the next step;

[0020] S53: Determine whether the vehicle mode M is equal to 3. If so, set N1=0, N=N1max1+N2max1, S1=0, S2=1, N2=MIN(A*N, N2max1), control the operation of the corresponding motor according to the set torque value, and return to step S1; if not, go to the next step;

[0021] S54: Determine whether the vehicle mode M is equal to 4. If so, set S1=1, N=N1max1+N2max1, N2=MIN(A*N, N2max1), N1=A*N-N2, S2=1, control the operation of the corresponding motor according to the set torque value, and return to step S1; if not, set N1=0, N2=0, S1=0, S2=0 to control the first motor and the second motor to enter the standby mode, and return to step S1.

[0022] Furthermore, the vehicle driving signal obtained in step S1 also includes: vehicle articulated plate turning angle Q, first bridge left wheel speed X1f, first bridge right wheel speed X1r, second bridge left wheel speed X2f, second bridge right wheel speed X2r, third bridge left wheel speed X3f, third bridge right wheel speed X3r, first motor speed R1, second motor speed R2, first motor power P1, second motor power P2, steering wheel angle Z; each step in the preset mode control module also includes before returning to step S1:

[0023] S61: Determine whether |Q|>|Qmax|-2 is established, if not, proceed to the next step; if so, determine whether Q*Z<0 is established, if so, proceed to the next step, if not, set: N1=0, N2=0, S1=1, S2=1, and proceed to the next step; wherein Qmax represents the maximum allowable turning angle;

[0024] S62: Setting: N1 ′ =N1*(20-X2)*5%, N2 ′ =N2*(20-X3)*5%; and

[0025] Go to the next step, where: N1 ′ With N2 ′ All are intermediate variables;

[0026] X2=

[0027] MAX(|(X2f-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100, |(X2r-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100);

[0028] X3=

[0029] MAX(|(X3f-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100, |(X3r-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100);

[0030] Where X2 and X3 represent the slip rates of the second bridge and the third bridge respectively;

[0031] S63: Determine whether V>Vmax. If not, proceed to the next step. If yes, set N1=0, N2=0, S1=1, S2=1, and proceed to the next step; wherein Vmax represents the preset maximum vehicle speed;

[0032] S64: Setting: N1 = min (N1max, P1*9550 / R1, N1 ′ )、N2=min(N2max,P2*

[0033] 9550 / R2,N2′, controls the operation of the corresponding motor according to the set torque value and returns to step S1.

[0034] Furthermore, the vehicle driving signal obtained in step S1 also includes: brake pedal opening B; in step S2, it is determined whether the current vehicle speed V is equal to 0, if not, it is determined whether the brake pedal opening B is equal to 0, if so, it proceeds to step S3, if not, it is set:

[0035] N1=B*N1max1, S1=2, S2=2, N2=B*N2max1, and enter step S61.

[0036] Furthermore, in the step S3, it is determined whether the accelerator pedal opening A is equal to 0. If so, it is set as follows: N1=0, N2=0, S1=0, S2=0, and the process proceeds to step S61.

[0037] Furthermore, in the step S2, it is determined whether the gear position signal is a forward gear, if not, then the preset gear position determination module is entered; the preset gear position determination module includes:

[0038] S21: Determine whether the gear position signal is neutral. If so, set: N1=0, N2=0, S1=0, S2=0, and enter step S61. If not, enter the next step;

[0039] S22: Determine whether the gear position signal is reverse gear. If not, display the fault through the vehicle fault instrument, set N1=0, N2=0, S1=0, S2=0, and enter step S61; if yes, determine whether the current vehicle speed V is equal to 0. If yes, enter step S23, if not, enter step S24;

[0040] S23: Determine whether the accelerator pedal opening A is equal to 0. If so, set: N1=0, N2=0, S1=1, S2=1, and enter step S61; if not, set: N1=A*N1max, S1=1, S2=1, N2=A*N2max, and enter step S61;

[0041] S24: Determine whether the current vehicle speed V is greater than the preset vehicle speed value (10). If so, set N1=0, N2=0, S1=1, S2=1, and enter step S61; if not, set N1=A*N1max, S1=1, S2=1, N2=A*N2max, and enter step S61.

[0042] Compared with the prior art, the present invention has at least the following beneficial effects:

[0043] (1) The present invention installs a first motor on the second bridge and a second motor on the third bridge, obtains a vehicle driving signal through a controller, and controls the motor drive controllers corresponding to the first motor and the second motor according to the vehicle driving signal, so that the vehicle enters a dual-axle control mode, a middle-axle control mode, a rear-axle control mode, or a single-axle and dual-axle automatic switching mode, thereby avoiding the tire wear problem caused by a single-axle motor and wheel-side motors installed on the left and right rear wheels, thereby greatly reducing the wear on the tires;

[0044] (2) The present invention enters a preset mode setting module through a vehicle driving signal, sets the vehicle control mode in the preset mode setting module using the current driving slope P, and enters a preset fault judgment module, obtains the reporting signals of the first motor and the second motor in the preset fault judgment module, determines whether the corresponding motor is faulty according to the reporting signals, resets the vehicle control mode and the initial value of the torque intermediate variable corresponding to each motor according to the fault state of the motor, and enters a preset mode control module, sets the motor mode and output torque value corresponding to each motor in the control mode according to the set control mode using the accelerator pedal opening A and the initial value of the torque intermediate variable in the preset mode control module, and resets the vehicle control mode and the initial value of the torque intermediate variable according to the set motor mode according to the set motor mode. The operation of the motor corresponding to the output torque value control is set according to the current driving slope P and the fault state of the motor, and the motor mode and output torque value corresponding to each motor in this mode are set in the preset mode control module, so as to realize the function of controlling the vehicle to enter different control modes in different scenarios (uphill, downhill, starting, motor failure, etc.) to adapt to different road conditions or situations. In addition, in each control mode (dual-axle control mode or middle-axle control mode or rear-axle control mode or single-axle and double-axle automatic switching mode), the power is dispersed on different bridges, which avoids the wear of the wheel-side motor due to concentrated force, and enhances the climbing ability, comfort and stability;

[0045] (3) In the preset fault judgment module of the present invention, the control mode of the vehicle is switched according to the fault status of each motor, thereby improving the flexibility of control and solving the problem in the prior art that there is no substitute or automatic adjustment control scheme when a single-axis motor or a wheel-side motor fails;

[0046] (4) Steps S61 to S64 of the present invention implement over-angle protection for the articulated plate, vehicle slip protection, and overspeed protection;

[0047] (5) In the present invention, the vehicle has a dual-axle drive function, that is, two independent centralized drive systems, respectively located on the second bridge and the third bridge of the vehicle. This control method can work with a single-axle drive or a dual-axle drive system at the same time, and has redundancy. When one drive system fails, the other system takes over (i.e., switches the vehicle's control mode). The vehicle can automatically switch control modes during uphill and downhill driving, acceleration, and braking, taking into account the requirements of power, economy, and smoothness, and at the same time has functions such as drive anti-skid protection, overspeed protection, and articulated plate over-angle protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The present invention is a dual-axle drive control structure diagram of a vehicle;

[0049] Figure 2 A flow chart of a dual-axle drive control method for a vehicle;

[0050] Figure 3 A schematic diagram of the vehicle structure. DETAILED DESCRIPTION

[0051] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0052] Embodiment 1

[0053] To reduce tire wear, it automatically adapts to the power requirements in different situations, such as Figures 1 to 3 As shown, the present invention proposes a dual-axle drive control method for a vehicle, wherein the vehicle includes, from the front to the rear, a first bridge, a second bridge and a third bridge, wherein the second bridge is equipped with a first motor and the third bridge is equipped with a second motor; the vehicle also includes a controller for obtaining a vehicle driving signal, and controlling the motor drive controllers corresponding to the first motor and the second motor according to the vehicle driving signal, so that the vehicle enters a dual-axle control mode, a middle-axle control mode, a rear-axle control mode, or a single-dual-axle automatic switching mode; the dual-axle control mode means: controlling the motor drive controllers corresponding to the second bridge and the third bridge to output torque values, and controlling the first The motor mode of the motor and the second motor is a working mode (the working mode means that the motor is in a running state); the middle axle control mode means: the motor drive controller corresponding to the second axle is controlled to output a torque value, and the motor mode of the first motor is controlled to be a working mode; the rear axle control mode means: the motor drive controller corresponding to the third axle is controlled to output a torque value, and the motor mode of the second motor is controlled to be a working mode; the single-axle and double-axle automatic switching mode means: the control mode of the vehicle is controlled to switch between a double-axle control mode, a middle axle control mode and a rear axle control mode; an articulated plate is provided between the second axle and the third axle of the vehicle;

[0054] The present invention installs a first motor on the second bridge and a second motor on the third bridge, obtains a vehicle driving signal through a controller, and controls motor drive controllers corresponding to the first motor and the second motor according to the vehicle driving signal, so that the vehicle enters a dual-axle control mode, a middle-axle control mode, a rear-axle control mode, or a single-axle and dual-axle automatic switching mode, thereby avoiding the tire wear problem caused by a single-axle motor and wheel-side motors installed on the left and right rear wheels, thereby greatly reducing the wear on the tires.

[0055] Figure 1 The battery in the controller is used to provide power to the motor drive.

[0056] The control method comprises the steps of:

[0057] S1: Real-time acquisition of vehicle driving signals, including: vehicle gear position signal, current vehicle speed V, current driving slope P (0 degrees when the vehicle is in a horizontal state, positive when going uphill, and negative when going downhill) and accelerator pedal opening A (value range is 0-100%);

[0058] S2: Determine whether the gear position signal is the forward gear. If so, determine whether the current vehicle speed V is equal to 0. If so, proceed to the next step;

[0059] The vehicle driving signal obtained in step S1 also includes: brake pedal opening B (value range is 0-100%); in step S2, it is determined whether the current vehicle speed V is equal to 0, if not, it is determined whether the brake pedal opening B is equal to 0, if so, it enters step S3, if not, it is set:

[0060] N1=B*N1max1, S1=2, S2=2, N2=B*N2max1, and enter step S61.

[0061] In the step S2, it is determined whether the gear position signal is the forward gear. If not, the preset gear position determination module is entered; the preset gear position determination module includes:

[0062] S21: Determine whether the gear position signal is neutral. If so, set: N1=0, N2=0, S1=0, S2=0, and enter step S61. If not, enter the next step;

[0063] S22: Determine whether the gear position signal is reverse gear. If not, display the fault through the vehicle fault instrument, set N1=0, N2=0, S1=0, S2=0, and enter step S61; if yes, determine whether the current vehicle speed V is equal to 0. If yes, enter step S23, if not, enter step S24;

[0064] S23: Determine whether the accelerator pedal opening A is equal to 0. If so, set: N1=0, N2=0, S1=1, S2=1, and enter step S61; if not, set: N1=A*N1max, S1=1, S2=1, N2=A*N2max, and enter step S61;

[0065] S24: Determine whether the current vehicle speed V is greater than the preset vehicle speed value (10). If so, set N1=0, N2=0, S1=1, S2=1, and enter step S61; if not, set N1=A*N1max, S1=1, S2=1, N2=A*N2max, and enter step S61.

[0066] It should be noted that when it is neither forward gear, neutral gear, nor reverse gear, it means that there is a gear fault and it needs to be displayed on the vehicle fault instrument as a reminder.

[0067] S3: Determine whether the accelerator pedal opening A is equal to 0. If not, enter the preset mode setting module, set the vehicle control mode using the current driving slope P in the preset mode setting module, and enter the preset fault judgment module;

[0068] In the step S3, it is determined whether the accelerator pedal opening A is equal to 0. If so, the following are set: N1=0, N2=0, S1=0, S2=0, and the process proceeds to step S61.

[0069] The preset mode setting module includes:

[0070] S31: Determine whether the current driving slope P is greater than 1. If so (indicating that the vehicle is in an uphill state), set the vehicle control mode M=1. If not, proceed to the next step. When the value of M is 1, it indicates that the control mode is a dual-axis control mode.

[0071] S32: Determine whether the current driving slope P is less than -2 (the limit value of P can be adjusted according to actual conditions). If so (indicating that the vehicle is in a downhill state), set the vehicle control mode M=2. If not, proceed to the next step. When the value of M is 2, it indicates that the control mode is the central axis control mode.

[0072] S33: Determine whether the current vehicle speed V is greater than 0 and less than a preset value (5). If so (indicating that the vehicle is in a starting state), set the vehicle control mode M=3. If not (indicating that the vehicle is in a driving state), proceed to the next step. When the value of M is 3, it indicates that the control mode is the rear axle control mode.

[0073] S34: Set the vehicle control mode M=4, and enter the preset fault judgment module; when the value of M is 4, it means that the control mode is the single-axis and double-axis automatic switching mode.

[0074] S4: obtaining the reporting signals of the first motor and the second motor in the preset fault judgment module, judging whether the corresponding motor is faulty according to the reporting signals, resetting the control mode of the vehicle and the initial value of the intermediate torque variable corresponding to each motor according to the fault state of the motor, and entering the preset mode control module;

[0075] The preset fault judgment module includes:

[0076] S41: Obtain the reporting signals of the first motor and the second motor, and determine whether the first motor is faulty according to the reporting signal of the first motor. If so, set the torque intermediate variable N1max1 corresponding to the first motor to 0, the vehicle control mode M to 3, and proceed to the next step; if not, set N1max1 to N1max, where N1max is the preset maximum torque value corresponding to the first motor, and proceed to the next step;

[0077] S42: Determine whether the second motor is faulty based on the reporting signal of the second motor. If so, set the torque intermediate variable N2max1=0 corresponding to the second motor, the vehicle control mode M=2, and enter the preset mode control module; if not, set N2max1=N2max, and enter the preset mode control module; wherein N2max is the preset maximum torque value corresponding to the second motor.

[0078] In the preset fault judgment module of the present invention, the control mode of the vehicle is switched according to the fault status of each motor, thereby improving the flexibility of control and solving the problem in the prior art that there is no substitute or automatic adjustment control scheme when a single-axis motor or a wheel-side motor fails.

[0079] S5: In the preset mode control module, according to the set control mode, the motor mode and output torque value corresponding to each motor under the control mode are set using the throttle pedal opening A and the initial value of the torque intermediate variable, the operation of the corresponding motor is controlled according to the set motor mode and output torque value, and return to step S1.

[0080] The preset mode control module includes:

[0081] S51: Determine whether the vehicle mode M is equal to 1. If so, set N1=A*N1max1, S1=1, S2=1, N2=A*N2max1, where: N1 and N2 represent the torque values ​​corresponding to the first motor and the second motor respectively; S1 and S2 represent the motor modes of the first motor and the second motor respectively. When the value is 1, it indicates that the motor mode is the working mode, when the value is 0, it indicates that the motor mode is the standby mode, and when the value is 2, it indicates that the motor mode is the braking mode; control the operation of the corresponding motor according to the set torque value, and return to step S1; if not, go to the next step;

[0082] S52: Determine whether the vehicle mode M is equal to 2. If so, set N2=0, N=N1max1+N2max1, S1=1, S2=0, N1=MIN(A*N, N1max1), control the operation of the corresponding motor according to the set torque value, and return to step S1, where: N is an intermediate variable; if not, go to the next step;

[0083] S53: Determine whether the vehicle mode M is equal to 3. If so, set N1=0, N=N1max1+N2max1, S1=0, S2=1, N2=MIN(A*N, N2max1), control the operation of the corresponding motor according to the set torque value, and return to step S1; if not, go to the next step;

[0084] S54: Determine whether the vehicle mode M is equal to 4. If so, set S1=1, N=N1max1+N2max1, N2=MIN(A*N, N2max1), N1=A*N-N2, S2=1, control the operation of the corresponding motor according to the set torque value, and return to step S1; if not, set N1=0, N2=0, S1=0, S2=0 to control the first motor and the second motor to enter the standby mode, and return to step S1.

[0085] The vehicle driving signal obtained in step S1 also includes: the vehicle articulated plate turning angle Q (in this embodiment, the left turning angle is a positive value, and the right turning angle is a negative value), the first bridge left wheel speed X1f, the first bridge right wheel speed X1r, the second bridge left wheel speed X2f, the second bridge right wheel speed X2r, the third bridge left wheel speed X3f, the third bridge right wheel speed X3r, the first motor speed R1 (minimum value is 1), the second motor speed R2 (minimum value is 1), the first motor power P1, the second motor power P2, and the steering wheel angle Z (left turn is positive, right turn is negative); each step in the preset mode control module also includes before returning to step S1:

[0086] S61: Determine whether |Q|>|Qmax|-2 is established, if not, proceed to the next step; if yes, determine whether Q*Z<0 is established, if yes, proceed to the next step, if not, set: N1=0, N2=0, S1=1, S2=1, and proceed to the next step; wherein Qmax represents the maximum allowable turning angle, which is 0 degrees when driving straight; this step is used to implement over-angle protection of the articulated plate;

[0087] S62: Setting: N1 ′ =N1*(20-X2)*5%, N2 ′ =N2*(20-X3)*5%; and

[0088] Go to the next step, where: N1 ′ With N2 ′All are intermediate variables; this step is used to achieve vehicle skidding protection;

[0089] X2=

[0090] MAX(|(X2f-(X1f+X1r) / 2) / ((X1f+X1r)(2)|*100, |(X2r-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100);

[0091] X3=

[0092] MAX (|(X3f-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100, |(X3r-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100);

[0093] Wherein, X2 and X3 represent the slip ratios of the second bridge and the third bridge respectively (in this embodiment, when the slip ratio is greater than 20, 20 is taken, and the value range is 0-20);

[0094] S63: Determine whether V>Vmax. If not, proceed to the next step. If so, set N1=0, N2=0, S1=1, S2=1, and proceed to the next step; wherein Vmax represents the preset maximum vehicle speed; this step is used to implement overspeed protection.

[0095] S64: Setting: N1 = min (N1max, P1*9550 / R1, N1 ′ )、N2=min(N2max,P2*

[0096] 9550 / R2,N2′, controls the operation of the corresponding motor according to the set torque value and returns to step S1.

[0097] Steps S61 to S64 of the present invention realize the over-angle protection of the articulated plate, the vehicle slip protection and the overspeed protection.

[0098] The present invention enters a preset mode setting module through a vehicle driving signal, sets a vehicle control mode in the preset mode setting module using the current driving slope P, and enters a preset fault judgment module, obtains reporting signals of the first motor and the second motor in the preset fault judgment module, determines whether the corresponding motor is faulty according to the reporting signals, resets the vehicle control mode and the initial value of the torque intermediate variable corresponding to each motor according to the fault state of the motor, and enters a preset mode control module, sets the motor mode and output torque value corresponding to each motor in the control mode according to the set control mode using the accelerator pedal opening A and the initial value of the torque intermediate variable in the preset mode control module, and resets the vehicle control mode and the initial value of the torque intermediate variable according to the set motor mode and the output torque value in the preset mode control module. The output torque value controls the operation of the corresponding motor, which sets the vehicle's control mode according to the current driving slope P and the fault status of the motor, and sets the motor mode and output torque value corresponding to each motor in this mode in the preset mode control module, thereby realizing the function of controlling the vehicle to enter different control modes in different scenarios (uphill, downhill, starting, motor failure, etc.) to adapt to different road conditions or situations. In addition, in each control mode (dual-axle control mode, middle-axle control mode, rear-axle control mode, or single-axle and dual-axle automatic switching mode), the power is dispersed on different bridges, thereby avoiding wear of the wheel-side motor due to concentrated force, thereby enhancing climbing ability, comfort and stability.

[0099] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0100] In addition, in the present invention, descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0101] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0102] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A dual-axle drive control method for a vehicle, characterized in that: The vehicle includes, from the front to the rear, a first bridge, a second bridge and a third bridge, wherein a first motor is installed on the second bridge and a second motor is installed on the third bridge; the vehicle also includes a controller for obtaining a vehicle driving signal and controlling the motor drive controllers corresponding to the first motor and the second motor according to the vehicle driving signal, so that the vehicle enters a dual-axis control mode, a middle-axis control mode, a rear-axis control mode or a single- and dual-axis automatic switching mode; the dual-axis control mode indicates: controlling the motor drive controllers corresponding to the second bridge and the third bridge to output a torque value, and controlling the motor modes of the first motor and the second motor to be a working mode; the middle-axis control mode indicates: controlling the motor drive controller corresponding to the second bridge to output a torque value, and controlling the motor mode of the first motor to be a working mode; the rear-axis control mode indicates: controlling the motor drive controller corresponding to the third bridge to output a torque value, and controlling the motor mode of the second motor to be a working mode; the single- and dual-axis automatic switching mode indicates: controlling the control mode of the vehicle to switch between a dual-axis control mode, a middle-axis control mode and a rear-axis control mode; the control method includes the steps of: S1: Real-time acquisition of vehicle driving signals, including: vehicle gear position signal, current vehicle speed V, current driving slope P and accelerator pedal opening A; S2: Determine whether the gear position signal is the forward gear. If so, determine whether the current vehicle speed V is equal to 0. If so, proceed to the next step; S3: Determine whether the accelerator pedal opening A is equal to 0. If not, enter the preset mode setting module, in which the vehicle control mode is set using the current driving slope P, and enter the preset fault judgment module; the preset mode setting module includes: S31: Determine whether the current driving slope P is greater than 1. If so, set the vehicle control mode M=1. If not, proceed to the next step. When the value of M is 1, it indicates that the control mode is a dual-axis control mode. S32: Determine whether the current driving slope P is less than -2. If so, set the vehicle control mode M=2. If not, proceed to the next step. When the value of M is 2, it indicates that the control mode is the central axis control mode. S33: Determine whether the current vehicle speed V is greater than 0 and less than a preset value. If so, set the vehicle control mode M=3. If not, proceed to the next step. When the value of M is 3, it indicates that the control mode is the rear axle control mode. S34: Setting the vehicle control mode M=4, and entering the preset fault judgment module; when the M value is 4, it indicates that the control mode is the single-axis and double-axis automatic switching mode; S4: obtaining the reporting signals of the first motor and the second motor in the preset fault judgment module, judging whether the corresponding motor is faulty according to the reporting signals, resetting the control mode of the vehicle and the initial value of the intermediate torque variable corresponding to each motor according to the fault state of the motor, and entering the preset mode control module; The preset fault judgment module includes: S41: Obtain the reporting signals of the first motor and the second motor, and determine whether the first motor is faulty according to the reporting signal of the first motor. If so, set the torque intermediate variable N1max1 corresponding to the first motor to 0, the vehicle control mode M to 3, and proceed to the next step; if not, set N1max1 to N1max, where N1max is the preset maximum torque value corresponding to the first motor, and proceed to the next step; S42: judging whether the second motor is faulty according to the reporting signal of the second motor, if so, setting the torque intermediate variable N2max1 corresponding to the second motor to 0, the control mode M of the vehicle to 2, and entering the preset mode control module; if not, setting N2max1 to N2max, and entering the preset mode control module; wherein N2max is the preset maximum torque value corresponding to the second motor; S5: in the preset mode control module, according to the set control mode, the motor mode and output torque value corresponding to each motor in the control mode are set using the accelerator pedal opening A and the initial value of the torque intermediate variable, and the operation of the corresponding motor is controlled according to the set motor mode and output torque value, and the process returns to step S1; The preset mode control module includes: S51: Determine whether the vehicle mode M is equal to 1. If so, set N1=A*N1max1, S1=1, S2=1, N2=A*N2max1, where: N1 and N2 represent the torque values ​​corresponding to the first motor and the second motor respectively; S1 and S2 represent the motor modes of the first motor and the second motor respectively. When the value is 1, it indicates that the motor mode is the working mode, when the value is 0, it indicates that the motor mode is the standby mode, and when the value is 2, it indicates that the motor mode is the braking mode; control the operation of the corresponding motor according to the set torque value, and return to step S1; if not, go to the next step; S52: Determine whether the vehicle mode M is equal to 2. If so, set N2=0, N=N1max1+N2max1, S1=1, S2=0, N1=MIN(A*N, N1max1), control the operation of the corresponding motor according to the set torque value, and return to step S1, where: N is an intermediate variable; if not, go to the next step; S53: Determine whether the vehicle mode M is equal to 3. If so, set N1=0, N=N1max1+N2max1, S1=0, S2=1, N2=MIN(A*N, N2max1), control the operation of the corresponding motor according to the set torque value, and return to step S1; if not, go to the next step; S54: Determine whether the vehicle mode M is equal to 4. If so, set S1=1, N=N1max1+N2max1, N2=MIN(A*N, N2max1), N1=A*N-N2, S2=1, control the operation of the corresponding motor according to the set torque value, and return to step S1; if not, set N1=0, N2=0, S1=0, S2=0 to control the first motor and the second motor to enter the standby mode, and return to step S1; The vehicle driving signal obtained in step S1 also includes: vehicle articulated plate turning angle Q, first bridge left wheel speed X1f, first bridge right wheel speed X1r, second bridge left wheel speed X2f, second bridge right wheel speed X2r, third bridge left wheel speed X3f, third bridge right wheel speed X3r, first motor speed R1, second motor speed R2, first motor power P1, second motor power P2, steering wheel angle Z; each step in the preset mode control module also includes before returning to step S1: S61: Determine whether |Q|>|Qmax|-2 is established, if not, proceed to the next step; if so, determine whether Q*Z<0 is established, if so, proceed to the next step, if not, set: N1=0, N2=0, S1=1, S2=1, and proceed to the next step; wherein Qmax represents the maximum allowable turning angle; S62: Setting: N1 ′ =N1*(20-X2)*5%, N2 ′ =N2*(20-X3)*5%; and Go to the next step, where: N1 ′ With N2 ′ All are intermediate variables; X2＝ MAX(|(X2f-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100, |(X2r-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100); X3＝ MAX(|(X3f-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100, |(X3r-(X1f+X1r) / 2) / ((X1f+X1r) / 2)|*100); Where X2 and X3 represent the slip rates of the second bridge and the third bridge respectively; S63: Determine whether V>Vmax. If not, proceed to the next step. If yes, set N1=0, N2=0, S1=1, S2=1, and proceed to the next step; wherein Vmax represents the preset maximum vehicle speed; S64: Setting: N1 = min (N1max, P1*9550 / R1, N1 ′ )、N2=min(N2max,P2* 9550 / R2,N2 ′ ), control the operation of the corresponding motor according to the set torque value, and return to step S1.

2. The dual-axle drive control method for a vehicle according to claim 1, characterized in that: The vehicle driving signal obtained in step S1 also includes: brake pedal opening B; in step S2, it is determined whether the current vehicle speed V is equal to 0, if not, it is determined whether the brake pedal opening B is equal to 0, if so, it enters step S3, if not, it is set: N1=B*N1max1, S1=2, S2=2, N2=B*N2max1, and enter step S61.

3. The dual-axle drive control method for a vehicle according to claim 2, characterized in that: In the step S3, it is determined whether the accelerator pedal opening A is equal to 0. If so, the following are set: N1=0, N2=0, S1=0, S2=0, and the process proceeds to step S61.

4. The dual-axle drive control method for a vehicle according to claim 3, characterized in that: In the step S2, it is determined whether the gear position signal is the forward gear. If not, the preset gear position determination module is entered; the preset gear position determination module includes: S21: Determine whether the gear position signal is neutral. If so, set: N1=0, N2=0, S1=0, S2=0, and enter step S61. If not, enter the next step; S22: Determine whether the gear position signal is reverse gear. If not, display the fault through the vehicle fault instrument, set N1=0, N2=0, S1=0, S2=0, and enter step S61; if yes, determine whether the current vehicle speed V is equal to 0. If yes, enter step S23, if not, enter step S24; S23: Determine whether the accelerator pedal opening A is equal to 0. If so, set: N1=0, N2=0, S1=1, S2=1, and enter step S61; if not, set: N1=A*N1max, S1=1, S2=1, N2=A*N2max, and enter step S61; S24: Determine whether the current vehicle speed V is greater than the preset vehicle speed value. If so, set N1=0, N2=0, S1=1, S2=1, and enter step S61; if not, set N1=A*N1max, S1=1, S2=1, N2=A*N2max, and enter step S61.

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