Double-electric-power cooperative driving control method and system for all-terrain vehicle

Abstract

The invention discloses a double-electric-power cooperative driving control method and system for an all-terrain vehicle. The method comprises the steps that the maximum torque capable of being provided by the whole vehicle is determined; the demand torque of the user is determined, the demand torque of the user is compared with the maximum torque capable of being provided by the whole vehicle, and the minimum value of the two is selected as the real-time demand torque of the whole vehicle; and the real-time required torque of the whole vehicle is distributed to the front motor and the rear motor, so that the driving efficiency of the whole vehicle is optimal. According to the invention, ordered output of double motors can be effectively controlled, the driving efficiency of the whole vehicle is improved, and the dynamic property and safety of the whole vehicle are ensured.

Description

Technical Field

[0001] The present invention relates to the field of front and rear dual-motor drives, and specifically to a dual-electric power collaborative drive control method and system for an all-terrain vehicle. Background Art

[0002] Conventional electric all-terrain vehicles mostly adopt single-motor drives, and the control strategies are relatively simple, mainly focusing on the output regulation of a single power source, without involving the coordination and power distribution of front and rear dual motors. However, with the continuous improvement of the requirements for power performance, passing ability, and handling stability of all-terrain vehicles, the dual-motor drive architecture has gradually attracted attention.

[0003] In the prior art, the patent with the application publication number CN118544831A proposes a torque output control technology based on dual motors. Although it can select different motors and gears to achieve dynamic torque distribution, better balancing the operation efficiency and power requirements of pure electric vehicles, its rear motor has a two-speed reduction, and both the front and rear motors have clutches for power combination and disconnection with the output shaft, which cannot be applied to all-terrain vehicles with single-speed reduction for both front and rear motors. For such all-terrain vehicles, the front and rear motors are always in a combined state with the output shaft and have no clutches, which is a full-time four-wheel drive. For all-terrain vehicles, if the front and rear motors continuously output power and lack effective coordinated control, it will cause interference between motors, increased energy consumption, and even structural damage.

[0004] Therefore, to solve the above problems, a dual-electric power collaborative drive control method and system for an all-terrain vehicle are needed, which can effectively control the orderly output of dual motors, improve the driving efficiency of the whole vehicle, and ensure the power performance and safety of the whole vehicle. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to overcome the defects in the prior art and provide a dual-electric power collaborative drive control method and system for an all-terrain vehicle, which can effectively control the orderly output of dual motors, improve the driving efficiency of the whole vehicle, and ensure the power performance and safety of the whole vehicle.

[0006] The dual-electric power collaborative drive control method for an all-terrain vehicle of the present invention includes:

[0007] Determine the maximum torque that the whole vehicle can provide;

[0008] Determine the required torque of the user, compare the required torque of the user with the maximum torque that the whole vehicle can provide, and select the minimum value of the two as the real-time required torque of the whole vehicle;

[0009] Allocate the real-time required torque of the whole vehicle to the front motor and the rear motor so that the driving efficiency of the whole vehicle reaches the optimum.

[0010] Further, determining the maximum torque that the whole vehicle can provide specifically includes:

[0011] Obtain the maximum torques Nfmcu1 and Nrmcu1 that the front and rear electric drive systems can currently provide;

[0012] Allocate the current maximum output power of the battery pack to the front and rear electric drive systems according to the maximum power ratio of the front and rear electric drive systems, and use the relationship between the power, speed, and torque of the motor to calculate the maximum torques Nfmcu2 and Nrmcu2 that the current battery pack can provide to the front and rear electric drive systems;

[0013] Take the minimum value of Nfmcu1 and Nfmcu2 as Nfmcu3, take the minimum value of Nrmcu1 and Nrmcu2 as Nrmcu3, and add Nfmcu3 and Nrmcu3 to obtain the maximum torque Ntqmax that the vehicle can provide.

[0014] Furthermore, determine the maximum torque Nfmcu2 according to the following formula:

[0015] Nfmcu2 = ((Pbms – (Idc * Vdc)) * A1 * X1 * 9.55) / Rfmcu;

[0016] Where, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC; Vdc is the input voltage of the DCDC; A1 is the proportion of the front motor power; X1 is the output efficiency of the front motor relative to the input power; Rfmcu is the current speed of the front motor.

[0017] Furthermore, determine the maximum torque Nrmcu2 according to the following formula:

[0018] Nrmcu2 = ((Pbms – (Idc * Vdc)) * A2 * X2 * 9.55) / Rrmcu;

[0019] Where, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC; Vdc is the input voltage of the DCDC; A2 is the proportion of the rear motor power; X2 is the output efficiency of the rear motor relative to the input power; Rrmcu is the current speed of the rear motor.

[0020] Furthermore, determine the required torque of the user, specifically including:

[0021] Combine the throttle opening and the current driving and terrain modes to calculate the required torque N of the user 油门 :

[0022] N 油门 = a * x^b;

[0023] Where, a represents the maximum driving torque value of the vehicle under the current driving mode; x represents the percentage of the current throttle opening; b represents the torque change rate.

[0024] Further, distribute the real-time required torque of the whole vehicle to the front motor and the rear motor, specifically including:

[0025] Based on the efficiency MAPs of the front and rear electric drive systems themselves, and through the measured rotational speeds, torques, and efficiency maps of the front and rear electric drive systems, based on the principle of optimal efficiency, formulate a distribution table for the whole vehicle at different rotational speeds and different torques. By looking up the table, at different rotational speeds, distribute the real-time required torque Ntq of the whole vehicle to the real-time output torques of the front and rear electric drive systems according to the distribution table, so that the drive efficiency of the whole vehicle is optimal, ensuring and meeting the driving power requirements of users.

[0026] A dual-electric power collaborative drive control system for an all-terrain vehicle, including a torque determination module and a torque distribution module;

[0027] The torque determination module is used to determine the maximum torque that the whole vehicle can provide, determine the required torque of the user, compare the required torque of the user with the maximum torque that the whole vehicle can provide, and select the minimum value of the two as the real-time required torque of the whole vehicle;

[0028] The torque distribution module is used to distribute the real-time required torque of the whole vehicle to the front motor and the rear motor, so that the drive efficiency of the whole vehicle reaches the optimal.

[0029] Further, determine the maximum torque that the whole vehicle can provide, specifically including:

[0030] Obtain the maximum torques Nfmcu1 and Nrmcu1 that the front and rear electric drive systems can currently provide;

[0031] Distribute the current maximum output power of the battery pack to the front and rear electric drives according to the maximum power ratio of the front and rear electric drive systems, and use the relationship between the power, rotational speed, and torque of the motor to calculate the maximum torques Nfmcu2 and Nrmcu2 that the current battery pack can provide to the front and rear electric drive systems;

[0032] Take the minimum value of Nfmcu1 and Nfmcu2 as Nfmcu3, take the minimum value of Nrmcu1 and Nrmcu2 as Nrmcu3, and add Nfmcu3 and Nrmcu3 to obtain the maximum torque Ntqmax that the whole vehicle can provide.

[0033] Further, determine the maximum torque Nfmcu2 according to the following formula:

[0034] Nfmcu2 = ((Pbms – (Idc * Vdc)) * A1 * X1 * 9.55) / Rfmcu;

[0035] Wherein, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC; Vdc is the input voltage of the DCDC; A1 is the proportion of the front motor power; X1 is the output efficiency of the front motor relative to the input power; Rfmcu is the current speed of the front motor.

[0036] Further, the maximum torque Nrmcu2 is determined according to the following formula:

[0037] Nrmcu2 = ((Pbms – (Idc * Vdc)) * A2 * X2 * 9.55) / Rrmcu;

[0038] Wherein, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC; Vdc is the input voltage of the DCDC; A2 is the proportion of the rear motor power; X2 is the output efficiency of the rear motor relative to the input power; Rrmcu is the current speed of the rear motor.

[0039] The beneficial effects of the present invention are as follows: A dual - electric - power collaborative driving control method and system for an all - terrain vehicle disclosed by the present invention performs overall control on the battery pack, front and rear dual motors, low - voltage loads, etc. by the vehicle control unit. While ensuring the safety of the vehicle battery, torque value distribution is carried out for the front and rear motors, realizing the orderly output of the dual motors, enabling the vehicle to be normally driven, and achieving the optimal driving efficiency of the whole vehicle, ensuring the power performance and safety of the whole vehicle, and reducing the vehicle control consumption. Brief Description of the Drawings

[0040] The present invention will be further described below in conjunction with the drawings and embodiments:

[0041] Figure 1 is a schematic flow diagram of the dual - electric - power collaborative driving control method of the present invention;

[0042] Figure 2 is a schematic diagram of the torque distribution of the front and rear motors of the present invention. Detailed Embodiments

[0043] The following further describes the present invention in conjunction with the accompanying drawings of the specification, as shown in the figure:

[0044] This embodiment discloses a dual - electric - power collaborative driving control method for an all - terrain vehicle, including the following steps:

[0045] S1. Determine the maximum torque that the whole vehicle can provide;

[0046] S2. Determine the required torque of the user, compare the required torque of the user with the maximum torque that the whole vehicle can provide, and select the minimum value of the two as the real - time required torque of the whole vehicle;

[0047] S3. Distribute the real-time required torque of the whole vehicle to the front motor and the rear motor to optimize the driving efficiency of the whole vehicle.

[0048] The present invention comprehensively calculates the maximum torque that the whole vehicle can provide by considering the output capacity of the battery pack, the output capacity of the front and rear electric drive systems, and the consumption of low-voltage loads. Then, it calculates the required torque of the user, compares the required torque with the maximum torque that the whole vehicle can provide, and selects the minimum value as the real-time required torque of the whole vehicle. Then, according to the principle of efficiency priority, the real-time required torque of the whole vehicle is distributed to the front and rear motors. While ensuring the safety of the vehicle battery, the torque values are allocated to the front and rear motors in real time, enabling the vehicle to drive normally and optimizing the driving efficiency of the whole vehicle.

[0049] In this embodiment, in step S1, to determine the maximum torque that the whole vehicle can provide, it specifically includes:

[0050] Inside the vehicle, data sent by the front and rear motor controllers is read in real time through the CAN bus to obtain the maximum torques Nfmcu1 and Nrmcu1 that the front and rear electric drive systems can currently provide; that is, the maximum torques Nfmcu1 and Nrmcu1 can be directly obtained through detection under actual working conditions.

[0051] The current maximum output power of the battery pack is distributed to the front and rear electric drive systems according to the proportion of the maximum power of the front and rear electric drive systems, and by using the relationship between the power, speed, and torque of the motor, the maximum torques Nfmcu2 and Nrmcu2 that the current battery pack can provide to the front and rear electric drive systems are calculated;

[0052] Among them, the current maximum discharge power of the battery pack Pbms = the external voltage of the battery pack * the peak discharge current (both of these parameters are from the data sent by the BMS (Battery Management System) to the CAN bus); for example, Pbms is power-distributed according to the front electric drive A1 = 22% and the rear electric drive A2 = 78% (front motor power: 13KW, rear motor power 45KW, and the front and rear power ratio is 1:3.5);

[0053] Determine the maximum torque Nfmcu2 according to the following formula:

[0054] Nfmcu2 = ((Pbms – (Idc * Vdc)) * A1 * X1 * 9.55) / Rfmcu;

[0055] Among them, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC (direct current conversion system); Vdc is the input voltage of the DCDC. In the peak power distribution ratio of the front and rear motors, A1 is the power ratio of the front motor; X1 is the output efficiency of the front motor relative to the input power. The value of X1 is required to be calculated by using the look-up table method. All efficiency values are retrieved at the same speed, and the value of X1 is obtained by summing and averaging; Rfmcu is the current speed of the front motor.

[0056] Determine the maximum torque Nrmcu2 according to the following formula:

[0057] Nrmcu2 = ((Pbms – (Idc * Vdc)) * A2 * X2 * 9.55) / Rrmcu;

[0058] Among them, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC; Vdc is the input voltage of the DCDC. In the peak power distribution ratio of the front and rear motors, A2 is the power ratio of the rear motor, and A1 + A2 = 100%; X2 is the output efficiency of the rear motor relative to the input power. The value of X2 is required to be calculated by using the look-up table method. All efficiency values are retrieved at the same speed, and the value of X2 is obtained by summing and averaging; Rrmcu is the current speed of the rear motor.

[0059] Take the minimum value of Nfmcu1 and Nfmcu2 as Nfmcu3, take the minimum value of Nrmcu1 and Nrmcu2 as Nrmcu3, and add Nfmcu3 and Nrmcu3 to obtain the maximum torque Ntqmax that the vehicle can provide.

[0060] In this embodiment, in step S2, determining the required torque of the user specifically includes:

[0061] Combined with the throttle opening signal and the current driving and terrain mode. Among them, after the user selects the driving terrain mode through a button or a touch screen, the ICCU (integrated vehicle controller) controls the maximum output torque, the maximum speed, and the torque change rate (the torque change corresponding to the throttle opening change) of the front and rear electric drives through the built-in matching parameters, so as to control the vehicle acceleration performance (related to the maximum torque), the maximum speed (related to the maximum speed), and the throttle response (related to the torque change rate), and match the current driving terrain requirements;

[0062] Then calculate the required torque N of the user 油门 :

[0063] N 油门 = a * x^b;

[0064] Among them, a represents the maximum driving torque value of the whole vehicle in the current driving mode. If it is a dual-motor drive, a is equal to the maximum capacity of the front electric drive + the maximum capacity of the rear electric drive; if it is a single-motor drive, a is equal to the maximum capacity of that drive shaft; x represents the opening percentage of the current throttle; b represents the torque change rate (exponent), and different driving mode curves can be achieved by adjusting the value of b.

[0065] Compare the maximum torque Ntqmax that the whole vehicle can provide with the required torque N of the user 油门 , and take the minimum value of the two as the real-time required torque Ntq of the whole vehicle.

[0066] In this embodiment, in step S3, distributing the real-time required torque Ntq of the whole vehicle to the front motor and the rear motor specifically includes:

[0067] Based on the efficiency MAP of the front and rear electric drive systems themselves, and through the measured speed, torque, and efficiency maps of the front and rear electric drive systems, based on the principle of optimal efficiency, formulate a distribution table for the whole vehicle at different speeds and different torques. The ICCU (Integrated Vehicle Controller) distributes the real-time required torque Ntq of the whole vehicle to the real-time output torques of the front and rear electric drive systems according to the distribution table at different speeds, so that the driving efficiency of the whole vehicle is optimal, ensuring and meeting the driving power requirements of users.

[0068] For example, the distribution table formulated for a certain all-terrain vehicle is as Figure 2 shown. The header row represents the real-time required torque Ntq of the whole vehicle at present, and the header column represents the current speed of the rear motor; the total maximum output torque of the front and rear electric drives is 200 Nm (Nfmcu1 + Nrmcu1), the maximum speed is 10,000 rpm, and the torque response of the electric drive itself is very rapid; if the user switches the current driving terrain mode to the ECO (Economy) mode (oriented towards energy conservation, reducing power consumption as much as possible, and having the longest battery life), the ICCU will limit the total maximum output torque of the front and rear electric drives to 160 Nm according to the received ECO signal, limit the maximum speed to 8,000 rpm, and limit the torque change rate (torque change corresponding to the throttle opening change) to a small value. The purpose is to keep the maximum torque and maximum speed within the efficient range of the electric drive, improve the efficiency of the whole vehicle, and increase the battery life; in addition, it also reduces the acceleration performance (related to the maximum torque), the maximum vehicle speed (related to the maximum speed), and the throttle response (related to the torque change rate) of the whole vehicle, giving users an intuitive feeling of the ECO mode, and can also improve the efficiency of the whole vehicle (the lower the vehicle speed, the smaller the wind resistance of the whole vehicle, and the slower the acceleration and deceleration, the easier it is for the vehicle to maintain a relatively uniform speed stage, reducing energy consumption);

[0069] For example, by calculating that the real-time required torque Ntq of the current whole vehicle is 30 Nm and the rotational speeds of the front and rear motors are 1500 rpm, by checking the distribution table, it can be obtained that the front motor needs to output 6 Nm and the rear motor needs to output 24 Nm.

[0070] The present invention also relates to a dual-electric power collaborative drive control system for an all-terrain vehicle. The control system corresponds to the dual-electric power collaborative drive control method of the all-terrain vehicle in the above embodiment and can be understood as a system for implementing the above control method. The control system includes a torque determination module and a torque distribution module;

[0071] The torque determination module is used to determine the maximum torque that the whole vehicle can provide, determine the required torque of the user, compare the required torque of the user with the maximum torque that the whole vehicle can provide, and select the minimum value of the two as the real-time required torque of the whole vehicle;

[0072] The torque distribution module is used to distribute the real-time required torque of the whole vehicle to the front motor and the rear motor so that the drive efficiency of the whole vehicle reaches the optimum.

[0073] The present invention provides an objective and scientific dual-electric power collaborative drive control method and system. While ensuring the safety of the vehicle battery, it distributes the torque values of the front and rear motors, effectively controls the orderly output of the dual motors, enables the vehicle to drive normally, and the drive efficiency of the whole vehicle reaches the optimum, ensuring the power performance and safety of the whole vehicle and reducing the drive control consumption.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A dual-electric power collaborative drive control method for an all-terrain vehicle, characterized in that: Including: Determine the maximum torque that the whole vehicle can provide; Determine the required torque of the user, compare the required torque of the user with the maximum torque that the whole vehicle can provide, and select the minimum value of the two as the real-time required torque of the whole vehicle; Allocate the real-time required torque of the whole vehicle to the front motor and the rear motor, so that the driving efficiency of the whole vehicle reaches the optimum.

2. The dual-electric-power collaborative drive control method for an all-terrain vehicle according to claim 1, wherein: Determine the maximum torque that the whole vehicle can provide, specifically including: Obtain the maximum torques Nfmcu1 and Nrmcu1 that the front and rear electric drive systems can currently provide; Allocate the current maximum output power of the battery pack to the front and rear electric drive systems according to the maximum power ratio of the front and rear electric drive systems, and use the relationship between the power, speed and torque of the motor to calculate the maximum torques Nfmcu2 and Nrmcu2 that the current battery pack can provide to the front and rear electric drive systems; Take the minimum value of Nfmcu1 and Nfmcu2 as Nfmcu3, take the minimum value of Nrmcu1 and Nrmcu2 as Nrmcu3, and add Nfmcu3 and Nrmcu3 to obtain the maximum torque Ntqmax that the whole vehicle can provide.

3. The dual-electric-power collaborative drive control method for an all-terrain vehicle according to claim 2, wherein: Determine the maximum torque Nfmcu2 according to the following formula: Nfmcu2 = ((Pbms – (Idc * Vdc)) * A1 * X1 * 9.55) / Rfmcu; Wherein, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC; Vdc is the input voltage of the DCDC; A1 is the power ratio of the front motor; X1 is the output efficiency of the front motor relative to the input power; Rfmcu is the current speed of the front motor.

4. The dual-electric-power collaborative drive control method for an all-terrain vehicle according to claim 2, characterized in that: Determine the maximum torque Nrmcu2 according to the following formula: Nrmcu2 = ((Pbms – (Idc * Vdc)) * A2 * X2 * 9.55) / Rrmcu; Wherein, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC; Vdc is the input voltage of the DCDC; A2 is the power ratio of the rear motor; X2 is the output efficiency of the rear motor relative to the input power; Rrmcu is the current speed of the rear motor.

5. The dual-electric-power collaborative drive control method for an all-terrain vehicle according to claim 1, wherein: Determine the required torque of the user, specifically including: Calculate the required torque N of the user based on the throttle opening and the current driving and terrain modes 油门 : N 油门 = a * x^b; Wherein, a represents the maximum driving torque value of the whole vehicle in the current driving mode; x represents the opening percentage of the current throttle; b represents the torque change rate.

6. The dual-electric-power collaborative drive control method for an all-terrain vehicle according to claim 1, wherein: Allocate the real-time required torque of the whole vehicle to the front motor and the rear motor, specifically including: Based on the efficiency MAP of the front and rear electric drive systems themselves, and through the measured speed, torque and efficiency maps of the front and rear electric drive systems, based on the principle of optimal efficiency, formulate a distribution table for the whole vehicle at different speeds and different torques. By looking up the table, at different speeds, allocate the real-time required torque Ntq of the whole vehicle to the real-time output torques of the front and rear electric drive systems according to the distribution table, so that the driving efficiency of the whole vehicle is optimal, and ensure and meet the driving power requirements of the user.

7. A dual-electric power collaborative drive control system for an all-terrain vehicle, characterized in that: Including a torque determination module and a torque allocation module; The torque determination module is used to determine the maximum torque that the whole vehicle can provide, determine the required torque of the user, compare the required torque of the user with the maximum torque that the whole vehicle can provide, and select the minimum value of the two as the real-time required torque of the whole vehicle; The torque distribution module is used to distribute the real-time required torque of the whole vehicle to the front motor and the rear motor, so as to optimize the driving efficiency of the whole vehicle.

8. The dual-electric-power collaborative drive control system of an all-terrain vehicle according to claim 7, characterized in that: Determine the maximum torque that the whole vehicle can provide, specifically including: Obtain the maximum torques Nfmcu1 and Nrmcu1 that the front and rear electric drive systems can currently provide; Distribute the current maximum output power of the battery pack to the front and rear electric drive systems according to the maximum power ratio of the front and rear electric drive systems, and use the relationship between the power, speed and torque of the motor to calculate the maximum torques Nfmcu2 and Nrmcu2 that the current battery pack can provide to the front and rear electric drive systems; Take the minimum value of Nfmcu1 and Nfmcu2 as Nfmcu3, take the minimum value of Nrmcu1 and Nrmcu2 as Nrmcu3, and add Nfmcu3 and Nrmcu3 to get the maximum torque Ntqmax that the whole vehicle can provide.

9. The dual-electric-power collaborative drive control system for an all-terrain vehicle according to claim 8, characterized in that: Determine the maximum torque Nfmcu2 according to the following formula: Nfmcu2 = ((Pbms – (Idc * Vdc)) * A1 * X1 * 9.55) / Rfmcu; Where, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC; Vdc is the input voltage of the DCDC; A1 is the power ratio of the front motor; X1 is the output efficiency of the front motor relative to the input power; Rfmcu is the current speed of the front motor.

10. The dual - power collaborative drive control system for an all - terrain vehicle according to claim 8, wherein: Determine the maximum torque Nrmcu2 according to the following formula: Nrmcu2 = ((Pbms – (Idc * Vdc)) * A2 * X2 * 9.55) / Rrmcu; Where, Pbms is the current maximum discharge power of the battery pack; Idc is the input current of the DCDC; Vdc is the input voltage of the DCDC; A2 is the power ratio of the rear motor; X2 is the output efficiency of the rear motor relative to the input power; Rrmcu is the current speed of the rear motor.

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