New energy commercial vehicle driving force control system and control method

Abstract

The invention discloses a driving force control system for a new energy commercial vehicle. The driving force control system comprises a whole vehicle controller, an ABS / EBS controller, a middle axle motor controller and a rear axle motor controller. The vehicle control unit is electrically connected with the ABS / EBS controller, the middle axle motor controller, the rear axle motor controller and the accelerator pedal; the ABS / EBS controller is electrically connected with the rear axle left wheel speed sensor, the rear axle right wheel speed sensor, the middle axle left wheel speed sensor and the middle axle right wheel speed sensor; the middle axle motor controller is connected with a middle axle left driving motor, and the rear axle motor controller is connected with a rear axle left driving motor. And by comparing the driving efficiency under different driving force distribution coefficients, the optimal torque distribution proportion of each driving motor is found, and the energy consumption of the whole vehicle is reduced.

Description

Technical Field

[0001] This invention belongs to the field of commercial vehicle drive force control, specifically relating to a drive force control system and control method for new energy commercial vehicles. Background Technology

[0002] Current drive force control systems for new energy commercial vehicles map the accelerator pedal to the external characteristic curves of the drive motors, or the sum of the external characteristic curves of multiple drive motors. The maximum drive torque is determined based on the motor speed, and the overall vehicle drive torque is determined based on the accelerator pedal opening percentage and the maximum drive torque at the current speed. For multi-motor drive systems, an average distribution method is generally used to determine the allocation ratio of each drive motor.

[0003] Current drive force control systems determine the required torque for the vehicle based on accelerator pedal opening and vehicle speed, and this torque determination is independent of the vehicle's load. Commercial vehicles exhibit significant differences between empty and fully loaded states; when vehicle speed and accelerator pedal opening are constant, the driving experience varies greatly depending on the load. Furthermore, for vehicles with multiple drive motors, there is no effective solution for how to allocate power among the motors to fully utilize their performance advantages and achieve optimal drive efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a driving force control method for new energy commercial vehicles. This method maps the accelerator pedal opening to a target acceleration and combines driving force control with vehicle weight, achieving the same vehicle acceleration and driving experience at the same accelerator pedal opening. By comparing driving efficiency under different driving force distribution coefficients, the optimal torque distribution ratio of each drive motor is found, thereby reducing overall vehicle energy consumption.

[0005] To address the aforementioned problems in the existing technology, the technical solution adopted by this invention is as follows: A drive force control system for a new energy commercial vehicle includes: a vehicle controller, an ABS / EBS controller, a middle axle motor controller, and a rear axle motor controller; The vehicle controller is electrically connected to the ABS / EBS controller, the middle axle motor controller, the rear axle motor controller, and the accelerator pedal; The ABS / EBS controller is electrically connected to the rear axle left wheel speed sensor, the rear axle right wheel speed sensor, the middle axle left wheel speed sensor, and the middle axle right wheel speed sensor. The middle axle motor controller is connected to the left drive motor of the middle axle, and the rear axle motor controller is connected to the left drive motor of the rear axle.

[0006] The system includes an accelerator pedal, a vehicle controller, two centrally located electric drive axles serving as the middle and rear axles respectively, and an ABS / EBS controller. The middle and rear axles each integrate wheel speed sensors to detect the rotational speed of the left and right wheels. The centrally located electric drive axle contains a drive motor, a motor controller, and a multi-speed transmission. The motor controller controls the drive motor's output torque, which is then reduced and increased in torque by the multi-speed transmission before being used by the differential to drive the left and right wheels.

[0007] A method for controlling the driving force of a new energy commercial vehicle includes the following steps: Step 1: The vehicle controller receives the wheel speed signals from each wheel from the ABS / EBS controller and calculates the vehicle speed and acceleration; Step 2: The vehicle controller receives torque signals from each motor controller and calculates the overall vehicle driving force; Step 3: Calculate the vehicle weight based on the vehicle's acceleration and driving force.

[0008] Step 4: Calculate the total torque required for the vehicle based on the accelerator pedal opening signal and vehicle weight signal.

[0009] The vehicle controller receives the accelerator pedal opening signal, determines the target acceleration of the vehicle based on the accelerator pedal opening percentage and the preset acceleration pedal opening-to-target acceleration mapping curve, and calculates the total required torque of the vehicle based on the target acceleration and vehicle weight.

[0010] Step 5: Obtain the total torque requirement of the entire vehicle.

[0011] Step 6: Determine the maximum drive torque in the current gear. Based on the motor speed at the current vehicle speed, combined with the motor's external characteristic curve and the current gear ratio, determine the maximum drive torque of the middle and rear axles at the current gear and vehicle speed.

[0012] Step 7: Determine whether the maximum driving torque in the current gear is greater than the total required torque; If the maximum driving torque in the current gear is greater than or equal to the total required torque, proceed to step 8; If the maximum driving torque in the current gear is less than the total required torque, proceed to step 9.

[0013] Step 8: Determine the optimal torque distribution based on the total required torque, combined with the power transmission efficiency maps of the middle axle and the rear axle.

[0014] Step 9: Based on the current vehicle speed and the gear ratios of each drive axle, find the gear combination and torque distribution that meet the total torque requirements.

[0015] Step 10: Control the rear axle gear and motor to output torque based on the obtained gear combination and torque distribution.

[0016] The beneficial effects of this invention are as follows: 1. Consistent acceleration at the same accelerator pedal opening improves comfort. The vehicle controller determines the target acceleration of the vehicle based on the accelerator pedal opening percentage and a preset acceleration pedal opening-to-target acceleration mapping curve. Based on the target acceleration and vehicle weight, it determines the vehicle's driving torque, ensuring consistent acceleration under different loads. This reduces the impact of load variations on driver operation, decouples vehicle load and acceleration, and improves driving comfort.

[0017] 2. Distribute the driving torque of each motor according to the optimal driving efficiency to reduce power consumption. By analyzing and comparing the overall transmission efficiency under different driving torque distribution ratios of the middle and rear axles, the optimal torque distribution that meets the torque requirements is found. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the composition of the new energy commercial vehicle drive force control system of the present invention.

[0019] Figure 2 This is the step for determining the total required torque in this invention.

[0020] Figure 3 This invention relates to the torque distribution steps for the drive motor. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and reference numerals.

[0022] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0023] The terms “first,” “second,” “third,” etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example

[0026] like Figure 1 As shown, a new energy commercial vehicle drive force control system includes: a vehicle controller, an ABS / EBS controller, a middle axle motor controller, and a rear axle motor controller; The vehicle controller is electrically connected to the ABS / EBS controller, the middle axle motor controller, the rear axle motor controller, and the accelerator pedal; The ABS / EBS controller is electrically connected to the rear axle left wheel speed sensor, the rear axle right wheel speed sensor, the middle axle left wheel speed sensor, and the middle axle right wheel speed sensor. The middle axle motor controller is connected to the left drive motor of the middle axle, and the rear axle motor controller is connected to the left drive motor of the rear axle.

[0027] The system includes an accelerator pedal, a vehicle controller, two centrally located electric drive axles serving as the middle and rear axles respectively, and an ABS / EBS controller. The middle and rear axles each integrate wheel speed sensors to detect the rotational speed of the left and right wheels. The centrally located electric drive axle contains a drive motor, a motor controller, and a multi-speed transmission. The motor controller controls the drive motor's output torque, which is then reduced and increased in torque by the multi-speed transmission before being used by the differential to drive the left and right wheels. Example

[0028] like Figure 2 and 3 As shown, a method for controlling the driving force of a new energy commercial vehicle includes the following steps: Step 1: The vehicle controller receives the wheel speed signals from each wheel from the ABS / EBS controller and calculates the vehicle speed and acceleration; Step 2: The vehicle controller receives torque signals from each motor controller and calculates the overall vehicle driving force; Step 3: Calculate the vehicle weight based on the vehicle's acceleration and driving force.

[0029] Step 4: Calculate the total torque required for the vehicle based on the accelerator pedal opening signal and vehicle weight signal.

[0030] The vehicle controller receives the accelerator pedal opening signal, determines the target acceleration of the vehicle based on the accelerator pedal opening percentage and the preset acceleration pedal opening-to-target acceleration mapping curve, and calculates the total required torque of the vehicle based on the target acceleration and vehicle weight.

[0031] Step 5: Obtain the total torque requirement of the entire vehicle.

[0032] Steps 1-5 pertain to the calculation of total required torque.

[0033] Step 6: Determine the maximum drive torque in the current gear. Based on the motor speed at the current vehicle speed, combined with the motor's external characteristic curve and the current gear ratio, determine the maximum drive torque of the middle and rear axles at the current gear and vehicle speed.

[0034] Step 7: Determine whether the maximum driving torque in the current gear is greater than the total required torque; If the maximum driving torque in the current gear is greater than or equal to the total required torque, proceed to step 8; If the maximum driving torque in the current gear is less than the total required torque, proceed to step 9.

[0035] Step 8: Determine the optimal torque distribution based on the total required torque, combined with the power transmission efficiency maps of the middle axle and the rear axle.

[0036] In this embodiment, the total required torque of the entire vehicle is achieved by controlling the middle axle drive motor and the rear axle drive motor, which are then distributed to the middle axle drive motor and the rear axle drive motor according to a certain allocation ratio. Assume β is the allocation ratio, a number greater than or equal to 0 and less than or equal to 1, meaning the value of β ranges from [0, 1]. Assume β = 0, 5%, 10%, ..., 100%, and Treq represents the total required torque. The overall efficiency under different allocation ratios is calculated, i.e., the overall efficiency when the middle axle drive torque is 0, 5% Treq, 10% Treq, ..., 100% Treq, and the rear axle drive torque is 100% Treq, 95% Treq, 90% Treq, ..., 0, to find the optimal torque distribution between the middle axle motor and the rear axle motor.

[0037] Step 9: Based on the current vehicle speed and the gear ratios of each drive axle, find the gear combination and torque distribution that meet the total torque requirements.

[0038] Assuming the current vehicle speed is V, the current gear on the middle axle is N, and the current gear on the rear axle is M. First, check if the maximum speeds in gears N-1 and M-1 are greater than the current speed. If the maximum speeds in gears N-1 and M-1 are less than or equal to the current speed, then each motor outputs the maximum drive torque according to the current gear. If the maximum speeds in gears N-1 and M-1 are both greater than the current speed, then determine if the maximum drive torque is greater than the total required torque when the gear combinations for the middle and rear axles are {N-1, M}, {N-1, M-1}, and {N, M-1}, respectively. Assuming the maximum drive torque of {N-1, M} and {N-1, M-1} is greater than the total required torque, find the gear combination and torque distribution with the optimal overall transmission efficiency among the two gear combinations {N-1, M} and {N-1, M-1} using the method shown in 2.2.3.3.

[0039] The drive motor torque distribution method described in steps 6-9.

[0040] Step 10: Control the rear axle gear and motor to output torque based on the obtained gear combination and torque distribution.

[0041] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A drive force control system for new energy commercial vehicles, characterized in that: include: Vehicle controller, ABS / EBS controller, middle axle motor controller, rear axle motor controller; The vehicle controller is electrically connected to the ABS / EBS controller, the middle axle motor controller, the rear axle motor controller, and the accelerator pedal; The ABS / EBS controller is electrically connected to the rear axle left wheel speed sensor, the rear axle right wheel speed sensor, the middle axle left wheel speed sensor, and the middle axle right wheel speed sensor. The middle axle motor controller is connected to the left drive motor of the middle axle, and the rear axle motor controller is connected to the left drive motor of the rear axle.

2. A method for controlling the driving force of a new energy commercial vehicle, characterized in that, Includes the following steps: Step 1: The vehicle controller receives the wheel speed signals from each wheel from the ABS / EBS controller and calculates the vehicle speed and acceleration; Step 2: The vehicle controller receives torque signals from each motor controller and calculates the overall vehicle driving force; Step 3: Calculate the vehicle weight based on the vehicle's acceleration and driving force; Step 4: Calculate the total torque required by the vehicle based on the accelerator pedal opening signal and vehicle weight signal; Step 5: Obtain the total torque requirement of the entire vehicle; Step 6: Determine the maximum driving torque in the current gear. Based on the motor speed at the current vehicle speed, combined with the motor's external characteristic curve and the current gear ratio, determine the maximum driving torque of the middle and rear axles in the current gear and at the current vehicle speed. Step 7: Determine whether the maximum driving torque in the current gear is greater than the total required torque; If the maximum driving torque in the current gear is greater than or equal to the total required torque, proceed to step 8; If the maximum driving torque in the current gear is less than the total required torque, proceed to step 9; Step 8: Determine the optimal torque distribution based on the total required torque, combined with the power transmission efficiency maps of the middle axle and the rear axle. Step 9: Based on the current vehicle speed and the gear ratios of each drive axle, find the gear combination and torque distribution that meet the total torque requirements; Step 10: Control the rear axle gear and motor to output torque based on the obtained gear combination and torque distribution.

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