Electric vehicle energy recovery braking parking control method

Abstract

The invention relates to an electric vehicle energy recovery brake parking control method. The method comprises the steps of I when an electric vehicle is in an electric vehicle energy recovery brakeparking state, enabling a vehicle control unit to collect vehicle accelerator and brake pedal signals, and analyze and generate a corresponding internal torque instruction; II adjusting the internal torque instruction generated in the step I through an energy recovery attenuation coefficient y; III performing torque removal processing on the internal torque instruction adjusted in the step II to generate a motor torque instruction; and IV sending the motor torque instruction in the step III to a motor controller through CAN communication, and enabling the motor controller to control a motor toexecute corresponding torque output. According to the invention, the energy recovery attenuation coefficient y is increased in time to adjust the internal torque instruction before torque instructiontorque removal processing, so that the adjusted internal torque instruction curve can approach to the curve of the motor torque instruction, and the torque removal is quicker.

Description

technical field [0001] The invention relates to the field of electric vehicle motor braking, in particular to a control method for electric vehicle energy recovery braking and parking. Background technique [0002] During the braking energy recovery process of a pure electric bus, the vehicle controller analyzes the driver's braking intention, and sends the corresponding electric braking torque command to the motor controller through CAN communication, and the motor controller executes the corresponding torque output. In the process of the vehicle from braking to stopping, there must be a process of removing the electric braking torque to prevent the motor from still outputting negative torque when the vehicle stops, causing the vehicle to generate driving force in the opposite direction. [0003] The traditional pure electric bus braking torque control mainly adopts a fixed energy recovery attenuation curve, mainly that is, the energy recovery attenuation start speed, energ...

AI Technical Summary

Problems solved by technology

This control method has two disadvantages: 1. If the vehicle is equipped with a high-torque motor, the vehicle needs to start untwisting at a higher speed; if the vehicle is equipped with a small-torque motor, the vehicle can start to untwist at a lower speed

However, if the initial vehicle speed of energy recovery attenuation is set too high, the low-speed energy recovery capability of the low-speed motor cannot be fully utilized; if the initial vehicle speed of energy recovery attenuation is set too low, the high-torque motor may not be able to full withdrawal

2. If the untwisting trend of the energy recovery attenuation curve is slow, the motor may not be able to fully untwist when the vehicle brakes in an emergency; Ride comfort and energy recovery performance

The starting speed of the energy recovery attenuation is set too high. Although it can ensure that the motor has no residual torque when the brake is stopped, the vehicle cannot fully utilize the motor capacity below 20 km / h due to the premature attenuation of the torque, which is not conducive to driving performance. consumption reduction

Moreover, this method does not consider the untwist time that motors with different peak torques can achieve, and uniformly sets the starting speed of energy recovery attenuation, which cannot make full use of the energy recovery capabilities of motors with different torques.

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