A creep control method based on closed loop for electric vehicles

Abstract

A closed-loop creep control method for an electric vehicle, comprising the steps of: 1. Calculating a target vehicle speed based on a pedal opening: the pedal opening is a combined opening value of a brake pedal opening and an accelerator pedal opening. 2. Calculate the target acceleration based on the speed difference: look up the table to obtain the target acceleration through the difference between the target vehicle speed and the actual vehicle speed, and the target acceleration should meet the requirements of creep driving; 3. Based on the Calculate the wheel edge torque required for creep acceleration based on the target acceleration; 4. Calculate the creep drag force based on the actual acceleration: the actual acceleration is calculated by the least squares method through the actual vehicle speed; 5. Calculate the creep torque based on the drag force: creep Row torque is equal to drag plus acceleration wheel torque. The creeping of the whole vehicle can adapt to various complex road conditions and working conditions, such as when encountering slopes, potholes, obstacles, full loads, etc., it can drive normally according to the designed target speed or drivability.

Description

technical field [0001] The invention relates to the field of electric vehicle control, in particular to a closed-loop creep control method for electric vehicles. Background technique [0002] The creeping function is an operation method that can save the driver from frequent operations, free the driver's feet, reduce fatigue, and increase driving comfort under congested road conditions. Generally, the creep function is realized by controlling the output torque corresponding to the target creep speed. [0003] However, in the existing creeping technology, the existing electric vehicle creeping algorithm is generally based on the vehicle speed or the motor speed, setting the creep target vehicle speed or motor speed, and calculating the creep torque through PID. For example, the application number is 201711040153.9, and the invention application titled "Vehicle Hill Creep Control Method and Vehicle" is that when the vehicle performs hill creep control, the creep speed is used...

AI Technical Summary

Problems solved by technology

[0004] However, the above-mentioned technologies are generally limited to a single road condition. During the driving process of the vehicle, various complex road conditions and working conditions will be encountered. This type of algorithm is difficult to adapt to driving in various road conditions and working conditions, such as slopes, potholes, road conditions, etc. Obstacles, full load, etc. cannot drive normally according to the designed target speed or drivability, and the P value and I value of the PID algorithm are difficult to calibrate, because the P value and I value are generally one-dimensional or two-dimensional tables

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