Creep control method and system for pure electric vehicle without ramp sensor

Abstract

The invention discloses a creep control method and system for a pure electric vehicle without a ramp sensor. The method comprises the following steps: acquiring a vehicle driving condition and a driving road condition; when the vehicle travels on the flat road, obtaining a closed-loop control torque value Tq1, and controlling the creep torque value of the vehicle to be the closed-loop control torque value Tq1; and when the vehicle travels on the slope, obtaining a closed-loop control torque value Tq1 and an open-loop control torque value Tq2, and controlling the creep torque value of the vehicle to be the closed-loop control torque value Tq1. According to the creep control method for the pure electric vehicle without the ramp sensor, an open-loop and closed-loop combined method is adopted,the vehicle is controlled to stably run on a flat road in a creep state and can also be slowly started on a ramp, the control effect of the vehicle is improved, and the driving experience feeling isimproved.

Description

technical field [0001] The invention relates to the technical field of vehicle control, in particular to a creep control method and system for a pure electric vehicle without a slope sensor. Background technique [0002] When the handbrake is not pulled up, in the power gear, and the accelerator pedal and brake pedal are not stepped on, the vehicle, especially the pure electric vehicle, will enter a creeping state: the vehicle controller controls the vehicle to drive at a certain speed, generally less than 10km / h. At present, its control methods are mainly divided into two categories: one is closed-loop control, VCU collects current vehicle status signals such as vehicle speed, uses PID algorithm to calculate the requested torque with creeping vehicle speed as the target value, and the motor controller (MCU) controls the output of the motor. According to the torque, the vehicle speed is adjusted through a closed loop; or the VCU sends the speed mode command and the target ve...

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Problems solved by technology

[0004] However, these two types of methods have the following disadvantages: both require a lot of calibration and debugging work, occupying a lot of manpower and material resources; when the vehicle, especially the commercial vehicle, is in different states, such as full load, half load or empty load, or the road has a certain slope The control effect of the above two methods is not ideal under working conditions such as high road and high wind speed; the PID controller has a certain amount of overshoot and vibration, which affects the driving experience to a certain extent.

Through the traditional PID (PID regulating proportional, integral, differential) adjustment, the calibration workload is heavy and the work is cumbersome

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