EV Motor Torque Compensation During Brake Idle Stroke
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Solution Overview
Problem
Electric vehicles may slide during a brake idle stroke due to insufficient braking force, posing safety hazards, as the pressure of the brake master cylinder does not accurately reflect the opening degree of the braking pedal, leading to ineffective suppression of sliding.
Innovation Solution
A torque compensation method where the vehicle control module determines the sliding state and controls the motor to output a compensation torque based on the real-time pressure of the brake master cylinder, adjusting the torque according to different pressure levels to prevent sliding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the brake master cylinder pressure is used to determine braking force, then the braking control can be simplified, but the pressure does not accurately reflect the opening degree of the braking pedal, leading to sliding during brake idle stroke
Solution Approach 1:
The patent introduces an intermediary calculation process that combines brake master cylinder pressure with vehicle speed and braking pedal opening degree to determine the actual braking force. This intermediary step allows the system to use simple pressure sensing while achieving precise braking force determination through computational synthesis of multiple parameters.
Solution Approach 2:
The patent transforms the single parameter (brake master cylinder pressure) into multiple parameters (pressure, vehicle speed, braking pedal opening degree) to comprehensively determine braking force. By changing from a single-parameter to multi-parameter control system, the patent resolves the contradiction between simplicity and precision.
2Reliability
If the braking force is increased to prevent sliding, then the vehicle stability improves, but the braking system may cause wheel lockup or excessive stopping force
Solution Approach 1:
The patent implements a feedback mechanism where the control module continuously monitors vehicle speed, braking pedal opening degree, and brake master cylinder pressure, then dynamically adjusts the compensation torque. This closed-loop feedback ensures that braking force is precisely controlled to prevent both sliding and wheel lockup by constantly comparing actual conditions with target braking force.
Solution Approach 2:
The patent employs dynamic braking force adjustment where the compensation torque varies continuously based on real-time vehicle conditions. Instead of applying fixed braking force, the system dynamically modulates the motor torque to match the precise braking force needed at each moment, preventing both sliding and excessive stopping force.
3Reliability
If the compensation torque is increased to suppress sliding, then the anti-sliding effect improves, but the motor control complexity increases
Solution Approach 1:
The patent makes the motor serve multiple functions: it acts as both the drive motor during normal operation and as a compensation device during brake idle stroke. By programming the existing motor controller to detect sliding conditions and provide compensation torque, the patent avoids adding separate anti-sliding hardware while achieving reliable sliding suppression through multi-functional use of the motor system.
Data Source
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AI summary
This application provides a torque compensation method for a vehicle, a torque compensation apparatus of a vehicle, and an associated computer-readable storage medium. The torque compensation method includes: when a vehicle control module determines that the vehicle is in a sliding state during a brake idle stroke, obtaining, by the vehicle control module, a pressure of a brake master cylinder of the vehicle, and controlling a motor of the vehicle based on the pressure of the brake master cylinder to output a compensation torque. In this application, a range of the brake idle stroke of the vehicle can be precisely determined, so as to control the motor of the vehicle to output the compensation torque in a timely manner, thereby effectively suppressing sliding during the brake idle stroke of the vehicle and ensuring safe driving.