EV Drive Torque Control for Simultaneous Brake and Acceleration
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Solution Overview
Problem
Existing electric vehicle driving systems lack a method to effectively control torque when the accelerator pedal and brake pedal are simultaneously applied, leading to potential overheating and degradation of motor and brake systems, as well as reduced traveling performance and turning stability.
Innovation Solution
A control method that generates a combination of front and rear wheel motor torque commands and a friction braking torque command, allowing for real-time control of the driving system's torque based on the simultaneous input values of the accelerator pedal and brake pedal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the brake override function is operated to apply braking force and remove driving force when the brake pedal is applied while the accelerator pedal is applied, then the durability and safety of the driving system are secured, but the traveling performance and turning stability are significantly degraded
Solution Approach 1:
The patent applies different control strategies to different wheels based on their specific roles. The front wheel motor torque is reduced more significantly than the rear wheel motor torque when pedals are simultaneously applied, creating an asymmetric torque distribution that maintains turning stability while still providing braking effect. This local differentiation resolves the contradiction by allowing the system to prioritize stability in the front while maintaining propulsion in the rear.
Solution Approach 2:
The patent dynamically adjusts the torque distribution between front and rear wheels based on real-time detection of pedal application states. Rather than applying a static brake override function, the system continuously modulates motor torque commands to front and rear wheels independently, enabling adaptive response that maintains both safety and performance under varying driving conditions.
2Loss of time
If the driver steps on the accelerator pedal and the brake pedal at the same time, then the time delay between pedal release and application is reduced for track performance, but an overheating phenomenon of the driving system may occur
Solution Approach 1:
The patent enables continuous torque control during simultaneous pedal application by generating combined torque commands that smoothly transition between acceleration and braking states. Rather than interrupting the driving force completely, the system maintains continuous motor torque output while superimposing braking effects, eliminating time delays and preventing thermal shock to the driving system.
Solution Approach 2:
The patent merges the accelerator pedal input and brake pedal input into a unified torque control strategy. By combining both pedal signals and generating integrated front and rear wheel torque commands, the system achieves seamless transition between acceleration and braking without complete force interruption, reducing thermal stress while maintaining responsive control.
Data Source
AI summary
A method of controlling a torque of a driving system of an electric vehicle includes determining whether a brake pedal is additionally applied at a time when only an acceleration pedal is applied. The method also includes determining an amount of a braking torque corresponding to an amount of the applied brake pedal amount. The method further includes reflecting the amount of the braking torque in one or both of a front wheel torque command and a rear wheel torque command selected according to information indicating a current vehicle driving state and front and rear wheel torque distribution states. The method additionally includes controlling a front wheel motor and a rear wheel motor according to the front wheel torque command and the rear wheel torque command.