Torque Vectoring Control for Split-μ Wheel Slip Response
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Solution Overview
Problem
Conventional traction control systems (TCS) and electronic stability control (ESC) face challenges in effectively suppressing initial wheel slip on split road surfaces due to the slow response of hydraulic braking devices, leading to unstable vehicle control and a less-than-smooth driving experience.
Innovation Solution
A traction control method for vehicles equipped with a torque vectoring apparatus, which includes determining whether a split-μ situation exists and controlling the torque vectoring motor to adjust the driving forces on left and right wheels, thereby stabilizing the vehicle's launching response and linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydraulic braking devices are used for traction control, then braking force can be applied to prevent wheel slip, but the response speed is slow leading to unstable vehicle control
Solution Approach 1:
The patent replaces the hydraulic braking system with an electric braking system. The electric brake actuator directly converts electrical signals into braking force without the delays inherent in hydraulic fluid transmission. This substitution enables faster response speed while maintaining reliable vehicle control stability, directly resolving the contradiction between response speed and control stability.
Solution Approach 2:
The patent introduces an electric brake actuator as an intermediary component between the control system and the brake mechanism. This actuator serves as a mediator that translates control signals into mechanical braking force with minimal delay, improving response speed while ensuring stable vehicle control through precise force application.
2Productivity
If torque is applied to drive wheels on split road surface, then vehicle launching is enabled, but torque is transmitted to the wheel on lower friction surface causing excessive wheel slip
Solution Approach 1:
The patent applies different braking forces to different wheels based on their individual slip conditions. The control system independently adjusts the braking force on each wheel, allowing the wheel on the low-friction surface to receive appropriate braking intervention while the other wheel maintains propulsion. This localized control enables vehicle launching while preventing excessive wheel slip on the slippery surface.
Solution Approach 2:
Instead of trying to increase torque to improve launching capability, the patent applies braking force to the slipping wheel to counteract the harmful slip effect. This inverted approach of applying opposing force (braking) to prevent the harmful phenomenon (excessive slip) while maintaining overall launching capability through differential control.
Data Source
AI summary
A traction control method for a vehicle provided with a torque vectoring apparatus including a torque vectoring motor includes determining, by first and second controllers, whether a current situation is a split-μ situation occurring when the vehicle is driven on a split road surface, based on vehicle driving information collected in the vehicle, determining and creating, by the second controller, a target speed for control of a slip wheel speed when both controllers determine the split-μ situation, and transmitting the target speed from the second controller to the first controller, generating, by the first controller, a torque command for the torque vectoring motor for slip wheel speed control to follow the target speed received from the second controller, and controlling, by the first controller, operation of the torque vectoring motor in accordance with the torque command.