Four-Motor Torque Fluctuation Control for Low-μ Cornering Feedback
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Solution Overview
Problem
Existing vehicle control systems fail to provide adequate driver information during curve traveling on low-friction-coefficient roads, leading to reduced grip and increased risk of spinning and understeer.
Innovation Solution
A vehicle control apparatus that independently controls four-wheel motors by applying higher fluctuation torques to outer-wheel motors during turns, enhancing driver information through cyclic torque fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If uniform fluctuation torques are applied to all wheels, then the control system is simple, but driver information about reduced grip during turns is insufficient
Solution Approach 1:
The patent applies different fluctuation torque gains to different wheels based on their position during turning. Specifically, outer wheels receive higher fluctuation torque gains than inner wheels, creating localized quality differences that provide drivers with tactile feedback about grip conditions during turns without requiring complex system-wide changes
Solution Approach 2:
The control system segments the four wheels into different groups (outer wheels and inner wheels) during turning, applying different fluctuation torque strategies to each segment. This segmentation allows targeted information delivery to the driver about specific wheel grip conditions while maintaining overall system manageability
2Loss of information
If higher fluctuation torques are applied to outer wheels during turns, then driver awareness of reduced grip is improved, but the risk of wheel slip increases
Solution Approach 1:
The patent dynamically adjusts fluctuation torque gains based on vehicle operating conditions, specifically detecting when the vehicle is turning and automatically applying higher gains to outer wheels only during these conditions. This dynamic adaptation allows the system to provide necessary driver information while maintaining reliability by applying fluctuations only when and where needed
Solution Approach 2:
The system uses feedback from vehicle state detection (turning conditions) to modulate the fluctuation torque application. By continuously monitoring vehicle operation and adjusting fluctuation gains accordingly, the system provides driver awareness information while maintaining wheel grip stability through condition-based control
Data Source
AI summary
A vehicle control apparatus configured to control a vehicle including four wheels and four motors provided to the respective four wheels. The vehicle control apparatus includes a control processor. The control processor is configured to: acquire target torques of the respective wheels by adding fluctuation torques of the respective wheels to requested torques of the respective wheels, the fluctuation torques each fluctuating cyclically, the requested torques corresponding to an accelerator operation amount; perform torque control of the motors, based on the target torques of the respective wheels; and when detecting that the vehicle is making a turn, set a first gain of each of the fluctuation torques to be applied to respective outer-wheel motors out of the four motors to a higher value than a second gain of each of the fluctuation torques to be applied to respective inner-wheel motors out of the four motors.