In-Wheel Motor Torque Control for Collision Avoidance
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Solution Overview
Problem
Conventional vehicle collision avoidance technologies have limited performance as they rely on adjusting damping forces, which is not sufficient for effective obstacle avoidance, especially in electric vehicles equipped with in-wheel systems.
Innovation Solution
A method for controlling vehicle driving using an in-wheel system that determines specific steering and braking sections based on yaw rate, lateral acceleration, and other driving parameters to independently control motor torque, ensuring effective yaw moment and braking force distribution to avoid collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If damping force adjustment is used for collision avoidance, then steering control is achieved, but avoidance performance is limited
Solution Approach 1:
The control system segments the vehicle into four independently controllable wheels, each equipped with its own motor. This allows individual torque control of each wheel, enabling sophisticated collision avoidance maneuvers that go beyond simple damping adjustment. The segmentation of control authority to each wheel provides the flexibility needed for high-performance avoidance while maintaining a relatively simple overall system architecture.
Solution Approach 2:
The system dynamically adjusts torque distribution to each wheel based on real-time vehicle state and obstacle detection. During collision avoidance, the controller dynamically modifies the torque applied to cornering-inside and cornering-outside wheels, enabling adaptive response to varying avoidance scenarios. This dynamic control capability transforms the system from static damping adjustment to active, situation-aware torque management.
2Reliability
If independent wheel torque control is implemented, then braking and steering performance are improved, but system complexity increases
Solution Approach 1:
Each in-wheel motor serves multiple functions: propulsion, steering, and braking. The same motor unit that provides driving force also enables steering torque and regenerative braking, eliminating the need for separate mechanical steering and braking systems. This multi-functionality achieves high braking and steering performance while avoiding the complexity of additional dedicated systems.
Solution Approach 2:
The patent extracts the traditional mechanical power transmission components (transmission, differential gear) by implementing independent motor control at each wheel. This removal of complex mechanical transmission systems simplifies the overall vehicle architecture while maintaining or improving braking and steering performance through direct electronic control of each wheel's motor.
3Device complexity
If in-wheel motors are mounted at each wheel, then space utilization is improved and power transmission complexity is reduced, but control precision requirements increase
Solution Approach 1:
The control system continuously monitors vehicle state parameters (yaw rate, lateral acceleration, steering angle) and uses this feedback to adjust torque distribution to each wheel in real-time. During collision avoidance, feedback from sensors allows the controller to precisely modulate motor torque, achieving the required control precision without mechanical complexity. The feedback loop ensures accurate torque delivery despite the distributed motor architecture.
Data Source
AI summary
A method of controlling driving of a vehicle using an in-wheel system includes: calculating a time to collision (TTC) by dividing a distance between the vehicle and an obstacle located in front of the vehicle by relative velocity; determining whether the vehicle enters a braking avoidance section, based on the calculated TTC; and generating, by a motor mounted in each wheel, braking force of a brake by an amount of shortage of braking force of the brake compared with a demanded braking force if the vehicle enters the braking avoidance section.