FAULT TOLERANT APPARATUS AND METHOD FOR AN INDEPENDENT CONTROLLED STEERING IN A FOUR WHEEL DRIVE SYSTEM

摘要

The present invention relates to a device and a method to handle failures of independently controlled steering systems in a four wheel drive vehicle. The method includes: a state information transmission step of transmitting state information of steering systems respectively installed in the four wheels of a vehicle; a cornering center coordinate operation step of operating a cornering center coordinate to maintain a cornering radius of the failure time while converging normal lines of an entire wheel to one point if a failure information is included in the state information transmitted by the steering systems; a speed operation step of operating a speed to maintain the cornering radius of the failure time based on the cornering center coordinate operated in the cornering center coordinate operation step; a steering angle operation step of operating a steering angle of a steering system which has no failure based on the cornering center coordinate operated in the cornering center coordinate operation step; and a speed/steering angle control step of transmitting the steering angle operated in the steering angle operation step to the steering system which has no failure, and transmitting the speed operated in the speed operation step to an engine control unit to control the speed and the steering angle of the vehicle. According to the present invention, the device and the method are capable of: stabilizing a vehicle body by actively adjusting the steering angles of the normally operated wheels and the speed of the vehicle depending on the circumstances for failure; and maintaining a constant cornering radius before and after a failure during the process of handling the failure, thereby maintaining cornering performance of the vehicle.