Research on an Electric Power Steering System with Active Steering Ability

To introduce a new type of electric power steering system, the structure and working principle of the system were introduced, and the models of the car, the tire and the steering system were established. The assist characteristic of the power steering and the ideal steering ratio were also designed and optimized. At last, the simulation tests were carried out. The double planetary wheel mechanism is the most important component of the system. With this mechanism, the system synthesizes the force or motion from the steering wheel and the motor. So the power steering and a small steering ratio can be provided at a low speed, and the steering ratio can be changed initiatively at a medium or high speed. Whats more, the steering ability still exists when there is a fault in the system. The simulation results show this steering system can effectively improve the steering portability, low-speed sensitivity, and the vehicle handling stability.