Chapter 8 - Vehicle Dynamics with Active Motion Controls

Abstract

This chapter deals with vehicle motion when rear wheel steering is added to a conventional vehicle with front wheel steer. It involves studying the vehicle motion and the basic control concept of active front and rear steer in response to the steering wheel. It is assumed that the front wheels have no mechanical connection to the steering wheel. There are many possible methods for simultaneous steer of both the front and rear wheels. The simplest method is considered first, where the rear wheel steer is proportional to the front wheel steer. If the rear wheel is steered in response to the front wheel the sideslip angle of the center of gravity is always equal to zero. This ensures that the vehicle traveling direction and heading direction are always the same. The sideslip angle of vehicle center of gravity can be made equal to zero by steering the rear wheel an amount equal to the sum of the front wheel steer angle and yaw rate proportional.