Chen, L. and Chen, C., "Investigation of Rollover Prevention with Coupling from Driver Yaw Control Using a Scaled Vehicle," SAE Technical Paper 2017-01-1579, 2017, doi:10.4271/2017-01-1579.
The development of an integrated controller for a 4WS/4WD electric bus is investigated. The front wheel steering angle is assumed to be controlled by the human driver. The vehicle is controlled by the rear wheel steering and the yaw moment that can be generated by the differential torque/brake control on each wheel. The high speed cornering is used as the testing scenario to validate the designed controller. Due to the highly nonlinear and the multiple-input and multiple-output nature, the control design is separated into different stages using the hierarchical layer control concept. The longitudinal speed is controlled using a PI controller together with a rule-based speed modification. The other two control inputs, namely the rear wheel steering and the DYC moment, are then designed using the state-dependent Riccati equation method. The designed controllers are evaluated using computer simulations first, and the simulations showed promising results. A scaled electric bus is being constructed to serve as the experimental platform for the designed controllers. In the future the designed controllers will be evaluated with TruckSim simulations and the scaled electric bus experiments.