A New Control Strategy for Coordinated Control of Ground Vehicle Vertical Dynamics via Control Allocation

Abstract

The scope of this thesis concerns the basic research and development of a coordinated control system for the control of vehicle roll and pitch dynamics using suspension forces as actuators. In this thesis, the following question is explored: How can suspension control (particularly semi-active control) be generalized to control all vertical vehicle dynamics in a coordinated way, and which would ideally be integrable with modern ESC systems? The chosen approach to this problem will be the application of the control allocation methodology for overactuated systems, which makes use of online mathematical optimization in order to realize the desired control law. Background information on vehicle dynamics and modeling, suspension control, control allocation and optimization is presented along with a brief literature review. The coordinated suspension control system (CSC) is designed and simulated. High-level controllers and control allocators are designed and their stability properties are explored. Then, the focus is shifted towards implementation and experimentation of the coordinated control system on a real vehicle. The semi-active actuators are statistically modeled along with the deployed sensors. Both the hardware and software designs are explored. Finally, experiments are designed and results are discussed. Recommendations for future inquiry are given in the conclusion of this work.