Reference Governor-Based Control for Active Rollover Avoidance of Mobile Robots

Rollover is a potential dangerous factor for mobile robots to accomplish a task. However, to our best knowledge, there still lacks a systematic research on the rollover mechanism and active rollover prevention control of mobile robots in the literature. This paper aims to propose a general control framework for rollover prevention of high-speed wheeled mobile robots. First, the lateral dynamics of the robot is modelled and the Load Transfer Ratio (LTR) is used as an index to measure the rollover level. Second, an optimal algorithm-based reference governor (RG) is developed, by which the wheel speed command that satisfies the constraint is induced, retaining the actual LTR within the threshold safety value. In addition, an integral sliding mode (ISM) wheel speed tracking controller is proposed. Lastly, simulations results show that for both trajectory tracking and path following cases, the controlled robot avoids possible rollover successfully.