Hybrid control of a two-wheeled automatic-balancing robot with backlash feature

This paper investigates the application of hybrid control for an automatic balancing robot system subject to backlash effect. The developed controller is a type of sliding mode controller, refereed to as a switching controller, with respect to different situations i.e., whether the backlash is present in the system operation or not. The switching controller is further weighted by a tilt angle dependent weighting function, in order to enforce the linear controller at higher angles. The proposed solution is implemented and tested on a custom developed robot platform. The extensive tests and comparisons with other solutions show the proposed solution can lead to a very satisfactory anti-backlash performance, with an easy and cost-effective implementation.