Tip-up and stabilization of an autonomous four-wheeled vehicle

Abstract

An instrumented four-wheeled robot was constructed to investigate steering-induced tip-up and rollover of four-wheeled vehicles, and the possibility of stabilizing and driving while balanced on two wheels. Using an analogy to a cart-pole controller, an energy shaping controller was developed to drive the vehicle's roll energy to a fixed value and stabilize the vehicle in a tipped-up position. The controller was implemented on experimental hardware, which included an ARM7-based FEZ Domino microcontroller and a MicroStrain 3DM-GX2 inertial measurement unit. Data logged during experimental trials were analyzed in MATLAB to assess the stability and effectiveness of the controller. Experimental results indicate the controller is capable of driving the vehicle to the tipped-up balancing position. The addition of a steering angle sensor and tachometer are suggested to improve the effectiveness of the controller.