Nonlinear control of mobile inverted pendulum

The mobile inverted pendulum (MIP) is a robotic system with nonholonomic constraint due to no-slip condition imposed on the wheel. In particular, it has four configuration variables to be controlled using only two control inputs. In this paper, we propose a nonlinear control strategy to move the MIP from one point to another point in the configuration space while stabilizing the pendulum. The proposed single level controller is designed using a nonlinear co-ordinate transformation which leads to a simple three step navigation design procedure. The proposed controller stabilizes all four configuration variables without switching between the controllers. Simulation results are presented to validate the proposed technique.