Stability Control of Mobile Inverted Pendulum Through an Added Movable Mechanism

Mobile inverted pendulums (MIP) are good alternatives for three or four wheels vehicles used in industries or services such as robotic wheelchairs. However, they are statically unstable and controllers are applied to keep their stability. Most controllers developed so far are torque based, that is, they rely on the torques applied to MIPs wheels. In this paper a new control method is proposed in which a movable mechanism is in a form of pendulum is added to the MIP and its position can be varied by a computed torque controller to stabilize system. The controller is developed from the equation of motion of the system derived from the Newtonian method. Simulation results show that it has a better performance than the conventional wheel torque based controller, while the input torque to actuate the movable pendulum remains low.