Wheeled inverted-pendulum-type personal mobility robot with collaborative control of seat slider and leg wheels

In this paper, we describe the motion control for a personal mobility robot (PMR) that is a wheeled inverted pendulum vehicle. The structure of the PMR consists of a seat slider and two independent leg wheels attached on either side; this enables the driver to mount the PMR by changing the vehicle's height from the squatting position to the standing position. In addition, this structure can control the roll posture of the vehicle and thus prevent the PMR from toppling over because of a short tread. The seat slider facilitates a stable pitch posture with suitable control. We present an overview of the kinematic structure, three-dimensional dynamics model, and control method based on the linear-quadratic regulator (LQR), in order to achieve stable control of the PMR.