US Patent 8016060 Vehicle

A vehicle has a drive wheel, a seat, an attitude sensor, a balancer movable relative to the seat, a drive control, an attitude control for controlling the attitude of the seat by moving the balancer and a main controller. The main controller calculates a torque T1 for tilting the seat and a torque T2 for moving the balancer forward, compares T1 with T2max (the maximum torque which can be generated by the balancer), and outputs commands to the drive control and the attitude control. When the calculated torque T1 exceeds T2max, responsive to a command for T2max, the attitude control moves the balancer to generate a reaction torque corresponding to T2max, and the main controller supplies an adjustment torque value T3 for the drive wheel. The drive control controls the drive wheel in accordance with the drive command and the adjustment torque value T3.