Operability of joystick-type steering device considering human arm impedance characteristics

In this paper, we propose a new method to improve the operability of a joystick-type steering device, in consideration of the impedance characteristics of human arm. We develop the robot manipulator-based joystick for one-handed operation of the vehicle, where the reaction force of the joystick is controlled by the virtual impedance field tuned to match human arm impedance. Since the longitudinal and lateral movements of the steering system are coupled, the rotational movement of the joystick on the frontal plane was employed to represent the signals from the accelerators and break pedal. We proposed an extended man-machine system formulation, where the damping coefficient, one of important mechanical characteristics, is tuned to match the impedance characteristics of human arm. We investigate the operability when the viscosity coefficient is tuned to match stationary human arm impedance, and time-varying human arm impedance. The usefulness of the proposed method is confirmed through the experiments.