Operational assistance system using 3-DOF joystick with reaction force display to load transfer machine in a plane

This paper is concerned with an operational assistance system to a load transfer machine in a plane such as a manually guided vehicle and a crane without vertical transfer. In the transfer machine, collisions with obstacles are often occurred by the incorrect operations. Therefore, in order to avoid the obstacles to the transfer machine, the operational assistance system using 3-DOF(3 Degree of Freedom) joystick with reaction force display is proposed in this study. The 3-DOF joystick enables operator to manipulate the transfer machine with back-and-forth, left-and-right, and rotation motions. And, it has motors for presenting the reaction force on each axis. In this system, the joystick displays the reaction force which consists of the virtual elastic force and viscosity resistance, which are controlled by PD control gains. By associating the gains in the PD control with the distance between the obstacles and the transfer object, the joystick operation is constrained for avoiding the obstacles. The effectiveness of the proposed operational assistance system is verified by the experiments using the simulator of the transfer machine manipulated by the 3-DOF joystick.