Interfacing a Force-Feedback Joystick with a Hydraulic Robot Arm

Abstract

The interfacing of haptic and hydraulic systems produce great benefits and the application of these systems will increase over time. This research presents one approach to successfully interfacing a force-feedback joystick with a hydraulic robot arm. In order to complete this task, two mild-stones have to be achieved. First, an expression representing the value of the displayed force needs to be determined. Secondly, a real-time interface has to exist between the force-feedback joystick and the hydraulic arm. The method chosen to determine the displayed force is based on Lagrange-Euler recursive equations for generalized linkages. These equations represent the system dynamics and can be used to determine the desired drive efforts. The calculated drive effort combined with an experimentally modeled frictional effect is then used to compute the necessary display force. The force-feedback joystick chosen was an impulse engine 2000. From this research, it can be observed that modeling the effect of friction definitely improves the accuracy of the display force. It also can be inferred that using Lagrange-Euler to determine the display force is not a desirable method for mass production of hydraulic force-feedback systems.