Neural-net tuned PID control of a parallel type mechanism with force feedback for virtual reality applications

Abstract

This paper explores a new type of a parallel platform human interface manipulator based on virtual reality (VR) for mechanism design applications. A motion control of a six-link robot manipulator actuated by three active joints is presented here. The main components of the system include a user interface, a software simulating the environment, and a VR control system. The model of the VR system is built based on a force feedback behavior that enables the operator to feel the actual force feedback from the virtual environment just as he/she would from the real environment. A primary stabilizing controller is used to develop a haptic interface device where realistic simulations of the dynamic interaction forces between a human operator and the simulated virtual object/mechanism is required. The stability and performance of the system are studied and analyzed based on the Nyquist stability criterion. Experiments on cutting virtual clay are used to validate the theoretical developments. It was shown that the experimental and theoretical results are in good agreement.