Visual Servoing Based Synced Motion Control of an Eight Bar Parallel Manipulator

Abstract

Recently, there has been a significant recognition of user centered designs for interactive robotic systems. These computer-based activity-promoting interactive systems have proven to be potential therapeutic tools for exercise, injury, postural, and vestibular rehabilitation and control. This research focuses on working of such a user centered interactive system. This aim of the study is to design a phase and frequency controller based on visual servoing for a parallel manipulator to synchronize its motion with the head of a user walking or running on a treadmill. The synced motion of the platform would then enable the user to comfortably view a screen that will seem stationary to the user while running on treadmill. The purpose is to minimize relative motion between its end-effector that holds the device, and face of running user. The research work is divided into three modules: image processing, mathematical modeling, and interfacing of both modules. The platform is controlled based on visual feedback from fixed camera for face of user, and feedback from robotic manipulator for position of end-effector. The presented mechanical design and control strategy are tested for different users running with distinct speeds. The results show that motion of end-effector is successfully synchronized with the face of user at required speeds. The control strategy works effectively for the proof of concept yet modifications are recommended for increased computational accuracy.