Master slave tracking control using adaptive least squares filter

In this study, we have implemented master-slave tracking with tactile feedback using Geomagic
^®
Touch
^™
(Phantom Omni) haptic device. The system dynamics were modeled using adaptive filters and parameter estimation was done using Widrow's Least Mean Square (WLMS) algorithm. The filter update is based on minimizing the error between a given master angular position and the slave position. The filter employed is a slowly time varying filter with the time variation being dictated by the slave process up to the previous time instant. For implementation of these techniques, a mathematical model is developed and simulated in MATLAB
^®
. The simulations validate the concept as the results reveal that the slave is able to perfectly track the master with negligible RMS error and the master is able to perceive haptic feedback. We have also varied the filter length and the characteristics of environmental torque acting on the slave robot in order to analyze their effects on tracking accuracy. The errors remain almost same and the differences in tracking errors comes out to be negligible, with or without external torques in slave robot's environment, indicating effectiveness of the theory in bilateral teleoperation control.