Nonlinear control for teleoperation systems with time delay and random feedback errors

摘要

As far as robotics is concerned, teleoperation (TOP) extends human capability by allowing the manipulation of an object from a distance by recreating similar conditions of the remote location of the object. Although force feedback is essential in bilateral teleoperation for the master operator to ensure the accuracy of the work done, it can induce difficulty and instability if there exists some delay in transmitting this signal through the communication. The bilateral TOP system considered in this study consist of a master robot communicating with a slave robot. Because of the environment, the slave robot experiences a torque that changes its position as compared to the case of no environmental torque. This change should be communicated to the master robot through a feedback mechanism to ensure that the master realizes this change and act accordingly to perform the required task. It is assumed that the time delay ‘T’ exists in the communication, referring to the time taken for the propagation of the force feedback signals between the master and slave controllers. This delay is called the teleoperation delay and it is essential in producing the error signals to control the master and slave robots. This study analyses the TOP system in presence of random feedback errors and disturbances produced by the environment to determine the approximate correlation between the angular position of master and slave robots. The TOP delay is considered a slow timevarying delay, and the entire TOP system is modelled using the Lyapunov Energy function and solved using the Perturbation theory. Numerical simulations were obtained by using the numerical algorithm of the Runge-Kutta method of solving higher-order differential equations. The model is built using MATLAB and obtained results on the correlation of angular position using the same.