Smith-predictor compensator for a delayed omnidirectional mobile robot

Abstract

This paper deals with the discrete time control of an omnidirectional mobile robot subject to transport delays. A discrete-time model of the vehicle is obtained by considering an exact discretization of the continuous time model of the robot where the time delay induced by a communication network is considered. The path-tracking problem is addressed by means of a prediction strategy based on the well known Smith predictor compensator. The nonlinear nature of the omnidirectional mobile robot induces an approximate estimate of the future values of the systems that are used together with a feedback linearization approach to solve the tracking problem.

Trajectory tracking of two wheeled mobile robot

“…The parameters of the motor J, f, L, R, Ke, Kc are tacked from [7] and they are given in table Ι. In this simulation, we considered a start position (x start , y start ) = (1, 1) and a target point (x des , y des ) = (8,6). We considered the following PI controller parameters (K p , T i ) = (10,100).…”

“…The problem of trajectory-tracking was solved in [7] by using a fuzzy control of trajectory after demonstrating the kinematic model and the minimal dynamic model which are used to develop the control law. Authors of [8] used an estimation strategy that predicts the future values of the system's output based on the model of the robot. There were many traditional control techniques of the wheeled mobile robot which have limits and do not present good performances; they usually present undesirable oscillatory motions as results of the closed-loop trajectory.…”

“…We consider the following values of weighting I(3N, 3N)and I(2N, 2N)are identity matrix with dimension(3N, 3N) and (2N, 2N)respectively. We considered a start position (x start , y start ) = (1, 1) and a target point (x des , y des ) =(8,6).…”

Nonlinear Smith-predictor based control strategy for a unicycle mobile robot subject to transport delay

“…Remark 1: It is very important to notice that equations (15) represent a noncausal feedback that can not be directly implemented on system (9). This fact represents the main drawback of the developments presented before that is a common issue in the case of input delay systems.…”

“…The present proposal is based on the original works [13], [14] in the field of chemical processes and used initially to solve the path tracking problem of a an omnidirectional mobile robot (3,0) based on a feedback linearization approach. in [15].…”