Motion Planning & Control of a Dynamic WMR Model in Manufacturing Environments

In many manufacturing systems, precise movement along a given path of a mobile robot is an important control task. To achieve effective motion control, especially at relatively high speeds, the dynamics of the robot must be taken into account. (instead of seeing the system as a point in the workspace, or presenting it using only kinematic equations). Thus, this paper addresses the point-to-point control problem for a differentially driven nonholonomic Wheeled Mobile Robot (WMR) with nonlinear dynamics equations which may be applied in a relevant production environment. Based on the flatness property we present a motion planning procedure which determines a path from initial to final oriented points, i.e. points with associated prescribed initial and terminal directions of the WMR in a 2D workspace. In particular, using previous results we present here a suboptimal control law that ensures the transfer of the vehicle from a given initial state to a defined final state while minimizing a selected quadratic index of performance in following a reference path connecting the initial and final oriented points. Several examples illustrate the uses of the control algorithms with possible applications in a working environment within manufacturing places are presented throughout the article.