Experimental study of the dynamic based feedback linearization of an autonomous wheeled ground vehicle

In this paper a combined open/closed-loop method for point stabilization of autonomous wheeled vehicles using feedback linearization technique is presented. For point stabilization of the vehicle in planar motion (the vehicle has 2 degrees of freedom), both position (in two directions) and orientation must be stabilized (approach their desired values). Here, we propose to apply feedback linearization and exponentially stabilize the position of the center of mass of the vehicle in curvilinear coordinates (closed-loop part) and the vehicle's orientation along a path that connects the initial and final positions with the corresponding desired orientations (open-loop part with bounded error). The vehicle used for illustration in this paper has one front (steering and driving) and two rear (idle) wheels and also a computer, two dc motors, two batteries and two measurement systems is an example of an autonomous ground vehicle. The dynamic model of this vehicle is presented in the state-space form with steering and driving torques as inputs. The results of the simulation and the experimental study of the proposed controller on this three-wheel vehicle as a prototype show that when the arc length coordinate of the position of the center of mass of the vehicle reaches its desired value, the vehicle stops at the desired position with the desired orientation with small acceptable errors proving the validity of the proposed method. (C) 2004 Elsevier B.V. All rights reserved.