Wheeled Mobile Robot In Presence Research Articles

Integral Sliding Mode Control for Trajectory Tracking of Wheeled Mobile Robot in Presence of Uncertainties

Wheeled mobile robots present a typical case of complex systems with nonholonomic constraints. In the past few years, the dominance of these systems has been a very active research field. In this paper, a new method based on an integral sliding mode control for the trajectory tracking of wheeled mobile robots is proposed. The controller is designed to solve the reaching phase problem with the elimination of matched disturbances and minimize the unmatched one. We distinguish two parts in the suggested controller: a high-level controller to stabilize the nominal system and a discontinuous controller to assess the trajectory tracking in the presence of disturbances. This controller is robust during the entire motion. The effectiveness of the proposed controller is demonstrated through simulation studies for the unicycle with matched and unmatched disturbances.

Adaptive feedback linearizing control of nonholonomic wheeled mobile robots in presence of parametric and nonparametric uncertainties

In this paper, the integrated kinematic and dynamic trajectory tracking control problem of wheeled mobile robots (WMRs) is addressed. An adaptive robust tracking controller for WMRs is proposed to cope with both parametric and nonparametric uncertainties in the robot model. At first, an adaptive nonlinear control law is designed based on input-output feedback linearization technique to get asymptotically exact cancellation of the parametric uncertainty in the WMR parameters. The designed adaptive feedback linearizing controller is modified by two methods to increase the robustness of the controller: (1) a leakage modification is applied to modify the integral action of the adaptation law and (2) the second modification is an adaptive robust controller, which is included to the linear control law in the outer loop of the adaptive feedback linearizing controller. The adaptive robust controller is designed such that it estimates the unknown constants of an upper bounding function of the uncertainty due to friction, disturbances and unmodeled dynamics. Finally, the proposed controller is developed for a type (2, 0) WMR and simulations are carried out to illustrate the robustness and tracking performance of the controller.

OBSTACLE-AVOIDING PATH PLANNING FOR HIGH VELOCITY WHEELED MOBILE ROBOTS

This paper presents a new motion planning algorithm for wheeled mobile robots in presence of known static obstacles, especially well-suited for high velocity situations. It takes into account several conditions traditionally attached to smooth path planning, i.e. paths with continuous derivative and upper-bounded curvature. It makes use of a global path planner which exploits polynomial G3 curves characteristics.

Control of Unicycle-Type Robots in the Presence of Sliding Effects with Only Absolute Longitudinal and Yaw Velocities Measurements

In this paper we are concerned with the control of unicycle-type wheeled mobile robots in presence of sliding effects measurements. The slipping and skidding effects are known to be very noisy so we want to elaborate a control law which solves the velocity tracking problem by using only absolute longitudinal and yaw velocities. First, we choose to simplify the problem by taking into account only the more important component of the slip with respect to the trajectory. In a turn, we modelize the skidding effects, however we introduce the longitudinal slip in a straight line. Then, we got our inspiration from the approach used in these particular cases to elaborate a global control law which makes the lateral, longitudinal and yaw velocities tend to zero. This control law does not need sliding effects measurements but depends on the slip and cornering stiffness coefficients.

Distribution of pressure and temperature in a highly-loaded, lubricated contact : D. Dowson and M. D. Longfield, University of Leeds

In this paper we are concerned with the control of unicycle-type wheeled mobile robots in presence of sliding effects measurements. The slipping and skidding effects are known to be very noisy so we want to elaborate a control law which solves the velocity tracking problem by using only absolute longitudinal and yaw velocities.First, we choose to simplify the problem by taking into account only the more important component of the slip with respect to the trajectory. In a turn, we modelize the skidding effects, however we introduce the longitudinal slip in a straight line. Then, we got our inspiration from the approach used in these particular cases to elaborate a global control law which makes the lateral, longitudinal and yaw velocities tend to zero. This control law does not need sliding effects measurements but depends on the slip and cornering stiffness coefficients.