Stabilization Of Wheeled Mobile Robots Research Articles

Stabilization of wheeled mobile robot by social spider algorithm based PID controller

Stabilization of wheeled mobile robot by social spider algorithm based PID controller

Posture Stabilization of Wheeled Mobile Robot Based on Passivity-Based Robust Switching Control with Model Uncertainty Compensation

Thisstudy presents apassivity-based robust switching control for the posture stabilization of wheeled mobile robots (WMRs) with model uncertainty. Essentially, this proposed strategy is switching between (1) passivity-based robust control to lead the robot to the neighborhood of local minima with a finite time and (2) another robust control to perturb the w-rotational motion of the WMR before the v-kinetic energy of the WMR become meaningless, thereby, eventually converging to the desired posture. Thus, combining two switching control laws ensures the global convergence of (x,y)-navigation of WMRs from any initial position to desired set. Especially, the inter-switching time is intentionallyselected before the WMR completely loses its mobility, which ensures a strict decrease in (x,y)-navigation potential energy and a better global convergence rate. In addition, this control architecture also includes model uncertainty compensation, often neglected in practice, and analytical study of rotational perturbation was also conducted. The Lyapunov technique and energetic passivity wereutilized to derive this control law. Simulation results are presented to illustrate the effectiveness of the proposed technique. It wasfound from the results that the WMR wasquickly converged to the desired posture even under the presence of model uncertainty.

A kinematic Lyapunov-based controller to posture stabilization of wheeled mobile robots

Abstract In this paper, two non-smooth kinematic control strategies are proposed for the posture stabilization of a differentially driven wheeled mobile robot. The developed approach is based on kinematic coordinate transformation and Lyapunov-like stability technique. The presented control laws can stabilize the system asymptotically at a desired target and offer two different manoeuvers. Further, the response of the suggested algorithms is compared against recent previous studies. Next, the control laws are modified to tackle the obstacle avoidance problem while the robot approaches the final desired posture. The obtained simulation results as well as experimental tests prove the effectiveness of the presented techniques.

Point Stabilization for Wheeled Mobile Robots Using Model Predictive Control

A model predictive control method is proposed for the point stabilization of wheeled mobile robots (WMRs) subject to nonholonomic constraints. The problem is simplified by considering only the steering system and neglecting the vehicle dynamics. A linearized error model is then formulated by transforming the robot position into polar frame. The feedback control policy is obtained by minimizing a quadratic cost function which penalizes the predicted errors and control variables in each sampling time over a finite horizon. The proposed control law is proven to guarantee the exponential stability of the robot system by considering additive inequality constraints in the optimization process. The performance of the stabilization algorithm is verified through computer simulations showing that the proposed method has a good regulation performance and convergence.

Hybrid Model Predictive Control for the Stabilization of Wheeled Mobile Robots Subject to Wheel Slippage

This paper studies the problem of traction control, i.e., how to stabilize a wheeled mobile robot (WMR) subject to wheel slippage to a desired configuration. The WMR is equipped with a rechargeable battery pack which powers electric drives on each wheel. The drives propel the WMR in one mode of operation or recharge the battery pack (recover energy) in a second mode. These modes of operation are controlled, whereas wheel slippage, e.g., due to ice, is an autonomous mode change. The WMR can be thus modeled as a hybrid system with both controlled and autonomous switches. Model predictive control (MPC) for such systems, although robust, typically results in numerical methods of combinatorial complexity. We show that recently developed embedding techniques can be used to formulate numerical algorithms for the hybrid MPC problem that have the same complexity as MPC for smooth systems. We also discuss the numerical techniques that lead to efficient and robust MPC algorithms in detail. Simulations illustrate the effectiveness of the approach.

Trajectory tracking control of Skid-Steering Robot – experimental validation

In this paper authors consider the problem of practical stabilization of wheeled mobile robot equipped with skid-steering drive (also know as SSMR). The kinematic model of SSMR is approximated by kinematics of unicycle including small perturbation term which describes limited skidding effect. It is justified that SSMR can be regarded as a system with non-stationary first order nonholonomic constraint. Based on this result smooth control scheme robust to limited skidding is developed. The control law ensures practical stabilization in regulation and trajectory tracking case, i.e. position and orientation errors are bounded to the assumed but nonzero values. The effectiveness of control solution is justified and illustrated by experimental results.

Robust simultaneous tracking and stabilization of wheeled mobile robots not satisfying nonholonomic constraint

A robust unified controller was proposed for wheeled mobile robots that do not satisfy the ideal rolling without slipping constraint. Practical trajectory tracking and posture stabilization were achieved in a unified framework. The design procedure was based on the transverse function method and Lyapunov redesign technique. The Lie group was also introduced in the design. The left-invariance property of the nominal model was firstly explored with respect to the standard group operation of the Lie group SE(2). Then, a bounded transverse function was constructed, by which a corresponding smooth embedded submanifold was defined. With the aid of the group operation, a smooth control law was designed, which fulfills practical tracking/stabilization of the nominal system. An additional component was finally constructed to robustify the nominal control law with respect to the slipping disturbance by using the Lyapunov redesign technique. The design procedure can be easily extended to the robot system suffered from general unknown but bounded disturbances. Simulations were provided to demonstrate the effectiveness of the robust unified controller.

Quasi-exponential Stabilization of Wheeled Mobile Robots with Uncertainty

This paper deals with stabilization problem of nonholonomic wheeled mobile robots with unknown inertia parameters. Novel adaptive quasi-exponentially stabilizing laws (see Section 3 for definition) are presented based on new canonical forms and their two key facts. Extensive simulation demonstrates effectiveness of the control scheme.