Robust Nonlinear Control of a Mobile Robot (original) (raw)
Related papers
International Journal of Advanced Robotic Systems
This article propounds addressing the design of a sliding mode controller with adaptive gains for trajectory tracking of unicycle mobile robots. The dynamics of this class of robots are strong, nonlinear, and subject to external disturbance. To compensate the effect of the unknown upper bounded external disturbances, a robust sliding mode controller based on an integral adaptive law is proposed. The salient feature of the developed controller resides in taking into account that the system is MIMO and the upper bound of disturbances is not priori known. Therefore, we relied on an estimation of each perturbation separately for each subsystem. Hence, the proposed controller provides a minimum acceptable errors and bounded adaptive laws with minimum of chattering problem. To complete the goal of the trajectory tracking, we apply a kinematic controller that takes into account the nonholonomic constraint of the robot. The stability and convergence properties of the proposed tracking dynam...
Sliding Mode Motion Control of Nonholonomic Mobile Robots
IEEE Control Systems, 1999
s nonholonomic mobile robots have constraints imposed on motions that are not integrable, i.e., the constraints cannot be written as time derivatives of some function of the generalized coordinates, advanced techniques are needed for the tracking control. In this paper a robust control law is proposed for trajectory tracking of nonholonomic wheeled mobile ro-One important topic that requires much attention (but has been studied little) is the problem of control of nonholonomic systems when there are model uncertainties. In most cases, the control problem is stated in terms of stabilizing a simple mathematical model, and the state variables are supposed to be known exactly at any time. However, taking into account several intrinsic characteristics of nonholonomic systems such as the actual bots. The state variables of the mobile robot are represented in polar coordinates, and the dynamic equation of the system is feedback-linearized by a computed-torque method. A novel sliding mode control law is derived for asymptotically stabilizing the mobile robot to a desired trajectory. It is shown that the proposed scheme is robust to bounded system disturbances. Simulation examples and experimental results are provided to show the effectiveness of the accurate tracking capability and the robust performance of the proposed controller. [ 1 11, proposed a sliding mode control that exploits a property named differential flatness of the kinematics of nonholonomic systems. In Guldner, et al. [ 121, a Lyapunov navigation function
Applied Artificial Intelligence, 2018
This article designs a novel adaptive trajectory tracking controller for nonholonomic wheeled mobile robot under kinematic and dynamic uncertainties. A new velocity controller, in which kinematic parameter is estimated, produces velocity command of the robot. The designed adaptive sliding mode dynamic controller incorporates an estimator term to compensate for the external disturbances and dynamic uncertainties and a feedback term to improve the closed-loop stability and account for the estimation error of external disturbances. The system stability is analyzed using Lyapunov theory. Computer simulations affirm the robustness of the designed control scheme.
Sliding Mode Control for Nonholonomic Mobile Robot
2000
A new control scheme is presented for nonholonomic mobile robots. The main idea of this paper is to consider the natural algebraic structure of the chained form system together with ideas from sliding mode theory while designing the control law. At first, the system model is converted into a single-input time-varying linear system by setting one input as a time-varying function. We design the sliding mode control law by using pole placement based on pseudo-linearized model. The point stabilization and path-tracking problem for chained form are studied based on these ideas. Simulations for both unicycle car and car like robot showed this control algorithm can make the mobile robot stabilized at desired configuration and following the desired trajectory with a high precision.
Sliding mode control for trajectory tracking of nonholonomic wheeled mobile robots
IEEE Transactions on Robotics and Automation, 1999
This paper deal with a robust sliding-mode trajectory tracking controller, for nonholonomic wheeled mobile robots and its experimental evaluation by the implementation in an intelligent wheelchair (RobChair). The proposed control structure is based on two nonlinear sliding surfaces ensuring the tracking of the three output variables, with respect to the nonholonomic constraint. The performances of the proposed controller for the trajectory planning problem with comfort constraint are verified through the real time acceleration provided by an inertial measurement unit.
Asian Control Conference, 2019
This paper offers a novel approach to circumvent some problems derived from the nonholonomic structure of a two-wheeled mobile robot. It is shown that suitably extending a well-known thirdorder error model, new kinematics are found that allow direct Lyapunov-based control design as well as straightforward PDC control for its Takagi-Sugeno form. In the latter case, controllability issues are overcome thanks to the proposed design which decouples the uncontrollable mode from the rest of the system. Illustrative examples are provided that show the effectiveness of this technique.
A sliding mode controller with generalized H2 performance for dynamic of nonholonomic mobile robot
2013 3rd Joint Conference of AI & Robotics and 5th RoboCup Iran Open International Symposium, 2013
In this paper, a sliding mode controller with a generalized ℋ2 performance is proposed for a unicycle-like mobile robot to implement the trajectory tracking mission. First, a kinematic controller is introduced for the mobile robot and generating the desired values of the linear and angular velocity for the dynamic controller. Secondly, a dynamic controller based on the sliding mode control with a generalized ℋ 2 performance is proposed to make the real velocity of the mobile robot and reach the desired velocity command. The stability properties of the controllers are proved by the Lyapunov method. This control law providing smaller errors and better performance to deal with the slipping of the wheels and parameter uncertainty. Simulation is carried out for a mobile robot to verify the performance of the proposed control scheme.
Robust Adaptive Sliding Mode Controller for a Nonholonomic Mobile Platform
Journal of Engineering, 2019
In this paper, a robust adaptive sliding mode controller is designed for a mobile platform trajectory tracking. The mobile platform is an example of a nonholonomic mechanical system. The presence of holonomic constraints reduces the number of degree of freedom that represents the system model, while the nonholonomic constraints reduce the differentiable degree of freedom. The mathematical model was derived here for the mobile platform, considering the existence of one holonomic and two nonholonomic constraints imposed on system dynamics. The partial feedback linearization method was used to get the input-output relation, where the output is the error functions between the position of a certain point on the platform and the desired path. The dynamic error model was considered uncertain and subjected to friction torques on the wheels. The adaptive sliding mode control was utilized to design a robust controller, that will force the platform to follow the desired trajectory. The simulation of the proposed controller was done via MATLAB to reveal the ability of the robust adaptive sliding mode controller applied as a trajectory tracker for various path shapes.
Robust tracking control of mobile robots in the presence of uncertainties in the dynamical model
Journal of Robotic Systems, 2001
In this article, the robust trajectory tracking problem for the dynamical model of a wheeled mobile robot has been solved using sliding mode control. The presence of bounded uncertainties (parameter variations and input disturbances) has been considered. The control policy makes use of two nonlinear sliding surfaces, able to ensure the robust asymptotic vanishing of the three tracking errors. The control law has been tested by simulation. The reported results show the effectiveness of the proposed control law. © 2001 John Wiley & Sons, Inc.