Jin-Ho Shin

Design of a robust adaptive controller for a mobile robot

In the design of a controller for mobile robot, there are only few results on the problem of integrating the nonholonomic kinematic controller and the dynamic controller for mobile robots. Also there are only few literatures on the robustness of the controller in the presence of uncertainties or external disturbances in the dynamical model of mobile robot. In this paper, a robust adaptive controller which can achieve velocity tracking while considering not only kinematic model but also dynamic model of mobile robot is proposed. The proposed controller can overcome model uncertainty or external disturbances by the robust adaptive technique. The stability of the dynamic system is shown through the Lyapunov method.

Robust model reference adaptive control of underactuated robot manipulators

A robust control scheme, overcoming the uncertainty in an underactuated robot manipulator, is proposed based on the sliding mode and MRAC (model reference adaptive control) schemes. By introducing the model reference adaptive technique and robust control algorithm, the dynamic response of each joint of underactuated manipulators can be pre-determined without exact knowledge of the system parameters. To show the effectiveness of the proposed algorithm, simulations for a 2-link underactuated robot with 1 fault joint are done.

Robust Adaptive Fuzzy Tracking Control Using a FBFN for a Mobile Robot with Actuator Dynamics

This paper proposes a robust adaptive fuzzy tracking control scheme for a nonholonomic mobile robot with external disturbances as well as parameter uncertainties in the robot kinematics, the robot dynamics, and the actuator dynamics. In modeling a mobile robot, the actuator dynamics is integrated with the robot kinematics and dynamics so that the actuator input voltages are the control inputs. The presented controller is designed based on a FBFN (Fuzzy Basis Function Network) to approximate an unknown nonlinear dynamic function with the uncertainties, and a robust adaptive input to overcome the uncertainties. When the controller is designed, the different parameters for two actuator models in the actuator dynamics are taken into account. The proposed control scheme does not require the kinematic and dynamic parameters of the robot and actuators accurately. It can also alleviate the input chattering and overcome the unknown friction force. The stability of the closed-loop control system including the kinematic control system is guaranteed by using the Lyapunov stability theory and the presented adaptive laws. The validity and robustness of the proposed control scheme are shown through a computer simulation.

Experimental verification for robust adaptive control of an underactuated robot manipulator with second-order nonholonomic constraints

This paper presents a robust adaptive control scheme of an underactuated manipulator. The proposed control schemes are a joint position-to-position (PTP) control scheme and a Cartesian end-point control scheme tracking a continuous path in Cartesian space. The proposed joint and Cartesian controllers are verified by experimental results for an actual three-link SCARA robot manipulator with a passive joint. In this robot experiment, the third joint of this robot is passive.