• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.52 no.1
• /
• pp.31-37
• /
• 2003

A robust tracking control for nonholonomic dynamic systems is proposed in this paper. Since nonholonomic dynamic systems have constraints imposed on motions that are not integrable, i.e., the constraints cannot be written as time derivatives of some functions of generalized coordinates, advanced techniques are needed for their control. It is shown that if the state of nonholonomic systems is mapped into a bounded space by a coordinate transformation, a robust controller for dynamic models of nonholonomic systems with input disturbances can be designed using sliding mode control. Stability and robustness of the proposed controller are proved in the Lyapunov sense. Numerical simulations on the trajectory tracking of a two-wheeled mobile robot are conducted to validate the effectiveness of the proposed controller.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2005.06a
• /
• pp.287-292
• /
• 2005

In this paper, a state steering strategy using digital control method for chained system is presented. The chained system can be derived from the velocity or acceleration constraints that cannot be integrable. Especially, the chained system derived from an acceleration constraints is called the high order chained system. Such a system classified as a nonholonomic systems and cannot be controlled to its equilibrium points by continuous and time-invariant controller. Therefore discontinuous and time varying controller should be applied to control nonholonomic system. Using variable transformation, two sub system can be obtained from the chained or high order chained system. Deadbeat control and iterative state steering methods are proposed to control the systems that obtained from the variable transformation. Simulation results are given to show the effectiveness of the proposed control scheme.

• Journal of Advanced Marine Engineering and Technology
• /
• v.31 no.4
• /
• pp.455-461
• /
• 2007

In this paper a state steering strategy for high order chained system is presented. High order chained system can be derived from the acceleration constraints that cannot be integrable. The system classified as a nonholonomic system cannot be controlled to its equilibrium points by continuous and time-invariant controller. Using variable transformation two sub system can be obtained from the high order chained system. Deadbeat control and iterative state steering methods are proposed to control the system. Simulation results are given to show the effectiveness of the proposed control scheme.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.04a
• /
• pp.63-70
• /
• 2008

In this paper, we propose a bearing redundant coordinates and decoupled PD controller for 5-axes active magnetic bearing system, which consists of two bearing parts such as three-pole hybrid active magnetic bearing for stabilize the radial direction and ring-type permanent magnetic bearing stabilizing in axial and tilting motion. Based on derived system equation with decoupled control scheme, we conduct the modal analysis and measure of modal controllability and observability.

• Proceedings of the KIEE Conference
• /
• 2003.07d
• /
• pp.2378-2380
• /
• 2003

본 연구에서는 각 운동량 보존법칙으로부터 도출되어지는 공중부상체(flying objects)의 제어기법에 대해 논의하고자 한다. 먼저, 공중부상체에 대하여 각 운동량 보존법칙을 적용하여 적분불가능한 구속조건으로부터 비 홀로노믹시스템을 도출하고 상태변환과 입력변환을 행하여 제어가 용이한 체인드 폼(Chained form)을 유도한다. 체인드 폼에 대해서는 백스테핑제어기법을 적용하여 제어기를 설계하고 제어기법의 유용성을 검증하기 위하여 3개의 회전관절로 구성된 공중부상체를 대상으로 하여 초기자세로부터 목적자세까지의 제어를 행하였다.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.786-791
• /
• 2003

This paper proposes an adaptive control algorithm for nonholonomic mobile robots with unknown parameters and the proposed control method is used in numerical simulations for applying to a practical twowheeled welding mobile robot(WMR). The proposed adaptive controller to track an arbitrary given welding path is designed by using back-stepping technique and is derived for a nonlinear model under the assumption such that the system parameters are partially known. Moreover, the proposed adaptive control system is stable in the sense of Lyapunov stability. Inertia moments of system are considered to be unknown parameters and their values can be estimated simply by using update laws proposed in an adaptive control scheme of this research. The simulation results are provided to show the effectiveness of the accurate tracking capability of the proposed controller for two-wheeled welding mobile robot with a smooth curved reference welding path.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.4
• /
• pp.1824-1832
• /
• 2011

In this paper, a smart home service robot McBot II is newly developed in much more practical and intelligent system than McBot I which we had developed a few years ago. Thus far, vacuum-cleaners have lightened the burden of household chores but the operational labor that vacuum-cleaners entail has been very severe. Recently, a cleaning robot was commercialized to solve but it also was not successful because it still had the problem of mess-cleanup, which pertained to the clean-up of large trash and the arrangement of newspapers, clothes, etc. Hence, we develop a new home mess-cleanup robot McBot II to completely overcome this problem on real environments. The mechanical design and the basic control of McBot II, which performs mess-cleanup function etc. in house, is actually focused in this paper. McBot II is mechanically modeled in the same method that the human works in door by using the waist and the hands. The big-ranged vertical lift and the shoulder joints to be able to forward move are mechanically designed for the operating function as the human's waist when the robot works. The mobility of McBot II is designed in the holonomic mobile robot for the collision avoidance of obstacle and the high speed navigation on the small area in door. Finally, good performance of McBot II, which has been optimally desinged, is confirmed through the experimental results for the control of the robotic body, mobility, arms and hands in this paper.