• International Journal of Precision Engineering and Manufacturing
• /
• v.2 no.2
• /
• pp.48-56
• /
• 2001

This paper presents the position tracking control of a closed-loop cylinder system using electro-rheological (ER) valve actuators. After manufacturing three sets of cylindrical ER valves on the basis of Bingham model of ER fluid, a 3 dof(degree-freedom) closed-loop cylinder system having the heave, roll and pitch motions is constructed. The governing equations of motion are derived using Lagrange's equation and a control model is formulated by considering nonlinear characteristics of the system, Sliding mode controllers are the designed for these ER valve actuators in order to achieve position tracking control. The effectiveness of trajectory tracking control performance of the proposed cylinder system is demonstrated through computer simulation and experimental implementation of the sliding mode controller.

• Proceedings of the KIEE Conference
• /
• 2003.04a
• /
• pp.341-348
• /
• 2003

Photovoltaic systems normally use a maximum power point tracking (MPPT) technique ta continuously deliver the highest possible power to the load when variations in the insolation and temperature occur. A simple method of tracking the maximum power points (MPPs) and forcing the boost converter system to operate close to these points is presented through deriving small-signal model and transfer function of boost converter. This paper aims at modeling boost converter including equivalent series resistance of input reservoir capacitor by state-space-averaging method and PWM switch model with properly designed controller for maximum photovoltaic power tracking control.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.3
• /
• pp.165-173
• /
• 2000

This Paper presents the position tracking control of a closed-loop cylinder system using electro-rheological(ER) valve actuators. After manufacturing three sets of cylindrical ER valves on the basis of Bingham model of ER fluid, a 3 dof(degree-of-freedom) closed-loop cylinder system having the heave, roll and pitch motions is constructed. The governing equations of motion are derived using Lagrange's equation and a control model is formulated by considering nonlinear characteristics of the system. Sliding mode controllers are then designed fer these ER valve actuators in order to achieve position tracking control. The effectiveness of trajectory tracking control performance of the proposed cylinder system is demonstrated through computer simulation and experimental implementation of the sliding mode controller.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.9
• /
• pp.869-874
• /
• 2011

This paper addresses the trajectory tracking problem for ship berthing by using sliding mode technique. With significant potential advantages: insensitivity to plant nonlinearities, parameter variations, remarkable stability and robust performance with environmental disturbances, the multivariable sliding modes controller is proposed for solving trajectory tracking of ship in harbor area. In this study, the ship position and heading angle are simultaneously tracked to guarantees that the ship follows a given path (geometric task) with desired velocities (dynamic task). The stability of the proposed control law is proved based on Lyapunov theory. The proposed approach has been simulated on a computer model of a supply vessel with good results.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.8
• /
• pp.842-847
• /
• 2008

This paper proposes a new sliding-surface-based tracking control system for nonholonomic mobile robots with disturbance. To design a robust controller, we consider the kinematic model and the dynamic model of mobile robots with disturbance. We also propose a new sliding surface to solve the problem of previous study. That is, since the new sliding surface is composed of differentiable functions unlike the previous study, we can obtain the control law for arbitrary trajectories without any constraints. From the Lyapunov stability theory, we prove that the position tracking errors and the heading direction error converge to zero. Finally, we perform the computer simulations to demonstrate the performance of the proposed control system.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2006.06a
• /
• pp.85-86
• /
• 2006

In this paper, a nonlinear controller based on adaptive sliding-mode method which has a sliding surface vector including new boundary function is proposed and applied to a two-wheeled voiding mobile robot (WMR). This controller makes the welding point of WMR achieve tracking a reference point which is moving on a smooth curved welding path with a desired constant velocity. The mobile robot is considered in view of a kinematic model and a dynamic model in Cartesian coordinates. The proposed controller can overcome uncertainties and external disturbances by adaptive sliding-mode technique. To design the controller, the tracking error vector is defined, and then the new sliding is proposed to guarantee that the error vector converges to zero asymptotically. The stability of the dynamic system will be shown through the Lyapunov method. The simulations is shown to prove the effectiveness of the proposed controller.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.496-499
• /
• 1997

Field robot represented by excavator can be applied for various kinds of working in manufacturing, construction, agriculture etc. because of the flexibility of its multi-joint mechanism and the high power of hydraulic actuators. In general, the dynamics of field robot have strong coupling, various kinds of non-linearity, and time-varying parameters according to working conditions. Therefore, it is very difficult to describe the system well, and design controller systematically based on its model. This paper established the mathematical model of field robot driven by electro-hydraulic servomechanism and constructed the adaptive control system robust to external load variations. The proposed control system for the field robot was evaluated by the computer simulation and the performance results of trajectory tracking were compared with that of PID control system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.5
• /
• pp.592-599
• /
• 1998

In this paper, we design a tracking controller which satisfies transient response specifications and maintains tracking error within a tolerable limit for the uncertain track-following system of an optical disk drive. To this end, a robust $H_{\infty}$ control problem with regional stability constraints and sinusoidal disturbance rejection is considered. The internal model principle is used for rejecting the sinusoidal disturbance caused by eccentric rotation of the disk. We show that a condition satisfying the regional stability constraints can be expressed in terms of a linear matrix inequality (LMI) using the Lyapunov theory and S-procedure. Finally, a tracking controller is obtained by solving an LMI optimization problem involving two linear matrix inequalities. The proposed controller design method is evaluated through an experiment.

• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.6
• /
• pp.764-776
• /
• 1999

In this paper, a tracking algorithm for a maneuvering single target in the presence of multiple data from multiple sensors is investigated. Allowing individual sensors to function by themselves, the estimates from individual sensors on the same target are fused for the purpose of improving the state estimate. The filtering method adopted in the local sensors is the variable dimensional filter with input estimatio technique, which consists of a constant velocity model and a constant acceleration model. A posteriori probability for the maneuvering hypothesis is newly derived. It is shown that the relation function of the a posteriori probability is a function of only the covariance of the fused estimates. Simulation results are provided.

• Journal of Mechanical Science and Technology
• /
• v.19 no.spc1
• /
• pp.357-363
• /
• 2005

The non-minimum phase characteristic of a flexible manipulator makes tracking control of its tip difficult. The level of the tip tracking performance of a flexible manipulator is significantly affected by the characteristics of the tip reference trajectory as well as the characteristics of the flexible manipulator system. This paper addresses the question of how to best specify a reference trajectory for the tip of a flexible manipulator to follow in order to achieve the objectives of reducing : tip tracking error, residual tip vibration, and the required actuation effort at the manipulator joint. A novel method of tip-based learning controller for the flexible manipulator system is proposed in the paper, where a model of the flexible manipulator system with a command shaping filter is used to generate a smooth and realizable tip reference trajectory for a tip-based learning controller.