Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Institute of Control, Robotics and Systems
Journal Basic Information
Journal DOI :
Institute of Control, Robotics and Systems
Editor in Chief :
Volume & Issues
Volume 3, Issue 6 - Dec 1997
Volume 3, Issue 5 - Oct 1997
Volume 3, Issue 4 - Aug 1997
Volume 3, Issue 3 - Jun 1997
Volume 3, Issue 2 - Apr 1997
Volume 3, Issue 1 - Feb 1997
Selecting the target year
Robust stability of a two-degree-of-freedom servosystem incorporating an observer with multiplicative uncertainty
Kim, Young-Bok ; Yang, Joo-Ho ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 1~8
In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, if the mathematical model of the plant is exact and no disturbance input exists, the integral compensation is not necessary. From this point of view, a two-degree-of-freedom(2DOF) servosystem has been proposed, in which the integral compensation is effective only when there is a modeling error or a disturbance input. The present paper considers robust stability of this 2DOF servosystem incorporating an observer to the structured and unstructured uncertainties of the controlled plant. A robust stability condition is obtained using Riccati inequality, which is written in a linear matrix inequality (LMI) and independent of the gain of the integral compensator. This result impies that if the plant uncertainty is in the allowable set defined by the LMI condition, a high-gain integral compensation can be carried preserving robust stability to accelerate the tracking response.
Performance Controller Design with Parameter Uncertainty and Unmodeled Dynamics
Lee, Kap-Rai ; Oh, Do-Chang ; Park, Hong-Bae ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 9~16
The method of designing robust two degree of freedom(2 DOF) controllers for linear systems with parameter uncertainties and unmodeled dynamics is presented in this paper. Robust performance condition that accounts for robust model matching of closed loop system and disturbance rejection is derived. Using the robust performance condition, the feedback controller is designed to meet robust stability and disturbance rejection specifications, while prefilter is used to improve the robust model matching properties. The
controller for six degree of freedom vehicle with parameter variations are designed and compared. Simulations for hydrodynamic parameter variations and disturbance are presented to demonstrate the achievement of good robust performance.
A study on stability bounds of time-varying perturbations
Kim, Byung-Soo ; Han, Hyung-Seok ; Lee, Jang-Gyu ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 17~22
The stability robustness problem of linear discrete-time systems with time-varying perturbations is considered. By using Lyapunov direct method, the perturbation bounds for guaranteeing the quadratic stability of the uncertain systems are derived. In the previous results, the perturbation bounds are derived by the quadratic equation stemmed from Lyapunov method. In this paper, the bounds are obtained by a numerical optimization technique. Linear matrix inequalities are proposed to compute the perturbation bounds. It is demonstrated that the suggested bound is less conservative for the uncertain systems with unstructured perturbations and seems to be maximal in many examples. Furthermore, the suggested bound is shown to be maximal for the special classes of structured perturbations.
Sway Control of a Container Crane ( Part I ) : Modeling, Control Strategy, Error Feedback Control Via Reference Velocity Profiles
Hong, Keum-Shik ; Sohn, Sung-Chull ; Lee, Man-Hyung ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 23~31
The sway control problem of pendulum motion of a container hanging on a Portainer Crane, which transports containers from a container ship to trucks, is considered in the paper. The equations of motion are obtained through the Lagrange mechanics and simplified for control purposes. Considering that the fast traveling of trolley and no residual swing motion of the container at the end of acceleration and deceleration are crucial for quick transportation, several velocity patterns of trolley movement including the time-optimal control are investigated. Incorporating the change of rope length, a reference swing trajectory is introduced in the control loop and the error signal between the reference sway angle and the measured sway angle is feedbacked. Proposed control strategy is shown to be robust to disturbances like winds and initial sway motion.
Contour error analysis and PID controller design for machining center
Na, Il-Ju ; Choi, Jong-Ho ; Jang, Tae-Jeong ; Choi, Byeong-Kap ; Song, O-Seok ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 32~39
One of the most important performance criteria in tuning the gain of position loop controller for CNC machining center is the contour error. In this papre we analyze contour error in the linear and circular interpolations for the axis-matched and mismatched cases. To have small contour errors, it is necessary to set the P gain for each axis to be same. And the D gain should be much smaller than the P gain. Baded on the analysis in the frequency domain, we propose a gain tuning method for the P and PD controllers. We show that the PD controller is better than the P controller. The effectiveness of this method is demonstrated by experiments.
Design of disturbance observer and sliding mode controller for the hovering system of underwater vehicles
Kim, Jong-Sik ; Kim, Sung-Min ; Yang, Hwa-Joon ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 40~45
A robust disturbance rejection controller for the hovering motion of underwater vehicles in near the surface of sea is presented. The suggested controller consists of two control parts, the one is disturbance observer for taking into account the effects of sea wave and missile-launching forces, and the other is sliding mode controller for the robust stability of underwater vehicles with model uncertainties and nonlinearities. It is shown that the sliding mode control system with disturbance observer is more effective compared with the sliding mode control system, especially in case that large sea wave force is affected.
Optimal control of continuous system using genetic algorithms
Lee, Moo-Ho ; Han, Chonghun ; Chang, Kun-Soo ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 46~51
The optimal control of a continuous process has been performed using genetic algorithms(GAs). GAs are robust and easily applicable for complex and highly nonlinear problems. We introduce the heuristics 'dynamic range' which reduces the search space dramaticaly keeping the robust search of GAs. GAs with dynamic range show the better performance than SQP(Successive Quadratic Programing) method which converges to a local minimum. The proposed methology has been applied to the optimal control of the continuous MMA-VA copolymerization reactor for the production of the desired molecular wieght and the composition of VA in dead copolymer.
A genetic algorithm with uniform crossover using variable crossover and mutation probabilities
Kim, Sung-Soo ; Woo, Kwang-Bang ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 52~60
In genetic algorithms(GA), a crossover is performed only at one or two places of a chromosome, and the fixed probabilities of crossover and mutation have been used during the entire generation. A GA with dynamic mutation is known to be superior to GAs with static mutation in performance, but so far no efficient dynamic mutation method has been presented. Accordingly in this paper, a GA is proposed to perform a uniform crossover based on the nucleotide(NU) concept, where DNA and RNA consist of NUs and also a concrete way to vary the probabilities of crossover and mutation dynamically for every generation is proposed. The efficacy of the proposed GA is demonstrated by its application to the unimodal, multimodal and nonlinear control problems, respectively. Simulation results show that in the convergence speed to the optimal value, the proposed GA was superior to existing ones, and the performance of GAs with varying probabilities of the crossover and the mutation improved as compared to GAs with fixed probabilities of the crossover and mutation. And it also shows that the NUs function as the building blocks and so the improvement of the proposed algorithm is supported by the building block hypothesis.
Preview control and its application to robot force control
Yong, Boo-Joong ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 61~66
Tactile feedback device using repulsive force of the magnets for teleoperation
Ahn, Ihn-Seok ; Moon, Yong-Mo ; Lee, Jung-Hun ; Park, Jong-Oh ; Lee, Jong-Won ; Woo, Kwang-Bang ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 67~76
In this paper we developed a tactile feedback device using repulsive force of magnets. The force of the tactile feedback device was derived from the Maxwell's stress method by using the concept of magnetic charge. Magnetic repulsive force is linear function with respect to current and nonlinear to displacement. Experimental data shows these characteristics. To compensate the fact that the presented tactile feedback device can not be controlled by close loop control, we developed a simulation model which predicts output displacement and force by using Runge-Kutta method. And, this paper evaluated the presented tactile feedback device and compared it with commercial tactile feedback devices.
Management and control of fieldbus network traffic by bandwidth allocation scheme
Hong, Seung-Ho ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 77~88
Fieldbus is the lowest level communication network in factory automation and process control systems. Performance of factory automation and process control systems is directly affected by the data delay induced by network traffic. Data generated from several distributed field devices can be largely divided into three categories: sporadic real-time, periodic real-time and non real-time data. Since these data share one fieldbus network medium, the limited bandwidth of a fieldbus network must be appropriately allocated to the sporadic real-time, periodic real-time and non real-time traffic. This paper introduces a new fieldbus design scheme which allocates the limited bandwidth of fieldbus network to several different kinds of traffic. The design scheme introduced in this study not only satisfies the performance requirements of application systems interconnected into the fieldbus but also fully utilizes the network resources. The design scheme introduced in this study can be applicable to cyclic service protocols operated under single-service discipline. The bandwidth allocation scheme introduced in this study is verified using a discrete-event/continuous-time simulation experiment.
A study on automatic testing of powder metallurgy process using the visual inspection system
Kwon, Ki-Ryong ; Choi, Jae-Youn ; Choi, Sung-Lark ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 89~93
This paper describes the automatic testing system developed for powder metallurgy process using the visual inspection, and its some internal algorithms. The system consists of one unit from each of the five types of units; feeding, slot, vision inspection, volumn counter, and inferior good extractor units. Some applications of the system to powder metallurgy process has shown the possibility of reducing the rework and increasing the efficiency of operation.
Specification of a software architecture and protocols for automated VLSI manufacturing system operation
Park, Jong-Hun ; Kim, Jong-Won ; Kwon, Wook-Hyun ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 94~100
Initial requirements to the optimal performance of systems modeled by timed place Petri nets using the synchronic time ratio
Go, In-Seon ; Choi, Juang-Hwan ;
Journal of Institute of Control, Robotics and Systems, volume 3, issue 1, 1997, Pages 101~108
The initial token value required to the optimal performance of discrete event systems can be decided by Sum of Delay Time and Synchronic Time ratio, which are new synchronic variables in Timed Place Petri Nets. For the system consisting of two Live-and-Bounded circuits(LB-circuits) fused in common Transition-Transition-Path or common Place-Place-Path, we prove that the Synchronic Time Ratio is the initial token ratio between two LB-circuits to optimally perform system functions. These results are generalized and formulated as a theorem. The initial tokens of a specific place can imply shared resources. Using the theorem, we can decide the minimum number of the shared resources to obtain the optimal performance, and minimize the idling time of resources. As an example, an automated assembly system is modeled by Timed Place Petri Net, and the initial tokens to achieve the optimal system performance are identified. All the values are verified by simulation.