• 한국정밀공학회지
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• 제13권10호
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• pp.123-129
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• 1996

Computed torque method has been used for precise trajectory control of the robotic system that involves nonlinear dynamics. It is hard to know exact values of robot system parameters, and the robot arm receives umpredictable interference from the working environment. These disturbances, especially in a direct drive robot, are directly transmitted to actuating motor without reduction. Modelling error and distrubance can cause significant errors in a trajectory tracking problem. In this paper, we propose a new controller that $H_{\infty}$controller is conbined to robot system linearized by computed torque. Simula- tions are made for comparing the performance of the proposed controller with that of a nonlinear $H_{\infty}$ controller proposed by Chen and also computed torque method.hod.

• 제어로봇시스템학회논문지
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• 제17권2호
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• pp.139-144
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• 2011

We consider the stabilization problem for a class of networked control systems with random delays in the discrete-time domain. The controller-to-actuator and sensor-to-controller time-delays are modeled as two Markov chains, and the resulting closed-loop systems are Markovian jump nonlinear systems with two modes. The T-S (Takagi-Sugeno) fuzzy model is employed to represent a nonlinear system with Markovian jump parameters. The aim is to design a fuzzy controller such that the closed-loop Markovian jump fuzzy system is stochastically stable. The necessary and sufficient conditions on the existence of stabilizing fuzzy controllers are established in terms of LMIs (Linear Matrix Inequalities). It is shown that fuzzy controller gains are mode-dependent. Finally, a simulation example is presented to illustrate the effectiveness of the proposed design method.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1997년도 추계학술대회 학술발표 논문집
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• pp.356-359
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• 1997

Recently many studies have been conducted of fuzzy modeling since it can describe a nonlinear system better than the conventional methods. A famous researcher, M. Sugeno, suggested a fuzzy model which superbly describes a nonlinear system. In this paper, we suggest a new identification method for Sugeno-typo fuzzy model. The suggested algorithm is much simpler than the original identification strategy adopted in [1]. The algorithm suggested in this paper is somewhat similar to that of [2]. that is, the algorithm suggested in this paper consists of two consists of two steps: coarse tuning and fine tuning. In this paper, double clustering strategy is proposed for coarse tuning. Finally, the results of computer simulation are given to demonstrate the validity of this algorithm.

• 대한기계학회논문집A
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• 제25권2호
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• pp.283-288
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• 2001

A throttle/brake control law for the intelligent cruise control(ICC) systems has been proposed in this paper. The ICC system consists of a vehicle detection sensor, the control algorithm and a throttle/brake actuators. For the control of a throttle/brake system, we introduced a solenoid-valve-controlled electronic vacuum booster and a step-motor controlled throttle actuator. Nonlinear computer model for the electronic vacuum booster has been developed and the simulations were per formed using a complete nonlinear vehicle model. The results indicate the proposed throttle/brake control law can provide the ICC system with an optimized performance.

• 동력기계공학회지
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• 제12권1호
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• pp.72-79
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• 2008

This paper designs a looper-tension controller for mass-flow stabilization in hot strip finishing mills. By Newton's 2nd law and Hooke's law, nonlinear dynamic equations on the looper-tension system are firstly derived, and linearized by a linearization algorithm using a Taylor's series expansion. Moreover, a tension calculation model is obtained from the nonlinear dynamic equations which is called as a soft sensor of strip tension between two neighboring stands. Next, a looper-tension servo controller is designed by an ILQ(Inverse Linear Quadratic optimal control) algorithm, and it is combined with a minimal disturbance observer which to attenuate speed disturbances by AGC and operator interventions, etc.. Finally, it is shown from by a computer simulation that the proposed ILQ controller with a disturbance observer is very effective in stabilizing the strip mass-flow under some disturbances, moreover it has a good command following performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.68-70
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• 1996

A fuzzy network using genetic algorithm is investigated in the context of control for finite dimensional nonlinear discrete systems. The proposed FN(Fuzzy Network) constructed to identify various parameter of fuzzy control is used for the nonlinear system control. Each of two FN, presented FN control system is based on a framework of closed loop control. A proposed FNN model trains using the modeling error and the closed loop error. That case study shows that the presented FN model and closed loop control system is very useful in practical sense.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.79-83
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• 1989

In this paper an engine system model is developed to characterize abd dynamic interactions among various process of engine components in the system utillizing computer simulation. simulation of the dynamics or the entire engine process and emission, including alf-fuel inlet element, intake manifold, combustion unit is carried out.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.620-628
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• 1991

For a Stationary moving-target. the design technique of guidance system for underwater vehicle with a seeker of st type is developed. Using perturbation theory, a new method which linearizes the nonlinear intercept geometry is proposed. On the basis of the linearized system modeling, LQ and PID design technique is used to determine the structure and gain of the guidance system. Some simulation results applied underwater engagement are represented to show that the proposed guidance law is superior to the other guidance laws as pursuit, Bang-Beng, PN APN.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.34-39
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• 1998

This paper describes the simulation approaches employed for a vector control system of induction motor drive using SIMNON for windows program. SIMNON program tool can solve differential and difference equations for nonlinear dynamical control system. One powerful feature is its ability of allowing integration of individual program modules after each individual module is programed and tested independently. This particular feature is exploited here for an SVPWM inverter drive by real-time modeling and simulation. The suggested programs are provided a simple and complete simulation for induction motor vector drive system.

• Journal of Advanced Marine Engineering and Technology
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• 제23권2호
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• pp.244-251
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• 1999

Large dynamic loads act on the rotor in rotary compressors. There are unbalance forces due to eccentric rotation parts and gas forces induced by the pressure difference between compression and suction gases. Rotor-journal bearing system is nonlinear since the stiffness and damping coef-ficients of the lubrication oil film are not constant in the bearings. in this paper the program for predicting the behaviors of rotor-journal bearing system of rotary compressor is developed. Finite element modeling is used to analyze the flexible rotor. The numerical results are compared with experimental results.