• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1983-1989
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• 2005

Industrial robots are powerful, extremely accurate multi-jointed systems, but they are heavy and highly rigid because of their mechanical structure and motorization. Therefore, sharing the robot working space with its environment is problematic. A novel pneumatic artificial muscle actuator (PAM actuator) has been regarded during the recent decades as an interesting alternative to hydraulic and electric actuators. Its main advantages are high strength and high power/weight ratio, low cost, compactness, ease of maintenance, cleanliness, readily available and cheap power source, inherent safety and mobility assistance to humans performing tasks. The PAM is undoubtedly the most promising artificial muscle for the actuation of new types of industrial robots such as Rubber Actuator and PAM manipulators. However, some limitations still exist, such as the air compressibility and the lack of damping ability of the actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. In addition, the nonlinearities in the PAM manipulator still limit the controllability. Therefore, it is not easy to realize motion with high accuracy and high speed and with respect to various external inertia loads in order to realize a human-friendly therapy robot To overcome these problems a novel controller, which harmonizes a phase plane switching control method with conventional PID controller and the adaptabilities of neural network, is newly proposed. In order to realize satisfactory control performance a variable damper - Magneto-Rheological Brake (MRB) is equipped to the joint of the manipulator. Superb mixture of conventional PID controller and a phase plane switching control using neural network brings us a novel controller. This proposed controller is appropriate for a kind of plants with nonlinearity uncertainties and disturbances. The experiments were carried out in practical PAM manipulator and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with phase plane switching control using neural network and without regard for the changes of external inertia loads.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.4
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• pp.469-475
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• 2010

This paper presents controller design of a two wheeled mobile inverted pendulum robot for one man transportation vehicle. Since the overall mass is varying with different drivers, suitable controller gains are obtained through experimental studies. Variation of the center of gravity due to different masses also affects stable balancing control. Thus, the desired balancing angle si required to be modified with respect to different masses. To measure masses for different drivers, a weight scale is used and those data are used for balancing control through communication. The gain scheduling method of using data obtained from experimental studies allows the robot to have stable balancing performances.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.8
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• pp.1572-1576
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• 2011

The electromagnetic levitation(EMS) system is one of the well-known nonlinear system because of its nonlinearity and several control techniques have been proposed. We propose an ${\epsilon}$-scaling partial feedback controller for the ball position control of the EMS system. The key feature of our proposed controller is the use of the scaling factor ${\epsilon}$ which provides a function of controller gain tuning along with robustness. In this paper, we show the stability analysis of our proposed controller and the convergence analysis of the state observer in terms of ${\epsilon}$-scaling factor. In addition, the experimental results show the validity of the proposed controller and improved control performance over the conventional PID controller.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.10
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• pp.44-52
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• 1994

In this paper, we assume that the dynamics of DC motor and nonlinear load are unknown. We propose an inverse dynamic model of DC motor and nonlinear load using the artificial neural network and construck speed control system based on the proposed dynamic model. We also propose another dynamic model with speed prediction scheme using the artificial neural network that removes the undesirable time delay effect caused by the computation time during the real-time control. We suggest a dynamic model which has arbitrary number of speed arguments and is especially effective when the motor and load has large moment of inertia. Next, we suggest a controller that combine the neurocontrol and PID control with constant gain. We show that the proposed neurocontrol systems have capabilities of noise rejection and generalization to have good velocity tracking through computer simulations and experiments.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.286-286
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• 2000

We consider a negative unity feedback control system in which Che PIO, PI, PD or P controller and a transfer function having only poles are in cascade, We define the notion of the structural polynomial which means that there exists a subdomain of the coefficient space in which the polynomial is Hurwitz (left half plane stable) polynomial. We obtain the necessary and sufficient condition of the structure of the transfer function of which the characteristic polynomial is a structural polynomial, In addition, this paper present another necessary and sufficient condition for the existence of a constant gain controller with which the characteristic polynomial is structurally stable, For the structurally stabilizable P controller, it is allowed that the transfer function may not to all pole plants.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.173-174
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• 2007

In this paper, a new speed sensorless control based on an instantaneous reactive power and a fuzzy PI compensator are proposed for the interior permanent magnet synchronous motor (IPMSM) drives. The conventional fixed gain PI and PID controllers are very sensitive to step change of command speed, parameter variations and load disturbance. Also, to the estimated speeds are compensated by using an instantaneous reactive power in synchronously rotating reference frame. In a fuzzy compensator, the system control parameters are adjusted by a fuzzy rule based system, which is a logical model of the human behavior for process control. The effectiveness of algorithm is confirmed by the experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.506-510
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• 2004

A torque transmission system composed of several gears and couplings is flexible. In order to get an exact response of motor, the torsional vibration due to an unexpected change of motor speed must be suppressed. Therefore, it is very important that motor control suppress vibration. Various methods to control it including dual inertia system are proposed. Specially, the method of vibration suppression is that vibration can be suppressed to fee㏈ack the estimated torsion torque via the disturbance observer filter being of normal filter. The suitable Proportional controller and coefficient parameter can be designed using CDM and the torsional vibration also be suppressed, but it has a low degree of adaptability to disturbance. The PID controller can be designed easily, but makes the excessive overshoot and oscillation for system response in the early period. To resolve these problems, simple and practical PID controller with two degree of freedom is proposed recently that it ran improve performance of obeying the reference unconcerned in any disturbance by changing the proportional gain by two degree of freedom parameter. But it has also the defect that parameter a must be changed to obtain the ideal Proportional parameter. On this paper, we design the controller which automatically adjusts parameter u using fuzzy Algorithm to overcome such defects. Also, we compare the proposed method with established one and evaluate them to confirm performance of the designed controller.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.212-217
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• 2011

A scheduling technique for the improvement of yaw motion stability in in-wheel motor vehicle is proposed. Normally vehicle velocity is controlled via conventional PID method. When vehicle is encountered with different road conditions on left and right hand sides, unstable yaw motion is induced due to the driving force difference in both wheels. In this paper a scheduling formular for control gain is derived in terms of experimental results to generate proper counter control action. Simulation result reveals its effective performance in yaw control of in-wheel vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.176-187
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• 1995

The problem of designing intelligent cruise control system for a longitudinal motion of an automobile, which is powered by internal combustion engines coupled to an automatic multispeed transmission, is considered. The basic concept is a vehicle-following system which maintains desired spacing between vehicles. This system actuates throttle with the information of the spacing error so as to maintain proper spacing and improve passenger ride comfort. In designing the controller, a modified controller, i.e, PID gain scheduling and fuzzy controller with fuzzy compensator was developed in order to overcome the nonlinearities of the automobile and obtain better performance. The computer simulation results illustrate that the better vehicle responses were obtained with the modified fuzzy controller and, under this controller, the vehicle responses were found to be relatively insensitive to parameter variations.

• Journal of Wind Energy
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• v.2 no.1
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• pp.90-96
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• 2011

The purpose of this paper is to describe the control system for optimal performance of 2MW gearless PMSG wind turbine system, and to afford some techniques of the algorithm selection and design optimization of the wind turbine control system through analysis of load calculation and control characteristic. Wind turbine control system is composed of the main control system and remote control and monitoring system. The main control system is industrial PC based controller, and the remote control and monitoring system is a server based computer system. The main control system has a supervisory control of the wind turbine with operation procedures and power-speed control through the torque control by pitch angle. There are some applications to optimize the wind turbine system at the starting mode with increasing of rotor speed, and cut-in operating mode to prevent trundling cut-in and cut-out, a gain scheduling of pitch PID controller, torque scheduling and limitation of generation power by temperature limitation or remote command by remote control and monitoring system. Also, the server operation program of the remote control and monitoring system and the design of graphical display are described in this paper.