• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.648-653
• /
• 1993

This paper presents an nonlinear observer scheme for flexible joint robot manipulators. This nonlinear observer scheme is based on the sliding mode method. Sliding controllers have recently been shown to feature excellent robustness and performance properties for specific classes of nonlinear tracking problems. Dynamic equations of flexible joint robot manipulators are derived from the Euler-Lagrange equations by forming the corresponding Lagrangian. Simulation results are presented to show the validness of the proposed nonlinear observer scheme.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.22 no.3
• /
• pp.284-290
• /
• 2012

In this research, a new type of haptic master device using electrorheological(ER) fluid for minimally invasive surgery(MIS) is devised and control performance of the proposed haptic master is evaluated. The proposed haptic master consists of ER bi-directional clutch/brake for 2 DOF rotational motion(X, Y) using gimbal structure and ER brake on the gripper for 1 DOF rotational motion (Z). Using Bingham characteristic of ER fluid and geometrical constraints, principal design variables of the haptic master are determined. Then, the generation of torque of the proposed master is experimentally evaluated as a function of applied field of voltage. A sliding mode controller which is robust to uncertainties is then designed and empirically realized. It has been demonstrated via experiment that the proposed haptic master associated with the controller can be effectively applied to MIS in real field conditions.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.357-360
• /
• 1997

This paper presents a new anti-lock brake system(ABS) using electro-rheological(ER) valve actuators for the wheel slip control. The hydraulic dynamic model of the automotive brake system is formulated by incorporating electric field-dependent Bingham properties of ER fluid obtained experimentally. The brake system designed by this hydraulic model is able to control wheel slip by controlling the intensity of electric field which tunes the braking torque. The control fields of the ER valve to command desired wheel slip are determined by a sliding mode controller. A comparison between the proposed brake system and the conventional brake system is made by providing with computer simulations of vehicle motions under ABS performance requirement condition.

• Journal of Institute of Control, Robotics and Systems
• /
• v.9 no.4
• /
• pp.320-328
• /
• 2003

This paper proposes a new nonlinear adaptive guidance law. Fourth order state equation for integrated guidance and control loop is formulated considering target uncertainties and control loop dynamics. The state equation is further changed into the normal form by nonlinear coordinate transformation. An adaptive nonlinear guidance law is proposed to compensate for the uncertainties In both target acceleration and control loop dynamics. The proposed law adopts the sliding mode control approach with adaptation fer unknown bound of uncertainties. The present approach can effectively solve the existing guidance problem of target maneuver and the limited performance of control loop. We provide the stability analyses and demonstrate the effectiveness of our scheme through simulations.

• Proceedings of the KIEE Conference
• /
• 1991.11a
• /
• pp.144-147
• /
• 1991

For the control of induction motor, there are many methods which guarantee robustness. Especially, this paper proposes vector control strategy and sliding mode control method which has insensitivity to disturbances and parameter variations. Furthermore, by construction of a new switching function the controlled variable structure system can remove reaching phase deteriorating robustness at the transient state of the conventional sliding mode algorithm. The usefulness of the proposed control algorithm is verified by the simulations and experiments.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.915-918
• /
• 2006

This paper presents an active vibration control of a 1-DOF system using a hybrid mount which consists of elastic rubber and electromagnetic actuator. After identifying stiffness, damping properties of the elastic rubber and electromagnetic element, a mechanical model of the hybrid mount is established. The mount model is then incorporated into the 1-DOF system and the governing equation of motion is obtained in a state space. A sliding mode controller is designed in order to actively attenuate the vibration of the system control responses such as acceleration and transmitted force of the 1 -DOF system are presented in time domain.

• Proceedings of the KIEE Conference
• /
• 1991.07a
• /
• pp.508-511
• /
• 1991

In this paper, we have analyzed the transient and steady state characteristics of buck type DC-DC converter using the sliding mode control method based upon VSS. This control method provides the easier analysis tool due to the time domain analysis and the acquirement of desired transient characteristics if the slope of the switching line is properly selected, and guarantees the robustness against parameter uncertainties and load disturbances. Also, it can achieve direct nonlinear control without linearizing approximation of state space averaging method. PSPICE simulation results are then presented verifying these concepts.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.1
• /
• pp.70-75
• /
• 2010

The objective of this paper is to propose a new velocity measurement method for an electro-mechanical fin actuator. The model of the electro-mechanical fin actuator includes uncertainties such as unknown disturbances and parameter variations in flight condition. So, an electro-mechanical fin actuator system needs robust control algorithm which requires not only position information but also velocity information. Usually, analog tachometers have been used for velocity feedback in an electro-mechanical fin actuator. However, using these types of sensors have problems such as the cost, space, and malfunction. These problems lead to propose a new velocity measurement method using linear type Hall-effect sensor. In order to verify the proposed method, several experiments are performed using Model Following Sliding Mode Controller(MFSMC). It is shown that the MFSMC with a new velocity measurement method using linear type Hall-effect sensor can satisfy the requirements without using of velocity sensor.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.2
• /
• pp.551-559
• /
• 2015

This paper's focus is in reducing the torque ripple and increasing the average torque by optimizing switching angles of 8/6 switched reluctance motor while implementing a robust speed controller in the outer loop. The mathematical model of the machine is developed and it is simulated using MATLAB/Simulink. An objective function and constraints are formulated and Optimum turn-on and turn-off angles are determined using Particle swarm optimization and Genetic Algorithm techniques. The novelty of this paper lies in implementing sliding mode speed controller with optimized angles. The results from both the optimization techniques are then compared with initial angles with one of them clearly being the better option. Speed response is compared with PID controller.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.7 s.124
• /
• pp.617-623
• /
• 2007

This paper presents an active vibration control of a dynamic system using hybrid mount which consists of elastic rubber-piezostack actuator and elastic rubber-electromagnetic actuator, respectively. After identifying stiffness, damping properties of the elastic rubber, PZT actuator and electromagnetic element, a mathematical model of the hybrid mount is established. The mount model is then incorporated into the dynamic system and the governing equation of motion is obtained in a state space. A sliding mode controller is designed in order to actively attenuate the vibration of the system. Control responses such as acceleration and transmitted force of the dynamic system are experimentally evaluated and presented in time and frequency domains.