• Journal of Electrical Engineering and Technology
• /
• 제13권1호
• /
• pp.418-429
• /
• 2018

This paper studies the decentralized position/force control problem for constrained reconfigurable manipulator without torque sensing. A novel joint torque estimation scheme that exploits the existing structural elasticity of the manipulator joint with harmonic drive model is applied for each joint module. Based on the estimated joint torque and dynamic output feedback technique, a decentralized position/force control strategy is presented. In order to solve the problem of controller parameter perturbation, the non-fragile robust technique is introduced into the dynamic output feedback controller. Subsequently, the stability of the closed-loop system is proved using the Lyapunov theory and linear matrix inequality (LMI) technique. Finally, two 2-DOF constrained reconfigurable manipulators with different configurations are applied to verify the effectiveness of the proposed control scheme in numerical simulation.

• 전기학회논문지
• /
• 제56권2호
• /
• pp.383-388
• /
• 2007

This paper considers a low-order dynamic output feedback controller design problem. Since the proposed control law inherently has a low-pass filter property, it can alleviate the mal-effects of the sensor noise without additional filter designs. Frequency domain analysis shows the characteristics of the proposed control law against measurement noise. The effectiveness of the proposed control law is illustrated by numerical simulations with a rotary inverted pendulum and a convey-crane. Using only one integrator the proposed control law has the advantage to the stabilization problem with sensor noise as well as it can successfully replace the measurements of derivative terms in a state feedback control law.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1994년도 추계학술대회 논문집
• /
• pp.466-471
• /
• 1994

To make a dynamic system a given desired motion trajectory, a new feedback error learning scheme is proposed which is based on the repeatability of dynamic system motion. This method is composed of feedforward and feedback control laws. A benefit of this control scheme is that the input pattern that generates the desired motion can be formed without estimating the physical parameters of system dynamics. The numerical simulations show the good performance of the proposed scheme

• International Journal of Control, Automation, and Systems
• /
• 제5권1호
• /
• pp.70-78
• /
• 2007

We prove that TCP Vegas globally converges to its equilibrium point in finite time assuming no feedback information delay. We analyze a continuous-time TCP Vegas model with discontinuity and high nonlinearity. Using the upper right-hand derivative and applying the comparison lemma, we cope with the discontinuous signum function in the TCP Vegas model; using a change of state variables, we deal with the high nonlinearity. Although we ignore feedback information delay in analyzing the model of TCP Vegas, the simulation results illustrate that TCP Vegas in the presence of feedback information delay shows very similar dynamic trends to TCP Vegas without feedback information delay. Consequently, dynamic properties of TCP Vegas without feedback information delay can be used to estimate those of TCP Vegas in the presence of feedback information delay.

• 센서학회지
• /
• 제18권4호
• /
• pp.274-279
• /
• 2009

In this paper, a wide dynamic range active pixel sensor(APS) with output voltage feedback structure has been designed by a 2-poly 4-metal 0.35 $\mu$m standard CMOS technology. We presented a novel APS with output voltage feedback, which exhibits a wide dynamic range. The dynamic range increases at the cost of an additional diode and an additional MOSFET. The output voltage feedback structure enables the control of the output voltage level by itself, as incident light power varies. It is confirmed that the light level which the output voltage level of proposed APS is saturated is about 120,000 lux, which is higher than that of a conventional 3-transistor APS.

• 한국콘텐츠학회논문지
• /
• 제11권4호
• /
• pp.207-214
• /
• 2011

이 연구는 건강한 성인을 대상으로 30%체중지지 수행력이 되먹임 형태와 보행보조도구에 따라 차이가 있는지를 알아보고, 이를 통해 효과적인 체중지지 훈련방법을 제안하기 위해 실시되었다. 20명의 건강한 성인이 참여하였으며, 겨드랑이 목발과 바퀴보행기를 이용하여 3점 보행을 하는 동안 오른쪽 발에 체중의 30%만 부하하도록 하였다. 훈련을 위해 동적 되먹임과 정적 되먹임을 제공하였다. 훈련 직후와 훈련 3일 후, 보행 동안 %체중지지를 측정하기 위해 힘판을 이용하였고 보행관련 변수를 측정하기 GAITRite를 사용하였다. 30%체중지지의 정확성은 겨드랑이 목발을 이용하고 동적 되먹임을 받았을 때가 가장 정확하였다(p>0.05). 보행보조도구와 되먹임 형태에 따라 %체중지지는 유의한 차이를 보였으며(p<0.05), 훈련 직후와 훈련 3일후의 %체중지지는 유의한 차이를 보이지 않았다(p>0.05). 또한 보행보조도구에 따라 보행속도와 입각기비율이 유의한 차이를 보였다(p<0.05). 따라서 효과적인 체중지지 훈련을 위해서는 가능한 경우 겨드랑이 목발을 이용하여 동적 되먹임을 통한 %체중지지를 교육하는 것이 필요할 것으로 생각된다.

• Journal of Power Electronics
• /
• 제14권1호
• /
• pp.40-47
• /
• 2014

An average current mode control scheme that consistently offers good dynamic performance for LLC series resonant DC-to-DC converters irrespective of the changes in the operational conditions is presented in this paper. The proposed control scheme employs current feedback from the resonant tank circuit through an integrator-type compensation amplifier to improve the dynamic performance and enhance the noise immunity and reliability of the feedback controller. Design guidelines are provided for both current feedback and voltage feedback compensation. The performance of the new control scheme is demonstrated through an experimental 150 W converter operating with 340 V to 390 V input voltage to provide a 24 V output voltage.

• 대한기계학회논문집A
• /
• 제21권8호
• /
• pp.1188-1194
• /
• 1997

In this paper, we design output feedback nonlinear dynamic control law by using state feedback nonlinear dynamic compensator and PI observer and show that the controller can stabilize globally and asymptotically a class of nonlinear systems with mismatched uncertainties. We also show that it is possible for a nonlinear system to use the output of PI observer in place of state variables in case that the nonlinear dynamic control law is used, similarly as in the linear system. The effectiveness of the proposed control law is demonstrated by a numerical simulation.

• 대한기계학회논문집A
• /
• 제21권8호
• /
• pp.1184-1184
• /
• 1997

In this paper, we design output feedback nonlinear dynamic control law by using state feedback nonlinear dynamic compensator and PI observer and show that the controller can stabilized globally and asymptotically a class of nonlinear systems with mismatched uncertainties. We also show that it is possible for a nonlinear system to use the output of PI observer in place of state variables in case that the nonlinear dynamic control law is used, similarly as in the linear system. The effectiveness of the proposed control law is demonstrated by a numerical simulation.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제51권1호
• /
• pp.39-42
• /
• 2002

For the purpose of modeling EEG signal which has nonstationary and nonlinear dynamic characteristics, this paper propose a state feedback real time recurrent neural network model. The state feedback real time recurrent neural network is structured to have memory structure in the state of hidden layers so that it has arbitrary dynamics and ability to deal with time-varying input through its own temporal operation. For the model test, Mackey-Glass time series is used as a nonlinear dynamic system and the model is applied to the prediction of three types of EEG, alpha wave, beta wave and epileptic EEG. Experimental results show that the performance of the proposed model is better than that of other neural network models which are compared in this paper in some view points of the converging speed in learning stage and normalized mean square error for the test data set.