• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.703-708
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• 2012

This paper proposes the improvement of control performance in the wheeled inverted mobile robot system. and describes the modeling of a wheeled inverted pendulum type mobile robot driven by two different wheels for the position and velocity control. The system is sensitive on the parameter variation, therefore control signal should change to maintain desired state of the system in every instant. we designed proportional-plus-integral controller for our system, After linearization, the system was still unstable, throughout stability analysis of the system, we designed the values of the gains of a proportional-plus-integral controller. From the experimental results, we can find that the performance of the proposed method is better than of the manual tuning method.

• Journal of Drive and Control
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• v.6 no.3
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• pp.18-27
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• 2009

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1721-1726
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• 2004

The studies of the half active suspension have been performed using various suspension models. In the early days, the modeling considered the inputs to the active suspension as the linear forces. Recently, due to the development of new control theory, the forces input to the half car active suspension system has been replaced by an actual input to the hydraulic actuators. Therefore, the dynamic of the active suspension system now consists of the dynamic of half car suspension system plus the dynamic of the hydraulic actuators. This paper proposed a new modeling technique in integrating both dynamic models. The proportional integral sliding mode control technique is utilized to control the hydraulically actuated of the half car active suspension system. The performance of the half car hydraulically actuated active suspension system is simulated with a bump input. The results show that the proposed modeling technique and the proportional integral sliding mode controller are improved the ride comfort and ride handling of the half car active suspension system.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1217-1223
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• 2014

A novel half load-cycle worked dual input single output (DISO) DC/AC inverter is presented. The basic circuit consists of a dual buck regulator, which works in continuous current mode. The working principle of DISO DC/AC inverter has been used. The control method applied for half load-cycle worked DISO DC/AC inverter has been studied. The control effects of the open-loop proportional control and closed-loop proportional-integral control are compared by using PSIM software. The parameters are adopted in the realistic simulation and experiment test. Moreover, the waveforms, such as voltage of modulation reference signal and output voltage, were given. The simulation and experiment results proved that the half load-cycle worked DISO DC/AC inverter could achieve good performance, gain a line frequency of 50 Hz, and verify the correctness of theoretical analysis.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.373-378
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• 1994

This paper is concerned with assess the possibility of robust pole assignment of proportional integral(PI) state feedback control system. First, the equivalence relations between a PI control system and an argumented control system proposed by Kawaji and Kim(1994) are extended from the new points of views of invariant closed loop poles. Second, on the relations, a remarkable result that the integral gain of PI control system is directly related to the insensitivity of system is presented. And, it is shown that the design of robust PI pole assignment is possible under the certain conditions.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.186-189
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• 2005

In a clinical setting, developing a reliable method for the automated drug infusion system would improve a drug therapy under the unexpected and acute changes of hemodynamics. The conventional proportional-integral-derivative (PID) controller might not be able to achieve maximum performance because of the unexpected change of the intra- and inter-patient variability. The fuzzy PID control and the conventional PID control were tested under the unexpected response of mean arterial blood pressure (MAP) to a vasopressor agent during acute hypotension. Compared with the conventional PID control, the fuzzy PID control performed the robust MAP regulation regardless of the unexpected MAP response (average absolute value of the error between target value and actual MAP: 0.98 vs. 2.93 mmHg in twice response of the expected MAP and 2.59 vs. 9.75 mmHg in three-times response of the expected MAP). The result was due to the adaptive change of the proportional gain in PID parameters.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.5
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• pp.275-281
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• 2010

Car HVAC is one of main factors influencing a potential customer's first impression. It should be fault-free, which requires the most stable control performance. So, the control algorithm consists of a proportional feedback only, not with an integral action needed for elimination of steady-state errors. To reduce the errors and make the response faster, feedforward algorithm based on predicted thermal load is added. To evaluate the performance, car HVAC is dynamically modelled and its control logic is simulated. The results shows that the proportional feedback leads to about $4^{\circ}C$ of steady-state error. When the feedback is combined with the feedforward algorithm and with a set value update based on disturbances, it predicts less than $1^{\circ}C$ of control error and improved thermal comfort.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.46-56
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• 1999

A semi-actively controlled impact system which adjusts an impulse exerted by the external impact is studies. The main control variables are internal pressure difference inside the cylinder and the shock absorber displacement while it travels. Compared to a conventional one so called a passive system with a variable orifice inside the cylinder, a semi-actively controlled system utilizes an external orifice controlled by a highly fast responding electrical proportional valve. This device overcomes the temperature and viscosity change due to continuous operating and keeps the desired pressure difference and displacement in every operation. In this article a new prototype impact system is designed and manufactured based on a semi-actively control system. Through computer simulations and experiments, we verify the possibility of controlling the shock absorber pressure and displacement. After investigating the control performance a modified semi-actively controlled system with better control performance is also proposed.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.795-797
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• 1998

This paper suggests a design method of the optimal PD control system having robust performance. This PD control system is designed by applying genetic algorithm(GA) with reference model to the optimal determination of proportional(P) gain and derivative(D) gain that are given by PD servo controller. These proportional and derivative gains are simultaneously optimized in the search domain guaranteeing the robust performance of closed-loop system. This PD control system is applied to the fuel-injection control system of diesel engine and compared with ${\mu}$ -synthesis control system for robust performance. The effectiveness of this PD control system is verified by computer simulation.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.149-153
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• 2005

In the cardiovascular system, the waveform of the pulsatory blood pressure appears variously due to the cardiac impulse and compliance of blood vessels and arm tissue. We have constructed a blood pressure simulator to investigate effects of mechanical properties of artery walls and tissue on blood pressure measurements. The blood pressure simulator is designed to reproduce wave forms of blood pressure in human arteries. To minimize tracking error, we use a linear control valve, and adapt a hybrid control scheme which consists of a feedback controller and a feedforward controller. Any form of the pressure wave can be reproduced, changing function of the wave form in the computer connected to the simulator for control. From experiments, it has been shown that the simulator reproduces wave forms very well, and that the hybrid scheme adapted is superior to the feedback controller.