• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.113-118
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• 1993

This paper represents mechanical compliance & ZMP(Zero Moment Point) control algorithm for IWR(Inha Walking Robot) system. In case of walking in different environments, a biped walking robot must vary its gait(walking period or step length, etc.) according to the environments. However, most of biped walking robots do not have the capability to change their gaits or need more complex control algorithm, because ZMP cannot be defined in their control algorithm. Therefore new linear type with balancing joint is proposed which is used as an aid in balancing & ZMP control itself. In IWR system, ZMP can be defined by solving differential equations and it does not need to be predefined ZMP trajectory. Furthermore we can input the desired ZMP position. In parallel with the development, we also considered a mechanical compliance for reducing the inverse kinematics, dynamics and the control complexity. It will figure out some powerful adaptation with 3D irregular terrains.

• International Journal of Control, Automation, and Systems
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• v.6 no.3
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• pp.386-393
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• 2008

A position control method for interpolating aspherical grinding and polishing tool path was reviewed and experimented in a nano precision machine. The position-base algorithm was reformed from the time-base algorithm, proposed in the previous study. The characteristics of the algorithm were in the velocity control loop with position feedback. The aspherical surface was divided by an interval at which each velocity and acceleration were calculated. The theoretical velocity was corrected by position error during processing. In the experiment, a machine was constructed and nano-scale linear encoders were installed at each axis. Relation between process parameters and the variation of position error was monitored and discussed. The best result from optimized parameters showed that the accuracy was 150nm and improved from the previous report.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.896-899
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• 1996

A new algorithm for planning a collision free path is developed based on linear parametric curve. A collision-free path is viewed as a connected space curve in which the path consists of two straight curve connecting start to target point. A single intermediate connection point is considered in this paper and is used to manipulate the shape of path by organizing the control point in polar coordinate (.theta.,.rho.). The algorithm checks interference with obstacles, defined as GM (Geometry Mapping), and maps obstacles in Euclidean Space into images in CPS (Connection Point Space). The GM for all obstacles produces overlapping images of obstacle in CPS. The clear area of CPS that is not occupied by obstacle images represents collision-free paths in Euclidean Space. Any points from the clear area of CPS is a candidate for a collision-free path. A simulation of GM for number of cases are carried out and results are presented including mapped images of GM and performances of algorithm.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.9
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• pp.922-931
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• 2011

An efficient calibration algorithm for mobile robot localization using infrared range finder is proposed. A calibration is important to guarantee the performance of other algorithms which use sensor data because it is pre-process. We experimentally found that the infrared range finder PBS-03JN has error characteristics depending on both distance and scan angle. After obtaining 2-D grid error characteristic data on distance and scan angle, we proposed a simple and efficient calibration algorithm with a 2-D piecewise linear function set. The performance of our proposed calibration algorithm is verified by experiments and simulation.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.154-159
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• 1989

This paper presents a motion planning algorithm for conveyor tracking. We formulate the problem as the linear quadratic tracking problem in optimal control theory and solve it through dynamic programming. In the proposed algorithm, the steady-state tracking error is eliminated completely, and the joint torque, velocity, acceleration, and jerks are considered as some constraints. Numerical examples are then presented to demonstrate the utility of the proposed motion planning algorithm.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.581-584
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• 1998

This paper presents a scheme for fuzzy modelling and control of continuous-time nonlinear systems using a genetic algorithm. A fuzzy model is characterized by fuzzy "if-then" rules whose consequence part has a linear dynamic equation as subsystem of the system. The parameters of the fuzzy model are adjusted by a genetic algorithm. Then a tracking controller which guarantees stability of the overall system is designed. The simulation result demonstrates the effectiveness of the proposed method.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.6
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• pp.63-72
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• 2005

In this paper, we propose the bit-rate control algorithm for the block based image compression like H.263, H.263+ or MPEG-4. The proposed algorithm is designed to identify the quantization parameter set through the Lagrangian optimization technique based on the well-known linear source model. We set the Lagrangian cost function with the rates and distortion calculated from the linear source model. We calculate the quantization parameter set using the Vitervi algorithm to solve the Lagrangian optimization problem considering the Dquant method of H.263 and MPEG-4. The proposed algorithm improves the video quality by up to 1.5 dB compared with the TMN8 scheme, and is more effective in the video sources with dynamic activities than the consistent quality approaches.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1185-1188
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• 1996

In this paper we present a genetic approach for trajectory control algorithm of balancing weight for IWR biped walking robot. The biped walking robot, IWR that was made by Automatic Control Lab. of Inha University has a trunk which stabilizes its walking by generating compensation moment. Trunk is composed of a revolute and a prismatic joint which roles balancing weight. The motion of balancing weight is determined by the gait of legs and represented by two linear second order ordinary differential equations. The solution of this equation must satisfy some constraints simultaneously to have a physical meaning. Genetic algorithm search for this feasible motion of balancing weight under some constraints. Simulation results show that feasible motion of balancing weight can be obtained by genetic algorithm.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.29-43
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• 1997

An integrated optimal control modelhas been formulated to address dynamic freeway diversion control process. The purpose of this paper is to develop an effective and efficient approach for simultaneous]v solving optimal control measures, including on-ramp metering rates, off-ramp diversion rates, and g/C ratios for traffic signals, on a real-time basis. By approximating the flow-density relation with a two-segment linear function, the non-linear optimal control problem can be simplified into a set of piece-wised linear programming models and solved with the proposed SLP algorithm. consequently, an effective on-line feedback method has been developed for integrated freeway corridor control in the framework of the ITS

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.434-439
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• 2019

This paper proposed a control algorithm to compensate the delay time to improve the signal to noise, and the proposed control algorithm estimate the target information to apply the continuous wave radar equation. The proposed control algorithm improves the output signal of each array element bv multiplying the weight of the receive signal to the signal to noise ratio. Radar radiate a signal in spatial and the target information is estimated by the echoed signal from the target. But the signal in the wireless communication environment occurs the delay time due to the multipath which appear human and natural structures. It is difficult to accurately estimate the desired information because of the degradation for the system performance due to the interference signal and the signal distortion. The target information can be improved by compensating the delay signal to apply the weight to the received signal by using the uniform linear array antenna. As a simulation result, we show that the performance of the proposed control algorithm and the non-compensated delay time are compared. The proposed control algorithm proved that the target distance estimation information is improved.