• Journal of Institute of Control, Robotics and Systems
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• v.3 no.1
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• pp.46-51
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• 1997

The optimal control of a continuous process has been performed using genetic algorithms(GAs). GAs are robust and easily applicable for complex and highly nonlinear problems. We introduce the heuristics 'dynamic range' which reduces the search space dramaticaly keeping the robust search of GAs. GAs with dynamic range show the better performance than SQP(Successive Quadratic Programing) method which converges to a local minimum. The proposed methology has been applied to the optimal control of the continuous MMA-VA copolymerization reactor for the production of the desired molecular wieght and the composition of VA in dead copolymer.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.12
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• pp.1238-1243
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• 2008

This paper presents an HILS(Hardware in the Loop Simulations) based experimental study for the UAV's flight trajectory planning/generation algorithms and guidance/control laws. For the various mission that is loaded on each waypoint, proper trajectory planning and generation algorithms are applied to achieve best performances. Specially, the 'smoothing path' generation and the 'tangent orbit path' guidance laws are presented for the smooth path transitions and in-circle loitering mission, respectively. For the control laws that can minimize the effects of side wind, side slip angle($\beta$) feedback to the rudder scheme is implemented. Finally, being implemented on real hardwares, all the proposed algorithms are validated with integrations of hardware and software altogether via HILS.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.3
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• pp.142-149
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• 2002

As is well-known, the maximum power point (MPP) of PV power generation system depends on array temperature and solar insolation, it is necessary to track MPP of solar array all the time. Among various MPP control algorithms, the constant voltage control method, the perturbation and observation (P&O) method and the incremental conductance method (IncCond) have drawn many attractions due to the usefulness of each system. In this parer, the effectiveness of above mentioned three different control algorithms are thoroughly investigated via simulations and preposed efficiency evaluation method on experiment. Both the steady-state and transient characteristics of each control algorithms along with measured efficiency are analyzed, respectively. Finally, a novel MPPT control algorithm combining the constant voltage control and IncCond method for low insolation condition is proposed to improve efficiency of the 3KW PV power generation system.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2561-2563
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• 2000

In this paper, a mathematical vehicle model, the braking force control parameters, the wheel control logic, and vehicle control strategy are presented, in order to analyze the dynamic characteristics of a vehicle equipped with ABS(Antilock Brake System). The full vehicle dynamics model is constructed with sprung mass, brake system, and wheels to verify control algorithms. The valve control algorithms are designed with the wheel accelerations and slip ratio take into consideration. Theses algorithms are applied to the front and rear wheels independently. Simulation is performed under the wet road condition at initial braking speed of 60 [km/h].

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1786-1790
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• 2004

The main objective of this paper is to analyze the performance of various force control algorithms in improving and adjusting the compliance of industrial robots in contact with their environment. Some of fundamental force control algorithms such as sensorless control, impedance control and hybrid position/force control are theoretically analyzed and simulated for various situations of an environment, and then a series of experiments using them were performed. In this paper, a control scheme to use position control in implementing the impedance control was investigated in order to nullify the effect of joint friction. The new reference trajectory is generated using contact force feedback and original desired trajectory. And an inner position control loop is designed to provide accurate position tracking for the new reference trajectory and good disturbance rejection. Experiments to insert a peg in a hole (so-called the peg-in-a-hole task) were performed with HILS (hardware-in-theloop simulation) system based on the results of the analyses and simulations on the characteristics of each control algorithm. The experiments showed that various force control methods improved the performance of robots in close contact with the environment by adjusting their compliance with respect to an arbitrary set of coordinates.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.286-289
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• 1996

Two servo control algorithms are suggested to reduce the tracking error of a computer hard disk drive. One is the repetitive control to reduce the repeatable tracking error which is not explicitly taken into account in the design of a conventional controller. This algorithm was successfully applied to a commercial disk using a fixed point DSP. The other is the multi-rate sampling control which generates the control output between each sampling times since the sampling time of hard disk drives is limited. These algorithms were shown effectively to reduce tracking errors.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.138-143
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• 1989

In considering the singularities of robot, singularity avoidance control of robot wrist is very important. Because it is more difficult structurally to exclude the wrist singularity than the arm singularity. Since control policies with Jacobian may bring about mathematical singularities, control policies with Euler parameters that never cause mathematical singularities are necessary. In this research, singular status of robot wrist was analyzed and control algorithms for 3 and 4 axes robot wrist were proposed. Application results of the proposed control algorithms to the path including singularity showed us usefulness and validity.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.281-286
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• 1992

This paper describes a duplexed process control system for a boiler-turbine system of power plant, which is composed of supervisor, controller, and simulater subsystems. Its embeded POL(Problem oriented language) as a structured control language enables this system to do a real-time distributed control and fault diagnosis by simple programming with the actual implementation of advanced control algorithms such as PID autotuning and GPC, etc, the performance of overall system has been greatly enhanced.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.60-64
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• 1997

Designing fuzzy controller, there are difficulties that we have to determine fuzzy rules and shapes of membership functions which are usually obtained by the amount of trial-and-error or experiences from the experts. In this paper, to overcome these defects, genetic algorithms which is probabilistic search method based on genetics and evolution theory are used to determine fuzzy rules and fuzzy membership functions. We design a series compensation fuzzy controller, then determine basic structures, input-output variables, fuzzy inference methods and defuzzification methods for fuzzy controllers. We develop genetic algorithms which may search more accurate optimal solutions. For evaluating the fuzzy controller performances through experiments upon an actual system, we design the fuzzy controllers for the speed control of a DC series motor with nonlinear characteristics and show good output responses to reference inputs.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.639-644
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• 2003

An unstructured environment requires a robot to possess outstanding mobility and advanced control algorithms since there exist complicated configurations such as obstacle, uneven surface, etc. Especially, when a quadruped robot walks in these environments, obstacles in the walking route will obstruct the walking or may give rise to a serious trouble. In this paper, we introduce a strategy for the stable walking in unstructured environment. The proposed strategy consists of two control algorithms. One is a collision{free algorithm to avoid obstacles and the other is an algorithm to overcome any obstacle. These are based on the obstacle detection method and a shape reconstruction algorithm, Which algorithms are described in detail. In addition, the validity of these algorithms have been demonstrated through experiments using a quadruped walking robot called "MRWALLSPECT III(Multifunctional Robot for Wall inSPECTion version 3 )".