• Journal of Power System Engineering
• /
• v.8 no.1
• /
• pp.55-61
• /
• 2004

In general, the swing motion of the crane is controlled and suppressed by activating the trolley motion. In this paper, we suggest a new type of anti-sway control system of the crane. In the proposed control system, a small auxiliary mass(moving-mass) is installed on the spreader and the swing motion is controlled by moving the auxiliary mass. The actuator reaction against the auxiliary mass applies inertial control forces to the container in order to reduce the swing motion in the desired manner. In this paper, we apply the $H_{\infty}$ based control technique to the anti-sway control system design problem. And the experimental result shows that the proposed control system is useful and robust to disturbances like winds and initial sway motion.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.6 s.177
• /
• pp.1470-1478
• /
• 2000

Analysis of actuating forces and joint reaction forces are essential to determine the capacity of actuators, to control the system and to design the components. This paper presents an algorithm tha t calculates actuating forces(or torques) depending on the various driving types to produce a given system motion. The joint reaction forces(or torques) of multibody systems with closed-loops are analyzed in the Cartesian coordinate space using the inverse velocity transformation technique. Two numerical examples were carried out to verify the algorithm proposed.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.5
• /
• pp.537-542
• /
• 2014

This paper proposes a control system to keep the balance of a unicycle robot. The robot consists of the disk and wheel, for balancing and driving respectively, and the tile angle is measured and used for balancing by the IMU sensor. A PID controller is designed based on a non-model based algorithm to prove that it is possible to control the unicycle robot without any approximated linear system model such as the sliding mode control algorithm. The PID controller has the advantage that it is simple to design the controller and it does not require an unnecessary complex formula. In this paper, assuming that the pitch and roll axis are dynamically decoupled, each of the two controllers are designed separately. A reaction wheel pendulum method is used for the control of the roll axis, that is, for balancing and an inverted pendulum concept is used for the control of the pitch axis. To confirm the performance of the proposed controllers using MATLAB Simulink, the dynamic equations of the robot are derived.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.5
• /
• pp.763-768
• /
• 2005

An improved tandem time-of-flight (TOF) mass spectrometer for the photodissociation (PD) study of ions generated by matrix-assisted laser desorption ionization (MALDI), MALDI-TOF-PD-TOF, has been designed and constructed. Recording a full spectrum with better than unit mass resolution even in low mass range has been achieved without reflectron voltage stepping which was needed in the previous version. Other aspects of the improvement, such as those in the data system which now allow 10-100 times faster spectral acquisition than with the previous instrument, are described. Rationale for the ideas which have led to the improvements is presented also.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.6
• /
• pp.599-607
• /
• 2011

In this paper, a reaction-force compensation system for an XY linear motion stage, without an additional external isolation structure or extra motors, is developed. This system consists of a movable magnet track, a spring, a dummy weight, and a dedicated sensor module that measures the relative positions of the movable magnet track with respect to the motor coil. The reaction force compensation system is modeled, and simulations are carried out to optimize design parameters such as the moving distance of the magnet track, the transmission force, the dummy weight, and the allowed size of the mechanism. An XY linear motion stage is built, incorporating the reaction force compensation system, and the performance of the system is verified experimentally. For acceleration and deceleration values of 10 m/$s^2$, 85% of the reaction force is absorbed by the reaction force compensation system.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.51-55
• /
• 1995

An adaptive unified predictive control (UPC) algorithm is applied to a batch polymerization reactor for poly(methyl methancrylate) (PMMA) and the effects of controller parameters are investigated. Computational studies are performed for a batch polymerization system model developed in this study. A transfer function in parametric form is estimated by recursive least squares (RLS) method, and the UPC algorithm is implemented to control the reactor temperature on the basis of this transfer function. The adaptive unified predictive controller shows a better performance than the PID controller for tracking set point changes, especially in the latter part of reaction course when gel effect becomes significant. Various performance can be acquired by selecting adequate values for parameters of the adaptive unified predictive controller; in other words, the optimal set of parameters exists for a given set of reaction conditions and control objective.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.10a
• /
• pp.671-677
• /
• 2009

A reaction wheel is commonly used, as an important actuator, to control the attitude of a satellite. Operation of the reaction wheel plays a role of an excitation source to loading equipment inside the satellite. As requirements for environmental vibration to manifest the performance of precision equipment are getting more stringent, the research for analysis or reduction of unwanted action force in high frequency range when operating the reaction wheel is necessary. In this paper, the procedure to extract input forces and damping of a rotor system of reaction wheel is suggested. The analysis for measured action forces of reaction wheel is accomplished and important higher harmonics of action forces are determined. The input forces and damping of the rotor system are, then, extracted by curve-fitting and a particular solution for input force.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.3
• /
• pp.263-271
• /
• 2010

A reaction wheel is commonly used, as an important actuator, to control the attitude of a satellite. Operation of the reaction wheel plays a role of an excitation source to loading equipment inside the satellite. As requirements for environmental vibration to manifest the performance of precision equipment are getting more stringent, the research for analysis or reduction of unwanted action force in high frequency range when operating the reaction wheel is necessary. In this paper, the procedure to extract input forces and damping of a rotor system of reaction wheel is suggested. The analysis for measured action forces of reaction wheel is accomplished and important higher harmonics of action forces are determined. The input forces and damping of the rotor system are, then, extracted by curve-fitting and a particular solution for input force.

• The Journal of Korean Medicine
• /
• v.42 no.4
• /
• pp.197-207
• /
• 2021

Objectives: The purpose of this study was to confirm effect of reducing inflammation of Coptis chinensis extract-ceramide complex through the endocannabinoid system (ECS) control in atopic dermatitis. Methods: 8-week-old ICR mice were divided into normal group (Ctrl), lipid barrier elimination group (ADE), palmitoylethanolamide treated group after lipid barrier elimination (PEAT), and Coptis chinensis extract-ceramide complex applied group after lipid barrier elimination (CRA). After inducing atopic dermatitis, cannabinoid receptor (CB) 1, CB2, CD68, p-I𝜅B, iNOS, substance P and serotonin were observed to confirm the regulation of the ECS, macrophage activity and mast cell activity. Results: CB1 and CB2 showed higher positive reactions in the CRA than in the ADE and PEAT. CD68, p-I𝜅B and iNOS showed higher positive reaction in the ADE, PEAT and CRA than in the Ctrl, but the increase in the positive reaction was lower in the CEA compared to the ADE and PEAT. Substance P and serotonin showed higher positive reaction in the ADE, PEAT and CRA than in the Ctrl, but the increase in the positive reaction was lower in the CEA compared to the ADE and PEAT. Conclusions: The effects of Coptis chinensis extract -ceramide complex were confirmed on the regulation of the ECS, macrophage activity and mast cell activity.

• 제어로봇시스템학회:학술대회논문집
• /
• 1990.10a
• /
• pp.463-468
• /
• 1990

A VSC law is derived for the attitude control of an orbiting spacecraft in the presence of disturbance and parameters variation using reaction jets. The switching surface was chosen to be a linear function of tracking error, its derivative and integral. Simulation results are presented to show that in the closed-loop system, precise attitude control is accomplished in spite of uncertainty in the system.