• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.11B no.2
• /
• pp.28-33
• /
• 2001

The subject of this study is to improve the position performance of the linear motion for hybrid type Linear Pulse Motor (HLPM). Generally, there are two applicable methods to ensure precise position control ; a good processing method. This paper is suggested an electrical 125 microstep driving method so as to achieves the excellent control performance, besides the small mechanical manufacture of teeth pitch. The compensation method of digital PI control is apply to step response of stable position control, step error, vibration suppression and the approach to high stability, and the Ziegler-Nichols tuning method is applied to the proper design of control parameter. The proposed control method has been verified by simulation results of the suitable gain and phase margin of bode plot, and from experiment result of step response.

• Proceedings of the KIPE Conference
• /
• 1999.07a
• /
• pp.139-142
• /
• 1999

Recently, the application of the linear machine for industrial field is remarkable increased, especially for the gantry machine and machine tool system. In these application, high precise position control performance is essentially required in steady/transient state. This paper presents the generalized PID position control algorithm which have rare sensitivity to mass and disturbance. Through the experimental results, it is shown that the proposed algorithm have good performance for the linear machine drives in the steady state and transient state in spite of the load mass varing.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.44 no.4
• /
• pp.447-452
• /
• 1995

In this paper a simple method of a position control for brushless DC motor is presented. For precise position control, a high performance torque controller is needed and a novel current control method is proposed. The current controller detects the uncommutating mode current for every 60.deg. (elec. angle) and controls it with PI controller. The current control loop includes the feedforward of back EMF and the feedforward of the neutral voltage between the neutral point of the inverter and the neutral point of the machine. In the position control, the acceleration pattern is calculated from the position reference. Then the speed trajectory is calculated from the acceleration pattern. The experimental results are presented to verify the proposed methods.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.8
• /
• pp.81-87
• /
• 2020

A stable rotational-to-linear motion transformation structure using a driving mechanism with 2 degrees of freedom was developed for an orthogonal mechanism to prevent the interference of each axis in 2D motion. In this mechanism, a step motor was used for precise position control. This structure was developed to maneuver workparts in micro particle blast machining experiments. To determine the real-time performance of micro particle blast machining, the control, input, and output were operated simultaneously and precise position control was implemented, using a timer interrupt with multiple execution codes. The two step motors obtained precise position control by removing backlash with a ball-screw mechanism. The device has menu-type control codes for user-friendliness, and real-time sequence control was simultaneously adopted for user control input.

• International Journal of Precision Engineering and Manufacturing
• /
• v.4 no.5
• /
• pp.5-14
• /
• 2003

Tracking control schemes on the precise mechanical system in presence of nonlinear dynamic friction is proposed. A nonlinear dynamic friction is regarded as the bristle friction model to compensate fer effects of friction. The conventional SMC method often shows poor tracking performance in high-precision position tracking application since it cannot completely compensate for the friction effect below a certain precision level. Thus to improve the precise position tracking performance, we propose the SMC method combined with the disturbance observer having tunable transient performance. Then this control scheme has the high precise tracking peformance as well as a good transient response when it is compared with the conventional SMC method and the similar types of observers, The experiment on the XY ball-screw drive system with the nonlinear dynamic friction confirms the feasibility of the proposed control scheme.

• Proceedings of the KIEE Conference
• /
• 2002.11c
• /
• pp.249-252
• /
• 2002

For a precise position control with the resolution of a micrometer, a dual servo system is constructed using a linear motor and a piezoelectric actuator. The switching mode dual servo algorithm is implemented on a DSP board in which A/D and D/A converters are also mounted. It is shown by the experimental results that the precise position control is performed within a few micrometer of position error by using the dual servo system.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.1052-1055
• /
• 1996

Piezoelectric actuator is widely used in precision positioning applications due to its excellent positioning resolution. However, serious hysteresis nonlinearity of the actuator deteriorates its precise positioning capability. Evenworse, its hysteresis nonlinearity changes as the actuator input frequency varies. In this study, a simple feedforward scheme is proposed and tested through experiments for precision position control when the variance of the system input frequency is significant.

• Proceedings of the KIEE Conference
• /
• 2001.04a
• /
• pp.311-313
• /
• 2001

This paper deals with a precise position synchronous control of two axes rotating systems by a cooperative control method. The system's dynamics including motor drives described by a motor circuit equation and Newton's kinetic formulation about rotating system. Current and speed controllers are designed very simply by conventional PID control law. Also, position synchronous controller designed to minimize position errors according to integration of speed errors between two motors. Then, the proposed control enables the distributed drives by a software control algorithm to behave in a way as if they are mechanically hard coupled in axes. Finally, the validity of the proposed system is confirmed through some simulations and experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.156-160
• /
• 1997

This paper introdues the development of hydraulic cylinder with magnetic sensor detecting absolute and precise position for automation of excavator. The system which is developed can detect absolute position witha little displacement by using algorithm for recognizing datum points, 1/4 divider algorithm and high precision algorithm improved position precision and robustness to noise etc. The solenoid valve and PWM control using saw-toothed wave are used for absolute position control of cylinder, respectively

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.10
• /
• pp.73-80
• /
• 1998

Recently, we have developed a linear brushless DC motor(LBLDCM) with high speed and precise position control performance to apply it to the semiconductor assembly and inspection machinery. It is composed of double side alignment by two armature-stator pairs and each pair is consist of a moving armature with 8 poles by 3 phase coils and a stator with rare earth permanent magnet (Nd-Fe-B) arrays. Through the thrust force analysis on a simplified and whole model of the suggested LBLDCM by an Electromagnetic FEM solver, skew angle of magnet arrays to reduce the thrust force ripple and the winding conditions of the armature is designed. From experimental results, the user's requirements was satisfied and we confirmed distinctly that the repeatable accuracy less than a micron of the linear motion can be obtained at high speed by the developed LBLDCM. This is owing to directly drive the work without the gear train.