• Journal of the Korean Society for Precision Engineering
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• v.14 no.5
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• pp.118-127
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• 1997

In this study, We use microstep control to reduce vibration of step motor. Microstep control of step motor is usually thought of as an extension of conventional step motor control technology. The essence of micro stepping is that we divide the full step of a step motor into a number of substep called microstep and cause the stepmotor to move through a substep per input pulse. In ideal case, by controlling the individual phase currents of a two-phase step motor sinusoidally we can get uniform torque and step angle. But due to the nonlinear characteristics of the step motor, we need to compensate current waveform to improve the over-all smoothness of the conventional micro stepping system. We implement digital Pulse Width Modul- ation (PWM) driver to drive step motor and microphone was used for detecting vibration. Driver enables speed change automatically by increasing or decreasing micro stepping ratio which we call Automatic Switching on the Fly. To compensate the torque harmonics, neural network is applied to the system and we found compensated optimal input current waveform. Finally we can get smooth motion of step motor in a wide range of motor speed.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.56-59
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• 1996

In this paper, we developed a micro-stepping drive circuit of step motor and proposed software algorithm for parallel operation of step motors drived by micro-stepping circuit. Also, we implemented a parallel operation controller with a 16-bit micro-controller.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.70-75
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• 2001

In this study, we developed a measuring system utilizing machine vision for measuring the precision of positioning of micro stepping motor. The measuring system equipped with CCD Camera, ring illumination and diffuser measures the repeatability and the hysterisis of a micro stepping motor by means of the pointer attached to the motor directly. With the measuring system, it was possible to measure the precision of the micro stepping motor in the resolution of $50{\mu}m$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.448-455
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• 1996

In this study, to reduce vibration of step motor we use Microstep control. Microstep control of stepmotor is usually thought of as an extension of conventional stepmotor control technology. The essence ofmicro stepping is that we divide the full step of a stepmotor into a number of substep called microstep and cause the stepmotor to move through a substep per input pulse. In ideal case, bycontrolling the individual phase currents of a two-phase step motor sinusoidally we can get uniform torque and step angles. But due to the monlinear characteristics of the step motor, we need to compensate current waveform to improve the overall smoothness of the conventional micro stepping system. We implement digital Pulse Width Modulation(PWM) driver to drive step motor and microphone was used for detecting vibration. Driver enables speed change automatically byincreasing or decreasing micro stepping ratio which we call Automatic Switching on the Fly. To compensate the torque harmonics, Neural Networks is applied to the system and we foundcompensated optimal input current waveform. Finally we can get smooth motion of step motor in a wide range of motor speed.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.5
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• pp.358-363
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• 2000

In this paper, a voltage equations, a thrust force equations and kinetic equation are derived from the basic structure of a 2-phase hybrid type linear stepping motor(HLSM). And a micro-stepping method in order to eliminate effectively the resonant phenomena and to increase the positional resolution of the HLSM was proposed. The proposed micro-stepping method can divide one step into the maximum 128 micro-steps under simple control system. The dynamic characteristics of proposed micro-stepping method were analyzed by the ACSL(Advanced Continuous Simulation Language) with the voltage equations, the thrust force equations and the kinetic equation, and were measured by laser experimental system. As the result, the justice of theory was confirmed, and the resonant phenomena, the positional resolution and dynamic thrust were improved by the proposed micro-stepping method.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1261-1263
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• 2005

The micro permanent magnet(PM) type stewing motor preferred solution for many small electronics position determination devices since it is small in size. Thus, there are growing demands for PM type stepping motor that greater mechanical output, smaller size. But, the design of the it, having high performance and small size is very difficult because of its complex mechanical structure. This paper deals with a development of the newly structured micro PM type stepping motor with claw-poles. We introduced the small-sized PM type stepping motor that has new structure and analyzed the magnetic characteristic of it versus general type model using 3-D finite element analysis(FEA).

• 전기의세계
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• v.31 no.1
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• pp.68-73
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• 1982

An accurate mathematical model of permanent magnet stepping motor is proposed. On the basis of this model, micro-stepping control is experimented. A comparison is made between the Data experimented by micro-stepping control and the data predicted by the proposed model and by Leenhouts' earlier model. The result shows that the proposed model is more accurate than the earlier model, and micro-stepping can be attained by dividing a given step electrically, without adding much complexity to the control circuit, or degrading the speed of stepping motors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.420-424
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• 2012

A 2-axis gimbal system is one of main disturbance sources affecting on image jitter response of a satellite. The gimbal system can be rotated on its azimuth and elevation axes, resulting in variation of its moment of inertia and structural modes, so that generates non-linear vibration characteristics. In order to estimate the jitter response, it is an indispensable process to characterize micro-vibration disturbance of the 2-axis gimbal system. In the present research, the vibration characteristics of the 2-axis gimbal system was investigated with respect to the types of stepping motors. The micro-vibration tests were performed for 2-phase and 5-phase stepping motors. The test results show that the disturbance can be reduced with vibration attenuation ratio of 60% by replacing the 2-phase stepping motor with the 5-phase one.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1858-1862
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• 2005

Stepping motor normally operates without feedback and may loss the synchronization. This problem can be prevented by using positional feedback. This paper introduces one method for closed loop control of stepping motor and a method for combining full-step control and micro-step control. This combination controlling apparatus can perform position control with high accuracy in a high speed, so that it will not suffer from vibration (or hunting) problem when stopping motor. Controlling apparatus contains a position counter block for detecting rotor position of stepping motor, a driving block for supplying current to windings of stepping motor, a control block for comparing output signal of position counter block with command position (desired position) and outputting current command signal based on deviation between current position and command position of rotor. To output current command signal, the control block refers to a sine wave data table. This table contains value of duty cycle of Pulse Width Modulation signal. As the second object of this paper, the process of building this data table is also presented.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.23-31
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• 2005

The purpose of this study is to design a disturbance observer for a micro-stepping stage to eliminate the disturbances from cables, friction, mass unbalance of the moving part, etc. The disturbance observer is designed for air-floating X-Y precision micro-stepping X-Y stage which widely used in stepper machine or semiconductor manufacturing systems. The micro-stepping X-Y stage has a weak point of the variation of characteristics with position locations, which caused by various disturbances. In this study, it will be described that a simple and high throughput disturbance observer algorithm improves the dynamic error and settling time of the micro-stepping stage.