• 한국정밀공학회지
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• 제13권7호
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• pp.90-99
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• 1996

In the area of assembly process of micro-chips and electronic parts on the printed circuit board, surface mounting device(SMD) is used as a fundamental tool. Generally speaking, the motion of the SMD is based on the ball screw system operated by any type of actuators. The ball screw system is a mechanical transformed which converts the mechanical rotational motion to the translational one. Also, this system could be considered as an efficient motion device against mechanical backlash and friction. Therefore a dynamic modeling and state sensitivity analysis of the ball screw system in SMD have to be done in the initial design stage. In this paper, a simple mathematical dynamic model for this system and the sensit- ivity analysis are mentioned. Especially, the bond graph approach is used for graphical modeling of the dynamic system before analysis stage. And the direct differentiation method is used for the state sensit- ivity analysis of the system. Finally, some trends for the state variables with respect to the design variables could be suggested for the better design and faster operating based on the results of dynamic and state sensitivity.

• 한국산업융합학회 논문집
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• 제11권4호
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• pp.209-216
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• 2008

The ball screw position control system driven by a pneumatic motor using continuous sliding mode is proposed. The design and performance of proposed servo system are presented by means of examples tested under practical service conditions. Results of experimental implementation on the proposed system illustrate the effectiveness of the ball screw position control system driven by a pneumatic motor using continuous sliding mode as a servo pneumatic actuator driven by a pneumatic motor.

• 대한기계학회논문집A
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• 제20권1호
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• pp.154-162
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• 1996

Ball screws are commonly used in linear motion feeding systems of various machine tools and automated systems. They are known to have relatively little backlash, high precision and efficiency compared to ordinary lead screws. Furthermore, the effectiveness of ball screw has made it the preferred choice of many newly developed high speed precision feeding units. The motivation of this work is to establish the groove edsigh basis of ball screws for the reduction of contact fatigue failure. In most instances, fatigue failure between ball and shaft groove is due to excessive contact pressure. Especially, the excessive load is causative of plastic flow below the contact surface, which can contribute to surface failure. But, in spite of small load, if groove conformity rate is large, contact pressure is increased and internal shear stress reach the yield value of the material. In such a point, the authors deal with design procedure for deciding the permissible conformity rate of a ball screw groove with the computational evaluation of contact pressure and maximum shear stress.

• 한국컴퓨터정보학회논문지
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• 제22권10호
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• pp.1-7
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• 2017

In this paper, the separation force measuring system is developed. The separation force aries due to adhesive strength between semiconductor epoxy molding compound(EMC) and the metal plate in semiconductor formed plate. In general, when removing the metal plate in semiconductor formed plate from semiconductor epoxy molding compound, excessive strength can result in a increase in semiconductor defect rates, or conversely, if too little force is exerted on the metal plate in semiconductor formed plate, the semiconductor production rates can decrease. In this study, the design criteria for the selection of the AC servo motor, the role of the ball screw, the relationship between the load cell and the ball screw, and the rate of deceleration are given. In addition, minimizing the reject rate of semiconductors and maximizing the semiconductor production rate are achieved through the standardization of the collected separation force data measured by the proposed system.

• 한국정밀공학회지
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• 제13권2호
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• pp.76-83
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• 1996

We have developed the unconventional robot arm which is composed of the two main parts, one is a ball screw and the other is a robot arm. The dynamic systems of the robot arm and ball screw are unstable systems coupled with each other. The ball screw mechanism is unstable system but controllable system. The robot arm's dynamics is quasi stable system when ball screw's angular position is zero, else, unstable system. Our system has the duality between stability and controllability at the view point of control. This duality causes difficulty to control of the robot arm using normal control law. We have investigated the location of the characteristic roots of the dynamic equation. And we have found out that the best condition for the control of the arm is quasi stable state. In this paper, we have proposed multiple control laws which are consist of three components to guarantee the stability and controllability simultaneously. The computer simulations were carried out based on VSC about the angular position control of the robot arm, and it is confirmed that the good performances could be obtained by using new controller.

• 대한기계학회논문집A
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• 제25권1호
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• pp.145-152
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• 2001

Thermal deformation of a machine tool structure can be evaluated from the analysis of the whole temperature field. However, it is extremely inefficient and impossible to know the whole temperature field by measuring temperatures at every point. So, the temperature estimator is required, which can predict the whole temperature field from the temperatures of just a few points. In this paper, a 1-dimensional heat transfer problem is modeled with modal analysis and state space equations. And then the state observer is designed to estimate the intensity of heat source and the whole temperature field in real time. The reliability of the estimator is verified by making comparison between solutions obtained from the proposed method and the exact solutions of examples. The proposed method is applied to the estimation of temperature distribution in a ball screw system.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 춘계학술대회 논문집
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• pp.39-44
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• 1999

It can be acquired the high effective productivity through of high speed, precision of machine tools, and then, machine tools will be got a competitive power. Industrially advanced countries already developed that the high speed feed is 60m/min using the high speed ball screw. Also, a lot of problems have happened the feed drive system. It is necessary to study about the character of positioning accuracy, heat generation and high speed control for feed drive system of high speed. In this study, we make use of the feed drive system with a ball screw of large-scale-lead. We'll develop the feed drive system at the speed of 60m/min. Using the design of the mechanical element and the high speed control, the basic design concept can be established. After manufacturing one-shaft feed drive system and conducting the performance test, it'll be analyzed properties of the high speed feed drive system.

• 한국정밀공학회지
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• 제22권4호
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• pp.113-120
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• 2005

This paper presents the development of the design of the robot element. Robot element design is an important part of robot design since it decides the performance and life time of the robot. It is necessary that the robot kinematics and the robot dynamics are accomplished to design the robot elements. The robot kinematics and dynamics determine the design parameters of the element. We developed a robot element design program with which a designer can design the robot element with convenience and reliability. The program is composed of motor, harmonic driver and ball-screw design. The program is founded on the virtual robot design program. The virtual robot design program is the powerful software which may be used to solve various problems of the robot kinematics and dynamics. The robot element design program may be used to calculate the design parameters of the element that are necessary to design robot element. Therefore, the designer can decide upon the available robot elements available to perform the objective of the robot. The robot element design program is expected to increase the competitiveness and efficiency of the robot industry.

• 한국지능시스템학회논문지
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• 제22권1호
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• pp.22-27
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• 2012

본 논문에서는 볼 나사의 구동에 의해 물체의 파지가 가능한 로봇 그리퍼 메커니즘을 제시한 후, 시뮬레이션을 통하여 제시한 그리퍼 메커니즘의 파지 동작에서 나타날 수 있는 기구학적인 특성을 분석한다. 이를 위하여 구동기의 관절 공간과 그리퍼의 끝 공간간의 기구학적 관계를 파악한다. 제안한 로봇 그리퍼는 하나의 구동모터를 사용하고, 좌우 대칭인 폐체인(closed-chain)을 형성하고 있는 것이 특징이다. 결과적으로, 제안한 로봇 그리퍼는 구조적으로 외력에 강인하고, 하나의 구동모터에 의해 파지 동작이 구현되므로 수월한 파지가 가능하다. 또한 제안된 그리퍼는 파워 파지에 유용한 조임 효과를 갖는다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.221-226
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• 1999

It can be acquired the high effective productivity through of high speed, precision of machine tools, and then, machine tools will be got a competitive power. Industrially advanced countries already developed that the high speed feed is 50m/min using the high speed ball screw. Also, a lot of problems have happened the feed and servo drive system. It is necessary to study about the character of positioning accuracy, heat generation and high speed/accuracy control for feed/servo drive system of high speed/accuracy. In this study, we make use of high performance vertical machine center with a ball screw of large-scale-lead. Also, we'll apply the high-speed/accuracy control technology in this part of feedforward control, multi-buffering block size, etc. Using the design of the mechanical element and high-speed precision control, the basic design concept can be established.