• 한국정밀공학회지
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• 제16권5호통권98호
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• pp.66-73
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• 1999

To enhance machining efficiency, tool exchange time have to be reduced. Most automatic tool changer is made up of compound cam and motor. it is not easy to design and manufacture compound cam, and it has no flexibility. But if servo motor is used, it is easy to changer is developed with servo motor, clutch, ball-screw and spline nut. Experimental results show that automatic tool changer designed with servo motor have good faculties.

• 한국자동차공학회논문집
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• 제8권1호
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• pp.124-134
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• 2000

The power wteering system for automobiles is becoming core popular for supporting steering efforts of the drivers, especially for a parking lot maneuver. Though hydraulic power steering has been widely used for a long time, the efficiency of that is not high enough. The motor driven power steering system can solve the problems associated with the hydraulic power steering system. In this study, dynamic model and control algorithm of the ball screw type of MDPS systenem have been derived and analysed by using the method of discrete modeling technology. To improve steering feel and power steering characteristics, the additional scheme is proposed to the conventional power boosting control algorithm. Through simulations, control gain effects to the steering angle gain in the frequency domain were verified. The steering returnability and steering torque phase lag in on-center handing test were performed also.

• 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.

• 한국정밀공학회지
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• 제17권1호
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• pp.21-26
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• 2000

This paper describes a positioning system for ultra-precision that will be utilized in semiconductor manufacturing field and precision machinery. This system is composed with laser scale unit with 10nm resolution, ball screw with LM guide, brushless DC servo motor, vibration isolator and is equipped in chamber for continuous measuring environment. The dynamic of table, the problem of servo control and the traceability for micro step motion are described. These data will be applied for getting more stable system with 50nm resolution.

• 한국기계기술학회지
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• 제13권4호
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• pp.169-173
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• 2011

This study is about the development of remote controlled bollard using the BLDC motor and ball screw with mechatronics theory. A bollard is composed of the sensor part and the control part. The sensor part is consisted of sensors that detect the locations of a bollard. The role of the control part is adjusting motor speed and power through variable resistance. In order to confirm required performance, the speed of decent and ascent of the bollard, the time and the RPM of BLDC motor were tested according to the variable resistance and the applied load with 10 to $72kg_f$.

• 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.

• 한국기계가공학회지
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• 제10권1호
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• pp.54-61
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• 2011

Ball screw systems are largely used in industry for motion control and motor applications. But the problem of noise, which really perplexes us, is highly correlated with the quality in ball screw systems all the way. In this paper, machining process parameters were evaluated in respects of technique, business, produce and quality to verify which impact influences the noise most. In order to adjust and compare, two comparison groups were set with the present parameters bench mark. Different ball screws were produced as specimens for the noise tests. Through comparing the noise performance of different parameters in the machining process respectively, a group of optimized machining process parameters were obtained. Another noise test was proceeded to know how noise performance was improved by optimizing the machining process parameters. At last, surface roughness tests have been done to know how surface roughness improved by optimization. The improvement of surface roughness is the main factor influences the noise performances.

• 한국정밀공학회지
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• 제18권6호
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• pp.133-140
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• 2001

This paper suggests another system for a cutting force measuring tool in a milling process. Generally, tool dynamometer is taken into account for the most appropriate cutting force measuring tool in the analysis of cutting mechanism. However, high price and limited space make it difficult to be in-situ system for controllable milling process. Although an alternative method using AC current of servo-motor has been suggested, it is unsuitable for cutting force control because of small upper frequency limit and noise. The cutting force measuring system is composed of two load cells placed between the moving table bracket and the nut flange part of ballscrew. It has many advantages such as low cost and wide range measurement than tool dynamometer because of the built-in moving table and the low cost load cell. The static and dynamic model of the measuring system using imbeded load cell is introduced. Various Experiments are carried out to validate both models. By comparing the cutting forces from a series of end milling experiments on the tool dynamometer and the system developed in this paper, the accuracy of the cutting force measuring system is verified. Upper frequency limit is measured by the experiment of dynamic characteristics.

• 한국산학기술학회논문지
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• 제11권2호
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• pp.435-442
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• 2010

이동하중을 받는 구조물의 동적 거동은 이동물체의 속도에 따라 정하중을 받을때 보다 큰 처짐을 나타내게 되어 구조물의 설계에 중요한 영향을 미치게 된다. 기계가공이나 볼스크류우를 이용한 위치제어분야에서 개선 및 성능 유지를 위한 해석의 기법이 요구되고 있다. 회전하는 티모센코축을 따라 이동하는 두 개의 이동하중을 받는 시스템에 대한 운동방정식이 Hamilton의 원리로 유도되었다. 무차원화된 속도비, 질량비, Rayleigh 계수비의 영향이 시스템의 응답에 미치는 영향을 해석하였다.

• 한국생산제조학회지
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• 제20권5호
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• pp.589-597
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• 2011

In this paper, optimal tuning of a cross-coupled controller linked with the feedforward controller and the disturbance observer is studied to improve contouring and tracking accuracy as well as robustness against disturbance. Previously developed integrated design and optimal tuning methods are applied for developing the robust tuning method. Strict mathematical modeling of the multivariable system is formulated as a state-space equation. Identification processes of the servomechanism are conducted for mechanical servo models. An optimal tuning problem to minimize both the contour error and settling time is formulated as a nonlinear constrained optimization problem including the relevant controller parameters of the servo control system. Constraints such as relative stability, robust stability and overshoot, etc. are considered for the optimization. To verify the effectiveness of the proposed optimal tuning procedure, linear and circular motion experiments are performed on the xy-table. Experimental results confirm the control performance and robustness despite the variation of parameters of the mechanical subsystems.