• 제어로봇시스템학회논문지
• /
• 제8권4호
• /
• pp.338-344
• /
• 2002

In this paper, neural network force tracking control is proposed. The conventional impedance function is reformulated to have direct farce tracking capability. Neural network is used to compensate for all the uncertainties such as unknown robot dynamics, unknown environment stiffness, and unknown environment position. On line training signal of farce error for neural network is formulated. A large x-y table is built as a test-bed and neural network loaming algorithm is implemented on a DSP board mounted in a PC. Experimental studies of farce tracking on unknown environment for x-y table robot are presented to confirm the performance of the proposed technique.

• International Journal of Precision Engineering and Manufacturing
• /
• 제3권3호
• /
• pp.76-81
• /
• 2002

In order to study the fatigue crack and retardation mechanism in variable loading, the effects of crack tip branching in crack growth retardation were examined. The characteristics of crack tip branching behavior were considered with respect to microstructure and crack tip branching angle was examined. Crack tip branching was observed along the grain boundary of finite and pearlite structure. It was found that the branching angle ranges from 25 to 53 degrees. Using the finite element method, the variable of crack driving farce to branching angle was examined. The effective crack driving farce (K$\_$eff/) decreased as the branching angle increased. The rate of decrease was 33% for kinked type and 29% for forked one. It was confirmed that the effect of crack tip branching is a very important factor in crack growth retardation. Therefore, crack branching effect should be considered in building the hypothetical model to predict crack growth retardation.

• Tribology and Lubricants
• /
• 제18권2호
• /
• pp.138-143
• /
• 2002

Abstract - Tribofilms formed on won surface protect the DLC coating surface and decrease the fiction coefficient. However it is very difficult to evaluate their micromechanical properties due to their small thickness, inhomogeneity and discontinuity. The phase contrast images in tapping mode atomic farce microscopy allow an estimation of inhomogeneity in micromechanical properties of the sample surface. The purpose of this investigation is to demonstrate how the phase contrast images contribute to the characterization of thin tribofilms.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제12B권1호
• /
• pp.1-6
• /
• 2002

The severe problem in improving the positioning precision of a permanent magnet linear synchronous motor (PMLSM) is the large detent farce caused by the permanent magnet arrangement. It is generally an undesired effect that contributes to the torque ripple, vibration and noise of machine. The detent force is arisen from the difference of the position of a permanent magnet end and a tooth position. In this paper, the four methods to reduce detent force were studied and analyzed. The methods are adjusting the width of permanent magnet, varying the shape of armature teeth, relocating the permanent magnet, and adjusting the width of permanent magnet and relocating the permanent magnet at the same time. To analyze the detent farce according to flour methods, a two-dimensional Finite Element Analysis [FEA] was used and we compared with the ratio of reduction of the detent farce according to the flour methods.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.497-502
• /
• 2002

This paper describes a design methodology of a tri-axial silicon-based farce sensor with square membrane by using micromachining technology (MEMS). The sensor has a maximum farce range of 5 N and a minimum force range of 0.1N in the three-axis directions. A simple beam theory was adopted to design the shape of the micro-force sensor. Also the optimal positions of piezoresistors were determined by the strain distribution obtained from the commercial finite element analysis program, ANSYS. The Wheatstone bridge circuits were designed to consider the sensitivity of the force sensor and its temperature compensation. Finally the process for microfabrication was designed using micromachining technology.

• 한국정밀공학회지
• /
• 제17권6호
• /
• pp.185-191
• /
• 2000

Recently, a slightest influence to the circuit can be a great damage because the size of semiconductor smaller. It must be controlled the chippingless dicing process and the precision dicing without any damage to tile circuit. In this study, the relationship between chipping effect and the force of dicing was analysed. The rate of chipping was decreased as the farce of dicing decreased. It was also examined that the farce of dicing decreased according to the lower feed rate and higher blade speed. The lower feed rate and the higher blade speed must be controlled to achieve the chippingless process.

• 한국자동차공학회논문집
• /
• 제10권4호
• /
• pp.1-6
• /
• 2002

Engine lubrication system is generally affected by vehicle driving conditions, which are composed of acceleration, braking deceleration and accelerating during cornering. The major reason is due to the oil pan system in which oil is directly influenced by inertia farce caused by vehicle driving conditions. Therefore, to confirm safety of engine lubrication system inertia farce effects are also considered in the developing state. For the purpose, we have carried the engine tilting tests using ourselves made test rig. Verifying the test results we also measured the inertia effects on the engine lubrication system using the circular tuning and slalom test with vehicle. Through the comparison study between two kinds of results we obtained that the engine tilting test rig was very useful to confirm the safety evaluation of engine lubrication system.

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
• /
• pp.288-294
• /
• 2001

Present CAM technology cannot provide important physical property such as cutting farce and machined surface. Thus, the selection of cutting conditions still depends on the experience of an expert or on the machining data handbook in spite of the developed CAM technology. This paper presents an advanced methodology to help the worker to determine optimum cutting condition for CHC machining that excludes the need for expertise of machining data handbook. The virtual machining system presented in this paper can simulate the real machining states such as cutting farce and machined surface error. And virtual machining system can schedule feed rate to adjust the cutting force to the reference force.

• 복식문화연구
• /
• 제9권3호
• /
• pp.447-457
• /
• 2001

Moliere completed classical French comedy by combining farce and commedia dell\`arte. Moliere believed that it was a plays obligation to give a lesson and entertainment. Moliere recreated commedia dell\`arte\`s typical acting patterns and characters in his work. He created with Lully comedie ballet that combined ballet and comedie for taste of Louis 14. Les precieuses ridicules critically displayed women at that time. Both contemporary high status women\`s custom and behavior were the targets of the author\`s synical criticism. There are three notable clothing imageries are shown in this work. First, Moliere used a variety of items in order to show emptiness of noble at that time. Items are ribbon and loop decorated rhingrave, feather decorated hat, perfumed wig and glove, lace covered canon and flower decorated shoes. Second, the author showed people\`s stutus through their clothes. Last, the author used clothing used clothing as a metaphor for hypocrisy. Thus when he said “take off the clothes” he meant take off hypocrisy and return truth.

• International Journal of Precision Engineering and Manufacturing
• /
• 제3권3호
• /
• pp.62-68
• /
• 2002

To satisfy the requirement of the one axis linear positioning system, which is following control of the desired trajectory without following error and is the high positioning accuracy, feed-forward loop having cogging force model is proposed. In the one axis linear positioning system with linear PM motor, cogging force acting as disturbance is modeled analytically. Analytic model of cogging force is verified by result measured from positioning system constructed with linear PM motor. Measured result is very similar with proposed analytic model. Cogging force model is used as feet forward loop in control scheme of linear positioning system. Cogging force feed-forward'loop is obtained from analytic model of cogging farce. Trajectory following error is reduced from 300nm to 100nm by applying the proposed cogging farce feed-forward loop. By using analytic model of cogging force, the control scheme is simplified. Also this analytic model is applicable to calculation of characteristic value of positioning system in design process.