• Journal of the Korean Society for Precision Engineering
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• v.6 no.2
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• pp.65-76
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• 1989

The objective of this paper is to design the variable structure system(VSS) controller for the tracking control of excavator which is driven by electro-hydraulic servomechansim. It is generally agreed that the dynamic characteristics of the robot arm such as excavator are coupled, time varying, and highly nonlinear, and also hydraulic system contains nonlinear characteristics in itself, so performing exact position control and trajectory tracking control need remarkable consideration. To solve this porblem, this system was designed as a variable structure system. The salient feature of VSS is that the sliding mode occur on a switching surface. While in sliding mode, the system remains insensitive to parameter variations and disturbances. This control algorithm was applied to a hydraulic excavator by simulaltion and to a simulator by experiment. And its effectiveness was verified. And the results of VSS for the electro-hydraulic excavator was compared with that of the PID when load disturbances and system parameter variations exist.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.291-292
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.825-826
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.821-822
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• 2013

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.231-234
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• 1998

In this paper, we proposed a adaptive controller which need not adjustment of the scale factor. We have verified by experimental results that applying this proposed adaptive control algorithm to a hydraulic servo system is very satisfactory.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.603-604
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.559-560
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• 2011

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2015.10a
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• pp.299-300
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• 2015

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.235-237
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• 2018

In spite of the superiority of the sliding method in the building construction field, the AC induction motor servo control device is used as the power control technology in the building construction field in order to improve the problems of the hydraulic power control method, thereby contributing to the precision control and the productivity improvement. Based on Induction Motor Servo Controller, we proposed the development of a mobile sliding method using a complex combination of PC and MITY (MS) Servo.

• Tribology and Lubricants
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• v.25 no.5
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• pp.330-334
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• 2009

Hydraulic servo cylinders have been used to control accurately a large machine in power plant. Especially, Piston head and bush of servo cylinder is assembled sleeve and piston head and bush made of Cu alloy and pad sealing part. A damages of sleeve and piston head, bush are caused by friction and wear. Thus, It is necessary to examine friction and wear characteristics of Cu alloys for the piston head and bush. In this study, to be reliable on the piston and cylinder parts, dry friction and wear experiments were carried out with Cu alloys of four kinds of AlBC, PBC, BC and BS using reciprocating friction tester of pin on disk type. From this study, the result was shown that the AlBC and PBC with alloy elements were excellent to resistance wear. As the sliding speed was increased, the wear loss of PBC decreased than another Cu alloy.