• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.04b
• /
• pp.113-117
• /
• 1995

Grinding operations is accomplished by rotating a gfinding wheel with lots of random abrasive at high speed, and its object is generally obtained the fanal workpiece surface of high quality as well as the maximization of workpiece removal rate. But, especiallysince grinding operations is related with a large amount of functional parameter, it is actually difficult to therapy that the grinding trouble occurs during the grinding process. Therefore, we trytodesign grinding trouble-shooting system utilizing the back-propagation model of neural network. The conceptual method is produced byidentifying the four parameters derived from the grinding power, and we are design te to the grinding trouble-shooting system on the basis of their data. In this paper, cognition and therapy method tothe grinding trouble which utilizes neural network based four identified models are suggested, and implementation results of computer simulation with respect to the grinding burn and chatter vibration is presented.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.1047-1050
• /
• 2002

In this paper, grinding characteristics of cylindrical plunge grinding in 200m/sec of grinding velocity was investigated by use of vitrified CBN wheel. From the experimental result, it was convinced that grinding power is decreased 2.5times and grinding efficiency is heightened 3times more according to increasing wheel velocity 80m/sec to 200m/sec And also, be expected to improvement of surface roughness and roundness by increasing the wheel velocity.

• Journal of Power System Engineering
• /
• v.6 no.1
• /
• pp.50-54
• /
• 2002

The surface roughness is one of important parameters to obtain the high quality of products in grinding process. In precision components, it's level must be limited to a certain range. This study evaluated experimentally grinding characteristics of workpieces in the surface grinding process. The grinding forces were obtained to compare with the grindability of workpieces such as STD11, STS304 and STB2. The surface roughnesses on various workpieces were measured according to increasing the feed and the depth of cut. In addition, the wear amount of wheels according to the number of grinding were obtained. Also the grinding wheel and the ground surface were observed with a microscopic instrument.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10b
• /
• pp.160-163
• /
• 1993

In this paper, design of an automatic grinding robot system for car brazing bead is introduced. Car roof and side panels are joined using brazing, and then the brazing bead is processed so that the bead is invisible after painting. Up to now the grinding process is accomplished manually. The difficulties in automation of the grinding process are induced by variation of position and shape of the bead and non-uniformity of the grinding area due to surface deformation. For each car, the grinding area including the brazing bead is sensed and then modeled using a 2-D optical sensor system. Using these model data, the position and the direction of discrete points on the car, body surface are obtained to produce grinding path for a 6 degrees of freedom grinding robot. During the process, it is necessary to sense the reaction forces continuously to prepare for the unexpected circumstances. In addition, to meet the line cycle time it is necessary to reduce the required time in sensing, signal processing, modeling, path planning and data transfer by utilizing real-time communication of the information. The key technique in the communication and integration of the complex information is obtaining in-field reliability. This automatic grinding robot system may be regarded as a jump in the intelligent robot processing technique.

• International Journal of Precision Engineering and Manufacturing
• /
• v.9 no.3
• /
• pp.3-6
• /
• 2008

Electrolytic in-process dressing (ELID) grinding is a new technique for achieving a nanoscale surface finish on hard and brittle materials such as optical glass and ceramics. This process applies an electrochemical dressing on the metal-bonded diamond wheels to ensure constant protrusion of sharp cutting grits throughout the grinding cycle. In conventional ELID grinding, a constant source of pulsed DC power is supplied to the ELID cell, but a feedback mechanism is necessary to control the dressing power and obtain better performance. In this study, we propose a new closed-loop wheel dressing technique for grinding wheel truing that addresses the efficient correction of eccentric wheel rotation and the nonuniformity in the grinding wheel profile. The technique relies on an iterative control algorithm for the ELID power supply. An inductive sensor is used to measure the wheel profile based on the gap between the sensor head and wheel edge, and this is used as the feedback signal to control the pulse width of the power supply. We discuss the detailed mathematical design of the control algorithm and provide simulation results that were confirmed experimentally.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.9 no.4
• /
• pp.108-116
• /
• 2000

Undesired trouble such as chatter vibration and burning on the ground surface appears frequently in the cylindrical plunge grinding process. Establishment of a credible fault diagnostic system for the grinding process is the major purpose of this study. Power signals generated during the grinding operation were sampled and analyzed to determine the relationship between grinding troubles and behavior of signal changes. In addition, a neural network was optimized with a momentum coefficient a learning rate, and a structure of the hidden layer through the iterative learning process. Based on the established system, success rates of the trouble recognition were verified.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.04a
• /
• pp.20-27
• /
• 2000

A chatter vibration and a workpiece burn are the main phenomena to be monitored in modern grinding processes. This study describes a trouble diagnosis of the cylindrical plunge grinding process using the power and acoustic emission (AE) signals. The raw signals of the power and the AE occurred during the grinding operation were sampled and analyzed to determine the relationship between each fault and change of signals. A neural network that has a high success rate of the fault detection was used. Furthermore, an analysis on the influence of parameters to the chatter vibration and the grinding burn was conducted.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.961-964
• /
• 1997

In this paper, grinding characteristics of ultra high speed cylindrical plunge grinding was investigated by use of vitrified CBN wheel. From the experimental result, it was convinced that grinding power is decreased according to the increase of wheel and workpiece speed due to changing of grinding mechanism which decreases depth of cut and length of contact curve according to increment of wheel speed. And also, stock removal reduction of each gram lead to improvement of surface roughness by increasing the wheel speed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.799-804
• /
• 1997

This paper is concerned with the heat flux distribution and energy partition for creep-feed grinding. Form measurements of transient grinding temperatures in the workpiece sub-surface using an embeded thermocouple, the overall energy partition to the workpiece was estimated form moving heat source theory for a triangular heat flux distribution as 3.0% for down grinding and 4.5% for up grinding. The higher energy partition for up grinding can be attributed to the need to satisfy thermal compatibility at the grinding zone. The influence of cooling outside the grinding zone can be analytically taken into account by specifying convective heat transfer coefficients on the workpiecs surface h /sab a/ heat source (grinding zone) and h /sab b/ behind the heat source. The smaller energy patition together with slightly lower grinding power favors down grinding over up grinding.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.6
• /
• pp.42-48
• /
• 1998

This paper is concerned with the heat flux distribution and energy partition for creep-feed grinding. From measurements of transient grinding temperatures in the workpiece sub-surface using an embedded thermocouple, the overall energy partition to the workpiece was estimated from moving heat source theory for a triangular heat flux distribution as 3.0% for down grinding and 4.5% for up grinding. The higher energy partition for up grinding can be attribute to the need to satisfy thermal compatibility at the grinding zone. The influence of cooling outside the grinding zone can be analytically taken into account by specifying convective heat transfer coefficients on the workpiece surface ha ahead of the heat source (grinding zone) and hb behind the heat source. The smaller energy partition together with slightly lower grinding power favors down grinding over up grinding.