Tai Yong Wang

Research on Material Removal Algorithm Model in Virtual Milling Process Based on Adaptive Dynamic Quadtrees Algorithm

The realistic dynamic image of virtual milling process is important in the field of virtual manufacturing technology. However, it is difficult to realize virtual 3-D workpiece model removing process. Material removal algorithm model based on an adaptive dynamic quadtrees algorithm is proposed in this paper. Based on mathematical model of virtual material removal, the 3D model of virtual CNC milling process was developed. The real-time simulation of material removal process was realized in the virtual reality environment.

Experimental research on the residual stress in the surface of silicon nitride ceramic balls

Abstract The influence of thermal stress produced in sintering and mechanical stress formed in the lapping process on the residual stress in the surface of silicon nitride ceramic balls is discussed in this paper. By measuring the specific volume, the distribution of residual stress was analyzed and calculated. Some experimental research on the influence of the lapping process on the residual stress in surface of the balls was conducted. The surface of silicon nitride ceramic balls presented residual compressive stress after sintering and residual tensile stress after lapping. In the lapping process, the abrasive particles were finer and the load acting on the lapped balls was larger, the amplitude of the residual tensile stress in the surface of the silicon nitride balls being greater.

Mathematical Model and Tooth Surface Representation of Face-Gear Drive with Curvilinear-Tooth Cylindrical Gear

A tilted head-cutter is considered the generating tool for the generation of the proposed face-gear and a mathematical model of face-gear with curvilinear shaped teeth is developed according to the differential geometry and meshing theory. The generation of a conjugated pinion is based on application of a tilted head-cutter as well. Computer graphs of the gear with curvilinear shaped teeth are presented based on the developed gear’s mathematical model, and then the equation of the gear-tooth surface is deduced. An example is presented to demonstrate the application of the proposed mathematical model.

Research on Intelligent CNC Platform Based on Hierarchical and Distributed Architecture for Grinding Machine

Grinding is a complex process and grinding automation based on CNC technology is developing forward flexibility, intelligence and integration. A CNC system for grinding machine is gradually becoming a complex controlling platform with all kinds of advanced functional units and interfaces. The trend of unlimitedly increasing functional modules and peripheral interfaces causes two unfavorable results. One is that more and more system resources are occupied, which weakens the ability of CNC system in real-time task controlling and rapid events responding. The other one is that the whole system is gradually falling into some chaotic and unstable expanding status. So it is necessary to add reasonable decentralization tactics to the architecture of integrated CNC system for a balance status of necessary functions and optimized performance. This paper aims at the establishment of an intelligent CNC platform for grinding machine, and brings forward the conceptions of hierarchical platform, decentralized control, sharable resources and disassembling tasks to realize the simultaneous satisfactions of completed functions, reliable performance and simple interactivity of an intelligent CNC system platform for grinding machine. Introduction Grinding is a complex process infected by all kinds of dynamic field machining conditions and grinding automation based on CNC technology is developing forward flexibility, intelligence and integration. CNC system for grinding machine is gradually becoming a complex controlling platform with all kinds of advanced functional units and interfaces [1]. Although there are many advantages about system integration such as united management, improved controlling ability, abundant interfaces and so on, the trend of unlimited increasing functional modules and peripheral interfaces causes two unfavorable results. One is that more and more system resources are occupied by the burdened process for coordinating and managing a great deal of task groups, which weakens the ability of CNC system in real-time task controlling and rapid events responding. When a system is assigned to strict real-time controlling tasks, any minor delay can cause unpredicted consequence or malfunction. The other one is that the whole system is gradually falling into some chaotic and unstable expanding status, that is, the scale and complexity are unexpectedly increased as the enriching process of new functional modules being integrated into the system, which makes the system more and more inflexible or overstaffed both in operating methods and peripheral interfaces [2]. This paper aims at the establishment of an intelligent CNC platform for grinding machine, and brings forward the conceptions of hierarchical platform, decentralized control, sharable resources and disassembling tasks to realize the simultaneous satisfactions of completed functions, reliable performance and simple interactivity of an intelligent CNC system platform for grinding machine. Dynamic and Floating Hierarchical Structure of CNC Platform Hierarchical system architecture is a well-chosen design scheme to resolve the complexity of highly-integrated CNC platform. But most of the current researches or applications on hierarchical system architecture are limited to the software fields, which can only solve the problem of complicated process controlling algorithm and massive information management, but can do little to Key Engineering Materials Online: 2004-03-15 ISSN: 1662-9795, Vols. 259-260, pp 715-719 doi:10.4028/www.scientific.net/KEM.259-260.715

Application of Complex Shifted Morlet Wavelet in Vibration Monitoring of Spindle Bearing of Crank Shaft Grinder

Grinder is one of key equipments in machining of crank shaft of automobile motor. So its vibration monitoring and fault diagnosis plays an important role in guaranteeing product quality and productivity. This paper builds an on-line vibration monitoring system for spindle bearings in which the complex shifted Morlet wavelet is adopted to realize the envelop demodulation and feature extraction so as to identify the type of fault. The main advantage of this method is that the center frequency and bandwidth are obtained not by user according to experience value manually, but by calculating for vibration signal. Therefore, it is very suitable for on-line monitoring and automatic fault diagnosis. The analysis of typical fault signal of rolling elements bearing shows that it can diagnose the fault accurately. Introduction The fault diagnosis of crank shaft grinder is critical for guaranteeing product quality and productivity and bearing fault is one of commonly encountered faults in grinder. Therefore, fault identification of rolling elements bearing has been the subject of extensive research. Different methods are used for detection of bearing defects, such as the shock pulse; envelop demodulation and acoustic emission method [1], etc. Among those, envelop demodulation based methods offer more reliable diagnosis potential, since they are based on more solid physical background. The traditional Hilbert transform is well established [2]. However, a major disadvantage of this method is that the selection of parameters is based on experience of the end user. So the complex shifted Morlet wavelet based demodulation is adopted in this paper to realize fault diagnosis of rolling elements bearing automatically. By analyzing of inner, outer race and roller fault signal, it will be concluded that this method can realize the auto-diagnosis of rolling elements bearing accurately. This paper is organized as follows. In section 1, a review of constant wavelet transform of discrete signal is given and the complex shifted Morlet wavelet is introduced in section 2. In section 3, the auto-envelop demodulation based on complex shifted Morlet wavelet is proposed to realize feature extraction of signal and the corresponding algorithm is given .In section 4, A monitoring system based on method proposed above is built to detect fault of rolling element bearing of grinder. By analyzing for signal sampled from grinder, the correctness of this method is testified. In section 5, the conclusions are given. Review of CWT of Discrete Signal Suppose that all constant signal x (t) satisfy the condition [3]

A Small Automated Enzyme Immunoassay Analyzer System Design and Implementation Based on Immunoenzymatic Techniques

A small automated enzyme immunoassay analyzer system based on immunoenzymatic techniques is designed and implemented in this paper. The working instrument process is determined according to immunoenzymatic techniques, and then enzyme analysis system is designed. Institutional innovation is implemented. Several forms institutions of absorbing and discharging and mobile are designed, according working principle instrument and the forms of the analyzer at home and abroad. A new photoelectric detection institution based on micro spectrometer is designed. Using fuzzy adaptive algorithm controls constant temperature. This paper offers a new viewpoint and direction of small automated enzyme linked immunosorbent assay analyzer system design.

Research on Agricultural Harvester Data Detection System Based on Remote Monitoring

On-line detection system of the harvester is an outcome from combination of modern computer technology and communication technology in harvester operations applications. With the help of the various sensors, the harvest yield, running routes, and threshing wheel speed, etc. are measured. These information and parameter are indicator of the harvesters working status. They are detected, processed, packed, and transmitted to the computer server in monitoring center via a wireless network. On the monitoring center server, the transmitted data is processed further, fault data are inspected, reliability data is calculated. Meanwhile, the harvester is controlled according to accepted data.

Approach to Extraction of Incipient Fault Features on Unstable Rotating Rolling Bearings Based on Time-Frequency Order Tracking and SPWVD

Frequency-smear phenomenon caused by fierce rotating speed variation made it difficult to extract the fault features of the rolling bearing. An approach based on time-frequency order tracking and SPWVD was proposed in this paper. The influence of speed variation was reduced by resampling the time-domain non-stationary signal at constant angle increments with order tracking analysis. The precision of instantaneous frequency estimation (IFE) in time-frequency order tracking was improved by the use of Smoothed Pseudo Wigner-Ville Distribution (SPWVD). The simulation signal and experiment on test-rig revealed that the proposed method was more effective than the traditional order tracking in clarifying incipient fault.

The Research on the Application of Kansei Engineering in the Product Design

According to the related concepts and theory of Kansei Engineering (KE), this paper kansei analyzed the shape of household scales by using AHP (analytic hierarchy process), aiming to conclude the relation between emotional intention and design considerations, and sequentially to provide significant design basis and references for product development. Mathematical methods, such as statistics, were applied to this study, which provided a fresh idea for the early stage research of product design.

Design, Generation and Bending Stress Analysis of Face-Gear with Curvilinear Shaped Teeth

A curvilinear-tooth face-gear has been developed in order to obtain a high contact ratio, reduced bending stresses and lower sliding velocities compared to the spur and helical involute face-gear drives. The generation of the face gear is based on application of a tilted head-cutter whereas the conventional method of generation is based on application of a hob. The tooth surface model of the face-gear is established, and then bending stress analysis is performed by using Finite Element Method. The developed theory is illustrated with numerical examples.