Key Engineering Materials Vol. 620

Abstract: NC machining simulation, as one of the key technology in the field of CAD/CAM, can effectively check out the interference collisions that may occur in the machining process, significantly improve the safety usage of NC machine tools, has important practical significance to prevent the occurrence of machine accidents. Based on the integrated simulation module of UG NX software, this paper established the simulation model of NC turning center and elaborated the establishing process of machining simulation system, including the creation and verification of tool path, the digital model assembly, machine driver and motion model and so on. So tool path simulation and processing simulation were achieved, and the phenomenon of over-cutting and under-cutting between the parts and the cutting tool can be discovered timely. Meanwhile, on the basis of UG/Post module, the special postprocessor for NC turning center was developed to automatically output NC program, and the generated NC program can directly enter the NC machine tool for processing without manual modification, which will improve the efficiency and quality of automatic programming of machine tools, thereby shortening production cycle and reducing processing costs. Finally, the product processing examples verify the correctness and practicability of the special post-processor and process simulation system.

Abstract: As the main supporting drive components of the automobile transmission, the transmission bearings are mainly used to support the moving parts installed on the gear shaft, and to ensure the rotary precision of the gear shaft and the rotating parts, which plays an important role on transmission performance. Aiming at the existing problems of the traditional check method of bearing, the objective of this study is to take a five-speed transmission as an example, to accomplish the fatigue life analysis of the bearings of the automobile transmission based on the MASTA software. The simulation modeling of the transmission is built completely to simulate the actual load conditions and complete the process of analysis for the bearings. Analytical results show that using MASTA software can effectively perform the fatigue life analysis of the transmission bearings instead of the general conventional theoretical calculation method in the actual manufacturing process, moreover, the analysis results will provide theoretical basis for the overall optimization structural design of the automobile transmission.

Abstract: With the Computer Integrated Manufacturing System and Information Technology rapid development, rapid retrieval multilingual becomes one of the hot spots in Machine Translation. The cross-language information retrieval (CLIR) provides a convenient way, enabling users to use their own familiar language to submit queries to retrieve documents in another language. Basic query expansion is one of the effective methods to improve recall of information retrieval. There are many researchers have proposed many extension methods, but most methods are simply added to the query expansion terms. If we do not distinguish the original query words and extended words, expanded query may deviate from the original semantics. So, it is very inconvenience for mechanical engineer and programmer. Based on Dempster-Shafer theory of evidence, we proposed a query expansion computing model, which considered as the main evidence of the original query terms, while the extensions as a secondary evidence of the original query terms. Which method to use semantic dictionary Han and Uygur-Chinese bilingual dictionary of synonyms forest and How to get the query word synonyms, near-synonyms and hypernym. Latent Semantic Analysis is used to obtain semantic relationships query words related words the using potentially large-scale text. The combination of these two types of evidence is in order to put forward a weighted combination of the Dempster-Shafer rule. Experimental results show that this method can effectively improve retrieval efficiency in Mechanical Engineering and Information Technology. The research results can be provided a reference for CIMS multilingual quick retrieval.

Abstract: Cutting force is usually obtained based on the experimental data which is conducted under certain cutting condition with certain cutters because metal cutting mechanism study is not mature. As the data are numerous, in different types, and the relationships between them are complex, the commercial database can be used directly. A new approach based on ANN is introduced here for unstructured and discrete data modeling, which transfers the unstructured and discrete data into ANN topology and net weight matrix. In this paper, the experimental data of union cutting force modification are taken as examples for verifying the feasibility of the ANN model. The ANN modeling, inputs, outputs and ANN training are discussed. Compared with other modeling approaches, this model is general and can process discrete data with unified data structure. This model can be used for cutting force calculation as well as intelligent and general CAPP.

Abstract: The V-groove component which needs to be machined by ultra-precision CNC (Computer numerical control) machine tool is a core part in optical fiber connector. A design of keyboard module for V-groove ultra-precision CNC system based on LPC1343 is presented. This paper introduced the functions and features of LPC1343 and described the overall hardware structure of the keyboard module at first. Then the basic design, such as scan and decoding, design principle of module circuit and communication process between keyboard module and upper computer, were emphasized in detail. Afterwards, the functional design including data editing, LED indicator driving, override switch adjusting and motion control operating were also finished. A series of test have been conducted and the results have shown that this kind of keyboard module is reliable and stable.

Abstract: The virtual reality technology has been widely applied in virtual manufacturing; virtual environment which integrated with visual, auditory and tactile can be established. In this paper, a single - channel immersion machine assembly simulation system was built by EON Studio of virtual reality software and virtual peripherals. For building immersion virtual environment, three dimensional entity model of machine was established by the CATIA software, rendering and coloring it through the 3ds Max, inputting interface of EON convert file. Researching on interactive virtual assembly technology of machine was done, two interactive methods were developed through the keyboard ,mouse and other input devices or data glove ,(Flock and Bird) and other virtual peripherals respectively: one was to realize the interaction based on keyboard by the triggering sensor node, event driven and routing mechanism ; another was established the virtual hand, achieving the spatial position of manpower through driving virtual hand by data glove and (Flock and Bird) , and converted it into the position of virtual hand in virtual space, to complete the grasping, moving, releasing the object operation in immersion virtual environment, so that completing the virtual machine assembly, assembly trajectory visualization was realized, the basis was provided for the path of assembly analysis. The human-computer interface of assembly simulation system of machine develop, each module integration was realized by the transmission of information between EON Studio and machine, and reasonable guidelines for machine assembly training was provided.

Abstract: Constructing the semi-physical real-time simulation system with Matlab/Simulink, the interface cards are used to transmit information with the external equipments. The real-time operating system based on Matlab/xPC Target almost doesn't support the drivers provided by the interface card manufacturers. In order to meet the requirement to construct the semi-physical real-time simulation system with Matlab/Simulink and utilize effectively the newer kind interface cards, it is very significant to develop the interface card drivers based on xPC Target. With the example of PCI-1710 data acquistion card in the paper, the drivers were developed based on xPC Target with S-function. In addition, the performance of the drivers were tested. The results show that the drivers have the characteristics of convenient use, good real-time performance, strong portability etc. This has the certain guiding significance for developing drivers for the various interface cards based on xPC Target.

Abstract: Failure, because of the important role in the product life cycle for improving product design and manufacturing, is becoming important data information and being taken seriously. High-speed trains are complex electromechanical integration systems, and its failure occurred in operation may directly relate to people's life and property safety. FRACAS is a reliability engineering method, which allows the product fault information to follow Discovering, Report, Analysis, Correct and Confirm closed-loop management process, provides data and information to support effectively for improving the reliability of the train. This paper analyzed the fault information management needs of high-speed trains, combines high-speed trains product structure tree and fault model base to generate a high-speed train fault information database, by customizing and developing Relex FRACAS software. Then high-speed trains (CRH3) closed-loop management system is established. High-speed train FRACAS can easily build enterprise information platform for product reliability. Through the establishment of a unified failures database and solutions knowledge base, standardized information transferring and sharing are achieved. The train products faults can be timely reported and corrected. The accumulated data of troubleshooting in the whole process can be used in the failure statistical analysis and reliability prediction, which can effectively avoid major failures and repeated failures.

Abstract: In order to realize high speed, high precision, high reliability, miniaturization performance of the CNC (Computer numerical control) system, this paper proposed a hardware platform of embedded CNC system based on OMAPL138 and FPGA. OMAPL138 is a SOC using C6748 DSP kernel and ARM9 kernel dual-core structure, the kernel frequency can achieve up to 375/456 MHz. ARM kernel of the CNC system which runs the Linux operation system is responsible for task management, DSP kernel is in charge of real-time interpolation and look-ahead algorithm, and FPGA module generates pulses to control the movement of the servo motor. Firstly, the overall hardware architecture of the embedded CNC system was designed. Meanwhile the hardware circuit design of CPU core module based on OMAPL138, human-computer interaction module, EMIFA bus interface of the FPGA core module were emphasized in detail, and also the serial port, Ethernet, USB communication interface module were introduced. A serial test experiments have been conducted and the results have shown that this embedded CNC system is powerful and stable.

Abstract: The backup power plays an important emergency supply role in industrial field and agricultural field. The emergency supply power (such as generator and Uninterrupted Power System etc.) is a standby state in most of the time. These devices only start to ensure electricity supply on the condition of power lose or power failure. It is difficult for users to know its real load performance. This paper designed a kind of intelligent AC (Alternating current) load test system based on PLC (Programmable Logic Controller) to solve the problem. There are signal acquisition part, the dummy load component and parameter display control part in testing load testing system, which can meet the general users of emergency power supply in daily inspection. We design the intelligent control for high performance and fine test users. The test results show that the intelligent AC load systems based on PLC can effectively detect power generation units and UPS emergency power supply in according with national standards.