Applied Mechanics and Materials Vols. 29-32

Abstract: A new design method for surface micromachined devices is proposed to reduce process complexity and improve intuitiveness of traditional design method of mask-to-shape-to-function. In the method, solid geometric models of MEMS devices are efficiently built up by selecting 3D features from the established MEMS feature database. Mask and process flow can be automatically generated with the developed aided design system based on SolidWorks. A practical example shows that the design method can shorten design cycle and improve design success rate.

Abstract: AFDX (Avionics Full DupleX Switched Ethernet, ARINC 664) utilized in Airbus A380 and Boeing 787 represents a major upgrade in both bandwidth and capability; however some legacy systems are difficult to connect into the AFDX bus smoothly. A low cost AFDX end system based on SOPC (System On a Programmable Chip) is presented. A Xilinx Spartan 3AN FPGA is employed to build the whole system; and then a dedicated reduced Ethernet MAC controller for AFDX end system is designed; a MC8051 open core microcontroller is employed as the system controller and protocol processing unit. The whole design costs small FPGA resources and the experiments show that the designed AFDX end system works robustly and correctly.

Abstract: A certain type of radar was equipped in the main fighter jets. It is main equipment which can ensure the completion of the task of the fight in the air. But at present, this type of radar transmitter outside the room does not have special test equipment and the manual testing process is also more complicated. So, to achieve rapid testing of this transmitter for technician and improve the measurement’s accuracy, need a new system. In this new system used bus control technology, virtual instrumentation technology and database technology. Besides these, brought them to combine organically, then we get the system with fault diagnosis, detection intelligently and the test database. In order to achieve test and communication with radar transmitters, the system used the MIL-STD-1553B bus as a control bus, the USB bus as a program-controlled instrument control bus and in LabWindows/CVI 8.5 development environment designed software of the system. After a trial showed that the system reached the requirements of the test specification.

Abstract: An optimization approach for manufacture parameter design of the SGM spiral bevel gears with modified tooth geometry is proposed. The approach is accomplished by application of local synthesis, tooth contact analysis (TCA) and dual-objective optimization of transmission error function. A computer program to obtain a set of manufacture parameters based on the proposed theory is developed and illustrated with an example. The proposed method provides a set of machine-tool settings for pinion NC-grinding which ensures: (i) a localized bearing contact pattern less sensitive to misalignments, (ii) a parabolic transmission error function to reduce vibration and noise in mesh.

Abstract: This paper deals with the head-type torque sensor, on the basis of magnetoelastic effect, installed on the main shaft of machine tool for sensing cutting torque in order to monitor cutting process. The tests of two types of sensor are carried out under various cutting conditions. In order to confirm the accuracy of these sensors measuring cutting torque, the torque values obtained by two types of magnetic torque sensor are compared between measuring value of strain gauge and calculating value of cutting force experimental formula. The investigation demonstrates that the on-line monitoring of cutting force can be detected through measuring cutting torque by means of magnetoelastic torque sensor, and the cutting state can be shown by cutting parameters.

Abstract: In order to reduce the channel errors influence on the decoding quality, the H.264/AVC uses a series of effective error- handling mechanism. This paper introduces error control technology in H.264/AVC, and focused on the FMO. On this basis, error pattern are used to simulate of the FMO, and the quantificational performance of the FMO will be given out.

Abstract: Draw rod is one of the main mechanical parts of vehicle steering system，which is required extremely high quality. At present the way to produce the draw rod is machining after common open-die forging. This technology will produce big flashings，damage the metal’s fibrous structure and reduce the material utilization. In this essay, we will use the technology of closed multiple-ram forging to produce it. We will utilize numerical simulation on several blanks through numerical simulation combined with experiments. In this way, the defects that some parts of the blank are folded and cannot fill well during forming process can be effectively avoided. Besides, there will be free of flashing and the draw rod forgings do not need to be cut. The weight of the original blank will be about 3.5 kg after being optimized, down by 36.4 percent compared with that of original material about 5.5 kg. And we will make different settings for the loading way of the plunger chips during the forming process, then compare with the simulation results and ultimately find out the best loading way. At last, we will verify the feasibility of such an optimal technology through experiments on the material-lead.

Abstract: Enterprise alliance is a basic organization which achieves network-based manufacturing. One of the key factors which affect the enterprise alliance’s buildup is that the candidate enterprise can make a correct decision in the selection of a cooperative project. This paper proposes a fuzzy AHP model to select the bid projects made by the leaguers to be selected basing on the analysis of the inportance of these bid projects. This model provides a comprehensive consideration for the various evaluation factors affecting the selection of a bid project. According to this model, candidate enterprise can select a bid project correctly.

Abstract: The severe lateral vibration and impact of drill string will not only cause the damage of drill string but also have bad effects on the quality of directional drilling operation. It is difficult to control lateral vibration amplitude and impact intensity even with advanced measurement apparatus while drilling. So it is feasible to use a theoretic method to analyze and predict lateral vibration of drill string in order to adjust and optimize drilling parameters in real-time. On the basis of beam-column series and spring-concentrated mass model, a new analytical model is established to realize the control of lateral vibration and impact by controlling some key factors, such as under-gauge stabilizer, initial phase angle and initial deformation, WOB (weight on bit) and ROB (rotation of bit).

Abstract: The process of air separation unit has the characteristics of many types of equipment, long flow, and strong relativity and complicates structures. A multi-variable model predictive control strategy to achieve the goal of automatic variable-load for the control limits in the variable-load process of air separation unit was proposed. Regard model predictive controller as the core, the problems of coupling in the various technological parameters were solved. Moreover, the non-linear control request for global variable-loading process was satisfied, and the perfect operation character and rate were ensured. Production characteristics, structure, scheme and application processes for the control strategy were described in detail. The system succeeds in applying to the air separation unit in an iron and steel enterprise, the multi-variable control system shows its effectiveness and efficiency in the automatic variable-loading.