Applied Mechanics and Materials Vols. 433-435

Abstract: Firstly, through the fishbone diagram and Causal table method to find the factor which effect the time of temperature and humidity reach standard. Secondly, collect various time, temperature and humidity data of every time air conditioning boot, analysis and arrange the data, build the three-dimensional relationship between workshop temperature, humidity and the reach standard time, and fitting, finally, find the regular pattern between environmental factors and the time of temperature and humidity reach standard.

Abstract: This paper designs a virtual spectrum analyst based on LabVIEW,chirp signal is used for pumping signal of the system. A fast frequency estimation method is realized by the graph programming language LabVIEW. Compared with traditional virtual spectrum analyst, this method can better and faster measure amplitude-frequency characteristic and phase frequency characteristic. The interference factors emerged frequently during the data acquisition were described briefly, and the technology of verification and manipulation of the anomalous signals were studied.

Abstract: Neutron velocity selector is widely used on neutron scattering instruments as key component. To calibrate it (wavelength and wavelength-resolution-rate measurement), it is necessary to design calibration instrument and develop calibration technique. Based on small angle neutron scattering instrument (SANS) at China Advanced Research Reactor (CARR), instrument structure was designed and instrument parameters were determined. Count loss influence on measurement of wavelength resolution rate (WRR) was studied for the first time. Measurement error of WRR is decided by product of dead time and Gauss peak count rate (GPCR) and increases with increasing GPCR for the same dead time. In order to ensure WRR measurement error less than 0.9%, upper limits of GPCR for detector adjoining chopper and detector far away from chopper are less than 10000[s^-1] and 2500[s^-1] respectively. According to upper limits of GPCR, floor limit of total measurement time for each spectrum is calculated to be 6.66 minutes.

Abstract: This paper firstly establishes a finite element model of a fuselage panel, and then an assembly variation model is derived from the method of influence coefficients (MIC) and principal component analysis (PCA). With the calculation of Fisher information matrix and effective independence (EFI), 49 measurement points are extracted from a number of finite element nodes by the optimum selection method, and the mathematical relation between the position errors of measurement points and the positioning errors of frames is established, which is utilized to analyze the impact of positioning errors of each frame on fuselage panel assembly variation. Finally, the key frame that is important to ensure assembly accuracy and to improve the assembly process is determined.

Abstract: To improve processing precision of numerical machine tool ,research on analyze the thermal error of spindle, the grey correlation analysis method is used to optimize the thermal key points to build the model of temperature field on the basis of temperature measurement experiment. By optimizing, the number of temperature measuring points from 8 to 3. In this way, the precision of thermal error model and thermal error prediction can be improved.

Abstract: This paper presents metal oxide arresters (MOA) resistive current on-line monitoring and expert diagnosis system. The system combined the harmonic analysis method and the compensation method to measure the MOA resistive current. The on-line monitoring system used MAX11046 for signal A/D conversion and TMS320F2812 DSP for data processing. It used IEC 60870-5-103 protocol to upload the data to the expert diagnosis system through the RS-485 bus. Based on the real-time monitoring data, the historical data and the environmental parameters, the expert diagnosis system can analyze and judge the MOA status. The system adopted many anti-jamming measures to make the measurement data stable and accurate. The results show that the resistive current of the 35KV MOA fluctuates based on 20μA.

Abstract: We present some new idea to implement shadow modeling which is an important process for simulation of fringe projection system: The dot product between normal vector of object’s surface and vector that connecting projector lens centre and point on object’s surface, and the dot product between normal vector of object’s surface and vector that connecting camera lens centre and point on object’s surface are used to model the shadow on object’s surface. Our algorithm do not need to implement the calculation of the silhouettes of the occluders. Simulation result validates that the accuracy of our shadow modeling algorithm is same as shadow volumes algorithm, but our algorithm runs faster than shadow volumes algorithm.

Abstract: We present an algorithm based on variable-step-iterative (VSI) to search line-surface intersection point, which is very important process for simulation of fringe projection system. Our VSI algorithm can avoid the difficult process such as finding iterative start point and selecting parameters to obtain a correct result. Simulation result validates the reconstructed RMS errors obtained by our VSI simulation algorithm are far smaller than those obtained by previous reported simulation method.

Abstract: It is very prevalent in medical industry to adopt robotic technology such as robotic minimally invasive surgery (RMIS). This causes the surgeon not to sense viscosity and stiffness of the tissue or organ. In order to generate the tactile recognition of human organ, this work proposes a novel tactile device using magnetorheological (MR) fluid. The MR fluid is fully inserted into diaphragm and several pins. Due to controllability of rheological properties by the intensity of the magnetic flux density, the operator can feel different force from the proposed tactile device. In order to evaluate the performance of tactile device, two method is proposed. One is to measure the repulsive force with applying several control inputs. The other method is to check the performance of tactile sensation using psychophysical experiments. From these results, the usability of the tactile device is proved.

Abstract: High-speed multi-frame camera has been widely used for time-resolved measurement of electron beam parameters (especially for high energy and high current beam) for its fast response and high resolution. According to the requirements of a electron beam observation experiment, a three-channel framing camera optical system is designed. The system has 300mm focal length, 2.5 F^#, 200lp/mm resolution. To validate the design results, visual microscope and magnify methods are used to test the consistency of image quality of three image planes. Test results show that the system fully meet the design requirements.