Abstract: The measurement error contains many errors in NC machine tools processing and those errors will be mapped to workpiece at certain regularity. The control of error caused by cutting parameters during the precision and ultra precision process is one of the key technologies in NC machine tools processing. This article introduces Bayesian networks into the dynamic error separation modeling, with the learning process of Bayesian network structure and establishes the error separation model based on Bayesian networks, then carries out the comparison and analysis between simulate and experimental data to verify the feasibility of the method.
Abstract: The paper proposes a mono-station TOA/AOA positioning method based on ultra-wideband (UWB) antenna array. The article calculates accurately the signal's angle of arrival (AOA) by measurement of the UWB-pulse amplitude of the reference base-station antenna array received, combined with the antenna beam pattern. With the estimation of the information of arrival time using the skewness and the maximum slope, the location of the label can be found. The ranging error of the localization algorithm can achieve centimeter-level and angle of arrival is less than or equal to 1.0.In the paper, the accuracy of positioning method is not affected, eliminating the high-precision synchronization requirements of the traditional reference base-station and significantly reducing the system requirements of clock accuracy and system complexity.
Abstract: This paper used high resolution stereo-pair images from PRISM of Advanced Land Observing Satellite to generate high precision digital elevation model of target areas, which adopts the method of object space automatic matching and control detection. Compared with the same resolution of DEM from the other way in the same area, the paper educes the area of land subsidence and changed trend and analyzes the factors of accuracy for building DEM. The New DEM has higher precision than the standard DEM and reflects the real geomorphology. Through the experimental statistical analysis, the proposed method can be used for large areas of land subsidence and deformation monitoring, which is timeliness to explore reasons of region deformation.
Abstract: According to the characteristics of the wire rope, this paper introduces some methods of flaw detection. The thesis takes flux leakage detection as core and develops the detection method which is effective and undamaged to study and analyze the wire rope. In order to improve the accuracy of signal detection analysis and the reliability of detection , this thesis has got abundant experimental signals of broken wire to denoise and decompose the signal with wavelet analysis.It extracted the fault signal characteristic parameters with wavelet reconstruction to judge the fault type for building fault signal sample datebase. The thesis eatablished a typical wire rope fault diagnosis system.
Abstract: Optimization of cylindrical ion trap is to be done for testing low mass ions such as H2+, H3+ ,He+. The principle of optimization is reducing the higher order fields, not the “-10% compens- ation” rule introduced by R.Graham Cooks. The model of CIT is built by CST. The best z0 is obtained when r0=10mm. At last, the MS of Hydrogen and Helium shows the optimization is successful.
Abstract: In order to realize the inspection of rail surface defects with high speed and high precision, an automatic detection system based on machine vision is presented. The hardware structure of the system consists of the mechanical system, control system and visual imaging system. The software structure using histogram threshold segmentation, multi-structural morphological edge detection and other image processing methods to detect and identify defects automatically, and also built the simulation rail detection platform. The experimental results show that the cracks, scars and other detects can be accurately detected and extracted in real time, and meet the requirement of the rail surface inspection.
Abstract: In order to improve the dynamic stability of level control system in the steam drum of boiler, a fault diagnosis approach is proposed by using IDEF method, which can analyze the control system structure by the IDEF model. When the faults occur, the possible causes of fault can quickly be identified by using the model. The approach can provide a reliable basis of decision-making for the control and make a reasonable fault diagnosis in a timely and accurate manner. Using the method can effectively improve the speed of fault diagnosis, prevent the fault occurs, ensure safety and stable operation for the boiler control system.
Abstract: Scanning measurement is a basic means to achieve high precision geometric measurement. However, the scanning device has a congenital defect which is the presence of a mechanical scanning device, thus, it has some issues such as wear, vibration, temperature sensitive.This articlecreatively put forward a kind of control method which is using acousto-optic deflection technology to realize the laser scanningfrom the general character of scanning measurement.The method has the advantages of the principle, it eliminatestheinherent defect of rotary machine structure on the measurement accuracy, speed, controllability, and stability. The exploration and research of this method will provides a new non inertial rotation scanning means for optical scanning measurement. More important, the implementation of the method will provides a new thought and method for the kind of problem about beam scanning measurement of geometric measurement.
Abstract: This paper presents a new real-time monitoring method based on the explosion source location technique on the underground mining activities in the situation the state can not achieve the full uninterrupted supervision because of the backward monitoring tools and equipment. The supervise mode results in some small coal mines in the profit-driven to ultra-layer or cross-border mining which causes a many of safety accidents. The five acceleration vibration sensors buried underground in the mining area pick up blasting vibration waves coming from blasting tunneling. Every signal acquisition sub-station deals with the according sensor output signals by using wavelet transform to identify the P waves and using energy eigenvalue method to determine the arriving time of P wave to the sensor, then translates the sensor’s spatial and temporal parameters to the principal computer. The principal computer locates the explosion source by the Geiger algorithm and displays the explosion source’s spatial message in the mine’s electronic map. The method is feasible and the positioning horizontal error is less than 10m by field-proven.
Abstract: Aimed at the features of large quantity and wide distribution of oil wells, this paper designs a pumping well remote monitoring terminal based on the two way automatic communication technology (TWACS). Processing signals from voltage sensor and current sensor, the terminal obtains electrical parameters so as to remotely monitor the well electrical facilities. Meanwhile, the modulation time domain of signals is determined by matched filter，and then the demodulation of TWACS signal and the transmission of monitoring data are achieved through the other technologies such as cross-correlation algorithm.