Nanometer displacement measurement technology and corresponding devices are served as the eye for fabricating machinery to realize nanometer precision positioning and control. However, current measuring methods with n...
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Nanometer displacement measurement technology and corresponding devices are served as the eye for fabricating machinery to realize nanometer precision positioning and control. However, current measuring methods with nanometer precision are difficult to balance the wide measuring range and measuring precision. Therefore, a new method using standing waves based on alternating electrical field to compose electrical travelling wave is proposed and a novel nanometer timegrating displacement sensor is presented. The operation principle of nanometer timegrating is presented in details. The expressions of the travelling wave modulated by 4 channel displacement information are established. The measuring error characteristics are analyzed through the theoretical deduction of the expressions for the cases of two channel standing waves with unequal amplitudes, single channel standing wave with unequal positive and negative amplitudes, and the standing wave with high order harmonic components. Based on above, lots of experiments were conducted;the results prove the correctness of the theoretical analysis. According to the theoretical analysis and experiment result, the reasons that cause the first order, the second order and the fourth order errors of nanometer timegrating are clarified, based on which the structure and parameters of the nanometer timegrating sensor are optimized;and finally, the accuracy of the sensor reaches ±300 nm within the measurement range of 200 mm.
In the wireless sensor network (WSN), the operation reliability is usually evaluated by processing measured datas at network nodes. As the traditional algorithms exist the problems of the complex calculation and large...
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ISBN:
(纸本)9781479970926
In the wireless sensor network (WSN), the operation reliability is usually evaluated by processing measured datas at network nodes. As the traditional algorithms exist the problems of the complex calculation and large energy consumption, a method for fault diagnosis of nodes in WSN based on rough set theory (RS) and support vector machine (SVM) is proposed in this paper. In this paper, we collect various kinds of fault symptoms and integrate them first and then diagnose the fault nodes through rough set theory (RS) and support vector machine (SVM). Firstly, the rough set theory is used to reduce the attributes of sampling data in order to select the decision-making attributes for constituting a new simple dataset. Then we use the new simple dataset to train the SVM. And finally classify failure modes of WSN through the trained SVM model. The result shows with RS-SVM the diagnosis time is only 0.16s and the diagnosis accuracy is up to 95%. The algorithm in this paper makes full use of the RS and the SVM and the result shows the effectiveness of the algorithm in fault diagnosis of WSN, and also shows it can improve the efficiency and accuracy of fault diagnosis.
A simple all-optical binary phase-coded ultra-wideband (UWB) signal generation scheme using a DWDM-based frequency discriminator for multi-user communications is proposed. Encoding, decoding and transmission in fiber ...
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A new numerical control (NC) rotary table with high accuracy is presented. timegrating, which was taken as the angle measuring unit, was installed inside the rotary table to measure the angular displacement in real t...
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With a good many advantages, the worm and gear has been widely used in mechanical equipment. To realize transmission error (TE) detection of worm gear pair is important for the comprehensive detection of large worm ge...
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Aiming at the deficiences of small measurement range and critical requirement on measurement environment in existing nanometer measurement technologies, a new nanometer displacement sensor is proposed, which adopts hi...
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Aiming at the deficiences of small measurement range and critical requirement on measurement environment in existing nanometer measurement technologies, a new nanometer displacement sensor is proposed, which adopts high-frequency clock pulse as the metrological reference;and the alternating electric field constructed with differential and parallel capacitance plates is used to perform the precise measurement. In order to optimize the sensor parameters and improve measurement precision, the electric field distribution and error characteristics of the nanometer time-grating sensor are studied under different parameter conditions. Firstly, according to the characteristics of the nanometer timegrating displacement sensor measurement model, a two-dimensional simulation model is built using the ANSYS software to analyze the electric field distribution under different parameter conditions. The relationship between the model parameters and error characteristics is obtained with experiment verification. Based on the simulation and experiment results, the sensing parameters can be optimized. The experiment results prove that the precision of the sensor reaches ±300 nm within the measurement range of 200 mm. The study result provides a reliable theoretical basis and technical support for the design optimization and precision improvement of nanometer time-grating sensor.
This paper proposes a high-speed transmission error (TE) dynamic detection system based on NIOS-II and USB. The detection system is in the realization of data acquisition on a FPGA chip, and sends the collected data t...
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A new numerical control(NC) rotary table with high accuracy is presented. timegrating, which was taken as the angle measuring unit, was installed inside the rotary table to measure the angular displacement in real ti...
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A new numerical control(NC) rotary table with high accuracy is presented. timegrating, which was taken as the angle measuring unit, was installed inside the rotary table to measure the angular displacement in real time. Moreover, the signal of timegrating was used as the feedback to realize full-closed loop control for improving the control accuracy of the NC table. Furthermore, the problem of insufficient subdivision of the step angle of the stepping motor could be solved by increasing the transmission ratio of motor shaft and rotary table. Experiments prove that the NC rotary table has the advantages of high control accuracy and running steadily, and the NC system shows a good application prospect in the field of machining.
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