Applied Mechanics and Materials Vols. 313-314

Abstract: To overcome the problem of the de-icing for high-voltage wire which is nowadays done artificially and dangerously, a kind of impact type de-icing device was designed in this paper. A cam and de-icing tool are designed specially for the device. The device can conduct deicing operation automatically and realize the automatic reciprocating walking on the transmission line. In conclusion, the impact type de-icing device for transmission line can effectively solve the problem of the ice coating on the transmission line and has a large value of reference and promotion.

Abstract: As the main tool of electricity measurement and economic settlement, the smart meter directly related to the nation and peoples interests. This paper devises a vertical analysis model of fault data of running smart meter. The model firstly clean the useless data, then do the regress analysis, and get the fault data and changing rate of the fault of each batch, which are utilized to do the cluster to evaluate the stability of the quality of the factory. The method and the result of the model can assess the quality of the batch of the smart meter, and can be beneficial to estimate the quality of factory.

Abstract: Since smart meters work at the long status without any supervision, their confidence is very important. This paper proposes an algorithm model of analyzing the related attributes with the running breakdown information of the smart meter, which can be utilized to predicate reliability of the life cycle of the smart meter. Because the limited data, the model mainly consider the attributes: the producer, application unit, and the failure information, without considering function, failure criteria, complexity, design, production process, working conditions, and the cost of installment and maintenances etc. The model utilizes the algorithm of neural network as the aid, and use producer, application unit, and failure info as the main attributes. Through the experiments of all the 16000 data, the fault predicting rate is 1%, which can prove the practicality.

Abstract: By optimizing the related parameters of the helix antenna, the maximum radiation direction is changed from 0 degree to 90 degrees. The fast-wave mode is exited along the helix at the same time. The simulation result shows the magic beam shaping performance of helix antenna. The relationship among the radiation pattern, the working frequency, and the parameters of the helix is also described.

Abstract: Semiconductor DC tiny current source is the equipments that can produce pA tiny current level. It is widely used in aerospace engineering, semiconductor circuit testing, new nanomaterials research, analysis science of development of life, etc with its unique advantages of high sensitivity and resolution in producing tiny current signal. It is a new challenge to calibrate these precise semiconductor DC tiny current sources in metrology. This passage did detailed studies on the domestic and foreign existing calibration methods, then developed a high resistance box, built semiconductor DC tiny current source calibration device, and developed automatic calibration software. In this paper, also the uncertainties of the calibration results had analyzed to fulfill the calibration of this tiny current source.

Abstract: In order to effectively inhibit the influence of constant bias of inertial sensors on strapdown inertial navigation system accuracy, a self-compensation method based on single-axis rotation modulation is proposed. It is shown by theoretical analysis that, the gyro constant drift and zero errors of accelerometer perpendicular to the rotation axis can be modulated to sinusoidal signal, which will be eliminated by integral. The constant bias along the rotation axis cannot be modulated. The effectiveness of the rotation scheme is proved by experiment and the influence of rotation speed is demonstrated.

Abstract: The precision torque instrument was researched and manufactured successfully by Taizhou Institute of Measurement Technology (TIMT). The twisting performance can be measured and evaluated by metal material and coupled by interference fit. Metal material twisting analysis can be used for analysis the part by metal material and coupled by interference fit. Fixing a displacement sensor on one coupling part, and fixing one hold back on another coupling part, this structure measures the twisting angle. At the same time, the dynamometer sensor connects one coupling part through level arm, and other coupling part connects instrument activities end. The action force presses the dynamometer through instrument activities end, coupling part, instrument fixed end and level arm. The dates of displacement and dynamometer sensor will be put into the computer through synchronizer. The TorqueAngle Graph will be established by these data. The maximum torque T_m and effective torque T_e will be established from the TorqueAngle Graph.

Abstract: A new method for the properties measurement of polymer optical fiber (POF) using pseudo-random sequence is introduced. The light source modulated by pseudo-random sequence is injected into the POF. The output optical signal after photoelectric conversion is made the correlation detection with pseudo-random sequence, and finally the correlation operation is carried out based on Labview software. Because pseudo-random sequence performs well on randomicity and it has the correlation properties similar to that of white noise, interference and noise have little influence on the peak of correlation function during the measurement, and the signal-to-noise ratio (SNR) of the output signal can be improved obviously. The measuring method is studied both theoretically and experimentally. Experimental results show that the SNR of the output signal can be improved by 25~40dB for the signal with SNR-15dB to 6dB, and the measuring precision is improved by this method.

Abstract: The indexing precision of power tool rest cutter head is the prima choice to judge the performance of the tool rest and the test of it is the premise of the tool rest quality. Considering the lack of an effective indexing precision detection method of power tool rest cutter head, the testing methods of the indexing precision of power tool rest cutter head are discussed and an indexing precision testing system based on photoelectric auto collimator is set up. The testing results can show the indexing error of every tool. The studied system of the indexing precision of power tool rest cutter head is suitable for various indexing device to realize dynamic indexing accuracy testing and the system has a high reliability and testing accuracy.

Abstract: Experiments were carried out to learn about the frictional resistance of gas flow in vertical helically coiled pipe. The expression of friction factor was established and the formula used to calculate the frictional resistance of gas flow in vertical helically coiled pipe was defined based on partial data got from different experiment conditions. The calculating formula was verified by the experimental data. The results show that the formula is accurate enough to calculate the frictional resistance of gas flow in similar operating conditions.