Advanced Materials Research Vols. 756-759

Abstract: Concrete crushing of the municipal engineering by traditional broken tools has flaws of inefficient, high dust pollution, high noise, high labor intensity. Hydraulic crushing equipment with ultra-high pressure water jet is designed, which includes the ultra-high pressure five-plunger pump unit and its control system. Engineering applications show the equipment owns characteristics of high efficient, cold state, security, and cannot produce stratified thermal aggregation, heat-affected zone in concrete and dust pollution. Then qualities of concrete hydraulic crusher in a complex environment are improved effectively. It provides an effective method to solve the problems of concrete hydraulic crushing.

Abstract: Control and monitor system of foamed cement mixing device are designed based on PLC and MCGS(Monitor and Control Generated System) configuration software, it realizes data collection and dynamic monitoring, data processing. Through the control system, it achieves automatic control to foamed cement mixing device. Experiments show the system has advantanges of high precision, reliability and good maintain.

Abstract: This paper describes the intermittent chaos detection principle, combined with differential form the double Duffing oscillator difference system to the weak signal frequency detection, gives the detailed steps of the method and flow chart. Use the feature that Duffing oscillators with specific reference frequency are insensible to other frequency signals interference, only sensitive to a small part of the nearby specific frequency signal, it comes to a conclusion that small amplitude periodic motion and intermittent chaos motion may appear at the same time in the detection system, which can be used to detect complex frequency signals. At last, takes the single frequency signal and the complex frequency signal detection for simulation, the results show that, compared with traditional Duffing oscillator array method, this method not only reduces the array number, and improved frequency detection bandwidth without affecting the detection accuracy, reduces the calculation amount, so its much better than the traditional method for frequency detection.

Abstract: In straight pull single crystal furnaces pulling system, Traditional PID controllers parameter cant meet the changes of the DC motor system. In view of this defect that the traditional PID controller parameter can not turn in a timely manner with the DC motor speed change. This paper used a new control method PID neural network to the monocrystalline pulling speed control system and established PID neural network pulling system, at any time to adjust to the optimal PID parameters, to achieve an adaptive control effect and improve the quality of monocrystalline silicon.

Abstract: In recent years, Internet traffic classification using machine learning has become new direction in network measurement. In this method, choose the appropriate traffic features is the key. The selection of feature in previous studies dependent on the specific data set and does not have the versatility to identify the data sets captured in the actual network conditions. We analyze and select a group of features based on public data set and the data collected in the actual network. Experimental results show that the selected feature set with stable performance and effective identification ability by using C4.5 decision tree method.

Abstract: In order to verify the protocol conformance of radio resource control (RRC) connection reestablishment in LTE system, a new testing method is designed by implementing testing and test control notation version 3(TTCN-3) abstract test suit. Furthermore, the test suit is operated on the TTworkbench developed by German Testing tech. It also generates graphical presentation format (GFT) to check the protocol conformance of RRC functions. The scheme has been successfully applied in the project development of TTCN extended test set instrument in LTE system.

Abstract: A control method for position servo control of Transverse flux machine (TFM) by controlling armature current Root-Mean-Square (RMS) and initial phase is proposed in this paper. Specifically, the voltage balance equation of TFM is provided, and the phasor diagrams are analyzed to achieve the expression of electromagnetic power of TFM. The expression indicates that the electromagnetic torque is determined by armature current RMS and the initial phase. A position servo control system of TFM is established based on the expression. The results of the position servo control curves show that the position servo control system of TFM is effective.

Abstract: For monitoring the water quality in river, and improving the accuracy of the transmission in network, the remote monitoring system based on wireless sensor network is designed. The topology of cluster for the wireless sensor network was adopted, and the amendment version of LEACH-H protocol is also designed based on LEACH. The circuit design of sensor for concentration of nitrite and DO is also presented. For the remote wireless communications between the sink node and remote control center, the GPRS module is adopted. The test show that communications among the system are realized reliably and the requirements are met respectively. The application of the system can well meet the demands of remote monitoring system for water quality.

Abstract: This paper discusses the establishing method of DC voltage of modular multilevel converter (MMC). Firstly the structure of MMC and the charging principle of sub-modules (SMs) are introduced in order to control the DC voltage of MMC and reduce the switching loss. It is pointed out that the DC voltage control in MMC includes two parts, the DC voltage establishment of system and the voltages control of SMs. For the DC voltage control in system, the control theory is analyzed, and the corresponding control strategy is proposed. Meanwhile an improved voltage balance control strategy for SM is proposed by the improvements of the traditional voltage sorting method to reduce the high switching frequency caused by the blind action of switching devices in the SM control. Finally, the simulation results based on PSCAD/EMTDC show that DC voltage in MMC can run in the rated value steadily, and the switching frequency is reduced significantly.

Abstract: The paper introduces modeling of Doubly-fed induction machine (DFIG) on orthogonal dq rotating coordinates based on per-unit value system and designs control part on space-vector-orientation, for which relative modules, in RTDS (Real time digital simulator) library, are introduced. Whole single-machine DFIG wind farm is built on RTDS and the maximal wind energy tracking is realized. Simulating results show control is correct and effective.