Applied Mechanics and Materials Vols. 321-324

Abstract: With the development and application of technique on high speed digital signal processing, wide bandwidth processing, high-speed data exchanging and flexible interlink structure have been the developing trend of modern high performance signal processing machine. In this paper, one universal signal processing machine is designed based on six pieces of ADSP-TS201 TigerSHARC processors, which owns good characteristics such as: large memory, excellent processing and data-exchanging performance, reconstitution, good expansibility. This signal processing machine adopts 64Bit, 66MHz CPCI bus standard and supports the function of extending processing performance by interlinking multiple boards. The high-speed data-exchanging is realized with multiple channel optical fiber. Furthermore, it owns board-level BIT function.

Abstract: Harmonic wavelet transform (HWT)and harmonic wavelet time-frequency profile plot (TFPP) is introduced firstly in practice to identify weak singularity in a signal with noise clearly. With TFPP method, emulational signal and vibration data of the rubbing of the large practical turbo-generator units are analyzed successfully, which prove that the method is effectively extract the rubbing signal feature which is can not gained by the other signal analysis methods, and the rubbing of the turbo-generator units is identified effectively.

Abstract: This paper presents a neurofuzzy signal control system to improve the efficiency at closely-spaced signalized intersections. Building on the conventional actuated-coordinated control system, the neurofuzzy controller establishes a “secondary coordination” between the upstream coordinated phase and the downstream non-coordinated phase based on real-time traffic demand. Under the neurofuzzy signal control, the traffic from the upstream intersection can arrive and join the queue at the downstream left turn lane and be served, and therefore reduce the possibility of being delayed at the downstream intersection. The membership functions in the fuzzy controller are calibrated to further the performance. The simulation results indicate that the neurofuzzy signal control consistently outperformed to the conventional actuated-coordinated controller, in terms of reduction in system-wide average delay and average number of stops per vehicle, under a wide range of traffic volumes, especially under higher demand conditions.

Abstract: The performance of 1553B bus network is very important to running safety of new generation armored vehicle. Because the current 1553B bus test equipment can only complete the translation performance test to DLL and cannot test the bus’ physical electrical performance, this paper brings forward a data acquisition technology to 1553B based on Physical Sampling Data and Decoding Software, fulfills the data acquisition experiment to 1553B with its bus nodes, and validates the feasibility of this technology.

Abstract: By analyzing the transmission characteristics of power line and the orthogonal frequency division multiplexing (OFDM) communication system, the concrete scheme of triple-network convergence based on the transmission medium of power line was given out. The Methods of constructing the intelligent triple-network convergence based on the OFDM technology, the system model and the hardware realization methods of power line communication system based on the DSP chip were given. Combining the latest OFDM technology, the channel coding technology and the modulation and demodulation technology in the power line communication system were researched, and new technology to high-speed data transmission on the radio channel was achived. And the simulation results of system design was given.

Abstract: Aiming at improving the unideal testing result by means of analog signal processing, wavelet analysis is introduced in the nondestructive testing of steel and iron materials, based on the characteristics of electromagnetic nondestructive testing signal. According to the requirement of wavelet algorithm for hardware, the advantages of DSP, digital signal processing function and high calculating speed, design scheme of the steel electromagnetic nondestructive testing device is proposed in this paper. Experiments show that this method can extract detection signal effectively.

Abstract: The Orthogonal Frequency Division Multiplexing (OFDM) technique is an effective method for suppressing multi-paths interference of underwater acoustic (UWA) channels. In this paper, a new communication system based on OFDM is presented, aiming at reliable 70km shallow water communications. The convolutional coding and frequency-domain equalization are also applied for the improvement of the OFDM system performance. The simulation results show that this proposed system can transmit data stream with low bit error rate (BER) in 70km UWA distance.

Abstract: Condensate pipe vibration in the air cooling system was analyzed. The flow pattern discrimination parameters were obtained through carrying out the iterative calculation on the continuity equation and flow equation. It was proposed to use the flow analysis method to determine pipe diameter and arrangement in the design, and to use the static and dynamic analysis methods to determine pipe support settings. These analysis methods are effective to actual engineering design proved by an example. Finally this paper puts forward the improvement measures to prevent condensate pipe vibration.

Abstract: It is conducive to reducedamage of blasting vibration to realize energy distribution and attenuation lawof single-hole blasting vibration signal. With the measured single-holeblasting vibration velocity curves, used wavelet packet analysis technologywith high-resolution character, the law of energy distribution of single-holeblasting vibration signals in different frequency bands, and the effect ofblasting source and distance from the source on single-hole blasting vibrationsignal energy distribution were analysised. The results show that the energy ofsingle-hole blasting vibration signals attenuation very quickly in thefrequency domain concentration distribution in 0~100Hz; and distance from thesource has significant influence on energy distribution in the frequencydomain; The energy is mainly distributed in the low frequency band whendistance from the source is larger, which has guiding significance inmitigation of blast-induced vibrations.

Abstract: Based on magnetic characteristics of inter turn circuit of rotor windings in turbo generator, and analysis the principles of detecting coil method. Based on the symmetry of generator structure and magnetic character between stator and rotor, three fault diagnose methods are presented in this paper: Wave form limitations, Half-wave sliding superposition and Reference wave forms. The application example shows that Reference wave forms method is capable of diagnosing inter turn fault, its severity, and especially locating the inter turn short circuit fault.