Advanced Materials Research Vols. 546-547

Abstract: When cruising underwater, the Autonomous Underwater Vehicle (AUV) oscillation will affect some sensors’ measuring precision. In this paper, the method of equivalent entities is used to build the AUV’s solid model, and the AUV’s fluid-solid coupling system together with its wet modal is analyzed using ANASYS software. In addition, the AUV’s bending mode and breathing mode under different depths are discussed, which will reflect the changing trends of AUV vibration frequencies during operation. The conclusion can provide the theoretical basis for the AUV structure design when certain measuring task is performed using sensors.

Abstract: Acoustic modem is one of the most important sensors on the deep sea AUV. A good performance of the acoustic modem has great effect on the safety and operation of deep sea AUV. According to the construction of deep sea AUV, acoustic modem is installed in the cavity behind the GPS antenna, it would cause flow noise around the acoustic modem and thus interference will occur when the communication is established between deep sea AUV and surface. Flow-induced noise around the acoustic modem is studied in this paper. Firstly the unsteady flow around the acoustic modem is studied by large eddy simulation (LES) method. Secondly based on the resolved information of flow field, acoustic noise distribution is studied using equivalent acoustic sources method. Compared with different positions of GPS antenna, flow noise distribution around the acoustic modem and the effect on communication is investigated. Then acoustic modem layout on the AUV is optimized.

Abstract: This paper proposes the basic concept of dynamical pattern recognition and introduces the implementation theories based on probability statistics .Based on the theory of the Discrete Hidden Markov Models (DHMM), the scalar quantization method of vibration spectrum vector of rotary machine is proposed, and then the fault diagnosis method based on DHMM is designed. The experiment of run-up process of rotor machine is made to verify the effect of the new fault diagnosis method.

Abstract: When early faults occur in rotating machine, the vibration signal being extraction the often contain heavy background noise .In this paper the analysis of degree of cyclostationarity (DCS) was proposed to vibration signal extraction of rotating machine. This method can overcome the shortcoming of Hilbert transformation that will be influenced by many factors, such as end effect, sampling frequency and the added noise in signal. The research results show that the DCS can not only extract vibration signal but also suppress the added noise in the signal. Therefore more accurate fault signal will be extracted and detected through this new method.

Abstract: A project about electric enclosed loading test system of gearbox is put forward by comparison. The structure and working principle of the system is introduced during the Control loop and the microcomputer monitoring software architecture figure of the system is given out. The test results show that the loading system runs steadily, loads conveniently, saves energy obviously, and satisfies the requirement of design.

Abstract: Aerodynamic characteristics of the wing NACA5312 in ground effect are investigated with the numerical simulation method. The N-S equations and the k-ε turbulence model are solved by the finite volume method in CFD software. This paper computes the flying states under different clearances, steam velocities and angles of attack. Compared with results under the unbounded flow, it studies the relations between the aerodynamic performances and the angles of attack, the steam velocity, and the relative heights. The aerodynamic performances include the lift coefficient, drag coefficient, and lift-drag ratio.

Abstract: A full-annulus unsteady quasi-3D simulation for a transonic compressor was conducted to investigate the low engine order excitation sources. A special inlet total pressure distortion was used in the simulation to account for the effect of non-axisymmetric tip clearance. The unsteady aerodynamic forces were obtained by integrating the static pressure along the blade surface. Furthermore, the effect of downstream rotor detached shock on upstream stator was analyzed. It was shown that the unsteady aerodynamic excitation of the rotor was subjected to the first two harmonic frequencies of the inlet distortion, and the adjacent stators’ basic frequency and lower harmonics. It was found that the detached shock had a significant impact on the surface static pressure distribution of the upstream stators.

Abstract: Based on the configuration and working state analysis of the ISG hybrid electric cars, the torque distribution strategy of a hybrid system is designed to delineate the maximum and minimum work torque curves of the engine, achieve optimization of engine’s range so as to make sure the target torque of the engine and ISG motor, and finally through the calibrated driving characteristics MAP and battery SOC state to achieve the calculation of total vehicle torque demand. Taking the Hafei Saibao ISG hybrid car as a test model, the test of fuel economy and emissions carried out under specific conditions showed that using the torque distribution strategy has increased by 12.8 % of the ISG hybrid car fuel economy and improved emissions performance to some extent compared to the traditional Hafei Saibao cars.

Abstract: In order to control the focal plane and guarantee the imaging quality of space camera, the focusing system was proposed. Firstly, the reasons of defocusing were analyzed and a solution method was given. Secondly, the system structure and operating principle were introduced. Thirdly, the system design was presented in detail. Finally, the system was experimented. Experimental results indicate that the defocusing amount of camera can be controlled below 10 um and the focusing system satisfies the requirement of system design.

Abstract: High-definition intelligent video surveillance system of Henan Power is constructed in 220KV&500KV substation with uniform marginal pattern, multi-level management and image resources sharing. The video sever control and communicate with the monitoring equipment at the substation with WDM-PON channel based on SIP protocol, and can achieve a truly high-quality picture format up to D4(1280*720). Gateway Protocol is researched and developed to convert SD (Standard Definition) video image with different formats to unified H.264 format. The SD and HD video image access to video surveillance platform based on SIP protocol, then give solutions to the existing substation video surveillance platform with low transmission rate, incompatible interface protocol and low quality video image. Furthermore, intelligent analytical processing for data traffic carrying feeder in substation, icing equipment, transmission line galloping and meteorological monitoring, together with the HD video image transmitted on WPON. Aid decision is made for power network production operation and emergency support.