Applied Mechanics and Materials Vols. 128-129

Abstract: The advantages and disadvantages of the current constant-flow control method for the constant-flow pump (CFP) are analyzed. By using the experimental data and the BP neural network (BPNN), the model between outlet pressure and flow loss coefficient established. In order to realize constant-flow control for the CFP, a feed-forward controller based on the model is set up finally. Experiments show that this controller can improve the flow control accuracy for the CFP greatly.

Abstract: In view of the increasing scale of electric power optical cable and the problem that it is difficult to ensure the quality of the line, combining the actual situation of power system, using OTDR, program-controlled optical switch, PC computer to form a electric power optical cable circuit automatic monitoring system. The design make use of PC computer to control the starting and stopping of OTDR and which channel of program-controlled optical switch is to be guide circuited and receive the data of OTDR to detect the malfunction spot of fiber cable. The system provides an advanced maintenance measure for electric power optical cable, reducing the duration for repair of fiber cable troubles, can be widely used in electric power optical telecommunication network.

Abstract: The crop leaf disease spots image recognition technology has a great significance in identifying diseases and in effective spraying of pesticides to liminate diseases. We researched and designed the portable leaf disease spots image acquisition system since current PC-based processing system is high cost and lack of flexibility and real-timing, This system uses a high-performance 32-bit DSP chip based DM642 as its main processor, and also uses ultra-low power consumption and ultra-small size video decoder chips, large-capacity memories and high-performance communicator interfaces. As a result of the reasonable design of hardware architecture, this system realized leaf disease spots image features collecting and processing ，video transmitting, and achieved strong real-time processing capability, easy operation, low cost, anti-interference ability and other characteristics. The system prototype works well, and meets the design requirements.

Abstract: One of the main drawbacks of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) of the OFDM signal. How to reduce the PAPR is the key to applying the technology of OFDM efficiently. In this paper, companding transform method is presented. The performance of the systerm BER is analysised, then PAPR is reduced by using the method through simulation. Simulation results have shown that the proposed methods are very effective and flexible to improve PAPR performance in the OFDM based on the performance of the system BER is not changed very much compare to the original system.

Abstract: This paper presents the using vibration spectrum of transformer operational status with online monitoring methods, analyzes and discusses the transformer vibration spectrum about the producing mechanism and extraction scheme . At the same time, it also discusses the feasibility and necessity of using vibration spectrum methods to monitor the transformer fault .Some vibration spectrum methods ,relating to the transformer research contents and key technical breakthrough direction, are summarized in detail. Finally, it put forward a new immune from organization antibody network model and antibody generating algorithm that is used for vibration spectrum power transformer fault diagnosis.

Abstract: The measure technology of static friction coefficient of traffic engineering communication and cable ducts by using inclined plane method is introduced in this paper. The calibrated method for that equipment system of static friction coefficient is discussed, furthermore.

Abstract: In the deepwater semi-submersible platform, the multiplexed electro-hydraulic (MUX) control system is typically used in the deepwater subsea blowout preventer (BOP) stack. In this paper the system architecture and the subsea electronic module (SEM) spatial layout for the MUX control system are presented, and the SEM housing is designed and the finite element model of the housing is built by using ANSYS software. The analysis results show the designed SEM housing can work well under 30MPa external hydrostatic pressure.

Abstract: The current status and the future development trend of the body control modules are analyzed by this paper, and a new design idea of the centralized body control module based on the ARM-MCU and the Linux operation system is presented. Also the communication protocols between the main controller and the sub-nodes, the communication interfaces between ARM and MCU, and the operation interfaces on the touch screen are researched. Based on the teamwork of the ARM9 and the 16 bits MCU, the Linux OS is embedded to make the control of body network much more centralized, efficient and faster.