As one of the basic supporting technologies of 5G system, wireless sensor networks technology is facing a new challenge to improve its transmission energy efficiency. This paper considers combining simultaneous wireless information and power transfer (SWIPT) technique and routing technique, and applying them to multi-hop clustered wireless sensor networks (MCWSN), where each node can decode information and harvest energy from a received radio-frequency signal. And the relay nodes in MCWSN can utilize the harvest energy to forward data to their next hop nodes according to the routing scheme. First, we formulate an energy-efficient routing problem of MCWSN with SWIPT. Then, a heuristic energy efficient cooperative SWIPT routing algorithm (EECSR) is presented to find a transmission path with the maximum energy efficiency. Specifically, in EECSR, the resource allocation problem in each hop of the path is transformed to some equivalent convex optimization problems, which are resolved via dual decomposition. Moreover, a distributed routing protocol based on EECSR is proposed. As far as we know, this is the first solution that considers energy efficiency optimization based on routing and SWIPT in MCWSN. Simulation results show that our EECSR algorithm has high energy efficiency and good robustness. And our distributed routing protocol has better real-time performance than traditional protocols.

Wireless sensing is an effective method for the acquisition of the mechanical failure signal. Many researchers have been studying in this field for decades. Due to the difficulty of the sensor installing and replacement caused by the special environment condition of mechanical equipment, the energy-efficiency of the wireless transceiver is necessary to guarantee the long lifetime. In this paper, we present a novel energy-efficiency wireless sensing method for mechanical failure signal. Actually, we are only concerned with the feature of signals in the failure visible phase, in the application such as the mechanical failure diagnosis or alert. Therefore, according to the signal feature, a real-time data compressing algorithm is proposed, where the compressibility of data can dynamically be adjusted, on the basis of application demand. Then the clock frequency can be adjusted intelligently and the energy conservation can be accomplished, through the handshake between the sampling node of the front end and the received node, based on the compressing situation. In the conversion of clock frequency, an improved dif-frequency preamble sense way is adopted to achieve the seamless change between different frequencies. Finally, the method is analyzed and the feasibility is evaluated.

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The fluid state of the straight conical draft tube is simulated by using Fluent software. The distributing condition of the axial pressure and flow speed inside the straight conical draft tube is analysed and the recovery coefficient of the corresponding running condition is calculated, when the diffused angle is changing.

The article, three-phase squirrel cage induction motor as the research object, introduces the design of a new dual-PWM VVVF system based on ARM. The rectifier link design control strategies based on the power of the inner power loop and outer voltage square loop control system. The inverter link design a double infinite loop vector control speed regulation system of torque, flux linkage to the inner ring, rotational speed to the outer ring a double infinite loop vector control . And then, to combine rectifier link and inverter link to build dual-PWM VVVF system. Focuses on realization of the control system software and hardware-based LPC2132 and μ C/OS-II. Gives the hardware design of the overall program, as well as software realization based on the hardware μC/OS-IIoperating system . Introduce some of the specific features of the program as well as hardware and software anti-jamming technology . Conduct simulation verification to the dual-PWM VVVF system. The results show that: The dual-PWM control system can realize better control effect.