Applied Mechanics and Materials Vols. 427-429

Abstract: This paper proposes a method of the fault detection and diagnosis for the railway turnout based on the current curve of switch machine. Exact curve matching fault detection method and SVM-based fault diagnosis method are adopted in the paper. Based on envelope and morpheme match algorithm, exact curve matching method is used to match the detected current curve with the reference curve so as to predict whether the curve would have fault or not. Moreover, the SVM-based fault diagnosis method is used to make sure that the fault conditions could be diagnosed intelligently. Finally, the experimental results show that the proposed method can accurately identify the turnout fault status in the conversion process, and the accuracy rate in the diagnosis of the fault location is above 98%, which verify the effectiveness of the method in the fault detection and diagnosis.

Abstract: The edible fungus industry has relatively high output rate and high added value. In the production of edible fungus, the environmental factors have great impacts. This paper studies the intelligent monitoring system for producing environment of the factory-farmed edible fungus based on the internet of things and aiming at online real-time management. The monitoring system can realize real-time surveillance and visual operation during production by dynamically regulating the environmental factors needed for growing edible fungus and early warning of the environmental parameters fluctuation with traceable history records at any time. When parameters like temperature and humidity are beyond reasonable range, warning will be sent via text messages and equipments such as air conditioners and warming devices will be automatically adjusted for on and off so as to raise management level, increase the output, improve the quality and lower the risks.

Abstract: Converted current signal by mutual inductance coil is merely microampere level when using current transformers measure milliamps-power currents, the weak signal is too easily be interference by external environment to achieve accurate measurements. For the power current below 6mA, designed a system based on energy metering chip ADE7816. By analyzing the experimental results, proposed schemes to reduce the measurement error for the first time. The results show that, when the load is maintained at 10Ω and the value of PGA is set to 4 from 0, the average relative error of results is reduced to 0.63%; additionally, when the value of PGA is maintained at 0, but the load Increased to 52Ω from10Ω, the average relative error of results is 0.02%.

Abstract: There exists harmonic interference problem when micro grid-side inverter connecting to grid with nonlinear load. The harmonic impedance loop is added in the voltage output loop to suppress harmonic in grid-side inverter. Using instantaneous reactive power theory to extract the main frequency harmonics, a new harmonic impedance is synthesized in the voltage control loop. The voltage control loop mainly presents the performance of resistive impedance and suppresses the harmonic interference while the inverter grid-connected. The Matlab/simulink simulation shows the method can effectively suppress the harmonic of grid.

Abstract: Uniform sound pressure level (SPL) distribution of linear phased loudspeaker array is limited by frequency. This paper widens the applicable frequency band of uniform SPL distribution in a linear listening area. By using an improved adaptive genetic algorithm (which contains a novel objective function, modified genetic operators and parameter setups) to control the directivity pattern details accurately, uniform distribution of SPL on a linear listening line in a wider frequency is achieved. The simulation and experimental results show that the SPLs on the test listening line are basically uniform from 200Hz to 500Hz, which demonstrates that the improvement of adaptive genetic algorithm is effective.

Abstract: State feedback exact linearization method in Buck converters have been widely recognized in the domestic, and it achieved a good control effect, but because the method is based on the accurate modeling, so when the model of controlled object is not accurate enough or circuit parameters in the application are changed, state feedback exact linearization method will be difficult to achieve the ideal control effect. In this paper we use the based on data-driven model-free adaptive controller (MFAC) on Buck Converter Applications for the first time. We analyzed the output characteristic of model-free adaptive control and the state feedback when load changes by simulation. Through the experimental platform of practical, we compared MFAC and the state feedback. Results show that, when the circuit parameter varies in a large range, MFAC has better robustness and resistance mismatch capability, high steady accuracy.

Abstract: In order to diagnose the fault in analog circuit correctly, a Wavelet Neural Network (WNN) method is proposed that uses the Particle Swarm Optimization (PSO) algorithm to optimize the network parameters. For the improvement of convergence rate in WNN based on PSO algorithm, a compressing method in research space is introduced into the traditional PSO algorithm to improve the convergence in WNN training. The simulation shows that the proposed method has a good diagnosis with fast convergence rate for the fault in analog circuit.

Abstract: in the current days of the fast developed internet of things (IoT), the IoT technology is gradually extended to the construction of livestock cultivation industry. In order to advance the intensive level of the livestock cultivation and accelerate the construction of livestock cultivation IoT in our country, this paper presents the IoT system suitable for livestock healthy cultivation in our country and introduces the system from three aspects: system requirements, technical framework and system function, in which the main focus is the application system and the key technology involved in each system modules is analyzed.

Abstract: DEP (dielectrophoresis) technology has been widely researched and applied in measurement the properties of various of biological particles. The design for every part to the whole system has been completed based on the requirement of broadband and wide-amplitude drive power in dielectrophoresis. As well as, the source and output detected feedback system are been designed respectively to ensure the output signals amplitude and phase of 4 channel is synchronous. Amplitude detect uses the double diode with temperature compensation to make up the detect circuit, the theory analysis and simulation of it has been performed. Experimental results show that the accuracy reach 5%, resolution 1v.

Abstract: Impact resistance angular displacement sensors are widely used in motion mechanical system, which not only requires the sensor having the advantages of large measurement range, long life, also the sensor need to withstand shock and vibration. We use the finite element analysis on the key structure of the sensor and design the sensor circuit.. The sensor has the advantages of high strength shell and flexible packaging, and it can withstand the impact of the gravitational acceleration 100g on three directions.