Applied Mechanics and Materials Vols. 336-338

Abstract: A model of hyperboloidal catadioptric panoramic imaging system is built, and equations between the maximum system field angle and other parameters of the system model are derived. The influence of the maximum system field angle on reflector surface shape, effective pixels width, system resolution and observation distance are analyzed by using quantitative analysis method. Meeting the requirements of system design, the simulation results indicate that the maximum system field angle should be less and stay as far as possible away from 105 °. The experiment results indicate that the actual maximum system field angle and the physical maximum system field angle should overlap in order to avoid system resource waste and performance degradation.

Abstract: Cerium activated lanthanum bromide (LaBr₃:Ce³⁺) scintillator crystal has shown very promising characteristics for high-resolution and high-sensitivity gamma ray imaging and spectrometric applications [1,2,. In this paper, we present some preliminary results of a compact gamma camera based on LaBr₃:Ce³⁺ crystal. The detector module consists of a continuous LaBr₃:Ce³⁺ crystal with a sensitive area of 50x50 mm² and 5mm thickness coupling to a Hamamatsu H8500 position-sensitive photomultiplier tube (PSPMT). A compact multiplexed readout based on symmetric charge division circuit (SCD) was developed to reduce the 64 anode signal to 16 readout channels, and a resistive division network to reduce the readout channels from 16 to 4. The performance of the imaging detector module was tested using a ⁵⁷Co source. The preliminary results showed that this detector module can achieve an effective field-of-view (FOV) of ~39x39 mm² with a good intrinsic spatial resolution around 1.5mm and energy resolution of 9.2% at 122 keV.

Abstract: A optical biosensor used in index dynamic detection has been proposed combining the tunable filtering characteristics of defect photonic crystal with the surface wave resonance principle. The sensing model of the biosensing chip based on defect photonic crystal has been established based on rigid coupled wave method, which obtained the relationship between the change of resonant angle for reflective spectrum and the variation of refractive index for biomolecule detected. Using the photonic crystal with the defect layer in place of the metal film in the surface plasma resonance (SPR) sensor, repeatedly total reflection would take place in the defect layer, which would increase the senstivity of the measurement system.

Abstract: A portable data terminal design based on wireless sensor network was came up for agriculture equipment working status monitor, a JN5139 module was used as the hardware core of the terminal and Zigbee as the wireless communication protocol. Effect caused by time-delay and pocket loss was simulated and analyzed with Truetime1.5 under matlab, data acquisition software was developed according to the simulation that effectively reduced the influence. Error measurement test showed the analog average absolute error was 6.33mv and frequency average absolute error was 0.56Hz, that indicated the reliability and availability in agriculture application.

Abstract: Wear is one of the most common failure modes in mechanical machines and the lubricating oil carries a lot of wear information. For monitoring the ferromagnetic debris in oils, a sensor is developed based-on electromagnetic induction principle. The magnetic transient model of sensor coils and particle was established by using Maxwell. The experiment results can reveal the total ferrous debris in an oil sample.

Abstract: This paper presents a kind of verification platform similar to Wiimote infrared spots tracking, which is based on the ordinary camera, FPGA, MCU, and Bluetooth. By the maximum of data compression and algorithm optimization, this platform reduces the SW/HW resources and achieves the requirements of low-cost ASIC integration.

Abstract: Considering the multi-valued mapping relationship of equipment response event to voltage sag, a lattice ordered evaluation method is proposed in this study. Each possible resulting state of equipment response event is described by an interval number. The interval numbers is with the characteristics of lattice order presented by the upper and lower probabilities. The possibility degree matrix is introduced to compare resulting states without satisfying the axioms of connectedness. Personal computer is simulated and compared testing results. The results have shown the validity and feasibility.

Abstract: A generalized synchronization scheme for two new different fractional-order chaotic systems is considered. The control scheme is simple and theoretically rigorous. The numerical simulations demonstrate the validity and feasibility of the proposed synchronization scheme.

Abstract: In order to enhance metrical precision of radar on the vessel, Kalman filter based on Singer model is designed to filter angle-error signals in servo system of the radar in this paper. Precision of angle-error signal in the servo system is a key factor influencing precision of tracking and control. But it inevitably corrupted by external disturbances and internal noise during transmission and detection. Kalman filter, which is a kind of linear minimum variance estimation, can estimate state vector at any time when a parameter variable changing with time (state vector) and a linear model (system model) are provided. Therefore, it’s extremely suitable for filtering the angle-error signals in servo system. Experiments on practical signal show that Kalman filter can reduce noise of the angle-error signals effectively and hence enhancing metrical precision of the radar.

Abstract: Reasonable modeling and simulation of power battery, optimization of the estimated power battery parameters that can contribute to power balance control efficiently, prolong the service life of the battery power and reduce the cost of electric vehicles. Using the lithium iron phosphate (LiFePO4) power battery that adopted in current electric vehicles widely as the research object, choose PNGV equivalent circuit battery model based on the analysis of the static and dynamic characteristics of the battery. An improved least square method to identify the model parameters was proposed, the matlab/simulink simulation results show the estimation error of the proposed method is less than 3%, and validate the proposed method is effective.