Applied Mechanics and Materials Vols. 313-314

Abstract: According to the characteristics of image wavelet decomposition and statistical characteristics of high frequency wavelet coefficients after wavelet decomposition, this article improves the traditional threshold function de-noising algorithm. Improved threshold function not only overcomes wavelet coefficient discontinuity caused by hard threshold function de-noising and certain deviation witch always exists between wavelet coefficients caused by soft threshold function de-noising and its real value. The experimental results show that, the improved threshold function de-noising results are better than traditional soft and hard threshold method either in the visual effects, or the PSNR gain.

Abstract: The autonomous underwater vehicle can be affected by sea flow and other factors when in a motion to a certain fixed depth. To guarantee the stability of cruise trajectory of autonomous underwater vehicle and considering the influence of sea flow on its motion, the underwater six-free-degree motion mathematical model for the vehicle is established in combination with the sea flow model. Besides, dynamic features of the longitudinal plane, horizontal plane and crosswise-rolling of the vehicle at different navigation speeds are simulated with the three-channel closed-loop control system. The simulation result indicates that the vehicle can move stably at a certain depth and with the achieved accuracy by means of closed-loop control.

Abstract: PNAVSIM is a package for numerical investigation of pulsar navigation. It contains a number of methods and algorithms for the simulation purpose in navigation. The photon-level integrated simulation model can be built easily based on the PNAVSIM library. The toolkit API can also be conveniently used by the developer in his own program. Functions are packed into modules at different levels. The top-level modules dealing with the spacecraft orbit dynamics, the pulse signal time delay, and the navigation algorithms are introduced. The structure of the PNAVSIM package makes it possible for developers to build simulation models flexibly and quickly, which enables more efficient applications of pulsar navigation.

Abstract: Thispaper puts forwards a design method base on a electric power-assisted HybridElectric Vehicle (HEV), which take dead-weight into account to design itsparameter of pivotal components among many actual design methods. Then simulatingand analyzing are made in ADVISOR about its fuel economyand emission. The results of simulation indicated that the fuel economy andemission levels of electric power-assisted HEV which take dead-weight intoaccount to choose its powertrain parameters is far better than the vehiclewhich used the conventional method.

Abstract: In this paper, a numerical simulation model based on discrete element method (DEM) has been developed to analyze the burden distribution in the Melter gasifier of COREX process. The burden trajectory, the location and the burden surface profile are analyzed in the top charging of melter gasifier. The distribution of ore and coke and the porosity in the radial direction are given under the different charging mode. The results can be used to optimize the charging patterns in order to obtain the reasonable gas distribution.

Abstract: In the paper, the control and calibration method on laser simulator is studied, which is based on optoelectronic confrontation hardware-in-loop (HWIL) simulation system. The control of the laser energy and spot size are necessary in the simulation system, and it is important to make the test successfully. The laser simulator simulates the changing of laser energy by the continuous rotation of Glan prism and the changing of the spot size by the telescope system. To get high accuracy of laser power and spot size, the accurate calibration of the relation of the rotation position and the attenuation process and the relation of spot size and the position of the motion platform in laser simulator is necessary. We apply dual calibration on the laser energy. In order to achieve precision simulation of spot diameter changes, we need to calibrate the relationship between four parameters accurately, they are the laser frequency, expansion beam lenss linear position, the distance of the receiver screen to the laser beam exit and spot diameter. And the feasibility was proved by the calibration data.

Abstract: the control strategy has a direct impact on the performance of active power filter. Creating system model in the simulation software to research and analyze. Results show that the hysteresis comparison control method can track the harmonic current accurately, and control inverter circuit generate compensation current quickly and accurately. And doing spectrum analysis for the power grid currents before, the spectrum figures show that the power grid current harmonics has been suppressed greatly, and the compensation effect is very significant.

Abstract: In order to achieve the dynamic simulation of vehicle clutch, the paper calculated the dynamic parameters of the locking and sliding process of vehicle clutch and established a Matlab/Simulink simulation model which can describe the revolution state of vehicle clutch. Also, it analyzed the dynamic behavior of clutch locking and sliding process. The research illustrates that the simulation model can correctly describe the dynamics of moving vehicle with combining and separating process of the clutch, and the dynamic simulation analysis reflects the alternation of clutch locking and slipping process more intuitively than the static model. Moreover, the method provides a reference for the dynamic control and integral optimization design of automatic clutch.

Abstract: The greenhouse temperature and humidity monitoring base on the application of virtual instrument technique apply LabVIEW as the software development platform, taking computer technology as the core. It equipment with the sensor, data acquisition, signal conditioning circuit and other hardware devices to achieve the greenhouse temperature and humidity parameters such as real-time acquisition, analysis, display, data storage function. The virtual instruments and the traditional monitoring equipment compared to display more intuitive, more easy to achieve functional expansion.

Abstract: This paper establishes the mathematical model of the volume speed-modulating system and simulates dynamically with Matlab/Simulink. Provide a theoretical basis for algorithm of close loop control [ of the three variables which are diesel engines, variable pump and variable motor. Use PID control algorithm, through simulation and analysis, find out the parameter optimization adjustment rule [2,, seek matching operation between three variables. Provide a theoretical basis for the study on dynamic system of full-hydraulic loaders and have very important practical significance in realizing high efficiency energy saving and reducing energy consumption.