Showing papers in "Journal of Xi'an University of Technology in 2004"

Dynamic Evaluation of a Whole Structure of an Industry Robot

Abstract: A systemic procedure is proposed to predict and evaluate the dynamic behaviors of a whole robot structure rapidly at its design stage. The dynamic model is composed of elements of beam and lumped-mass, which is linked by joints. The receptance equation of the element is established based on Boundary Element Method. And the receptance equation of the whole robot structure is established by synthesis of the receptance equation of elements. Natural frequencies and mode shapes of the whole robot structure are rapidly received by the equation. The software to analyze the dynamic behaviors of the whole robot structure were developed based upon the proposed method. The dynamic behaviors of a conveying robot with 5-degrees were predicted by the software at its design stage, and the dynamic behaviours of three schemes of the robot were evaluated so as to provide the theoretical base for the structure selection of the robot.

The Research on Chua's Circuit Improved by Simulated Inductor

Abstract: In this paper, Chua's circuit and its characteristics, as well as the circuit of realizing non-linearity resistance are firstly described; And then, a simulated inductor composed of op amps, linear resistances and capacitances is designed, Chua circuit is also improved by means of simulated inductor with good results obtained A drive-response chaotic synchronization system is constructed using the improved Chua's circuit This synchronization system is characterized by a certain stability and resistance to interference so as to lay a solid foundation for the chaos in the practical application in secret communication

Flexible Fractional Frequency Transmission System Simulation Based on Matrix Converter

Abstract: The Flexible Fractional Frequency Transmission System (FFFTS) using matrix converter as AC-AC transformation equipment is proposed in this paper. The simulation model in the case of MATLAB/Simulink environment is set up. The problems such as transmission capacity,transmission efficiency,harmonics and reactive power compensation are studied and compared with other power transmission systems in the simulation. The analysis results show that FFFTS is a promising transmission type in developing hydroelectricity resources and long distance power transmission in our country.

The Theory of Water Resources System Jieke and Its Application Prospects

Abstract: The basic concepts and its components of water resources system Jieke theory are described, and the application prospects of its theory in water resources system are analyzed.The research results show that the protection and exchange function of water resources system Jieke is dual and identical with the functions of protection, exploitation, utilization of water resources system and optimal allocation adjustment whereby the optimal adjustment and control mathematics model of protection, exploitation and utilization of water resources is suggested in this paper.

The Characteristics Analysis of Neuron MOS

Abstract: Based on the basic structure and the principle of neuron MOS, the device is simulated with HSPICE using the equivalent circuit model and the "variable threshold" characteristics of the device is obtained. The application research of the device is introduced—the applications in CDMA matched filter and digital PWM generator, the research result shows that the circuit can be simplified much through using neuron MOS. Finally, the operation precision of the device is analyzed, the conclusion that the parasitical capacitor of the MOS transistor is the main factor to affect the precision is obtained.

Determination Method of Branch Stiffness and Load for Parallel Machine Tool

Abstract: A method for determination of equivalent nonlinear stiffness and load of branchs on parallel machine tool is presented. In this method, numerical analysis model of parallel machine tool with joint contact deformation is first established and then, deformation data of the parallel machine tool ending obtained via the experiments are ushered in the analysis model so that a set of nonlinear equations concerning the equavalent stiffness of branch chain of parallel machine tool can be obtained. Also, the linearization method of the nonlinear stiffness matrix is used to obtain the solution. After the branch chain stiffness and load of parallel machine tool are obtained, the branch chain can be considered as the serial machanism, whereby the stiffness and load on each joint of branch chain can be further obtained in such a way as to lay a solid foundation for the static and dynamic characteristic analysis of the whole parallel machine tool. With a set of parallel machine tool as an example, the joint load is calculated. As compared with the literature result, this method is reliable and effective.

Research on NURBS Curved Surface Weighted Factor and Its Application

Abstract: In this paper,the weighted factor of the Non-Uniform Rational B-Sample(NURBS) is analyzed and researched. Firstly,the geometric sense of the weighted factor of the NURBS curved surface is described,thus,indicating that the weighted factor is the cross-ratios for 4 related points. The limiting character of weighted factor and the effect of the zero weighted factor on the curved surface shape are analyzed. Secondly,the computation formula for the weighted factor in adjusting the curved surface shape is suggested in the two cases of one point on the curved surface moving towards the direction of controlling top point or the random direction. Finally,an application example of changing the weighted curved surface is given.

A Chaos Optimize Design Method of Wavelets Neural Network Based on Immune Evolving Algorithm

Abstract: In this paper, a chaos optimized method of wavelets neural network based on immune evolving algorithm is presented under the foundation of introducing chaos mechanism and combining the immune algorithm with evolving algorithm aiming at the"degenerative"problem of evolving algorithm and the"dimension overrun"problem of wavelets neural network. This method both exerts fully the fast characteristic of wavelets neural network and makes good use of global and adaptive characteristic of immune algorithm. The results of simulation experiment indicate the algorithms effectiveness.

The Design of Optical Collimated System in Atmosphere Laser Communication

Abstract: Based on the analysis of the law of luminous energy coupling efficiency varying with the numerical aperture of optical collimated system,this paper presents a method to determine the numerical aperture of optical collimated system in terms of the luminous energy coupling efficiency (being different from the method to determine numerical aperture in the imaging optics system). Accordingly,the optical collimated system is rationally designed whereby an effective method to determine the numerical aperture of optical collimated system in atmosphere laser communication is provided.

Research on Scanner Color Management Based on ICC Standards

Abstract: According to the open color management standards formulated by International Color Consortium(ICC),the polynomial regression algorithm,the matrix-based model and LUT-based model are used to create the profile protocol to describe the device features of scanner so as to realize the scanner color management based on ICC standard. The research results are of the guiding importance for the improvement of the popularization and application of ICC standards as well as the application level of color management.

MOL Numerical Solution Method for Burgers Equation

Abstract: In this paper, Method of Lines is used to research homogeneous and inhomogeneous nonlinear Burgers equation, and also the numerical solution to the initial value and the boundary value problem is derived. The results of numerical simulation show that the method is characterized by good stability and high accuracy.

Analysis of Vibration Characteristic of Complex Form Cable-Truss Supporting System

Abstract: This paper deals with the common use of layout patterns and behaviors of the dot-pattern glaze cable-truss supporting system and advances the basic analysis method of the vibration characteristics. For the analysis of plane form cable-truss supporting system, ANSYS program was adopted to exam the influences of parameters of pre-stress, cross-sections and lengths of cables and bars to the vibration characteristic systematically. The relationships between each parameter and self-vibration frequency are obtained. These conclusions are of guiding significance for anti-wind and anti-earthquake design of this structure as well as the analysis of the anti-resonance of main and sub-main structures.

Non-Orthogonal Coordinate Measuring System

Abstract: In order to achieve the auto-and noncontact measurement of ball-shell working pieces with special requirement within the limited space,a new type of noncontact and non-orthogonal coordinate measuring system is developed on the basis of combination of robot technology with laser non-contact measuring technology,the laser displacement sensor and CCD camera are adopted in the system with the serial link manipulator as the main measuring body to carry out the noncontact measurement, whereby the noncontact high accurate measurement of geometrical dimensions and surface defects of the ball-shell and revolving working pieces can be realized. The testing data indicate that the measuring system has reached the measurement with the high accuracy.

The Method of Calling MATLAB under VC6.0 Environment

Abstract: Several methods of calling MATLAB under the VC6.0 environment are described.The mechanism of calling MATLAB engine is analyzed in particular.As compared to other methods,calling MATLAB with engine can provide support to M files of various kinds.The engine calling method is concretely described with an example of a programme of FFT in dealing with a signal.

Evaluation on Study of Mathematical Modeling of Hydrology

Abstract: Great progress has been made in mathematical models of hydrology in the world in recent years, but relatively not so fast in our country. Based on brief review on history of hydrological modeling, the problems in modeling and possible solutions were discussed, and the propect of hydrological modeling was made, too.

The Comprehensive Evaluation of Economic Returns of Hi-Tech Development Zone Using DEA Method in China

Abstract: This paper analyzes the existing development situations of hi-tech development zone in our country. The data envelope analysis(DEA) method is used to carry out the comprehensive evaluation of economic returns of 30 hi-tech development zones. Also,through the projection analysis,the improvement direction of Non-DEA available hi-tech development zone for the future is found out, and the countermeasures and suggestions are advanced.

The Overall Optimization Algorithm Based on Parallel Recombination Simulated Annealing

Abstract: Aiming at deficiency in solving non-linear multi-extremum optimization problems using present optimal theory, the parallel recombination simulated annealing algorithm (PRSAA) is proposed. Two examples are evaluated using PRSAA in simultaneous analysis of algorithm perforances,and compared with PRSAA and genetic algorithm in this paper. The results show that the PRSAA is simple,reliable and of high precision and strong adaptability.

Integration System of CAPP and Production Scheduling Based on MAS

Abstract: The Agent technology of the distribution artificial intelligence is adopted to suggest CAPP and production scheduling integration model based on Multi-Agent System(MAS). This model is Dynamic Open Level/Layer(DOLL) control structure. The Contract Net protocol and active blackboard controller methods are adopted to realize information interaction and system execution. The prototype system based on this model is set up under the network environ so as to make the process planning and production scheduling Agent structure become the independent model which can better carry out the consultation feedback information. The scheduling process is simulated. The simulation results indicate that the system model suggested and the framework realization are correct and an effective way to solve the problem of scheduling bottleneck.

The Small Fluctuation Stability Analysis of Water Turbine Controlling System with Complicated Conduit System

Abstract: Based on the design scheme of Yao Heba Power Station in Nan Yahe River, the small fluctuation mathematical model for complicated conduit system, elastic water hammer and governor with law PID regulating of water turbine adjusting system is set up in this paper,on the basis of which the source programme is prepared and the simulation computation was performed. Accordingly,the optimal parameter groups and regulating range for the governor are obtained via the combined computation of various operational conditions and parameter groups of the hydropower station so as to guarantee the stability of the small fluctuation regulations.