Delay measuring technique of BOC signal channel

The delay caused by signal transmission channel of navigation satellite is a part of the total delay of the satellite-to-earth link,and it must be deducted in the actual positioning and timing applications. Delay measurement of satellite channels must be carried out in ground tests. Test accuracy of the channel delay will affect users ranging accuracy and precision time transfer. A BOC(binary offset carrier) signal channel delay measuring technique using partial correlation is proposed. BOC navigation signals and 1 PPS(1 pulse per second) signal are high-speed synchronous sampled. Partial correlation processing is made for the sampling BOC signal data and the integration time is less than a pseudo-random code cycle. The starting point of the pseudo-random code sampling data obtained by processing,then the transmission channel delay of the BOC navigation signals can be calculated. The uncertainty of the test method is less than 0.2 ns for sampling frequency of 10 GHz.     

Improved CMI code in passive induction setting system 〖JP〗

Aiming at the low energy transmission efficiency of the passive induction setting system with the existing codes, an improved CMI code is proposed as baseband code by changing the equivalent average time of high level during a code cycle under 2ASK modulation. The properties are analyzed, such as energy transmission efficiency, power spectrum and the error probability in incoherent demodulation in AWGN channel. The code is successfully applied to passive induction setting system, and the decoding method and measured voltage waveform are given. With the code, the energy transfer efficiency is improved by 60% than that of CMI code. It is not only beneficial to energy transmission, but also has the merit of CMI code that the bit timing information is extracted easily, which is fully utilized in incoherent demodulation to solve the sampling moment error accumulation problem resulted from the instability of internal oscillator.     

Study and Design on S5933 Special Chip Data Acquisition System Based on PCI Bus

The paper explains the data transfer mechanism based on the PASS-THRU channel of S5933, and gives a method to develop data acquisition system based on PCI bus, the problem of designing the PCI interface controller is avoided, saving time and cost of development production. The use of CPLD makes the stucture of the system more integrated. The 32-bit data acquisition system,the speed of data transmission is faster,the CPU resource and PCI bus resource are spared.     

The Design of the High Speed Data Collecting System in Curved Surfaces Measurement

In high speed data collecting system , the way of data transmission is very important. This paper has analyzed in detail the necessity of DMA in data collecting of curve surface measurement and given out the circuit for DMA and described the theory and programming method.     

Calculation of lumped parameter of two-port network forvolume conduction energy transfer

Skin electrode unit is a channel through which energy can be transferred to the implanted device by volume conduction. The unit can be equivalent to lumped circuit, but so far there are no appropriate calculation methods of these circuit parameters, so variable load method based on field-circuit coupled is proposed. A skin electrode unit field circuit coupled model is established to obtain the relationship of the network parameters between voltage and current at electrode port, and the amplitude and phase of the power signal is extracted by the use of all phase FFT spectrum analysis. On this basis, equivalent circuit impedance parameters of the skin electrode unit under various conditions are obtained by the application of variable load method and the validity of the method is verified. As a result, the equivalent circuit impedance parameters obtained in this way can be used for the circuit analysis and optimization of the volume conduction energy transfer system.     

Design of the distributed wireless monitoring system

For the limitations of the traditional monitoring systems under the circumstances of dispersed monitoring points, wide distribution range and the harsh environment, a distributed wireless monitoring system based on radio frequency technique is designed. The system adopts the ultra low power consumption MCU MSP430 as the main control chip and extends several processing module in the periphery. In addition, the multi channel transceiver nRF905 is used for wireless data transmission. The software and hardware design scheme of the proposed system and the communication protocol for distributed data transmission are discussed. Frequency hopping mechanisms are employed to increase the reliability of data transmission. The results show that the proposed system has the characteristics such as flexible use and excellent mobility, while can monitor multipoint data in special environment in real time.     

Realization of high speed transmission system of ICT based on USB 2.0

Aiming at solving the problems existing in the traditional data transmission system of Industrial Computerized Tomography (ICT), which usually uses PCI and ISA bus, resulting in high price, poor scalability, low transmission rate, complex fixing and complex routing, and cannot fulfill the demand for research and production, a set of ICT based USB 2.0 high speed data transmission system model is proposed. The system takes a FPGA chip as core logic control module, which controls communications with the USB chipset. The whole hardware designation is described in terms of the performance of reliable data transmission, high speed and stability. Experimental results show that the proposed method improves the system’〖KG*8〗s stability and reliability. It can satisfy the requirements of ICT transmission .     

Computerized Simulation of the Transmission Line in High-speed PCB

With the rapid development in logic circuit,the effect of transmission line in PCB becomes a confined factor.In the design of high-speed PCB,the factors which affect the integrity of signal can be found by computerized simulation of the transmission line,simultaneously the signal quality could be optimized.The capacitance matrices of transmission line in high-speed PCB have been computed with this method that is the total charge Green's functions with method of matrix,then the time-domain model is built.Connected to IBIS model of the I/O buffer these models can be used in computerized simulation of the transmission line.The result of simulation is equal with the result produced by EDA software-Specctraquest of cadence Co.and the efficiency of simulation is advanced.     

Integrated Control Strategy for Dual State Continuously Variable Transmission System

Continuously variable transmission (CVT) is the ideal transmission for automobile, it is also one of the most important research items of researchers and automobile companies all over the world. In order to research vehicle with torque converter as starter and metal pushing belt as high speed transmission equipment(dual state CVT system), based on the test data of engine and torque converter, the integrated control strategy for vehicle with dual state CVT system is proposed and integrated control simulation for car with dual state CVT system is finished at the condition of multi mode. The research results provide the theory method of analysing and designing for CVT vehicle.     

The method of dual focusing beamforming based on virtual element in ultrasound imaging

According to the resolution and investigation depth deficiency of traditional dynamic receiving focusing (DRF) beamforming in ultrasound imaging,a dual focusing beamforming method based on virtual element is proposed. Firstly,single fixed focus point is used in the first focusing; and then the delay parameters used in the second focusing are calculated with the concept of virtual element; in the end the second focusing is carried out by delay-and-sum dynamic focus technique to obtain the imaging data. The experiments based on point pattern are used to verify the proposed method. The experimental results indicate that dual focusing beamforming applied to ultrasound imaging can resolve the contradiction between resolution and investigation depth in some extent and the method of dual focusing beamforming can effectively improve the imaging quality.     

Micro Displacement Measurement System

In order to solve the shortcoming of generally used measure method for Micro displacement,which is expensive and unable to automotive longtime watch,a sort of MDMS is gwen based on the corner reflector and microwave phase measurement.In the situation in which the direction of the micro displacement parallels to that of electromagnetic wave radiation,the basic MDMS is recommended.Otherwise the bend MDMS is recommended.The principle of MDMS is described.The example of channel calculation and circuit for transmitting measure result are also provided.The communication circuit transmits measurement to termination demanded.Finally the experiment results are given.     

Wavelet Neural Network Equalizer Using Error Feedback Structure and Algorithm

The inter-symbol interference in the nonlinear time-varying channel is a serious problem in the wireless communication. In order to overcome it, wavelet neural network equalizer using error feedback is employed to cut the auto-correlation of the error signal. Exploiting the decent time-frequency localization of the wavelet analysis, as well as the self-training feature of the neural network, a quicker convergent nalysis and computer simulation confirm the effectiveness of the equalizer and a lower BER are attained. Theoretical aalgorithm. It at The wavelet neural network equalizer based on error feedback advances the communication in the nonlinear time-varying channel.     

Model and Numerical Analysis of Radiation Field Created by Lightning Overvoltage Wave on Transmission Lines

The radiation field created by the transmission line stroked by lightning far from the lightning channel has been analyzed by the FDTD method.The authors we establish the calculation model and FDTD calculation method of transmission line,and discusses the import of lightning excitation source.The simulation of lightning stroked on a single transmission line in free space or stroked on three-phase high voltage transmission lines in actual environments has been done,and gives the distribution of transient radiation field around the transmission lines when lightning overvoltage wave transmits along the transmission line.The simulation result shows that: the effect of the transient radiation field caused by lightning over voltage wave done with environment is obvious,and the high frequency component of transient radiation field may disturb or do harm to the electronic facility or communication facility around the transmission lines.     

A Test and Analyzing System of Manufacture Errors onPlang-generated Hourglass Worm

Aiming at solving the matter of fact of manufacture errors on worm, the worm test apparatus is studied by the tool research department in Chengdu.A kind of improved principle,hardware and software design of the project is discussed. The primary aim of the single chip microcomputer circuit of this project is data collecting, and the invention monopoly of professor Zhangguanghui of Chongqing university is applied. The high frequency inserted pulse is used, and the software is joined in constitute subsidiary calibration distributed on equal time. The task of online subdivision in the dynamic measure process is completed. The data are passed to PC, PC handle them and examination result is gotten. The integration of the process is very high, and the tedious and complicated hardware circuit is simplified like the tradition examination method.     

Malfunction Diagnosis of Three-phase Full-bridge Controlled Rectifier Based on BP Neural Network

The diagnosis of the power electronic circuit is very intricate. One of the main reasons is that the structure of the circuit will change if the power device is not working .The thyristor is the easiest to be mangled. So diagnosing the malfunction is the most important about the diagnosis of the power electronic circuit. The paper puts forward a malfunction diagnosis of the thyristors of three-phase full-bridge controlled rectifier with BP neural network. After analyzing the output waveforms of malfunctioning circuit and training a BP neural network with the sampling data of malfunctioning waveforms, a well training BP neural network is constructed and used to diagnose the malfunction. The simulation and experiment demonstrate that this method is valid.     

Fast modeling of the motor broadband equivalent circuit model

This paper proposes a modeling method of the motor broadband equivalent circuit model. The impedance amplitude-frequency characteristics of the motor terminal through measuring are obtained. The impedance amplitude-frequency characteristics are devided into several regions based on its first resonant point information,and the motor broadband circuit topology is developed with each region equaling a resonance unit. The RLC parameters of resonance unit are extracted through frequency and corresponding impedance of the any non-resonant and resonant point in each unit. This proposed method is used to build DC and AC motor broadband equivalent circuit model. Their impedance amplitude-frequency characteristics are simulated by the Saber software. The measurement results and the simulation result of references are compared. The DC motor simulation results coincide with the measurement results in 0.1~50 MHz,and the AC motor is in 0.1~40 MHz. The results show that the motor broadband circuit model is reliable and feasible.     

Status Quo and Expectation of Human-machine Interaction in HCR

Human-centered idea and human-machine collaboration are emphasized in the Human Centered Robotics, which is mainly used for human-machine cooperation required mission in dynamic and non-structural environment. This paper presents a WearComp based interface that gets over the space and time limitation on human-robot interaction. By adapting AR(augment reality) in outputting channel, the information of robotics status and warning was accentuated in the transmission. That method effectively saves the resources of transmission band and reappearance, lightens the burden of operators and contributes to a good operator consciousness to local condition and remote environment. By parallel and mutual compensation of MultiModality interaction, and by integrating and fusing the redundant information, the ambiguity and noise of inputting information can be eliminated. All of above get rid of input bottleneck; a more efficient and humanistic human machine interaction is provided.     

Post-process of Finite Element Method in Electrical Impedance Tomography

In the research of electrical impedance tomography (EIT), each calculation may produce a large amount of data(such as conductance , resistance etc.). The rule of these data is not clear and is hard to understand. How to express the calculation result by means of image in order that such parameters as conductance and resistance can be grasped from the image is significant in analyzing and understanding the calculation result and is helpful to the doctor. This paper has discussed the realization of the post-process of finite element method in electrical impedance tomography and we have developed the software of the post-process of finite element method using Visual C++ .NET and OpenGL. Some problems in drawing the contour line and color contour band have been solved properly.     

Gearing theory and transmission characteristic for dual drive planetary transmission system with large capacity of shield machine

On the basis of studying shield machine and planetary transmission, to address cutting drive system of shield machine, a novel dual drive planetary transmission system with large capacity is presented, and its principle and structure are analyzed. Through establishing a new kinematical model of the transmission system and analyzing its characteristics, the transmission ratio, rev and torque relationship and changing rules within the system are acquired. By comparing the simplified experimental results with theoretical results,it is shown that the variation is basically the same, which verifies the correctness of the model and analysis method. The high-power dual-driven planetary gear transmission system with great transmission ratio, strong carrying capacity, can perform the function of low-speed and high-torque output, and meet basic requirements of shield machine. It can not only replace the traditional multi-driven transmission system, but also achieve the transmission function in three different types of shield machine.