Theoretic analysis and verification of the closed-loopself-oscillation for an MEMS gyroscope

By analyzing the requirement of the closed-loop control for the vibratory gyroscope, the behaviour of the self-oscillation system with automatic gain control was analyzed with averaging method to achieve system stability and stable equilibrium. The theoretic analysis and experiment show that the reference voltage must be larger than a critical value; the larger the reference voltage is, the larger the signal-noise-ratio is; the system phase error will cause the resonance frequency drift and decrease the vibrating amplitude; different constants of the low pass filters result in different time to achieve the stable states. The experiment shows the frequency accuracy of the close-loop self oscillation system is about ±8ppm in 10 minutes and vibration amplitude is about 0.1% error in an hour.     

System Platform of Auto Industry Based ASP and SRM

In view of the situation of auto industry, a system platform is given based on ASP and SRM. For the Co-management and information exchange of SRM, dynamic co-mode and estimated principium are designed. Based on four influence factors of auto industry, focuses on the process of supply not the result. Based on problem definition, formulation of criteria, qualification and choice, the process of estimate is improved. Implementation result shows that this kind of system platform can improve the efficiency of information exchange and achieve the goal of Co-management.     

Enterprise Resouce Planning and the Data Warehouse

The traditional Enterprise Resouce Planning system belongs to the typical on-line transaction processing (OLTP) system. It just offers a management platform where enterprise policy-making level and staff can make decisions, but it can not offer necessary information satisfied for making decisions directly. The traditional ERP system is a very good back-office management system, but the developing enterprises need the ERP system with the front-office management function at the same time. The traditional ERP system integrated with data warehouse can realize the function change greatly because DW can remedy the limitations of the traditional ERP system. DW, integrated with the traditional ERP system in the way of system structure, can analyze the data drew from the ERP system, and deposit these sample data and analyzed results into itself so that users can inquire these later. It can help users find the potential value of data accumulated in the traditional ERP system, and then it can help enterprise gain extensive competition advantages for a long time.     

Creation of an Experimental System for Testing the Dynamic Tensile Stress of Cells Using Membrane Variable Stress Wave

The constitution, design ideas and working principles of the DDC experimental system for testing dynamic tensile stress of outside body cell using membrane variable stress wave are discussed in detail. A new design measure is put forward, i.e. using airtight liquid for transferring pressure, and a space mechanism which is made up of two moveable linking axes and controlled by DDC for producing dynamic tensile stress with variable stress wave. The space mechanism is made up of two moveable linking axes, the first axis is controlled by an alternative current servo system, at the same time it drives the modulating modulating disc, and its rotation velocity is uniform and adjustable, so the rotating velocity of the disc can be controlled. Second, the hydraulic pressure worktable is driven by step electric motor. By dynamically changing the relative position of the modulating disc and the worktable, the journey of the piston in hydraulic pressure vat can be changed accordingly. The resultant motion of the modulating disc rotation and the radial direction relative movement of the piston can create liquid pressure with variable frequency and amplitude range, and the pressure can be changed into membrane tensile stress with variable frequency and pressure amplitude range using pressure fine tuning, and muhi-path disporting pressure. The system is proved to be simple, reliable, economic and controlled expediently by the experiment conducted.     

Optimal Control of Semi-Active Suspensions with ER Shock Absorber

An ER shock absorber with mixed mode is designed and its mathematical model is built. The optimal control method with LQ is applied to semi-active suspension systems in vehicle. A optimal output tuner is designed on basis of 1/4 dynamic model and the characteristics of the ER shock absorber. Its aim function and the weighting parameter matrix are determined. The feedback gain vector is found from solving the Algebraic Equation. The result shows that the optimal controller could not only diminish the body acceleration effectively but also improve the ride and handling characteristics. The construction of the ER shock absorber is reasonable and its performance meets the optimal control requirements of semi-active suspension system under the 3 kV/mm. In additional, the optimal control has low cost and energy consumption as well as rapid response . Such a system can meet with the requirements of semi-active suspension control completely.     

Rectangular Cover System of Manifold Method and Its Auto Mesh Algorithm

In contrast to the finite element method, another form of numerical method which is based on the using of rectangular math covers in manifold method is proposed. In this method, the element data is not a necessary in the input data files and it can be incorporated with the CAD technology conveniently. The theory and application of the method are discussed and the auto mesh algorithm of the cover system is also given in this paper. The numerical examples indicate that the method and the algorithm are accurate and effective.     

Developing of Auto-control Position System in Push-coke Machine

The auto controlling based on PLC system realized the identifying of coking number and the accurate position.In this system the identifying of coking number was reached with the schematic binary system of PLC and the assistant of proximity sensor.With RS485 ,the digital was used for transducer controlling port which drive the motor and the high speed counter, AD61, was used for feedback adjusting the offset.The discrete digital increasing PID control algorithm compensating the position errors is discussed to arrive at the accuracy auto position.With the module ,RS485,we realize the serial communication and the report forms managing between the PLLC system and the computer.The technique can achieve the object of automatic control accuracy in practices.     

Dual mode AC DC AC converter for contactless power transfer system

A new type AC DC AC converter which can work in Buck or Boost mode is proposed in order to overcome the deficiencies of the primary circuit of the traditional contactless power transfer system. Through switching this two modes and turning the duty cycles of the switches, not only the resonant current amplitude of the primary resonant current can be controlled to be constant against a wide range variation of input voltage, but also the problems, such as surge current, high cost, complex control etc., caused by the DC filter and DC/DC converter in a traditional CPT system are effectively eliminated. The topology and operation principle of the proposed converter have been analyzed. The corresponding control strategy has been presented and verified by simulation results.     

Auto Mesh Algorithm of the Finite Cover System in the Numerical Manifold Method

A auto mesh algorithm of the finite cover system is presented by abstracting the finite cover system of numerical manifold method as independent data classes.The programs are made by Object Oriented Programming(OOP).The accuracy manifold element can be generated automatically when the continuous material is cut by crack.The calculation result shows that the algorithm is reliable and effective.     

Development and Design of ABS Dynamic Test-bed for Automobile

Aiming at the problems of ABS products tested on vehicle, a character test-bed of automobile and motorcycle ABS is studied.To provide an economic and efficient test method for vehicle anti-lock braking system(ABS) in laboratory,the idea of designing a dynamic test-bed is researched and developed,which can simulate actual working status of automobiles well and truly.The test-bed structure character,design principle and key techniques are discussed.It will provide a new method for testing ABS products of automobile and motorcycle.     

Design and Implementation of Role-based Access Control in a Teaching System

This paper discusses how to design and implement a security subsystem, which based on the Role-based Access Control technology. By taking a teaching web system as a practical example, the paper establishes an access control matrix, so dynamic menu, page jump, and data access control are loaded. The experimental shows that, the system can controls the access authorized data, and to avoid the illegality access. The practicability and robust in the system is evident.     

Analysis on Stability for Uncertainty Complex Control System Based on Knowledge

Concept of stability is vague, but it is basic characteristic of dynamic system, and precondition that make all kinds of control system run normally. Today it is still a challenge to analyze stability for uncertainty complex control system, whose mathematic modeling is impossible or very difficult, so it is very hard to judge whether a system running is stable or not by mathematic stability criterion. A kind of analyzing method is presented, which combine absolute stability with self-locked concept of heuristic search, it may analyze system stability in more range through adjusting self-collected loop parameters for uncertain control system based on knowledge control model. It is shown that stability analyzing method is effective and suitable for practical physical system in the engineering project.     

考虑预估驾驶行为的跟驰模型及其稳定性分析

在OV模型的基础上,进一步考虑预估驾驶行为对车流的影响,提出一个新的跟驰模型以获得预估驾驶行为与交通拥堵的关系。通过对新模型进行稳定性分析得到了系统的临界稳定条件。数值仿真结果表明：新模型能够模拟诸如时停时走、系统临界相变等实际交通现象,较OV模型更贴近于实际。同时,预估驾驶行为增强了交通流稳定性能,提高了车流陷入交通阻塞状态的阈值。最后以车速的平滑度和波动幅度最小为评价指标得到了新模型中预估参数的最优取值范围。     

THE OVERLAPPING DECOMPOSITION DECENTRALIZED CONTRAL FOR GENERATOR''S EXCITER/GOVERNOR SYSTEMS

In this paper the generator's exciter/governor system are decomposed by using the overlapping decomposition method, and an overlapping decomposition decentralized control (ODDC) system is designed for the exciter /governor systems. In or.dar to enhance the dynamic qualities of the decentralized control system, the concept of the second feedback system is introduced to modify the first feedback gain matrix on the condition of the structure of the original decentralized control system maintaining unchanged. The practical decentralized control system design and its; simulation results show that this method greatly improves the control effect of the ODDC system and also holds all the advantages of the ODDC system. Besides, this paper indicates that it is a simple and effective method to control excitor/governor system by overlapping decomposition decentralized control strategy.     

Design of Virtual Instrument for Automobile Based on PC/104

The design of virtual instrument for automobile based on PC/104 has been presented by comparing with the traditional auto meter. The paper focuses on the development environment, system construction and operation principle. The data of the virtual instrument is transported by CAN bus, and this system can monitor in real-time, display in digit and fire the alarm to the super-speed, save the record.     

Electro-circuit Design About the Data Acquisition and Wireless Transmission System Based on High-speed SCM

Considering the difficult of acquiring and transmission the signal from the moving equipment, a new fault diagnosis monitoring system is presented. The system acquires the state signal from the moving equipment by data acquisition module that based in W77E58 high-speed SCM, and transmits the data fast by wireless mode. The signal data can be use for fault diagnosis and precise analysis. The system has the ability for acquiring abundance of data with a high speed, the ability for high accuracy data conversion, and has a function of programme controlling gain and programme controlling low-pass filtering. The successful application of this system on the vibration monitor about the material-transporting bogie in an iron works of a domestic steel enterprise proves the stability and credibility about the design project, also testifies its practical value and versatility.     

Development of Automobile Noise and Vibration Analysing System with Object Otiented Technology

With the developing of the automobile industry, how to control the noise and vibration level of the products come to urgently for the auto factories during their developing and producing period. Finding out the main noise source and vibration source quickly, analyzing the noise and vibration signal effectively, contriving a noise descending algorithm reasonable and economical become the first and most important job for auto corporations. At the mean time it complicate the developing guide line of the noise and vibration testing system. With object oriented technology, we can develop the noise and vibration testing system in a short time and with a low cost. The object oriented technology emphasizes the circulation, exoteric and expandable of the codes. It enables us developing the system follow a flexible, integrable and economical procedure..     

Performance analysis on improved PDA AI for moving target tracking

Aim at the problem that the EO imaging tracking system is inconsistent with the model of probabilistic data association with amplitude information (PDA AI), which supposes that the greater the amplitude value is, the greater the probability of being the tracked target will be, a modified PDA AI (MPDA AI) is presented . Based on the fact that the amplitude and the motion of the interested target are consistent in a short period, the MPDA AI models the amplitude information and the motion information of the target as well as their consistency with Markov stationary signal to analyze the association procedure of motion and amplitude. The lower bounds of Cramer Rao estimation error for PDA AI and MPDA AI are calculated and discussed in detail. The theoretical analysis and experimental results show that estimating the target motion with the MPDA AI will be more accurate and more reliable than estimating with the original PDA AI.     

One-cycle Technique Based Adjustable Ac Source

By using one-cycle control theory, a novel voltage source inverter is proposed. The conventional one-cycle control technique needs that the integrator is reset instantaneously. But it is very difficult to realize with hardware due to the finite time constant of the reset circuitry. Therefore, based on the one-cycle technique, the paper gives a new control scheme to resolve the problem with dual switched integrator, and the performance of the integrators is close to ideal. The paper also uses the dc offset to implement the voltage measurement. Furthermore, the amplitude and frequency of the output voltage are effectively adjustable. The one-cycle control technique not only provides fast dynamic response, but also can admirably suppress the perturbation yielded by dc source and abate the undesired harmonic contents. Simulation studies were performed to prove the proposed scheme. The results show that the one-cycle control based voltage source inverter makes good use of dc source that is 92.8% and THD is only O. 255 9%.     

Network Security Monitor

Illegal traffics on network can be actively detected by network security monitor An advanced system is given which can capture network data stream and intercept malicious attack, so as to alarm or take response action in real-time. The system is composed by sniffer, monitor control center, remote management unit,etc. Attack activities under surveillance can be distinguished by two methods,which are rule based method and statistics based method. Intrusion recognition by sniffer is the key technology of the system. In addition, dilemma between real-time data stream and high inquiry speed, as well as dynamic addition of attack rules contributes to the main concern of system design. Backdoor of The system can be self detected, while intelligent analysis and bi-directional surveillance ability has also been implemented. With all these advance features, the system is presented not only as a strong assistant to traditional network security products, but also an important tool for counter-fighting with rampant network intrusion nowadays.