Ratio Control Principle and Mathematical Modal of Vehicle Traction Drive Type Continuously Variable Transmission

The traction drive continuously variable transmission is another kind of advanced transmission device for vehicle beside the metal pushing V_belt type CVT. It provides excellent driving performances including powerful driving capacity, high efficiency, good smoothness and economy, etc. The basic structure, transmission principle and the hydraulic servo control system of traction drive CVT are described. The mathematical model of the system is established. The study of this project provides the academic bases of further studying on the dynamic characteristics of CVT and vehicle.     

Directly Electromagnetic Driving of a Self-movable Wall-climbing Micro-robot

The method of directly driving a self-movable wall-climbing micro-robot and utilizing double electromagnetic forces interaction is studied.The principle of monolayer driving fashion, double deck driving fashion and differential driving fashion is analyzed.Three electromagnetic direct driving methods are contrasted by analysis and test, which established the foundation for the research of the self-movable wall-climbing micro-robot.     

Control Strategy for Asychronized Turbogenerators

Asynchronized Generator can better solve the excessive reactive and stability problem in power system.In order to improve the dynamic and transient performances of an asynchronized turbogenerator(ASTG),excitation control equation of it in the dynamic synchronous reference frame is presented.Control results are simulated in the synchronous and dynamic synchronous reference frames for ASTG.It is shown that the dynamic and transient performances in the dynamic synchronous reference frame are better than those in the synchronous reference frame.Consequently,the control strategy of dynamic synchronous reference frame can shorten more time on the dynamic process of ASTG.     

Application of state feedback and observer inmulti-axle vehicle steering system

A 3-degrees of freedom multi-axle vehicle dynamic model is established.Taking account of the practical difficulties for measuring the sideslip,rolling angles and rolling angle speed,a Luenberger observer is designed,and the simulation and analysis of the Luenberger observer are performed.The results show that the Luenberger observer has excellent characteristics in the considered speed range in tracking path.Then,a state feedback controller is designed on the basis of the Luenberger observer,and simulation of a multi-axle vehicle is also carried out.The results show that the performances of a multi-axle vehicle with the proposed control strategy is better than a multi-axle vehicle with front wheel steering strategy,and its control system has fine dynamic characteristic and strong robustness,so multi-axle vehicle with the proposed control strategy can improve vehicle handling stability and security.     

Modeling and Simulation of a Novel Drive Train for Wind Turbine with Large Capacity

On the basis of a planetary transmission, a novel hydrodynamic speed controlled transmission system for wind turbines with large capacity is presented. The new drive train consists of wind rotors, planet accelerators, hydro-mechanical and synchronous generators. The dynamic mathematical model of the drive train is established. The digital simulation of speed regulation characteristics for hydrodynamic speed controlled system is studied by using Matlab/Simulink. The simulation results show that continuously variable transmission and fixed speed control can be achieved, and the drive train works well in stability and dynamic performances. They can increase the power yield from the wind, smooth the electric power output, and alleviate the load peak in the new drive train .     

Modeling and simulation of a grid connected wind turbine withdoubly fed induction generator

In order to fully research the effects of external excitations, such as wind speed, wind direction and voltage disturbance, on a grid connected wind turbine with doubly fed induction generator, a co-simulation model of MW-class wind turbine system is established by using Simpack and Matlab/Simulink software. Also, by considering the actual control strategies in the process of simulation, the relationship between external excitations and mechanical system is studied. According to time-domain simulation under the turbulent wind condition, the dynamic meshing forces of gears are analyzed. Besides, the vibration responses of tower are calculated under the different external excitations. Research results lay a foundation for dynamic performance optimization and reliability design of a wind turbine.     

Intelligent Initiative Security Vehicle System

Auto driving and safe driving constitute a control system which has multiple variables and features of uncertainers and delay response. Anautomobile and its suroundings are considered as a whole and an auto-suroundings feature model is presented based on knowledge expressing method which describles the status appear in the driving process. The constitution of auto driving auxiliary operation expert system is discussed. The computer simulation results show that the proposed knowledge expressing method and sysytem constitution method are effective and feasible .     

Analysis of Equilibrium Runing Lines of Engine and Hydraulic Torque Converter for a Vehiele with CVT

The mathematical model of the torque converters is established based on test results. Equilibrium running lines of engine and hydraulic torque converter are analyzed. The idea of matching and controlling is put forward for CVT vehicle with torque converter in starting ability, crawl ability and fuel economical efficiency, which lays a foundation for the exploitation of CVT vehicle with torque converter.     

Research on Current Situation and Trend of Control Strategies for Hybrid Electric Vehicles

The vehicle's driving performances is determined by the control strategies and constructions of hybrid electric vehicles (HEV). The constructions of HEV are classified according to the change of state of charge of battery pack, and a study on current situation and trend of control strategies for HEV is presented in this paper. The research indicated that the current control strategies for HEV are not perfect and need further optimization. The control strategies should realize the optimum match among engine, motor, battery and transmission according to the characteristics of each component and vehicle's driving conditions. Many aspects including the fuel economy, emission, the life of battery pack, drivability, the reliability of each component and HEV's manufacture cost should be considered in the control strategies. A study on the control strategies and its optimization that take account of the aspects mentioned above is a work emphasis in the future. This paper also points out the PHEV equipped with small motor, small engine and continuously variable transmission is an ideal system construction for getting optimal fuel economy, lower emissions, steady drivability, lower manufacture cost and HEV's mass.     

A Dynamic Grey Fuzzy Evaluation Method for Financing Risk in Freeway Project

There are many risks that influence freeway project financing and the influence of these risks differ by project stage. However, it is impossible to analyze the total risk of project financing objectively and accurately merely using the fuzzy or grey evaluation methods. These methods cannot reflect the dynamic characteristics of financing risks during freeway project construction. A dynamically grey fuzzy comprehensive evaluation method was established and used to evaluate the financing risks of a freeway project. The results indicate that this method can not only make full use of the rich experience of the experts, but also reduce the influence of subjective factors. In addition, this method can reflect the dynamic characteristics of the financing risks during freeway project construction. Investors therefore can pertinently prevent and control financing risks based on the results of the evaluation of financing risks in every stage of the project. A demonstration shows that the method is suitable for comprehensive evaluation of financing risks of infrastructure projects such as freeways.     

Model predictive control strategy of a medium hybrid electric vehicle

The intense coupled and nonlinear behaviors were observed on the tall long span tower line systems which were under the icing and wind loads in heavy icing areas. A set of stiffness equations of insulator, conductor and boundary conditions was deduced. Taking the ±800 kV UHV DC transmission line from Xiangjiaba to Shanghai as an example, the simplified numerical model of transmission tower, conductor, insulator and constraint was developed. The long span transmission tower line system models under seven loads conditions were analyzed by static nonlinear methods. It was found that the P Δ effect of tower components was small when the covered ice was uniformly distributed. The unbalanced wire loads on the tower would lead to twist effect when the covered ice was uneven distributed. The axial forces, moments at restraint nodes and the longest cantilever member were greatly affected by the P Δ effect, under which the unfavorable effect on the structure should be considered.     

Modeling and control system simulation of automobile DCT

In order to reduce development time and cost of dual clutch automated mechanical transmission(DCT) control system,the dynamic model of automobile DCT control system is established by Matlab/SimDriveLine and the engine model is improved by neural network.Based on Matlab/Simulink,the simulation models of DCT control during starting phase,shift phase and shift rule are set up,and then the whole system of DCT is simulated.The simulation result indicates that the DCT system dynamic model and the designed controller are reasonable and feasible,and proofs that the model is suitable for developing DCT control system and improves the design efficiency of DCT system.     

Establishment and Control of the Objective System of Construction Project Management

According to the quality of one-time ,uncertainty and high risk in engineering project, the importance of management by objetctive of construction project is expatiated. The features and structure model of the system of management by objects are analyzed and established. The principle to determine the superiority of objectives in different levels and the "Analytic Hierachy Process" to calculate the weight factors are put forward. The method of active and passive control is employed to manage the project dynamically so that the successful enforcement of the overall objectives will be ensured and meanwhile the best investment effect will be achieved.     

Serial Communication System Between PC and PLC Based on Visual C++

It is usually need to supervise and control gathering data and working status of PLC in industry control.There are some ways such as VB,DELPHI,PB to carry out the requirement.Visual C++ is an exploiture tool for Windows application program and has quite strong function in the aspect of image processing and database managing etc.It has faster speed to realize bottom communication control.Using Visual C++ and MFC,the authors implement the serial communication system between PC and PLC.The paper introduces the communication protocol and software design method and realizes data's sending and incepted rapidly,real-time auto-control accurately and quickly.This system is simple,economical,and reliable and has an application value,which has been applied successfully in real system.     

Design of Excitation Control System of A.C.Excited Generator

Dual-passage excitation control method based on dynamical synchronous reference frame is analysed according to the base theory of A.C. excited generator. Using the dual-CPU project basing on the high speed DSP, excitation control system of A.C. excited generator is realized. Considering the characteristic of this control system, taking full advantage of the high speed and the convenient peripherals of DSP, the hardware and software of the control system are designed appropriately. Dual-passage excitation control system is realized using the dual-CPU method. Dual-passage excitation control strategy based on dynamic synchronous reference frame is proved with the experiment.     

Dynamic Simulation for Hydraulic Pressure AGC of Rolling Mill

AGC control technology is one of the key techniques used in modern rolling mill, the effect of which has influence on the accuracy of the product. On the base of analysing system composition and dynamic characteristics of the main dynamic emelent, a danamic simulation model is put forward,and then dynamic simultion for the hydraulic AGC system of 3340 rolling mill is implemented. Then, it lays a foundation for the design of rolling system and the dynamic simulation of the rolling process.     

Application of Fuzzy Control in Direct Torque Control of an Induction Motor

The key of motor control is to control motor's torque essentially.Direct torque control,which emerged after the field-oriented control,directly stresses the instantaneous torque control of induction machine,which avoids some problems existing in field-oriented control,thus,it gets more attention.In conventional direct torque control system,switch vector is selected directly by the errors of stator flux-linkage and torque,after introducing fuzzy logic,optimal selecting switch state is realized by various strategies by distinguishing the grade of the errors of stator flux-linkage and torque,the dynamic and steady state performances of induction motors are improved.This paper presents a design method of the fuzzy controller.Simulation results demonstrate that it is effective,the stator currents pulsation at start-up and the torque pulsation are decreased.     

Responses of Rubber Bearing Isolation Structure Considering Soil-Structure Dynamic Interaction

By means of the substructure approach in the frequency domain, equations of motion of the rubber - isolated structures are established considering the soil-structure dynamic interaction. The seismic responses of two shear-type base-isolated structures with an embedded rigid rectangular foundation are numerically simulated, and the influences of the different rigidities of soil on the effect of the base isolation and the seismic responses of the structure are investigated. It is concluded that rubber bearing isolation can reduce the dynamic characteristics of structures and reduce displacement of floor and basement relative to ground. Meanwhile, considering the dynamic soil-structure interaction may reduce the isolation effect of the rubber-isolated structures and the effect level is in direct proportion to the stiffness of the superstructure and inverse proportion to the stiffness of foundation soil.     

PID Control for Multivariable System Based on Ameliorative RBF Neural Networks

Aiming at systems which are of characteristics of multi-input and multi-output, nonlinearity and time-variation in the industrial control fields, this paper presents a intelligent PID control method based on ameliorative RBF neural networks, which constructs RBF neural networks identifier on-line and identifies a controlled object on-line by means of adopting the nearest neighbor-clustering algorithm, and adjusts parameters of PID controller on-line and realizes decoupiing control of multivariable, nonlinear and time-variation system. The simulation result indicates that the controller can get parameters which are optimal under some control law, it makes the decoupled system, compared to the PID control method based on the conventional RBF neural networks, has perfect dynamic and static performances, possesses the advantages of high precision, quick response speed and is of great adaptability and robustness.     

沼气示范村建设与区域循环农业利用评价——以廊坊市安次区为例

通过调查廊坊市第一沼气示范村安次区农村沼气的利用状况,揭示了其地位、存在的问题和全面发展循环农业的必要性。采用AHP层次分析法赋权重、综合指数评价法对廊坊市安次区进行了循环农业的利用的综合评价。结果表明:廊坊市安次区的农业循环处于比较循环阶段。该区资源环境安全水平具有较好的条件,农业生产基础好,农产品产值较高,具备了发展循环农业的基础。但是该区农业的综合利用水平较低,仍处于现代化水平较低的农业发展阶段,资源过量投入、农民人均纯收入低、科技投入力度弱等成为制约该区农业循环发展的重要因素。针对评价结果,提出了保障安次区循环农业持续利用的途径:全面推广沼气工程建设;财政补贴与技术培训相结合;全面发展循环农业、提高农民收入。