Efficiency of Auto Transmission and the Penetrativity of Hydraulic Torque Converter

analyzing the primary characteristic and the power performance, this article discusses the changing regularities of the ratio in two types of HTC, which have different penetrativity. The effect to the AT efficiency is also discussed. It is pointed out that to find the best match of the percentage of penetrating and engine accommodation coefficient is a good way to increase AT efficiency and car driving power.     

THE AIGORITHM OF COMPUTED TORQUE -SELF TUNING CONTROL FOR ROBOT

Some control schemes for complex nonlinear systems have been developed recently and the robotic adaptive control is one of the typical examples. Due to the inevitable presence of unmodeled dynamics,if the adaptive control technique combined with nonlinear model-based control takes full advantages over any known parametric model while dealing with the remaining unknown parameters by using adaptive control,it may be an efficient control strategy, therefore.an algorithm of computed torque-self tuning control for robot is presented, whose simulation results have proved its effectiveness.     

A valve camshaft load torque calculation and camshaft vibration control analysis

Aiming at the overhead camshaft valve mechanism,the theoretical and numerical solutions of camshaft load torque are calculated respectively by a derived formula and transient finite element analysis. The two solutions show good agreement,thus the correctness of the transient finite element model is verified. By combining with camshaft instantaneous constraint modal analysis and vibration response with consideration of gas pressure,it is found the position of camshaft which easily excites resonance and the main influence factors of camshaft vibration. Then the effect of the width of bearing seat on the camshaft vibration is investigated and the results show that the vibration of camshaft is mainly bending vibration,appropriate width of bearing seat can effectively control the camshaft vibration.     

Electromagnetic torque ripple control of induction motor fed by dual frequency inverter

Direct torque control(DTC)of space vector modulation fed by dual frequency inverter is studied in order to solve the problems of large torque,big flux ripples and inconstant switching frequency of conventional DTC in large power occasions. On the basis of conventional DTC,factors affecting flux and torque ripples are analyzed and the space voltage vector mathematical model of induction motor is deduced,which is implemented by S-function. Based on dual frequency theory,the system is supplied by cascaded inverters to decrease losses. The high frequency unit is in charge of improving the dynamic performance of the system,whose switching current is relatively low;while the low frequency unit is in charge of energy delivery,whose switching frequency is far lower than that of the high frequency unit. The simulation results illustrate that by using this program,the system has a better performance in both dynamic and static performance,and the electromagnetic torque ripple,flux ripple and switching losses are significantly reduced. Thus the system efficiency is improved and suitable for medium and large power occasions.     

Testing Study on Hydraulic Torque Converter for Car

A test bed with computer control for hydraulic torque converter test is built up. The structure and principle of the test bed are introduced. The performance characteristic of torque converter for a CVT car is studied, and the mathematic model of the torque converter is established based on test results, which lays a foundation for the exploitation of automatic transmission car with hydraulic torque converter.     

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.     

Application of Hydraulic Torque Converter Incorporated in Mechanical Continuously Variable Transmission

Continuously Variable Transmission which is the ideal transmission for automobile can improve dynamical and economical performance and reduce pollution emission effectively. Vehicle equipped with CVT where hydraulic torque converter is acted as start clutch have better acceleration performance and its starting control is very simple. Based on performance test of hydraulic torque converter and simulation on lock-up dynamic process of torque converter clutch, matching characteristic between engine and torque converter is evaluated , and the lock-up control rule of torque converter clutch and the control strategy of standing start of vehicle equipped with Continuously Variable Transmission with torque converter is proposed. By computer simulation on start process, vehicle equipped with CVT have better acceleration performance than equipped with five-speed MT.     

Simulation of The Torque Control System of Motor for Hybrid Vehicle

A strategy for induction motor control based on the grade of errors is developed to improve the performance of hybrid vehicle drive system. The stator flux error, electric magnetic torque error and flux position angle are used as control variables, and rules for the switching states are chosen according to the errors and the principle of the Direct Torquc Control. This strategy improves efficiently the electric magnetic torque response of the system. The result of simulation shows that this strategy is an ideal control strategy of hybrid vehicle, which can make the motor generate the electric magnetic torque efficiently, steadily and quickly.     

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.     

Synthetic Control Strategy for a Car With Hydro-mechanical Continuously Variable Transmission System at Standing Start

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. The dynamic simulation model is established and integrated control strategy of standing start is proposed for dual mode CVT vehicle, aiming at automatic vehicle with torque converter as a starter and metal pushing belt as a higher transmission equipment (Dual mode CVT vehicle), on the base of engine and torque converter performance experiment. Simulation result shows that vehicle performance can be improved by using the control strategy proposed. The research results provide the theory method of analyzing and designing for CVT vehicle.     

Improvement of circulatory circle design method forautomobile hydraulic torque converters

A design method to reduce the circulatory circle axle size for automobile hydraulic torque converters is proposed. According to the beam flow theory, the variety of the axle size has little effect on the characteristics of torque converters. Based on analyzing traditional design method, it’s found that the basic reason for oversize of axle is the unreasonable semi-empirical expression of the first and third arc radius. An improved design semi-empirical expression is proposed for passage car torque converters based on the analysis of several foreign mature torque converters, and an improved design method is established. The improved method is used to design a torque converter, and the results show that the circulation circle axle size reduces about 26% in the condition of keeping the same characteristics of the traditional method. It means the improved design method can better meet the design requirement of automobile torque converters.     

Multifractal spectrum prediction of the running-in process of wet clutch

For predicting the running-in process of wet clutch test,a method based on multifractal spectrum and its parameters are proposed to predict the running-in state,combining with the geometry features of friction torque signal in test. Firstly,the concept of multifractal spectrum based on the box-counting method is introduced;and then the inherent relationship between the multifractal parameters and friction torque is discussed;finally,friction torque signals from a certain type wet clutch running-in test are analyzed and depicted by the multifractal spectrum and its parameters. The analytical results show that the geometry features of friction torque signals can be quantitatively described through multifractal spectrum and its parameters,and the breadth and fractal dimension difference of maximum-minimum probability subset of multifractal spectrum gradually decrease with the running-in process,while the minimum singularity exponent increases gradually with the running-in process. Therefore the running-in state of wet clutch can be effectively predicted by the multifractal spectrum of friction torque in test.     

Research and development of a parallel piezoelectric 4-axis force/torque sensor

This paper proposed a novel parallel piezoelectric four-axis force/torque sensor based on the bottleneck contradictions of elastic style multi-axis wrist force sensor, It introduces the sensor's structure and operating principle and discussed the selection and spatial layout of piezoelectric quartz wafer group.Then it derives the mathematic model of the sensor. The finite element model of the sensor is established, and the prototype of the sensor is manufactured. Finally, it obtains the input and output curve, voltage sensitivity, charge sensitivity and the coupling interference.The results indicate that the sensor has advantages of simple and rational structure, correct mathematic model, nice manufacturability, good linearity, good rigidity, and natural frequency greater than 30 kHz, less than 3% of the interference error without decoupling matrix.These can meet the requirements of sensor design.     

Electrocircuit principle’s research of ring space array torque sensor’s reader head

Based on the principle of electromagnetic induction of exchange and the measurement principle of the ring space array torque which is related to the sphere symmetry, the measurement principle of a ring space array torque sensor is discussed which is fit for measuring in extreme environment. The reader head electrocircuit is designed which is combined with the problems on measurement of mechanical torque in extreme environment. The experimentation is emulated and the preferably satisfied result is gained.     

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 .     

Electric Vehicle of Direct Torque Control System Based on TMS320LF2407 Controller

A fully digitized electric vehicle direct torque control system with DSPTMS320LF2407 controller is described. The system hardware and software structures are presented. The performance of the direct torque control system is studied by simulation with MATLAB. Based on the simulation of the induction motor, waveform of current, speed, torque and flux are obtained. The testing results are also presented. Experimental results show that the design is feasible.     

Coordinated torque control strategy for driving-mode-switch of strong hybrid electric vehicle

For a new type of strongly hybridized system, the vehicle ride performance is used as the study goal, a coordinated control strategy is put forward to suppress the torque surge after the analysis of the parameters changes of engine, motor, clutch and transmission during the driving-mode-switch process. The strongly hybridized vehicle simulation model is developed based on the coordinated control strategy. The typical drive mode switching process performance simulation and analysis are performed. The results show that introducing the coordinated control strategy reduces the torque surge during the driving-mode-switch process and improves the vehicle drivability.     

Improvement and simulation on direct torque control system of permanent magnet synchronous motor

To solve the problems of large flux, torque ripple and inconstant inverter switching frequency in conventional direct torque control (DTC), a space vector modulation (SVM) technique is introduced to the conventional PMSM-DTC system and analyzed thoroughly based on the mathematical model. This novel control method which enjoys the advantages of VC and DTC has only one easy adjustable PI regulator and is easy to realize. The simulation verifies that this control system is capable of effectively improving the steady state performance and keeping the excellent dynamic performance of the PMSM-DTC system simultaneously and remain the switching frequency constant.     

猪细环病毒k2型福建株ORF2基因克隆

为丰富福建省猪细环病毒的分子流行病学数据,本研究根据猪细环病毒1a型、1b型和k2型特异性检测引物对临床顽固性腹泻仔猪病料组织进行PCR检测,结果从1例病料中检测到猪细环病毒k2型阳性。并通过设计猪细环病毒k2型ORF2基因特异性引物对阳性病料扩增后进行克隆测序,获得猪细环病毒k2型ORF2基因完整编码区序列。分析发现所克隆的猪细环病毒k2型福建株ORF2基因全长为203 bp,编码有67个氨基酸。本实验株ORF2基因和猪细环病毒k2型代表株德国家猪分离株2p株(Gen Bank登录号AY823991)核苷酸同源性高达97.5%;和猪细环病毒1a型(Sd_TTV31株)和1b型(1p株)代表株核苷酸同源性均低于50.0%,分别为43.9%和47.3%。从遗传进化关系上看,本实验株ORF2基因和Gen Bank中猪细环病毒k2型处于同一遗传进化分支,而猪细环病毒1a型和猪细环病毒1b型均处于其他遗传分支。本研究首次在福建猪群中检测到猪细环病毒k2型感染。