JOURNAL OF BEIJING INSTITUTE OF TECHNOLOGY

Methods of Random Fatigue Design for Vehicle Transmission System Components

2000, 9(4): 353-357.

[Abstract](210)

Abstract:
Some representative working conditions were measured, and the amplitude distribution rule of each representative working condition after analysis of measured data was got. The building of 2 D distributing function between the range and the mean of random load was discussed. Experiment was carried out to get the fatigue strength data of the material of transmission component. Accessing the P S a S m N camber of combined load of bending and torsion on this material after analysis. And the process of calculating the 2 D fatigue life in multi working condition was discussed.

Conditions of Ratio Changing Continuously for Multirange-Split-Transmission

YUAN Shi-hua, HU Ji-bin, YANG Wen-zheng

2000, 9(4): 358-361.

[Abstract](171)

Abstract:
According to the flow chart and the characteristics of components, the equation of ratio changing of multirange split transmission (MRST) was established. By mathematical analysis,both the relations among the ratios of the components and the condition for the ratio of MRST changing continuously were obtained. With the help of two examples, the correctness was proved.

Influence of Buffering Pressure Characteristics on Shift Clutch Engagement Process

MA Biao

2000, 9(4): 362-369.

[Abstract](180)

Abstract:
The dynamic math model of shift clutch in engagement process was determined on the basis of hydraulic buffering valve and shift clutch of a power shift steering transmission. The influence of buffering pressure characteristic on shift clutch engagement process was analyzed. The study results could be used to the characteristics match of the shift clutch with the hydraulic system of the high speed tracked vehicle power shift steering transmission and the performance prediction.

Development of Mixed??Flow Turbine for

MA Chao-chen, SHI Xin

2000, 9(4): 370-374.

[Abstract](230)

Abstract:
To develop a mixed-flow turbine in order to achieve the high performance at high specific speed, an improved turbine design method, which links rotor flow analysis with turbine performance prediction by introducing the evaluation of the rotor velocity distr ibution, was carried out. With this method, a mixed??flow turbine was developed for the H1F turbocharger which is cur rently used in the J6110Z diesel. The predicted performance of the mixed-flow turbine shows a hig her peak efficiency at lower velocity ratio u/ c0 and a wider r ange of hig h effi ciency compared to the cur rent radial turbine.

H1F Turbocharger

QIN Wen-jie, ZUO Zheng-xing

2000, 9(4): 375-379.

[Abstract](188) [PDF 322KB](3)

Abstract:
The theory of multibody system dynamics is used to simulate valve trains’kinematics and dynamics characteristics , and the methods of establishing and analyzing the multibody sys-tem dynamics model for valve trains are discussed. Since most of the flexible bodies of a valvetrain are slender parts , the finite segment method is used to build their models. Other parts such as cams , valve heads etc. , are built as rigid bodies. After applying the constraints , forces andmotions , the establishing of the whole system is accomplished , and the Lagrange’s multiplier method can be used to obtain its dynamics constitutive equations. As an example , a valve trainps multibody system model of 4100QB engine made by the Yunnan Internal Combustion Engine Limited-Liability Company is established , and the analysis results obtained show that its work-ing performance is generally good except that the air2pass ability and the lubrication effect of the cam and the tappet have to be improved.

CAD System for Cylinder Head Used in High-Speed and Heavy-Power Diesel Engine

LIAO Ri-dong, ZUO Zheng-xing, WANG Kai

2000, 9(4): 380-386.

[Abstract](180)

Abstract:
A CAD system for the cylinder head is developed. As an integrated system , it can be used in 3-D modeling , 2-D drawing and finite element structural analysis and optimization. The key problems in system designing are introduced. Design flow , system structure and how to solve the key problems are focused on. All of those would form the base for more research on how to use the modern CAD technology to design complex engine parts. And it is also a good example of using the modern CAD technology.

Speed Disturbance in the Diesel Engine Electronic Control System

LIU Xing-hua, ZHANG You-tong

2000, 9(4): 387-390.

[Abstract](182)

Abstract:
In order to sample the speed signal of electr onic diesel eng ine in real time and make the eng ine wor k reliable, the diesel eng ine control systems speed acquisit ion was studied and the problem of speed distur bance w as solved. The control system was based on the 8 bit electronic control unit( ECU) system and the assembly language was used to design the software for controlling the eng ine fuel quantity and the turbocharger of the variable geometr y turbine for the heavy??duty diesel engine. By chang ing the timing method fo r speed acquisition, the problem of speed disturbance w as solved and the r eliability of the ECU w as improved.

Laser Measurement and Intensity Evaluation of Intake Swirl in Engine Using a Water Analog

SUN Bai-gang, LI Xiang-rong, DU Wei

2000, 9(4): 391-396.

[Abstract](185)

Abstract:
The intake sw irl in the cylinder was induced by a swir ler w hich was fixed in one of two intake ports. In order to understand t he characterist ics of the intake swirl, a transparent water analog w as designed which simulated 150??type single cylinder engine. At the same time,the part icle image velocimetr y was used to measure the flow fields induced by various swir lers in the analog . After measurement, a new method was presented to evaluate t he intensity of the in??take swirl. Then, when t he measured sections, the lifts of valve and t he swirlers were different,the calculated results of the flow field w ere compared.

Experimental Study of Diesel-NG Dual Fuel Electronic System for F6L912Q Engine

ZHANG You-tong, WANG Chun-fa, LIU Xing-hua, LI Tie-shuan, HAN Xiu-kun

2000, 9(4): 397-402.

[Abstract](218)

Abstract:
In order to impr ove the diesel eng ine emission performance and convert the diesel engine to dual fuel eng ine, a dual fuel ( diesel and compr essed natural gas ( CNG) )electronic system was developed, in which electromagnetic valves were used to control multi??point natural gasinjection. The system was designed for t ype F6L912Q diesel engine and the function of the system was testified on test cell. The test results show ed that the system had g reat advantag es in power ability and emission per formance. The average CNG substitution at rated load was over80%. The dual fuel system was pr actical. To adopt dual fuel system was a good w ay to improve the engine semission performance.

Embedded Data Acquisition in Vehicle Electronic System

WANG Jian-qun, CHEN Tie

2000, 9(4): 403-407.

[Abstract](264)

Abstract:
The embedded data acquistition technology in vehicle electronic system was discussed. This technology adopts the parallel working mode , gets vehicle electronic system data by com-munication. This technology can provide us a lot of information on the electronic control unit , is very useful for the development of the vehicle electronic system , and can be used in diagnosis. The key points to this technology are the timer interrupt , A/ D interrupt , communication inter2 rupt and real time operation. This technology has been validated by the application in the elec-tronic control mechanism transmission shifting system of the tank.

Fuzzy Control Method for Gasoline Engine Idle Speed Control

ZHANG Fu-jun, HUANG Ying, GAN Hai-yun, GE Yun-shan

2000, 9(4): 408-414.

[Abstract](256)

Abstract:
In order to improve the steady and dynamic characteristic of the idle speed control and study the performance of the fuzzy control method for the idle speed control, a fuzzy control system is developed to control the idle speed of gasoline engine. The construction and working principle of the fuzzy controller are described, and the design procedure of the fuzzy controller is given in detail. The control parameters are determined by computer simulation. The simulation and experiments on the engine test bench show that the idle speed is controlled accurately both in stationary and in dynamic states, and the fuzzy control method is robust to the changes of engine parameters.

Design and Development of the DTC Induction Motor Drive for Electric Vehicle

SUN Feng-chun, CHENG Xi-ming

2000, 9(4): 415-421.

[Abstract](177)

Abstract:
The design and development of the traction controller for electric vehicle is introduced, which is based on the induction motor. This drive is developed by using a digital signal processor at low cost and carried out with the module design concept of both software and hardware. Nevertheless, a scheme of the sensorless direct torque control is based on the developed hardware, of which the feasibility is tested by a trial program. Additionally, both the interface function of the drive hardware and the feasibility of its software are proved to be good by the trail programs. A test motor can run about 18?r/min by a variable frequency program with the space vector pulse width modulation technology, of which the torque is visible pulsatile. In this presentation, based on the theoretical approach, the sensorless torque control is to be studied and applied to electric vehicles, of which the quick, smooth and stable torque response is emphasized because it quite benefits improving the drive performance of electric vehicles.

Synthetic Performance Simulation of E-Car HS2000

SUN Li-qing, SUN Feng-chun, ZHANG Cheng-ning

2000, 9(4): 422-427.

[Abstract](185)

Abstract:
The simulation model of the E car HS2000 including the permanent magnetic direct current motor with the augment magnet winding is constructed based on tests in order to simulate the synthetic performance of the electric car. The performance of E car HS2000 is analyzed by means of modeling and programming according to data acquired during tests. The simulation results show that the performance of E car HS2000 is successfully predicted and the model and the corresponding simulation software are feasible for simulating E cars. They can be used as effective tools for analyzing the performance parameters as well as specifications of E cars during prototype stage.

New Adaptive Cruise Control Method

LU Jiang, LIU Zhao-du, SHI Kai-bin, AN Wei

2000, 9(4): 428-433.

[Abstract](240)

Abstract:
A new adaptive cruise control (ACC) method based on the desired safety headway distance is investigated for improving the vehicle traffic safety at high speed by regulating the additional throttle opening and braking torque of driving wheels only. The selection of headway distance sensors, the determination of desired safety headway distance and desired deceleration are elaborated. The ACC flowchart and simulation, as well as signal misinformation and its resolutions are described. The simulation proves that the new ACC method is simpler and feasible. The new method is easily integrated ACC with ABS/ASR to form an organic ABS/ASR/ACC system.

Passive Magnetorheological Fluid Filled Hydraulic Engine Mount

YAN Wei-ge, LIU Shu-yan, LI Jun-jie, XU Yong-qiang

2000, 9(4): 434-438.

[Abstract](190)

Abstract:
Using magnetorheological (MR) fluids in hydraulic engine mount for damping vehicle noise and vibration is opposed firstly, the structure of passive type and its mechanical model are described. The analysis of the experimental data show that the dynamic characteristics of MR mount such as dynamic stiffness and loss angles vary distinctly as the excitation frequency, and MR fluids as one type of attracting controllable fluids are fit for hydraulic engine mounts. The author advises to work out potentialities of MR fluids, the semi control or active control MR fluids filled hydraulic engine mount must be developed.

Simulation Study on Active Roll Control of Vehicles

GU liang, WANG Guo- li, DONG Ming-ming, GU Zhi-qiang

2000, 9(4): 439-444.

[Abstract](189)

Abstract:
The effects of active control on the vehicle roll were studied. Based on the theory that distributing the greater roll stiffness to the rear axle can improve tracking trajectory capacity and increase maneuver stability, an eight degrees of freedom vehicle model was established and feedforward feedback control strategy was devised to control distribution of lateral load transfer on the front axle and the rear one. Simulation results showed that the proposed control strategy can improve comfort, maneuver stability and safety effectively.

Dynamic Performance Simulation of Power Shift Clutch During Shift

FENG Neng-lian, ZHENG Mu-qiao, MA-Biao

2000, 9(4): 445-450.

[Abstract](215)

Abstract:
Based on the theoretical analyses, the dynamic and mathematical models of the system were developed. The models were implemented in the ambit of the Matlab/Simulink environment, and an integrated simulation model was developed. The dynamic performance of the power shift clutch during engagement and disengagement was studied by using this assembly model. The sliding speed, torque transmitted through the clutch, and the rate at which energy is dissipated during the process were determined. Using this model, the calculation during simulation can be simplified. This lays a foundation for the dynamic performance research on the power train with the power shift clutch, and provides a powerful tool for developing an automatic, electronically controlled transmission.

Applications of Computer Aided Modeling Techniques to Complex ICE Components

ZUO Zheng-xing, FENG Hui-hua, LIAO Ri-dong, ZOU Wen-sheng

2000, 9(4): 451-458.

[Abstract](200)

Abstract:
Design of internal combustion engine (ICE) components is one of the earliest and also the most active areas in which computer aided modeling techniques are applied. Computer aided modeling techniques could provide requisite information for follow up designing segments such as structural analysis, design of technological process and manufacturing etc, and thereby lead to the reduction of product design period and the quality and reliability improvement of ICE components. So the developing situations of ICE components' 2-D drafting, 3-D modeling of ICE, overall CAD of ICE as well as component design expert system etc. are surveyed, which are the typical applications of computer aided modeling techniques in ICE component design process, and some existent problems and tasks are pointed out so as to make some references for the further research work.

Dynamic Simulation Study of Friction and Lubrication on ICE Bearings

WANG Wen-qing, WANG Jing

2000, 9(4): 459-464.

[Abstract](217)

Abstract:
Friction and lubrication simulation analysis of internal combustion engine bearings are studied. A series of software implementary precepts for mathematical modeling, to analytic calculating and realizing simulation outcome are brought forward. As a dynamic simulating technique is introduced into the process of engine bearing design, simulation models of the oil film are built and the emulational analysis of the shaft center track is carried out. A software program package “Engine Bearing Friction and Lubrication Dynamic Simulation System” is developed to realize the real time simulation of the working status of bearing during the design process. Through developing virtualized products, the defects of the product design can be found in time and improve the products at once. Thus the purpose of predicting and controlling the cost, quality and design period of the products can be achieved.

Principle, Modeling and Control of DC-DC Convertors for EV

ZHANG Cheng-ning, SUN Feng-chun, ZHANG Wang

2000, 9(4): 465-471.

[Abstract](225)

Abstract:
DC DC convertors can convert the EV's high voltage DC power supply into the low voltage DC power supply. In order to design an excellent convertor one must be guided by theory of automatic control. The principle and the method of design, modeling and control for DC DC convertors of EV are introduced. The method of the system response to a unit step function input and the frequency response method are applied to researching the convertor's mathematics model and control characteristic. Experiments show that the designed DC DC convertor's output voltage precision is high, the antijamming ability is strong and the adjustable performance is fast and smooth.

Identification of Traffic Accident Causal Factors Through Dynamic Driving Behavior Analysis

WANG Wu-hong, SUN Feng-chun, LIU Shu-yan

2000, 9(4): 472-478.

[Abstract](235)

Abstract:
The reliability expression of dynamic driving behavior is derived from the driving shaping behavioural model, and then, in accordance with the combination of computer simulation and mathematical expression of driving reliability, an approach for assessing the effect of driving erroneous actions on the dynamic performance of the driver vehicle system is presented. The analysis of driving erroneous actions in the driver vehicle system has been performed to show that the reliability during perception with variety widely could result in the incidents and/or accidents in traffic system.

2000 Vol. 9, No. 4