Study On Automatic Shift Technology With Four-parameter Of Construction Vehicle

Automatic transmission takes an important role in vehicle electronics and it is the trend of engineering vehicles development. Automatic transmission can greatly improve performance, efficiency and quality of engineering vehicles, and it greatly alleviates the driver's working intensity. Under the DOCTOR Foundation Project: Study on Automatic Shift Technology with Four-parameter of Engineering Vehicle, taking the ZL50 Wheel Loader as the research object, aiming at improving the performance of drive and economy, the paper is the research shift strategy with four-parameter on theory and experiment. The paper includes such contents as below:1. On the base of referring to a great deal of external and internal vehicle automatic transmission information, the development status of automatic transmission box and automatic shift technology and the meaning of automatic shift are introduced. At the same time from the viewpoint of saving energy and enhancing transmission efficiency, the feasibility and the key techniques of engineering vehicle automatic shift technique research are discussed. At last, main contents of this paper is set forth.2. The drive analysis on hydrodynamic mechanical transmission system. The composing and character of hydrodynamic mechanical transmission are introduced generally, through analyzing the character of power distributary, set up power distrubutary model. On the basis of experiment data, model of diesel and torque convertor and gearbox are established, gearbox's work principle is introduced. All the work is ready for the automatic shift control in theory.3. Shift strategy with four-parameter. Automobile's shift strategies are mature, but engineering vehicle can't use its shift strategies because they are used for too different purpose and have different characteristics. Automatic shift rule of four-parameter are bring forth, it consider pump's work status. It's shift theory is recommended and shift point is confirmed with experiment method.4. The computer simulation of automatic shift control system. Resistance calculate model and dynamics model of transmission system are given, this makes preparation for simulation model. Simulation system model is compose of several submodel. With the help of Matlab/Simulink, simulink system which includes transmission system and shift control system is build. Simulink experiment is done under certain original condition. At last, experiment result is obtained.5. Bench experiment of four-parameter automatic shift. Hardware condition of experiment system and measure method and scale experiment of variable are presented. After that measure and control program are designed and program's outlines are illuminated. Experiment result indicates that program can adjust transmission to fit load automaticly.6. The whole paper summarizing and suggesting. The study productions and innovation discoveries in this paper are set forth. Suggestion is given.