Research On Three Parameters Automatic Transmission Schedule And Electronic Control System Of Wheel Loader

As one important member of the engineering machinery, loader is widely used. At present, the multi-gear power shift transmission is used in loaders in domestic, which improves the adaptability to external load. However, in the actual operation process, the shift is very frequent, leading to high labor intensity and low operating efficiency. In order to reduce the driver’s manipulation differences and labor intensity, improve the working efficiency and the use performance of loader, research on the loader automatic transmission technology has a great significance. Based on theoretical analysis, control technology, computer simulation technology, software and hardware development and bench test, the automatic transmission schedule and electric control system is studied in the paper.First of all, the automatic transmission system included the basis of transmission system and the transmission control system are elaborated. The function requirements of automatic transmission shift scheme of loader have been identified and six kinds of automatic shift modes are put forward, including five kinds of operation conditions of automatic shift modes and one used in driving over long distance driving or light load condition of automatic shift mode.Secondly, the control parameters are analyzed. The throttle opening, rotating speed of pump wheel and turbine speed are selected. Combining with the best dynamic shift schedule and the energy saving shift schedule in the basic shift schedule, the three-parameter comprehensive shift schedule is put forward. The loader’s simulation model is established, and the simulation results are compared. According to the analysis results, it shows that the proposed comprehensive shift schedule is relatively more superior, and the schedule is corrected by segmenting for operating conditions. In order to improve the shift schedule and in allusion to the curve driving conditions encountered in the long distance driving process, the fuzzy downshift strategy is proposed and the fuzzy downshift controller is designed by using the fuzzy control technology. For the ramp driving, the ramp shift strategy is put forward and the fuzzy controller is designed for the improved variable.Then, combining with the shift schedule and the functional requirements of automatic shift, automatic transmission electronic control system is designed on the basis of the existing manual shift system which includes the design of the operation panel, the content of display panel, the electric control system of hardware and software and the automatic shift test controller is produced eventually.Finally, the preparation experiment is conducted using the vehicle transmission test bench in the Xiamen Machinery Co.,Ltd construction. Via the output signal of related sensors on the simulation test platform, the simulation experiment is carried out for the automatic shift test controller, the effectiveness of the shift schedule and the feasibility of the automatic transmission control functions is validated in the end.