Study On Automated Transmission And The Integrated Control For The Tractor-implement Combination

In this paper, the study was based on the emulational experience system of the tractor-implement. The emulational control system was composed of three parts: master PC monitor system, transmission and throttle control subsystem, engine load simulated control subsystem. Using the system, many studies and experiments could be carried out on the implement units.Engine load simulated control system was consisted of two unattached parts of work resistance simulated control subsystem and electric bow wave dynamometer control subsystem. With the mathematic models of engine load simulation controller, which transferred the work resistance's change to engine load change immediately, the system can met the need of the simulation control system. Real monitor software of the master PC was developed by using VC++6.0 and adopting the method of Object-Oriented Programming. The monitor software has two functions of manual and automatic control. The operator can adjust the setting parameters online in order to meet different quality and needs of the control.The dynamics of a tractor-implement combination were complex in the atrocious working environment and fluky work status. A lot of components were not assured. The system had an evident non-linearity problem about large inertial and response lag due to its machine and hydraulic structure. These characteristics were hard to describe by using exact mathematic model. It was difficult to study unit's integrated control by using classic control theory relying on exact mathematic model, or modern control theory relying on status function.Based on the analysis of the real work state of the tractor in the field, take the typical plough implement unit as an example; a further study was made in this paper, including the theory of the automatic transmission and the quality of gearshift. In the experiment, we developed the gear shifter and optimized the quality of the gearshift by adopting the theory of fuzzy control. These circuits had the characteristic of quick adjustment and good stabilization, which met the real needs of tractor work.It also studied the integrated control problems and optimal matching methods on the Tractor-implement combination in this paper. Based on the further study of dynamic characteristic of the tractor-implement combination, according to the integrated control model, which including the flowing three parameters: the engine load rate, drive wheel slip and work resistance, and the three control strategies, which are: highest production efficiency control strategy, oil consume economic control strategy and give attention to the above control strategy, we can adopt different control strategies according to different purpose of the task. Applying the theory of the hybrid dynamic system to this case, the three control strategies can be abstracted to three discrete matters, and then the exchange model of the discrete matters of the top layer (which called manage layer) of the tractor-implement combination and the function decision model, which based on the nerve network, can be established. Through this way, the best adaptive controlling of the tractor came true.The simulated experiment showed that the control system, control model and control arithmetic designed by author in the paper achieve the expected control purpose. It gives a practical and referenced method on study auto-control of walking implement combinations.