Abstract: In view of the complexity of loader’s working condition, an automatic gear shifting strategy adopting combination of multiple shifting schedules according to the driving intention is proposed. Fuzzy logic is applied to the recognition of driver’s intention. A ZL50G loader is refitted, and an automatic gear shifting control system is constructed. Field spading and walking test of the whole machine is carried out. The results indicate that the control logic of the automatic gear shifting strategy is correct, and that the driver’s operation is simplified. The fuel consumption data of “V” shape spading operation and walking condition indicate that this automatic gear shifting strategy has the functions of saving energy and reducing labor intensity of drivers, thus giving consideration to fuel consumption, power performance, and practicability of the loader work.

Key words: Automatic gear shifting, Fuzzy logic, Loader, Saving energy