M A, V. and Rajagopal, M., "Electronic Bi-Directional Shift Control Design and Calibration for Farm Vehicle," SAE Technical Paper 2017-01-2205, 2017.
Agricultural tractors are often subjected to various applications like front end loading work, cultivation work, where frequent forward and reverse gears are needed. Most of Indian agricultural tractors are equipped with mechanical transmission system which demands repeated clutching and de-clutching operation for such applications resulting in increased operator fatigue and lesser productivity. Also need of electronics in Indian agricultural industry for better farm mechanization is growing high. This research work depicts development of electronic bi-directional shifting (power shuttle) control design and calibration for farm vehicle fitted with wet clutch transmission. This research also reduces operator fatigue via frequent directional shift through electronic transmission. The control system is designed without any electronic interfacing with engine and also provides clutch-less gear shifting and auto-launch which offers ease to drive even for novice driver. The power shuttle transmission control system offers more functionality and features in adjunct to in-built safety features without any additional sensors or components. Use of minimal sensor for system control and calibration delivers cost effect solutions. Adaptive control strategy is adopted for achieving efficient and optimal clutch fill modulation which is calibrateable for various climatic zone, vehicle loads, gears etc. Control software is designed by considering the vehicle variants pertinent to clutch load and engine characteristics. Modular control system design is employed in this research which can be extended across all tractor variants.