Simulation of components of a power shuttle transmission system for an agricultural tractor

•Simulation of the components of power shuttle system.•System provides variable clutch engagement time so that same vehicle can be used for variety of operations.•Variation in duty cycle of proportional valve changes the pressure building time of proportional valve.•Slow increment in duty cycle of proportional valve cause smooth clutch engagement. The usage of tractors is widely extended to various non-agricultural and construction applications like with front end loaders, dozers, backhoe, etc. Tractors which are predominantly used in front end loader application requires frequent shifting of gear due to repetitive fore and aft travel requirements of the vehicle. In this application, tractors usually move forward and reverse direction at the same speed within a short duration by using a mechanical shuttle, synchro shuttle or by power shuttle transmission. This research article presents an idea on the simulation of the power shuttle transmission system of an agricultural tractor. A model of the individual component of power shuttle transmission system has been developed and integrated, to make it as a whole vehicle model, using MATLAB as a simulation platform. The model has been used to study the proportional valve characteristic, vehicle shift time and motion inversion time of modelled tractor and comparison was made between actual and simulated results. The model was validated with the help of an instrumented test tractor. The findings indicated that the time required to develop required actual system pressure was 1.85s whereas the simulated time was 3.1s which was optimized to 1.94s.The simulated shift time was 5s which was optimized to 3.1s. Similarly the actual and simulated motion inversion time of the tractor was 6.4s and 10s. The modification in the model was done to bring the resemblance between actual and simulated results by providing the actual simulation environment. Thus the simulation study presented here may be beneficial in the design and simulation of other types of power transmission systems used in the tractors.