Longitudinal Dynamic Modelling And Experimental Investigation Of The Snowmobile With CVT

Due to the incomparable advantages, such as the excellent cross-country performance on the snowfields as well as on the ice road, snowmobiles equipped with continuously variable transmission(CVT) are popular among these special driving conditions. The application of the rubber V-belt CVT has made it possible for the engine working in a relative narrow speed range most of the time and delivery the power continusouly without interrupt, which sounds outperform the conventional gear box. Based on the longitudinal dynamic modell of the snowmobile, simulation with simulink is investigated.The following results has been conducted with the dynamic modelling and the experimental investigation: (1) Based on the test rig data of the engine prototype, the universal characteristics of the engine prototype is acquired. The optimum operating line(OOL), which represents the minimum brake specific fuel consumption for every brake engine power level on the generic engine characteristics map is also depicted; (2) Running resistance of the snowmobile driving on the snowfield and the iceroad are calculated respectively which shows that the air drag cannot be ignored when the vehicle is running in a high speed; (3) Longitudinal dynamic modelling of the snowmobile has been proposed in Simulink and simulation is compared with the test data. Results show the ensured reliability to predict the dynamic response of the snowmobile with further detailed modification in the model; (4) Optimization of CVT regulating characteristic is conducted with the fuel economy consideration. The Simulink modelling with the new CVT regulating line is compared with the original one, results show when taking the fuel economy in consideration, a relative negative effect on power performance of the vehicle will be performed. It suggests when determining a CVT speed regulating characteristic, the compromise between the power ability, the fuel economy performance, etc. shoule be paid special attention to.Though acceptable deviation happens when compared with experimental result, reliability is ensured for the Simulink longitudinal dynamic model. With further amendments in details of the model, such as a more authentic simulation for the slip state of the CVT when launching the snowmobile, the system model can be applied to the practical engineering as an effective tool. There will be an enormous potential of the snowmobile market, especially in China. Investigation in the dynamic performance, as well as the fuel economy performance of the snowmobile is with great value.