Modeling and control of a Continuously Variable Transmission in a constant speed power take-off application

Traditional control design techniques like manual tuning are widely employed within the Continuously Variable Transmission (CVT) industry. However, manual tuning comprises of trial and error and is therefore time consuming. Moreover, the results are likely far from optimal in the sense of some predetermined set of criteria for ratio tracking performance and control effort. For such a complex dynamic system involving nonlinearity and time variance of parameters, robust control design following control oriented modelling is expected to deliver better results for both performance and control effort, faster than manual tuning; which is unjustifiably preferred for its quickness in the industry. In this paper, a manually tuned controller is designed for benchmarking the performance for a novel chain CVT application. In this application, the CVT is used in order to power an on-board generator through the internal combustion engine (ICE) of the truck; which in turn supplies power for the auxiliary consumers on the truck. In this arrangement, the task of the CVT is to convert the variable speed of the ICE into a constant speed input for the generator shaft. Such a power take-off point is called as Constant Speed Power Take-Off (CS-PTO). Moreover, steps are taken towards the modelling of the CVT system for control design. The simulation results of this model are compared to the experimental results.