Theoretical and experimental investigation on an integral time-delay feedback control combine d with a close d-loop control for an infinitely variable transmission system

A nonlinear closed-loop speed ratio control combined with an integral time-delay feedback control is developed to adjust the speed ratio of an infinitely variable transmission (IVT) for a desired output speed with any variable input speed. The speed ratio control of the IVT system is developed based on its nonlinear dynamic model, which involves a forward speed controller and a crank length controller for varying operating conditions. The closed-loop forward speed controller can operate with efficient driving performance based on an optimal operation line of a prime mover. System identification is carried out to achieve high control performance of the IVT system. Comprehensive results of experimental investigation are presented to validate the proposed control strategy for the IVT system. An instrumented rotation speed measurement system is designed so that quantities necessary for the time-delay control variable can be measured. Experimental results show that the speed ratio of the IVT with the proposed control strategy can achieve an excellent tracking response for the desired constant output speed. This study reveals that fluctuations of the output speed of the IVT system can be reduced by time-delay feedback control. (c) 2021 Elsevier Ltd. All rights reserved.