Robust torque tracking control for E-IVT hybrid powertrain

This study deals with the control of a hybrid vehicle powertrain, composed of three actuators (one engine, two electric machines). This powertrain belongs to the Electric-Infinitely Variable Transmission (E-IVT) class. In order to achieve low fuel consumption, drivability and electric power management, controllers have to achieve simultaneously three specifications, namely engine speed, wheel-torque and battery power references. Decoupled controlled-output behaviors and optimal performances are also required. In order to imitate a classical powertrain, the control structure is split in two parts. The interest is to decouple transmission speed ratio control and wheel torque control. A model-based design approach is proposed, that directly deals with robustness and decoupling, in a full multivariable and frequency-dependent framework (H∞ synthesis). Closed-loop simulations are presented. Stability and performances subject to disturbances and non-linearities are also evaluated, using the theory of linear parameter varying (LPV) systems.