A Control Oriented Model and Application for Control System Design of a Series Hydraulic Hybrid Vehicle

Fossil fuel depletion risk forecasting and growing environmental concerns are strong impetus for developing higher efficient transportation system nowadays. Hybridization is considered as one of the most efficient short and mid-term solutions. In particular, series hydraulic hybrid configuration provides a further advantage when it provides more degree of freedom of engine control. However, low energy density characteristic of hydraulic accumulator is also a significant obstacle. This challenge is an important part of motivation for a model-based approach to develop the control system. The aim of this paper is to propose a control-oriented model of a series hydraulic hybrid vehicle (SHHV) with minimum order and number of the parameters. The SHHV is then considered as a multi-input and multi-output system. A classical approach of control system design is applied to estimate an output-feedback servo control for the low-level controller. In addition, a multi-PID-based controller is also designed, tuned, and implemented using decentralized approaches. In addition, the proposed control system allows developing and evaluating the benefit of different power management strategies for a SHHV.