Sensitivity Analysis of Energy Management Strategies for Hydraulic Hybrid Vehicles

This paper presents a study of how different methods for designing energy management strategies (EMS) are affected by variations in drive cycle and system parameters. Specifically a rule-based strategy extracted from analysis of dynamic programming results over the Federal Urban Drive Cycle and a model predicative controller are considered. These strategies were validated on a hydraulic hybrid powertrain testbed. The hydraulic hybrid powertrain utilizes a high pressure accumulator for energy storage which has superior power density than conventional battery technology. This makes fluid power attractive for urban driving applications in which there are frequent starts and stops. Through a simulation study we will demonstrate the need to carefully consider the application and confidence one has in knowledge of the drive cycle and system model when choosing an EMS design method.