A MOVING HORIZON BASED SENSOR FUSION AND LOAD ESTIMATION CONCEPT FOR DRIVING PROFILE - BASED OPERATING STRATEGY OPTIMIZATION IN HYBRID HYDRAULIC TRUCKS

摘要

In this paper, a moving-horizon based concept for estimating the driving load profile of a hybrid hydraulic truck is proposed. First, a simple model of the hybrid hydraulic drivetrain is given. Based on this model and vehicle data, a sensitivity analysis is performed to determine which (time-varying) model parameters must be known to represent the driving load adequately. As a major contribution of this work, a Moving Horizon Estimation (MHE) scheme is developed to estimate mass and road grade from standard measurement data. Starting from an intuitive nonlinear formulation of the optimization task, the setup is then transformed to a constrained linear quadratic problem. It is shown how additional sensor information can be easily incorporated into the optimization framework to enhance the estimates, since an identifiability analysis shows that the parameters are usually not clearly distinguishable. Finally, it is demonstrated how the estimated load profile can be used to evaluate the fuel savings potential of a hybrid hydraulic truck by computing the fuel optimal operating strategy and comparing it to non-hybrid and rule-based strategies.