Gray box modeling of an excavator’s variable displacement hydraulic pump for fast simulation of excavation cycles

This paper describes the results of a study focused on the application of gray box modeling methodology on an excavator’s hydraulic pump. This modeling approach has been adapted to accelerate the control system development time for a complete excavator, while providing accurate system dynamics. This mathematical model has been developed using the bond graph methodology. The excavator is described by two models: a hydraulic model and a kinematic model; dynamic parameters are continuously calculated during an excavation cycle, providing a platform to study the pump’s behavior. The gray box model of the variable displacement pump has been validated on the basis of a set of experimental data collected on a test rig and on the field using an excavator. Herewith the results of this study are presented.