Heavy construction equipment as excavators are typical applications for the Hydraulics Library.  An excavator uses several hydraulic cylinders exposed to very high pressures, coupled with 3D multibody mechanics. 

Furthermore, an excavator consists of a house, a boom, a stick and a bucket. The latter three all are actuated with a hydraulic cylinder. The house is actuated by a hydraulic motor.

All four main parts are supplied with hydraulic power, that is oil high-pressurized by a pump.

The hydraulic system is controlled by a “load sensing” controller, which also prevents the pressure and flow from reaching too high loads.

Below we present a Dymola animation of an excavator system modeled and simulated and with the Hydraulic Library. Underneath you can see the system diagram in Dymola and some results for the pressure and flow rate for the pump feeding the main parts of the excavator.


Excavator Dymola diagram

Excavator model using Hydraulics Library 3D-mechanical components. The pump feeds three cylinders actuating the boom, bucket and stick, as well as the motor rotating the house.

Pressure and flow rate from the pump feeding the four main parts. Note how higher and higher pressures are built up as more parts require flow until the limit is reached.