Hydraulics Library

Excavator Control Circuit
Animation Hydraulics Diagram

Component icons follow Hydraulic circuit drawing standardsAnimation of diagrams helps understand the operation of the system


The Hydraulics Library is a Modelica model library for the modeling of hydraulics systems. It is suitable for all industries that involve hydraulic components and applications include machine tools, transmissions, and actuation systems.

It allows the user to optimize and verify the design of a hydraulic system from early design phases through control design and implementation. The Hydraulics library offers an open, object-oriented architecture suited for multi-domain systems modelling that is perfectly compatible with other Dymola libraries.

Key Features
Modelling Approach
    • System and component design in the same tool.
    • Easily integrated into any application domain.
    • Well suited for control design.
    • Fast, real-time capable.
    • Handles incompressible and compressible oils, cavitation.
    • Open and customizable.
    Hydraulics library
  • The Hydraulics Library provides models for the modeling of pumps, motors and cylinders, restrictions and valves, hydraulic lines, lumped volumes and sensors. The modeling concept allows hydraulic components to be connected in an arbitrary way by drawing connection lines, no special components for splits or mergers are required. Users can connect components freely as they desire, so it is easy to realize non-standard configurations and component designs.

    Contrary to special-purpose tools for the same type of simulations, the Hydraulics Library also has open source code in Modelica so that the available models can be duplicated and modified to fit user needs. This enables seamless virtual component and system testing in realistic scenarios, and reduced risk for humans, environment, and prototypes.

    The models can also be used for real-time and hardware-in-the-loop applications.

    Power Steering System
  • An excavator is a multi-domain, non-linear system with several degrees of freedom that strongly influence one another. The effects of varying static and dynamic loads due to the different positions of the arm must be handled by the control system to make the final product operator friendly. To get a realistic simulation model, the dynamics of both mechanics and hydraulics, as well as their combined interaction, have to be taken into account.

    Using the Hydraulics, FlexBody and Modelica Standard Libraries the complete system model can be created. This model captures the interaction between the control system, hydraulic system and the structure of the excavator under different load cases enabling the system to be optimised rather than working on the individual parts in isolation.

    Animation of excavator with flexbody model used for the boom

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