DLR Cables LIBRARY
The DLR Cables Library can be used to simulate ropes with nonlinear stiffness such as steel wire ropes / cables with and without non-metal core or coatings as well as flexible ropes. The rope itself is simulated as discrete element component, and can easily be connected to Modelica Multibody components. Additional components as winches, pulleys or sensors are included in the library. With those, complex rope systems with multiple interconnected pulleys become possible in Modelica.
FEATURES OF THE LIBRARY
- Modeled as discrete elements.
- Parameters: longitudinal stiffness and damping, bending stiffness and damping, mass, diameter
- Look-up-table based interpolation of rope stiffness characteristics
- Tear strength can be considered and rope tearing can be simulated
- Point-to-point initialization with definable initial tension
- Initialization as catenary arch between two points
- Linear initialization between two points
- User-defined initialization functions possible
- Winches and pulleys with 1-D connector to attach drivetrains
- Correct transmission of forces and torques between cable and mounting points
- Simulation of a combination of one cable over several pulleys
- Cable-Cable connections
- Several Cables holding other mechanical parts (e.g. cable robot)
FEATURES OF THE LIBRARY
Tower crane
Tower crane
The DLR Cables library has been used to create a fully functional model of a tower crane, as an example for educational purposes. The Tower Crane is equipped with two main cable systems, the main winch with the load cable and the trolley winch positioning the trolley. Furthermore, the electric drives, controllers and wind resistance are implemented, as well as an interface to a standard industrial PLC (Siemens SPS). The model is real-time capable and can handle load weights of up to 10 metric tons. |
Tower Crane |