The objective of a CoCoViLa demo package for dynamic simulation of hydraulic elements is to demonstrate using multi-pole models for modeling and simulation of real-scale mechatronic systems. The package covers a small part of modeling and simulation systems investigated and developed by the joint research group of the Institute of Cybernetics and the Department of Mechanics at Tallinn University of Technology.
The package includes models of low level hydraulic elements such as hydraulic resistors, hydraulic tubes, interface elements, and also hydraulic fluids, simulation process manager, supporting elements for defining inputs and outputs and few example tasks for simulation hydraulic schemes.
Theoretical basis for the package is described in [1, 2]. Some of example simulation tasks are taken from the paper. Some of the simulation results differ from the ones described in the paper as multi-pole models, simulation engine and some utilities have been modified (advanced) since the paper was published.
Models of a fluid power system are composed using components from a library of multi-pole models. For each component models of required causalities must be available. This enables to compose multi-pole models for systems of different configuration to follow signal propagation in correspondence to physical or computational behaviour.
Multi-pole mathematical models of basic hydraulic components such as hydraulic resistors, tubes, volume elasticities and hydraulic interface elements used in fluid power systems have been previously composed and tested. A library containing descriptions of physical properties of different hydraulic fluids is in use as well. Dependence of physical properties of hydraulic fluids on pressure is taken into account at each step of simulation.
Multi pole models of hydraulic elements are designed to be used for both static or steady state, and dynamic simulations. In the current package only simulating of dynamic transient responses caused by inputs depending on time are considered.