Structure Change - Essential Feature and Challenge of Hydraulic Systems
Sprache des Titels:
Proceedings of the 11th Workshop on Digital Fluid Power, Sep. 19-20, 200, Edinburgh, Scotland, UK.
Factually, any hydraulic system is a structure change system. Every reciprocating pump needs to connect its displacement chambers to at least two different ports and most valves change the actual topology of the hydraulic network. The relative ease of handling such changes is a stronghold of fluid power systems. But if these structural changes happen quickly, unwanted effects can occur: Flow and pressure pulsation, oscillations and fatigue of structural elements, noise, and coupling with the control system. Consequently, such effects have been and are still an important part of fluid power research and development. Various theoretical and experimental methods have been established and used to explore the situation and find systematic ways for the mastering of these effects.
Digital fluid power, at least digital hydraulics, causes structure changes with the risk of provoking such negative effects. Therefore, the development and practical application of digital fluid power is often accompanied with an intensive analysis of such phenomena and the development of means or methods for their reduction. A variety of analysis methods, theoretical and experimental and means for suppression were developed and applied. Many come from conventional hydraulic systems some are specific for digital hydraulic systems.
In this paper selected methods and means for the analysis and the solution of such structure change caused problems are presented and open problems, also concerning design guidelines for digital hydraulics, are addressed.