Abstract
Proper feedback control of digital fluid power machines (Pressure, flow, torque or speed control) requires a control oriented model, from where the system dynamics can be analyzed, stability can be proven and design criteria can be specified. The development of control oriented models for hydraulic Digital Displacement Machines (DDM) is complicated due to non-smooth machine behavior, where the dynamics comprises both analog, digital and non-linear elements. For a full stroke operated DDM the power throughput is altered in discrete levels based on the ratio of activated pressure chambers. In this paper, a control oriented hybrid model is established, which combines the continuous non-linear pressure chamber dynamics and the discrete shaft position dependent activation of the pressure chambers. The hybrid machine model is further extended to describe the dynamics of a Digital Fluid Power Transmission (DFPT) comprising two variable speed DDM’s with asynchronous control sampling schemes. A validation with respect to a non-linear dynamical model representing the physical system, shows the usefulness of the hybrid model with respect to feedback control development.
| Original language | English |
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| Title of host publication | Proceedings of 9th Workshop on Digital Fluid Power, DFP 2017 |
| Number of pages | 14 |
| Publisher | Department of Energy Technology, Aalborg University |
| Publication date | Sept 2017 |
| Publication status | Published - Sept 2017 |
| Event | 9th Workshop on Digital Fluid Power, DFP 2017 - Aalborg, Denmark Duration: 7 Sept 2017 → 8 Sept 2017 |
Conference
| Conference | 9th Workshop on Digital Fluid Power, DFP 2017 |
|---|---|
| Country/Territory | Denmark |
| City | Aalborg |
| Period | 07/09/2017 → 08/09/2017 |
Keywords
- Fluid Power
- Digital Displacement
- Hybrid system
- Control model
- Event-driven