Donkov, Viktor Hristov

PROJECT TITLE: Use of Digital Hydraulics in Secondary Control of Cylinder Drives    

PhD period: 2017.01.01 – 2019.12.31.
Section: Fluid Power and Mechatronic Systems
Research Programmes: Offshore Energy Systems & Fluid Power in Wind and Wave Energy
Supervisor: Torben O. Andersen
Co-Supervisor: Morten Kjeld Ebbesen
Contact Information

Collaborator: University of Agder.
Funding: SFI Offshore Mechatronics.


Hydraulics are popular in industry due to their high weight-to-power ratio and the flexibility of their use. Unfortunately, often the overall efficiency of the hydraulic transmission can be very low. Research has shown that this is due in part to the hydraulic components, which have low efficiency in a broad operating range. Recent research attempts to offset this problem by use of digital hydraulics.

One of the challenges in implementing digital hydraulics is that the hydraulic cylinder in such a solution is more complex than a standard hydraulic cylinder. Very limited research has been conducted, documenting the performance of digitally controlled cylinders on low speed high force applications. Therefore, there is a demand to investigate the reliability and performance that can be expected from a digitally controlled hydraulic cylinder under such conditions.

The main objective of the project is to investigate possible configurations for using digital hydraulics in secondary control of cylinder drives applied to low speed high force applications. The project will involve:

  • Developing and comparing hydraulic system architectures and associated control algorithms
  • Combining the most promising combination of hydraulic system architectures and control algorithms in a design
  • Implementing and testing the developed design


Publications in journals and conference papers may be found at VBN.