Digital hydraulics will change the concept of hydraulics
The research group concentrates on the new types of hydraulic systems. The general idea of the digital hydraulics is to use just a few different types of basic components and to introduce controllability by multiplying these components. Intelligent control implements all nesessary valve functions. The target is better efficiency, performance and fault tolerance. The group arranges also international workshops on Digital Fluid Power together with Johannes Kepler University Linz.
Digital valve systems
Digital valve systems are digital hydraulic version of distributed valves. The benefits of the approach are robust and leak-free valves, fault tolerance due to parallel connection and faster response. We have demonstrated 30-40 % reduced losses and significantly improved performance compared to traditional four-way proportional valves. The approach is used e.g. by Valmet in paper machine applications.
Digital hydraulic hybrid actuator
Digital hydraulic hybrid actuator is a radically new approach for the linear actuation. The basic principle is to integrate hydraulic accumulator and a digital hydraulic pressure transformation into the actuator. The result is an energy efficient actuator, which has big peak power, but which needs only average power from outside.
The prinsiple of digital microhydraulics is to use big number of mutually similar valves instead of traditional binary coding. The benefits are much faster response (up to 2 ms), improved fault tolerance and a bit surprisingly also reduced size of the valve package. A valve package with 64 valves and standard CETOP3 interface has been implemented.
Digital water hydraulics
The target of the digital water hydraulic research is to develop an environmentally safe and high-performance digital valve system. The research concentrates on the miniature on/off valves, control methods and compact valve systems. Areas of interest include tap water, demineralized water and sea water applications.
Digital hydraulic power management system – DHPMS
DHPMS is an extension of the digital pump-motor. It has several independent outlets, which can operate as pump, motor or transformer. The direct connection of DHPMS and actuators allows practically lossless actuation. Two prototypes have been implemented so far.
The complete list of digital hydraulics publications are available on TUTCris. Links to some general publications are listed below.
Linjama, M., Huova, M., Pietola, M., Juhala, J. & Huhtala, K. 2015. Hydraulic Hybrid Actuator: Theoretical Aspects and Solution Alternatives. The Fourteenth Scandinavian International Conference on Fluid Power, Tampere, May 2015, Tampere University of Technology, 11 p.
Adjunct Professor Matti Linjama