The Hydraulic Infinite Linear Actuator with Multiple Rods

Magnus Landberg
Saab Aeronautics, Linköping, Sweden

Magnus Sethson
Division of Fluid and Mechatronic Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden

Petter Krus
Division of Fluid and Mechatronic Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden

Ladda ner artikelhttp://dx.doi.org/10.3384/ecp17144279

Ingår i: Proceedings of 15:th Scandinavian International Conference on Fluid Power, June 7-9, 2017, Linköping, Sweden

Linköping Electronic Conference Proceedings 144:28, s. 279-293

Visa mer +

Publicerad: 2017-12-20

ISBN: 978-91-7685-369-6

ISSN: 1650-3686 (tryckt), 1650-3740 (online)


Future hydraulic actuation systems can be significantly improved by utilisation of a new type of hydraulic linear actuator technology. By enabling multiple actuating elements, integrated in a compact and lightweight single unit controlled by ordinary directional valves it is possible to achieve a high position accuracy. This is a new way to generate and distribute mechanical linear movement and force by using hydraulic actuators in a cost effective way, in less responsive closed loop systems. This is a variant on the Hydraulic Infinite Linear Actuator, HILA, invention. The technology also represents a new sort of digital hydraulics. The presented technology provides typical hydraulic actuator characteristics with high system pressure and potentially no external oil leakage. It is based on a well-known hydraulic clamping element technology used in a new way, where the piston and the piston rod can quickly be coupled and uncoupled by means of the clamping element in a failsafe way by using well defined incremental steps. HILA in its simplest usage, provides new features to hydraulic cylinders such as providing very long strokes, high rod speed, and small chamber volumes which means high stiffness and low capacitance. The aim of this study is to present a fundamentally new way of using hydraulic actuators. The invention is called the Hydraulic Infinite Linear Actuator with Multiple Rods, HILA MR. The study presents the idea, principles and feasible combinations of the technology. Also applications in the aircraft and robotic field will be presented.


Hydraulic actuator, incremental control, snake-like robot, robot arm


[1] K.-E. Rydberg,”Hydraulic servo systems”, https://www.iei.liu.se/flumes/tmhp51/filearchive/course material/1.105708/HydServoSystems_part1.pdf, pp. 3, 2008

[2] M Landberg, M Hochwallner, and P Krus, “Novel Linear Hydraulic Actuator”. ASME/BATH 2015 Symposium on Fluid Power & Motion, Chicago, United States

[3] J Li, “Design and development of a piezoelectric linear actuator for smart structures”, Department of Mechanical and Industrial Engineering, Concordia University, Montreal, Quebec, Canada, 2004

[4] M Hochwallner, M Landberg, and P Krus, “The Hydraulic Infinite Linear Actuator – properties relevant for control”. In 10th International Fluid Power Conference (10. IFK), Vol. 3, pp. 411–424, 2016

[5] S Mraz, “Comparing Electric Rod Actuators and Hydraulic Cylinders”, Machine Design, http://machinedesign.com/technologies/hydraulics, 2016

6] M Linjama, “DIGITAL FLUID POWER –STATE OF THE ART”, The 12th Scandinavian International Conference on Fluid Power, Tampere, Finland Linköping, 2011

[7] ETP-OCTOPUS, ETP Transmission AB, www.etptrans.se


[9] “Automated assembly of aircraft wings”, https://www.fraunhofer.de/en/press/researchnews/2014/may/automated-assembly-of-aircraftwings.html

[10] X Dong, M Raffles, S Cobos Guzman, D Axinte, J Kell, “Design and analysis of a family of snake arm robots connected by compliant joints”, Mechanism and Machine Theory 77 (2014) 73–91

[11] “Hydraulic Cylinders Industry Report”, July 2013, InterOcean Advisors LLC, 117 North Jefferson Street, Suite 205, Chicago, IL 60661, www.ioadvisors.com

Citeringar i Crossref