Fluid Power Research at the Mechatronics Department of Johannes Kepler University Linz,
Austria

Location Linz, Austria
Contact Person Prof. Rudolf Scheidl
Laboratory facilities About 200 m²
Address Department for Foundations of Machine Design
Johannes Kepler University Linz
Altenbergerstrasse 69
4040 Linz, Austria
Telephone number +43 732 2468 9745
Fax number +43 732 2468 9753
Email rudolf.scheidl@jku.at
Internet Site http://aml.jku.at

From Editor

International Journal of Fluid Power would like to introduce the fluid power research and education centres with their expertise and particular interests in this column. Jumping from continent to continent we like to offer every research centre the opportunity to present itself.


FLUID POWER RESEARCH CENTRES WORLD-WIDE

General Information

The Johannes Kepler University Linz (JKU) - founded in 1966 - is one of the youngest Austrian Universities. It comprises three faculties, social sciences and economics, law, natural sciences and engineering. At present, some 20,000 students are enrolled in the three faculties. The faculty for natural sciences and engineering has about 3000 students, 26 institutes, 52 professors, 162 assistant professors and other scientific staff, and about 150 project-financed scientists. It offers studies for mathematics, physics, chemistry, computer sciences, and - since 1990 - mechatronics.

JKU as one of the first universities worldwide established a full academic curriculum mechatronics to account for the changing needs in engineering education. 11 Professors and 35 public paid assistants teach about 700 mechatronic students in the mechanical and electrical engineering disciplines and in automatic control. The education in computer sciences is carried by the computer science department.

In their research work, the professors and assistants are supplemented by some 30 research scientists funded from different projects and research grants.

The research activities of the mechatronics depart-ment are grouped into the following divisions, each of which is associated with one chair:

Research in Fluid Power is done regularly by three research divisions: Foundations of Machine Design (Prof. Rudolf Scheidl), Design and Control of Mechatronical Systems (Prof. Luigi del Re), Automatic Control and Applied Control Engineering (Prof. Kurt Schlacher). Occasionally, support for the solution of fluid dynamical problems is given by the division for Fluid Mechanics and Heat Transfer (Prof. Philipp Gittler).

The mechatronics department has co-founded and is shareholder of the Linz Center of Competence in Mechatronics (LCM), a limited company, which carries out applied research in a broad scope. It runs a so called Kplus-program of the Austrian government, which aims at the erection of applied research centers for dis-ciplines of high relevance for the Austrian industry. Fluid power is a major field of research and together with electric drive technology forms a so called scope of competence for drives and actuation in this center. Fluid power research at LCM is done in very close co-operation with the divisions of JKU, because LCM's staff is sharing the same office area and is using JKU's lab facilities.


Fig. 1: Campus of the Johannes Kepler University Linz




Teaching of Fluid Power at JKU

The obligatory part of the mechatronics curriculum in Linz is oriented towards fundaments and is quite broad. The students have to choose two out of 10 different areas of specialization. One of these areas is drive technology. It covers electric drives, power electronics, and fluid power. The latter is split up in a basic hydraulic course, a hydraulic lab, courses on pneumat-ics and on servo hydraulics, and a special lab oriented seminar on the design of hydraulic drive systems. Other areas of specialization with relevance for fluid power are automation and robotics, and system analysis and optimization. About 50 to 60 students graduate each year in mechatronics, about 10 to 20 per year visit at least the basic hydraulic course and lab. The sound fundaments in control and electric network theory, electrical drive technology, and the existing skills in simulation of dynamical systems, enable to concentrate in the fluid power courses on the fluid dynamical and modelling aspects, the basic fluid power components, system aspects, and hydraulic and pneumatic circuitry design.

Each year about 5 to 7 students perform a master's thesis for a fluid power topic. They are related to special simulation and modelling problems, theoretical and experimental studies of new concepts for drive systems, components (like valves), sensor and measurement problems, control algorithms for specific applications, or parameter identification of components and systems. Many of these theses treat research problems of industrial companies.


Research Facilities

The main fluid power related research facility is the hydraulic lab of the division for Foundations of Machine Design. The total lab floor area is 140 m2. Two independent hydraulic power supply systems both with a rated pressure of 300 bar and maximum flow rates of 55 l/min and 110 l/min respectively enable independent experiments with an average power of 22 kW each. These supply units can run in a pressure or in a flow rate controlled manner.


Fig. 2: Fluid Power research at JKU and LCM


For the set-up of experiments the lab comprises a valve test-stand with two independent working platforms for testing single valves or valve assemblies, a linear test rig on a vibration isolated platform, a rotary test rig where motors and pumps can be arranged for testing hydraulic pumps or motors respectively. These rigs can be configured in a very flexible manner to realize different experimental arrangements of drive systems.

For these test rigs different pumps, motors, switching-, proportional-, servo-, and pressure regulating valves and accumulators are available.

The effective analysis of experiments is supported by the following measurement systems: pressure sensors, a high precision gauge for their calibration, flow meters, position gauges, accelerometers, force and torque gauges, and temperature sensors; data recording and processing is done by means of very powerful signal processing units of type dSpace. These systems also offer a very convenient way to realize control algorithms and to carry out and control complex test series.

The high flexibility for configuring experimental setups also needs a correspondingly adaptable electronics. For its own use, the division has developed a modular system based on the 19" rack standard which comprises different cards for signal adaptation, current drivers, analogue filters, etc. All these modules can be linked to the different dSpace signal processing cards or to micro-controller boards of the infineon C167 family.

The division for Design and Control of Mechatronical Systems is running a separate test stand for hydraulic elevators and one small for pneumatic servo drives. The latter mainly fulfils educational purposes. Measurement and control are also based on the dSpace signal processor cards.

The numerical simulation of fluid power systems, the development of control algorithms, and the identifi-cation of systems is based on Matlab/Simulink. A small library of hydraulic elements called `Hydrolib` for the convenient setup of SIMULINK models for hydraulic systems has been developed.

For the numerical study of 2D or 3D fluid flow processes, e.g. in valves, the CFD code FLUENT is available.


Fig. 3: Hydraulic lab - main room




Co-operation

Manifold types of fluid power related cooperation with industry and other research institutions exist. Among companies are main hydraulic manufacturers, like BOSCH Rexroth, and their affiliated company in Austria, companies related to steel production like Voest Alpine, to agricultural machines, like Pöttinger, to huge gas engines, like Jenbacher, to tool machines, like TRUMPF, to car industry, like BMW, to injection moulding machines, like ENGEL, or to hydraulic ele-vators, like Wittur.

Some of the projects are part of the LCM's Kplus program. Fluid power related cooperation also takes place with the industrial competence center for mecha-tronics, IKMA. This center is run by the mechatronics company vatron (a subsidiary of Voest Alpine Steel and Voest Alpine Industrieanlagenbau).

The Institute for Mechanics and Machine Design forms the Austrian node of Fluid Power Net Interna-tional (FPNI). This opens doors to many research institutions for fluid power worldwide.


Research Projects

The current research topics concerning fluid power are: These are applied in the following sectors:
MOBILE - agricultural machinery (hay harvesting and mowing machines, ploughs), automotive engineering (common rail diesel injection systems).
INDUSTRIAL - steel industry systems (rolling mills, continuous casting machines), elevators, tool machines (e.g. press brakes, automated assembly machines), hydraulic systems, gas engines.


Fig. 4: Automatic level control of the pick-up of a hay harvester; basic functioning tests



Fig. 5: Prototype of a variable valve train



Fig. 6: Hydraulic elevator test rig


 

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