RWTH Aachen, Germany Research Status Brief 2013

Technische Hochschule Aachen Institute of Fluid Technology Transmission and Control (IFAS - Institut fuerfluidtechnische Antriebe und Steuerungen, hereinafter referred to as the Institute of Fluid Technology) was formerly known as the Institute of Hydraulic Pneumatic Drive and Control (IHP) founded in 1968 by Professor Barker, the world's fluid technology leader. It is the oldest, largest and most talented university institute of fluid technology in the world. The current director, Prof. Dr.-Ing.H. Murrenhoff, completed his doctoral dissertation in the Institute in 1983 and served as chief engineer until 1986. After that, he first worked as the vice president of engineering and marketing in an American aviation technology company, and then served as the technical president of a famous German electromechanical company. He returned to the institute in October 1994 to succeed Professor Barker. The goal of the Institute of Fluid Technology is: to conduct creative R&D and teaching in the field of fluid technology, to enable young engineers to meet the requirements of the industry through Ph.D., to contact college students who are interested in this field through course design and master's thesis, and to train industrial mechanical technicians and electronic technicians. and professional information technicians.

From February 1979 to September 1981, Professor Lu Yongxiang, the former president of the Chinese Academy of Sciences, worked here as a Ph. So far, nearly 20 Chinese scholars have come here to study or pursue a Ph.D.

On August 16, 2013, the Institute of Fluid Technology held an academic report and scientific research report (opening day) to celebrate the 60th birthday of Professor Murenhoff. The author was invited to participate, and now I will briefly introduce the scientific research situation of the institute as follows.

In 2012, the Institute of Fluid Technology’s research funding was 3.33 million euros (approximately RMB 27 million), of which 40% came from scientific research contracts from enterprises, 29% from education grants from state governments, and 31% from scientific research contracts from various public departments and foundations . Now it has established long-term cooperative relationship with 134 enterprises. The test hall is 1250 square meters with about 50 test stands. There is also a movable control room with a controllable temperature of -70 to +70 degrees Celsius and a humidity of 95%, 4.7 meters x 3.5 meters x 3 meters, and a sound-absorbing room. In addition to general oil analysis methods, there are oxidation test, friction oxidation test, hydrolyzate test and high pressure test bench in the liquid laboratory. In the material and surface measurement room, there are ordinary microscopes, optical three-dimensional microscopes, light-transmitting microscopes, various general hardness testers, microhardness testers, rubber and plastic hardness testers, fixed and portable roughness testers, and a round Two sets of cylindricity testers, height tester and so on. In terms of tribological tests, there are self-made rotary friction testers, high-frequency response friction testers, fuel (low viscosity) rotary friction testers, etc. In terms of component testing, there are self-made pollutant addition test benches, fuel injection pump radial plunger test benches, hydraulic valve short-term aging test benches, gas flow test benches, efficiency test benches, hydraulic valve test benches, and radial plunger unit units. Plunger Test Bench, Pump Pollution Test Bench The institute currently has 18 managers, laboratory staff and technicians at all levels, 24 doctoral students, and about 70 master students who are doing course design and graduation thesis. Each doctoral student in the Institute of Fluid Technology has several master's students under him. The doctoral students are the actual organizers of scientific research projects, and the specific scientific research work is often assigned to the master's students. The research fields of the Fluid Technology Institute cover vehicle hydraulics, industrial automation, medical technology, environmental protection technology, manipulator technology, manufacturing technology and stationary hydraulics, etc. Divided into five research groups.

1. Tribology and Fluid Analysis

1 1 . 1 Research focuses include measuring the surface properties of friction pairs in the institute's surface laboratory and testing fluid properties in the oil laboratory. The testing equipment in the test hall allows practical testing of friction loss, wear and leakage. Knowledge gained from analyzing detrimental frictional systems can aid in optimization. Simulate tribological systems and predict fluid properties using general-purpose and self-developed digital tools to help optimize processes.

(1) Components

1) Using various methods to analyze, evaluate and optimize friction pairs in fluid technology components and their key features

2) Surface coating of mechanical components to improve friction characteristics

3) Study the effect of surface texture on friction and wear

4) Pollution and filtration of hydraulic circuits

5) Electrostatic accumulation of filter elements and interaction with fluid

(2) Pressure medium

1) Test and describe the aging characteristics of mineral oil and environmental protection fluid

2) Determine the interaction of fluids with metal and non-metal materials

3) Study fluid properties in a large temperature and pressure range

4) Test the effect of different fluids on the efficiency of the hydraulic system

(3) Sealing technology

1) Measure the friction, wear and leakage characteristics of translational seals

2) Hydraulic and pneumatic seal simulation

3) Visualization of soft elastic sealing gap process

(4) fuel

1) Prediction of fuel lubrication characteristics

2) Friction contact mode reproduction

3) Simulation of friction contact in fuel injection pump

1 1 . 2 Partially completed research projects

(1) Modeling, optimization and fabrication of the micro-texture on the contact surface of the hydraulic pump motor

(2) Simulation and test of the friction pair of the plunger unit

(3) Market entry project of the Federal Ministry of Economics for bio-based lubricants

(4) Approximate actual trial and condition monitoring of vegetable oil

(5) Development and application test of pressure medium based on sugar derivatives and vegetable oil

(6) The influence of surface condition and working medium on the sliding and sealing contact friction characteristics of hydraulic components;

(7) The compact combined sealing ring replaces the complex sealing system of biodegradable fluid for mobile servo hydraulics

(8) Chrome-free coating test on piston rod of hydraulic cylinder

(9) Realization of an environmentally friendly friction system on machine tools through appropriate composite materials and intermediate substances

(10) Aging characteristics of environmentally sustainable intermediate substances

(11) The hydraulic pump motor is adapted to the basic system of environmental protection

(12) Analysis and test of the separation function of the multi-layer filter in the hydraulic device

1 1 . 3 Research projects currently in progress

(1) Influence of pressure medium on energy consumption of hydraulic devices

(2) Research on electrostatic accumulation of pressure medium when passing through the filter

(3) Friction measurement of piston and piston rod seal at high speed

(4) Bio-based custom fuel (in cooperation with the second group)

2 2 . Pump and motor technology

2 2 . 1 The focus of the research is on the research of the hydraulic displacement mechanism, and the development of new components, including the improvement of the fluid technology drive, in order to improve the efficiency, power density, service life, environmental acceptability, and reduce the cost. Important R&D goals are on the one hand to improve the friction system by applying new materials and surface coatings, and on the other hand to increase the efficiency of various hydraulic components when they are not fully loaded. Apply the general simulation program, and also develop the special research and development tools for the displacement mechanism.

(1) Component development

1) Efficiency test

2) Improve sliding contact by testing in displacement mechanism

3) Effect of surface coating on component characteristics

4) Structure of water hydraulic transmission

5) Research and development of micro-hydraulic components for workpiece clamping mechanisms

(2) Noise and pulsation

1) Air noise measurement

2) Transmission vibration measurement and calculation

3) Pattern analysis

4) Reduce solid noise by improving the structure

5) Reduce fluid noise by improving the controller

(3) Design tools

1) Development of design software for pumps and motors

2) Control process simulation

3) Calculation of hydraulic pressure, mechanics and tribology in the displacement mechanism

2 2 . 2 Some completed research projects

(1) The hydraulic displacement mechanism adapts to the environmental protection system

(2) Improve the efficiency of non-full load conditions

(3) Reduce solid noise by improving the structure

(4) Reduce noise and fluid pulsation of hydraulic components and systems

2 2 . 3 Research projects currently in progress

(1) Friction system in the plunger mechanism

(2) Bio-based custom fuels (in cooperation with the first group)

(3) Industrialization project "Sliding friction pair using vacuum coating in plunger mechanism"

(4) Hydraulic drive chains in wind energy installations

(5) Hybrid hydraulic drive

3 3 . Valve technology and mechatronics

3 3 . 1 Research Focus on the development and optimization of valves, actuators and sensors, in addition to proportional valves and servo valves, there are on-off valves that combine mechanical components, valve actuators, sensors and information and communication technology. These, due to the high demands and the emergence of new operating principles, constitute extremely challenging mechatronic systems. The goal of further development is to systematically improve these components, taking into account the necessary control power, functional reliability, wear and dynamic behavior. At the same time, environmental protection should also be considered, such as avoiding leakage and reducing noise.

(1) Valve technology

1) Improve the static and dynamic transfer characteristics of switching valves and regulating valves

2) Reduce the driving power of the valve

3) Development of high dynamic proportional valves and servo valves

4) Design of slide valve pressure balance groove

(2) Fluid Mechanics

1) CFD simulation of flow lines in the valve aiming at compensating hydraulic force and reducing pressure loss

2) Measurement of valve flow characteristics (hydraulic force-, flow-stroke curve)

3) Streamline calculation to reduce the pressure loss of pipes and joints

4) Incorporate the cavitation model into the simulation software to improve the simulation results

(3) Sensors and drivers

1) Development and testing of new valve actuators, such as piezoelectric ceramic drives and immersed coil drives

2) Development of new sensors, such as eddy current-stroke sensors

3) Manganese-nickel-copper alloy wire pressure sensor

3 3 . 2 Completed research projects

1) Servo-hydraulic drive with high load stiffness

2) Drive chain scheme for mobile working machinery

3) Expert system of servo hydraulic pressure

4) Explosion-proof switch valve driven by bus

5) Self-driven hydraulic clamping system for autonomous manufacturing cells

6) Hydraulic slide valve pressure balance tank

7) Pilot stage for piezoelectric actuation of highly dynamic hydraulic valves

8) High dynamic hydraulic drive

3 3 . 3 Current research projects

1) Short-term aging test of hydraulic valves

2) Power switch drive

3) Valve simulation

44. System and control technology

4 4 . 1 Research The focus is on the dynamic characteristics and energy consumption of fluid technology transmission systems. Fluid Technology Institute's rich experience in establishing mathematical models of fluid technology components has laid a solid foundation for this. One of the priorities is the development of modern modulating control concepts as well as reliable adaptation strategies, which increasingly simplify the integration of hydraulic systems for the user. The research supports users in applying modern regulation schemes that help reduce the energy consumption of fluid transmissions.

(1) Fluid technology system simulation

1) Nonlinear simulation

2) Establishment of simulation model

3) Test and analysis of fluid technology system

(2) Bus system

1) Bus connection of hydraulic valves, pneumatic valves and drive systems

2) Equipment concept for fluid technology

3) Decentralized control scheme

(3) Energy saving strategy

1) Develop a new circuit scheme

2) System optimization and cycle optimization of hydraulic transmission

(4) Condition monitoring

1) Error monitoring of process valves

2) Remote diagnosis of hydraulic components

(5) Adjustment quality

1) Adaptation of the adjustment strategy to the system

2) Reliable adaptive strategy

4 4 . 2 Research projects completed

(1) Condition monitoring of hydraulic oil and transmission oil

(2) High rigidity servo hydraulic drive

(3) High dynamic servo drive using electrohysteresis

(4) Reduce the noise of servo driving

(5) Intelligent integrated single-wheel drive brake module for rail vehicles

4 4 . 3 Current research projects

(1) R&D environment of fluid technology mechatronics system

(2) Self-reinforcing electro-hydraulic brake

(3) Simulation of multiphase flow system with quality preservation

(4) Wave energy conversion and absorption test bench

(5) Obtain ocean energy with the help of hydraulic system

(6) Synthetic simulation of high pressure pump and constant pressure system

55. Pneumatic

5 5 . 1 Research focuses on the design, analysis and simulation of pneumatic components and systems. In terms of material conveying technology, research and development of step conveying replaces existing conveying schemes. New miniaturized servo-pneumatic adjustment solutions enable the construction of highly flexible grippers and manipulators. By evaluating the sensor signals already present in the pneumatic system it is possible to predict the condition of the equipment so that maintenance intervals can be optimally planned and the system operated with the most energy savings. At present, in system simulation, the friction caused by the sealing system has not been paid enough attention. Therefore, the further research and development goal is to combine the structural mechanism of the sealing ring and improve the friction model in the system simulation.

(1) Development and improvement of pneumatic components

1) Reduce the control power of the valve

2) Miniaturization of the valve controller

3) Application of micro-mechanics

4) Miniaturization of pneumatic components

5) New proportional valve

(2) Pneumatic system simulation

1) Modeling of pneumatic components

2) Streamline simulation CFD

3) Expand the component library

(3) New application areas

1) Automation technology

2) Transmission and grabbing technology

3) Walking machinery

4) Servo pneumatic

5 5 .2 2 Completed Research Projects

(1) Pneumatic stepping conveying

(2)Servo pneumatic hand

(3) Pneumatic equipment diagnosis

(4) Sealing of miniature pneumatic seat valve

(5) Intelligent two-pliers grabber

(6) Unsteady calculation for improving the dynamic characteristics of the pneumatic valve magnet

(7) Pneumatic regulating valve to control power reduction

5 5 .3 3 Ongoing research projects

(1) Rapid measurement of pneumatic components

(2) Highly integrated multi-driver servo pneumatic hand drive

(3) Friction model of sealing contact

(4) Improved modeling in aerodynamics by considering flow pulses, flow guidance and pressure wave propagation

(5) Improving efficiency by using exhaust In the flow technology institute, all theoretical research, simulation, and modeling must be compared with actual test results. In the academic report meeting in the afternoon, Dr. Bauer from Hytek introduced the role of the accumulator in this hybrid drive. Prof. Post from Festo explains how automation can be improved through biomimicry. Dr. Kempermann from Frutronics explains how to provide integrated systems in mobile hydraulics. Dr. Breuer from Rexroth explains how modern development tools are currently used in the development of hydraulic pump motors: MKS, FEM, EHD, CFD, M.Elemente. In the evening, Professor Murenhoff paid out of his own pocket and held a banquet in the ancient castle of Lahr without accepting gifts. During the dinner, his friends, mentors, colleagues, and children gave speeches, reviewing the journey the professor has traveled so far in all aspects, with many well-intentioned sarcasm, humor, and constant laughter and applause until late at night. Professor Murenhof told the author that he is willing to cooperate with Chinese companies, for example, to provide Chinese companies with their research results, to accept tests commissioned by Chinese companies, or to participate in research projects.