Tokyo Institute of Technology
Tokyo and Yokohama, JAPAN
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
Tokyo Institute of Technology was established in 1881 and has been the leading Institution of higher education in the field of engineering and science in Japan. The Institute has three faculties: Science, Engineering, and Bioscience and Biotechnology, and five Graduate schools: Science and Engineering, Bioscience and Bio-technology, Interdisciplinary Graduate school of Science and Technology, Information Science and Engineering, and Decision Science and Technology. The number of undergraduate students is 5700, and graduate students 4200. The total staff number is 1800, including 700 professors.
The annual expenses amounted to 36,000 million yen, including Educational and Research Activities of 11,000 million yen. The Educational and Research Activity consist of roughly equal three parts: allocation of Ministry of Education and Science, and grant-in-aid for scientific research of Ministry of Education and Science, and Donation or Contract Research with the Private Sector (Company).
The Institute has two big campuses, the one is O-okayama campus in Tokyo, and the other is Suzukakedai campus in Yokohama city. They are about 20km apart from each other.
In Tokyo Institute of Technology, there are three research groups in the field of Fluid Power Control.
- KITAGAWA Group (in O-okayama campus)
- YOKOTA Group (in Suzukakedai campus)
- KAGAWA Group (in Suzukakedai campus)
Introduction of Graduate School of Science and
Engineering in O-okayama Campus
Graduate school of Science and Engineering was reorganized to 20 departments in 2000 based on faculty of Science and faculty of Engineering. Department of mechanical and control engineering is one of the department of Graduate school of Science and Engineering. In this department, the system of philosophy to realize the advanced machine as the mechanical control system which cooperates with human and nature has been built by combining mechanical engineering and control engineering. Faculty of engineering which is the base of the school has long history of research on fluid power control. In 1940's, Professor Dr. Shigeru Tsuji and Professor Dr. Toshio Takenaka started the research on fluid power control.
Now, Professor Dr. A. Kitagawa is the member of the department of Mechanical and Control Systems, and Kitagawa group belongs to the department.
Introduction of P & I Lab. in Suzukakedai Campus
The Precision and Intelligence Laboratories (P&I Lab.) is one of the four research laboratories attached to Tokyo Institute of Technology. The Laboratory is located at Suzukakedai-campus.
The former Research Laboratory of Precision Machinery was founded in 1939. In 1954, the laboratory was renamed.
The laboratory has five Divisions consisting of 15 research sections, two Guest Chairs and several supporting facilities. It is an interdisciplinary research organization with staff members from the fields of mechanical, control, electronic, information and materials engineering. The activities are oriented towards developing advanced technology combining precision and information engineering for which joint effort is frequently attempted among researchers in different fields. The staff members are also engaged in education for graduate students, offering lectures and supervising researches toward doctor's and master's degrees.
In the history, Professor Dr. Yo Ikebe directed the laboratory from 1978 to 1980. Also, Professor Dr. Kazuo Nakano directed the laboratory from 1989 to 1991.
Kagawa group and Yokota group belong to Advanced Mechanical System Division. Professor Dr. T. Kagawa and Professor Dr. S. Yokota are also the faculty members of Interdisciplinary Graduate School of Science and Engineering, and manage Department of Precision Machinery System.
Fig. 1: Precision and Intelligence Laboratory
Department of Mechanical and Control Systems
Graduate School of Science and Engineering
(Kitagawa Group)
Outline
From the viewpoint of the flexible characteristics and the high-powered density of fluid power, we aim to develop new types of fluid power actuators and robots which are durable in the inferior environment. And the research outputs are expected to be applied to the human-machine cooperative systems such as rescue operation, welfare activity, and so on. In addition to basic researches, some have been studied with the aim of the practical application at the disastrous site and are also cooperatively commercializing with the disaster prevention equipment manufacturers. Water hydraulics and pneumatics as well as oil hydraulics are investigated in the group and are properly selected as the working fluid in order to realize the aim.
Fig. 2: Members of Kitagawa group
The staffs are Prof. Ato Kitagawa, Assoc. Hideyuki Tsukagoshi and Secretary Yoshiko Kuroda (Fig. 2). At present, 9 research projects are cooperatively progressing with all 13 students composed of 4 Dr. E. students, 6 M. E. students and 3 senior students including 5 foreign students from China and Thailand.
For details, please visit our
homepage.
Research Projects
Research projects can be divided into the next three fields, rescue robots, human-machine cooperative system, and new type of fluid power actuators and control valves. The projects already announced are enumerated in the following.
- Rescue robots
- Active Hose: The artificial elephant's trunk driven by pneumatic power can take the arbitrary curved posture (Fig. 3) and is expected to dive into collapsed buildings caused by a big earthquake in order to search the victims and supply fresh air or water to them.
- Fire Fighting Robot Driven by Water Hydraulic Power: It can climb the stairs smoothly by means of cycloid wave mechanism driven by only two water hydraulic motors (Fig. 4), and is expected to extinguish fires instead of firemen.
Fig. 3: Active Hose passing through ditch by
transmitting the wave from its front to its rear
- Human-machine cooperative system
- Pedaling Type Manpowered Pneumatic Pump for Rescue Operation: Pedaling is the most efficient human motion to obtain manpower energy and we proposed a driving method to convert it into pneumatic energy based on the human-engineering approach.
- Wearable-fluid-power by means of Wound-tube-actuator: This is the soft pneumatic actuator and is wearable so that it can drive the human joint flexibly and softly, and is expected to assist the nursing operation, the spacecraft outside activity for astronauts, or to improve the sport skill, etc.
- Master-Slave System to Detect Victims under Debris: This is the intelligent excavator driven by oil hydraulic system equipped with new type master-slave control method called "Parallel impedance control" for the operator to detect the victims under earth and sound at the disastrous site.
- New type of fluid power actuators and control valves
- On-off control valve for Water Hydraulic use.
- Control valve for mechanical brake of rolling stocks
- IP Motor: New mechanism (Inner touch pinch roller) realizes the low pressure tap water motor.
- Chameleon Type Prismatic Actuator: Like the tongue of the chameleon, the stroke of this pneumatic actuator is very large.
Fig. 4: Fire Fighting Robot climbing stairs
smoothly driven by water hydraulic power
System Control Section
Advanced Mechanical Systems Division
Precision and Intelligence Laboratory
(Yokota Group)
Outline
In the System Control Section (Yokota group), Advanced Mechanical Systems Division of Precision and Intelligence Laboratory (P&I Lab.), to realize autonomous robots for extreme environments and micromachines using fluid power, new actuators using functional fluids, sensors and advanced control technologies are investigated and developed. Hardware technologies are thought to be significant and most of the research projects are performed through fabrication and experiments. Several research projects are related to micromachining process and are performed by utilizing micromachining apparatus such as an electron beam lithography, a multi purpose evaporator, and so on in a clean room (200 m2, class 1000) for mechanical engineering sections of the P&I Lab. Some research projects are performed in collaboration with companies.
The staffs are Prof. Shinichi Yokota, Assoc. Prof. Kazuhiro Yoshida, Assoc. Yutaka Kondoh, and Assoc. Jung-Ho Park (see Fig. 5). At present, this section has 3 Dr. E. students (including 1 foreign student from South Korea), 10 M. E. students and 2 senior students. Each student has an independent research project.
As for the facilities, this section has 11 rooms for desk works and experiments. In the largest experimental room, hydraulic power supply units are equipped and the maximum flow rate of 90 l/min and the maximum pressure of 35 MPa are supplied to the experimental setups. In the other room, several precision machining apparatus such as micro electro-discharge machine, a wire bonding machine, and so on are equipped and the micromachine researchers utilize them as well as micromachining apparatus in the clean room of the P & I Lab.
For details, please visit our homepage.
Fig. 5: Members of System Control Section, Advanced Mechanical Systems Division of P & I Lab
Research Projects
Advanced fluid control elements using functional fluids
For advanced fluid control systems, advanced fluid control elements such as microvalves are developed by using functional fluids. A micro ER valve using homogeneous ER fluid is proposed and fabricated with micromachining technologies. ER fluids change their apparent viscosity by the applied electric field and the homogeneous type is suitable for micro systems without dispersed particles. By using the homogeneous ER fluids, microvalves without moving parts can be realized (see Fig. 6). Also, a microvalve using a MR fluid drop as a valve-body is proposed, fabricated, and tested. The valve utilizes the pulling force of MR fluid to the applied magnetic field and can shut off the flow irrespective of the machining errors. For larger fluid control systems, a pressure control valve using MR fluid is proposed and developed, which utilizes the apparent viscosity change of MR fluid by the applied magnetic field.
A constant pressure system to drive hybrid vehicle
Advanced fluid control elements using functional fluids
It is of prime importance to reduce fuel consumption and exhaust gases of vehicles in city traffic. To recover vehicle's kinetic energy easily which is wasted as heat during braking, we propose an application of Constant Pressure System (CPS) to driving hybrid vehicles using flywheels. The CPS is a simple hydraulic drive system mainly composed of three hydraulic pump/motors, fly-wheels and pressure compensators. During braking, kinetic energy of vehicle is recovered to flywheel with hydraulic pump/motors. And then the energy of flywheel is recycled during acceleration with hydraulic pump/motors (see Fig. 7). Furthermore, we are proposing and studying application of CPS to Super All Terrain Vehicle (SATV) which have high traveling capacity both on road and off road.
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SEM micrograph of channel on silicon surface |
Fig. 6: Microvalve using homogeneous ER fluid
Fig. 7: A constant pressure system to drive hybrid vehicles
Other research projects
- New hydraulic actuators using functional fluids
- Robust control of electrohydraulic manipulators
- In-pipe working micro machines using fluid power
- High output micro fluid power sources
Intelligent Systems
Advanced Mechanical Systems Division, Precision and Intelligence Laboratory
(Kagawa-Kawashima Group)
Outline
For the purpose of developing intelligent pneumatic device and applying new technology to pneumatic industry, we engaged in the researches and developments of new flow-meter used in compressible fluid, the pneumatic robot, the pneumatic system characteristics analysis and simulation, energy saving in pneumatic system, process control and measurement and so on. Some of our researches, such as analysis of Large-scale Gas Transmission System and Development of Micro Flow Meter etc., have been patented and put into practical use.
The staffs are Prof. Toshiharu Kagawa, Assoc. Prof. Kenji Kawashima and Assoc. Toshinori Fujita. At present, this section has 27 members (4 researchers, 8 Dr. E. students, 14 M. E. students and 1 senior student) including 6 foreign students from China, Korea and Peru. Each student has an independent research project.
For details, please visit our homepage.
Fig. 8: Members of Intelligent Systems Section Advanced Mechanical System Division of P&I Lab
Research Projects
Pneumatic system simulation
Large-scale Gas Transmission System: The City Gas supply system consisting of regulators and pipe lines is investigated. The simulation model has been proposed considering heat transfer between gas and pipe wall. (see Fig. 9).
Simulation of air cylinder system: We have developed the simulation of pneumatic cylinder systems consisting various separations. This model can also be used for analyzing the characteristics of pneumatic pipe-net.
Fig. 9: Large-scale Gas Transmission System
Research Projects
Flow rate measurement of compressible fluid unsteady flow rate measurement
Unsteady flow rate measurement: A method to measure gas flow rate from the pressure change in an isothermal chamber was proposed. The proposed method has been proved to be effective not only at steady flow but also for unsteady oscillating flow up to 40 Hz by experiments (see Fig. 10).
Micro flow meter: The new high response micro flow meter was developed, which is installed on the velocity boundary layer in the pipe line, and sinusoidal flow up to 10 Hz could be measured (see Fig. 11). We also have developed a new flow meter with variable opening area. It is equipped with large range ability, simple construction and low cost.
Flow rate characteristics measurement of pneumatic components
Discharge Method: Besides the ISO method for measuring sonic conductance, in Japan, a simple method, called "Discharge Method", has been adopted without using flow-meter. In Discharge Method, compressed air is discharged from chamber through the test component, and sonic conductance would be obtained from the chamber pressure response during discharging (see Fig. 12). The investigation of Discharge Method has been carried out.
Charging Method: A new simple method, called "Charging Method", has been proposed for measuring flow rate characteristics. In Charging Method, an isothermal chamber is charged by compressed air though the test component, sonic conductance C and critical pressure ratio b can be obtained simultaneously from chamber pressure response.
Energy saving
This study has clarified the mechanism of energy loss in pneumatic equipments and given the definition and calculation equations of energy of compressed air, based on the energy transformation from air compressors to actuators.
Process control and measurement
Pneumatic Robot Arm: We have developed the Robot by using pneumatic servo system, which can be employed in bad environment.
Chiller: This is a control system for governing the water temperature variation within 0.5 K, which can be used in semiconductor production.
Other research projects
- Displacement sensor using nozzle-flapper system
- Electric power generator with pneumatic vibrator
- Numerical analysis of Thermopile sensor for temperature measurement
- Development of new servo valve
Fig. 10: Unsteady flow rate measurement
Fig. 11: Micro flow meter
Fig. 12: Discharge Method
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