Ichiryu Fluid Power Research Laboratory
Department of Mechatronics Faculty of Engineering
Tokyo University of Technology Japan

Operational idea: Research and education in fluid power Main research areas: Hydraulics, pneumatics, and robotics
Location Tokyo, Japan
Contact Persons Univ.-Prof. Dr.-Ing. Ken Ichiryu
Address 1404-1 Katakura, Hachioji, Tokyo
192-0982, Japan
Telephone number +81 426 37 2472
Fax number +81 426 37 2472
Email
Internet Site http://www.teu.ac.jp/ichiryu/

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




Introduction




Since its foundation in 1986, Tokyo University of Technology has committed itself to educating new generations of core researchers and engineers in advanced technology fields who will bring the new century closer to a more humane society where technology truly enriches our life. This is in fact an extension of the mission that the Katayanagi Institute, the university’s parent organization, took upon itself at its inception in 1947 as a vocational college to help reconstruct Japan’s industry by building up a solid work force of highly competent engineers and technicians. Over the relatively short span of less than 20 years, the university has grown to be one of the nation’s leaders in hightech education, with a high-caliber faculty consisting of some 130 professors, associate/assistant professors, and lecturers.
In this laboratory, the main objective is to create futuristic first of kind machines. Therefore, this lab is promoted powerfully by industry-university cooperation. For the industrial world, the features of our laboratory are innovative and attractive in machine development.
This must be attractive also for a student who gives them big power to create and development. Moreover, the result of industry-university cooperation was able to be raised gaining support of many companies. Typical example of our projects such a 3-dimensional Pipe bending machines, field robots vehicles, and Active suspension mounts.






Development of MOS bending machines





Here are some examples of research that applies kinematic parallel link mechanism, known as Stewart platform. These machines apply hydraulic actuators.
There are various processing method of pipes in industrial world. For example, press-bending, rotation pull bending and pressure bending. But, it is difficult to process pipes to these bending. Then, MOS bending was proposed. It is processed by using positional relation of movable die and fixed die. We turned out prototype using parallel kinematics mechanism for working head in this project. As a result, high accuracy and high rigidity was obtained. And, we developed innovative bending machine. In this development, we improved the bending accuracy. It is necessary to solve problem of bending angle by gradual curve part. We control or shear away gradual curve part. And, such problems could be solved by this bending machine. In Fig. 1, a 3 dimensional image of the pipe bender is shown.



Fig. 1:  proposed MOS bending machine

Another pipe bender research is under development. This machine has an effective bending process that allows it to produce less quantity but various shapes and types of work. This bending machine differs form the previous by its unique motion base platform mechanism. The uniqueness of this design allows the system to bend stiff and hard material pipes into small radius. As the previous machine this applies parallel mechanism to moving die´s drive mechanism too. And the main objective is to develop a bending machine that is flexible and has high processing accuracy.





Fig. 2:  Pipe bending machine







Development of testing device using parallel mechanism





Due to the 6 DOF of the kinematic parallel link mechanism a new Bike frame testing device have been proposed. The research frame of motorcycle receives complicated force and moment in actual running. Some time, damage is considerable and motorcycle components fail. This is very dangerous and efficient test method was proposed. But application of conventional test method of single or multiple actuators is difficult, because test object is relatively small and fragile. In this situation, we developed new method of load test using parallel mechanism. Advantage of this method is possibility to generate any assigned force or moment vector at desired point. That is, combined skew force or three-axis moment test becomes possible with just a change in software.



Fig. 3:  Overall view of the testing machine






Development of Active suspension mounts




Hydraulics could be applied in automobile engine mounts to reduce vibration. As far as diesel cars are concerned, idle vibration makes passengers uncomfortable. Each car company has developed active engine mount of the active control method. The developed mount is an extension of rubber mount having liquid room inside for damping. When actuating part is outsidethe liquid room, this device is called, dry type.




Fig. 4:  Results of the active engine mount experiment







Fig. 5:  Active suspension mount concept image

This study develops a new hydraulic active engine mount, whose inside is filled with oil for the enginesupport. By using a new active engine mount, the authors aim to reduce the transmitted vibration in the car. Here, the vibration reduction about 25 Hz of the idling frequency is assumed as main target of this study. The effectiveness of this device is compared with the rubber mount.
Similiar mount was applied in automobiles suspensions. Recently, the vehicle improvement of riding comfort and drivability is being widely researched. At present, most of the cars are using a passive type suspension. However, it is difficult to get satisfaction of comfortable ride and drivability by passive suspension. Therefore, an active suspension that can realize those requirements is being developed. The purpose of our research is not only to develop a new active suspension but also an experimental device. For simulation, Car- Sim and MATLAB are used. The suspension is shown in Fig. 6.




Fig. 6:  New active suspension device






Research of CPS hybrid vehicle










Fig. 7:  Hydraulic circuit image and experiment vehicle

In this research we applied Constant Pressure System [CPS] on the hydraulic hybrid vehicle, and actually installed it on an experimental vehicle to undergo several experiments. From these experiments and results we evaluated the system. In addition, we aimed to compare various hybrid vehicle and fuel economy that has been put to practical use now and to confirm the effectiveness of the system.





Research on FST(Fluid Switching Transmission) Hybrid Vehicle






This system uses fixed capacity pump and motor. But the speed control and the flow rate control become possible because it uses switching valves. This vehicle consists of gear pumps/motors, switching valves, accumulator, small engine and flywheel. In this vehicle, engine accumulates energy into an accumulator by the FST switching process, and then the accumulator starts to rotate the flywheel by FST process. When the flywheel is fully charged, the flywheel drives the 6 wheels through another accumulator by FST process. And the vehicle speed is controlled also by FST process.




Fig. 8:  FST hybrid vehile





Development of demining robot




Specialists, known as de-miners, who detect, dig, and defuse landmines, do the whole process using their bare hands. In our research, we developed a robot that detects and defuse landmines. First, landmine field area will be detected by the metallic sensor. Then if a metallic object is found, surrounding topsoil will be blown off with a high pressure impulse gun. Finally the robot aims the impulse gun toward the landmine and destroys it before igniting. Now we installed a new system called a crawler tilting mechanism that enables the robot to go over obstacles such as stairs as shown in the Fig. 9. The crawlers are driven by hydro static transmission pump and motors. Steering mechanism and crawler tilting mechanism are controlled by hydraulic cylinders.




Fig. 9:  Demining Robot & Crawler tilting mechanism




Fig. 10:  Four track steering mechanism applied



Development of multileg locomotion robot




Octopod locomotion robot is developed for material transportation in rescue or hazardous areas. This octopod robot has eight units of similar legs. Each leg is designed as a module unit that could be installed to any object. Pneumatic cylinder is attached to each axis of the leg module. The combination of the eight legs allows the robot to maneuver its way in all directions. Even skid turning is possible.





Fig. 11:  Multi Leg Robot






Miniature Parallel Mechanism for RGB Alignment




Not only fluid hydraulics and pneumatics, electronic are applied in our laboratory. We have developed a new convergence structure for RGB alignment system that could be applied into visual display devices such as LCD Projector, HDTV and Projection TV etc. Regarding to the importance of high accuracy, miniaturization and high degree of freedom (DOF), this convergence structure was built up by applying the concept of parallel kinematics mechanism. The parallel mechanism was designed to be 6-DOF and capable of working at micrometer (µm) resolution.








Table: 1: Specifications





Fig: 12 Miniature Parallel Mechanism





Research of the power control system on PKM




PKM (Parallel Kinematic Machine) is expected to be applied to a processing machine from the feature of being a high output and high accuracy. Power control is indispensable in the improvement of processing accuracy. So, this research studies the power control system on PKM.The load cell is attached in each axis of PKM as a power sensor, and the Compliance Control which estimates the virtual stiffness when receiving power, and the Hybrid Control which applies arbitrary power to an object under investigation.





Fig: 13 PKM for experiment






Development of Hybrid Car using Electric Double Layer Capacitor (EDLC)




The series method is used for the hybrid system of the vehicle. For a long drive at constant speed, a small engine drives a generator which in turn powers the electric motor. When the car is accelerated, an electric double layer capacitor is used as an energy source rather than the small engine. Moreover, the electric double layer capacitor is used to collect the resurrection energy generated by driving motor when the car is decelerated. Efficiently collecting the electric power from a usual battery with an electric double layer capacitor becomes possible.




Fig: 14  Hybrid system vehicle


 

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