Transactions of the Society of Instrument and Control Engineers
Online ISSN : 1883-8189
Print ISSN : 0453-4654
ISSN-L : 0453-4654
Volume 53, Issue 5
Displaying 1-4 of 4 articles from this issue
Paper
  • Saori MIYAJIMA, Takayuki TANAKA, Takashi KUSAKA
    2017 Volume 53 Issue 5 Pages 299-307
    Published: 2017
    Released on J-STAGE: May 18, 2017
    JOURNAL FREE ACCESS
    These days, inertial sensors are often used to capture human movements. A complimentary filter is the one method of sensor fusion, which several sensors data are combined to set off each sensor's disadvantages. It is often used for wearable devices because of its high measurement accuracy at low calculation cost. Human motion contains various speeds and frequency. However, in a complementary filter, combined frequency range is fixed and the filter can not cope with motion out of the range. Thus, a coefficient of the complimentary filter is replaced with sigmoid function in order to fluctuate along with motion speed of subjects. This fluctuating coefficient enables measuring irregular motions of human. Experiment shows that using this method rises accuracy of motion measurement.
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  • — The Case of 2 or 3 Coupled Periodic Input Control System —
    Hidekazu KAJIWARA, Naohiko HANAJIMA, Manabu AOYAGI
    2017 Volume 53 Issue 5 Pages 308-318
    Published: 2017
    Released on J-STAGE: May 18, 2017
    JOURNAL FREE ACCESS
    In our previous work, we proposed periodic input control method that can control energy of a system using forced entrainment. Furthermore, we showed forced entrainment is caused by inputted periodic external force to a periodic input control system whose energy is controlled by our method. In this paper, we analyze mutual entrainment of a coupled periodic input control system that some periodic input control systems are coupled to mutually, and show synchronization patterns can be controlled by switching coupling state of the system. First, we derive a synchronization condition that mutual entrainment is caused by analyzing a mathematical model of a coupled periodic input control system. Next, we describe that our synchronization pattern control method can control the in-phase and the anti-phase mode in two coupled periodic input control system or the 3-phase mode like a three-phase alternating current in three coupled system. This method switches the coupling condition of a system after periodic motions is attracted to neighborhood of a desired pattern. As a result, the systems synchronize by mutual entrainment. Finally, we show the result that inspected validity of our method by experiments.
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  • Takao MAEDA, Susumu HARA, Takeshi OZAKI, Shintaro MATSUI, Masatsugu OT ...
    2017 Volume 53 Issue 5 Pages 319-326
    Published: 2017
    Released on J-STAGE: May 18, 2017
    JOURNAL FREE ACCESS
    The landing system which is adaptable to different kind of terrain condition is required to achieve touchdown on rough and inclined terrains. However, it is difficult to design a landing system which is applicable to a wide variety of terrains. In the conventional landing gear system, aluminium honeycomb crush and oil damper are used to mitigate landing impact. These classical mechanisms have advantages of simplicity and large shock absorption capability. However, those classical passive landing gears are ill suited for landing to the uneven and inclined areas and for landing with lateral velocity. To prevent from lander tip-over, it is necessary to make landing gear adaptable to wide condition of terrain. In order to solve this problem, we propose a new mechanism for safety landing on an inclination. In general, tipping-over of spacecraft is caused by the torque which is generated by the difference of the force acting on each leg. However, it is difficult to synchronize force acting on the all the landing legs. Here, we focused on the difference of the force acting on each leg. In case of touchdown on the inclination, the force acting on the upper leg is larger than any other legs. In case of touchdown with a lateral velocity, the force acting on the former leg is larger than any other legs. Therefore, if we can convert this force to torque which is acting to the direction against to the rotating of the spacecraft, it becomes possible to prevent tip-over of the spacecraft.
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  • Yuta HANAZAWA, Fumihiko ASANO
    2017 Volume 53 Issue 5 Pages 327-334
    Published: 2017
    Released on J-STAGE: May 18, 2017
    JOURNAL FREE ACCESS
    In this paper, we show a novel foot mechanism for energy-efficient biped walking. Biped robots with fixed ankle springs have achieved energy-efficient dynamic walking. The fixed ankle springs, however, prevent flexible foot rotation. We propose a foot mechanism with asymmetrically arranged rubbers at the ankles. Furthermore, we show the effectiveness of the proposed method through numerical simulations.
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