著者
髙石 吉將 荒井 篤 岡田 真幸 藤原 大悟 鵜山 淳 近藤 威
出版者
日本脊髄外科学会
雑誌
脊髄外科 (ISSN:09146024)
巻号頁・発行日
vol.33, no.2, pp.179-183, 2019 (Released:2019-09-10)
参考文献数
16

Various complications are found in ventriculo-peritoneal shunts (V-P shunts) used in hydrocephalus. Overdrainage can be the source of some of these complications and is the primary cause of orthostatic headache, nausea, and vomiting. Here, we report a case of overshunting-associated myelopathy with progressive tetraparesis. A 56 year-old female had undergone placement of a V-P shunt four years prior to presentation in our clinic. She presented with progressive spastic tetraparesis and dysarthria but had no headache. In a brain magnetic resonance image (MRI), enlargement of the bilateral subdural space was noted. Gadolinium enhanced MRI showed dural enhancement. The presence of intracranial hypotension was suspected. Engorgement of the epidural vein at the C2 level in the cervical epidural space was also observed in the gadolinium enhanced cervical MRI. Since overdrainage of the V-P shunt was obviously present, a programmable valve was placed, and the flow of cerebrospinal fluid was controlled. The symptoms improved, and the epidural enhanced lesion diminished in subsequent MRIs. Here, we report a case of overshunting-associated myelopathy after placement of a V-P shunt and a review of the currently available literature.
著者
藤原 大悟 塩川 貴之
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 (ISSN:21879761)
巻号頁・発行日
vol.83, no.854, pp.17-00087-17-00087, 2017 (Released:2017-10-25)
参考文献数
12

Aiming at the realization of agile autonomous flight for the extension of the flying range of single-rotor helicopters in the limited flight time, the flight control system design and the control performance verification for the high-speed turn flight are conducted. To achieve the reference following control for large attitude angles and the rotor thrust, the control system is composed of the main-rotor thrust and body torque centralized controller based on the MIMO (Multiple-Input, Multiple-Output) helicopter model including the blade motion dynamics, rotor speed proportional-integral controller, the attitude controller designed via the backstepping method based on the quaternion attitude model, and the guidance controller based on translational motion model. Simulation results show that the hovering and 10-m/s straight cruise flight followed by over 45-degree bank turn is feasible by using the proposed control system. In addition, flight tests have been conducted using the experimental small unmanned electric helicopter equipped with the flight control computer, and the high speed turn agile autonomous flight was successful in the real environment.
著者
磯村 直道 藤原 大悟
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 (ISSN:21879761)
巻号頁・発行日
vol.83, no.854, pp.17-00013-17-00013, 2017 (Released:2017-10-25)
参考文献数
9

Flight control system with position compensation applicable to trajectory tracking of agile maneuvers that require an attitude rotation and a reverse of main rotor thrust of single-rotor helicopters is proposed. The outer loop position compensator calculates the desired attitude and rotor thrust which reduce position tracking error by utilizing a kinematics equation established near the reference trajectory. The desired attitude is set using the magnitude of the rotor thrust in the reference trajectory, which enables continuous position feedback compensation based on the fact that the relationship between rotational and translational motion becomes independent as the rotor thrust decrease. To achieve high-bandwidth control of lateral-longitudinal angular rates in the inner loop, two-degree-of-freedom servo system is designed using a linear model with blade flapping motion dynamics. The control system is applied to autonomous control of flip maneuvers which include transition between upright and inverted hovering. The reference trajectory of a flip maneuver is generated as a parameterized simple equation which can be adjusted to the helicopter ability. Simulation and outdoor flight tests of the autonomous flip maneuvers demonstrated the capability of position feedback compensation that reduces position tracking error during out-of-trimmed flight state. This control technique can be extended to various agile flights for quick execution of flight tasks or recovery maneuvers from dangerous state.
著者
五十嵐 一弘 羽沢 健作 辛 振玉 藤原 大悟 野波 健蔵
出版者
The Japan Joint Automatic Control Conference
雑誌
自動制御連合講演会講演論文集
巻号頁・発行日
vol.47, pp.259-259, 2004

小型無人ヘリコプタは、その優れた運動性能を生かし、様々な局面や分野に柔軟に適用することができる。例えば、エンジントラブルが起きても、風からエネルギーを取り出し、ローターを自転させることにより、安全に着陸することができる。この飛行法をオートローテーションと呼ぶ。本研究ではオートローテーションを自律化することを目標とし、制御器の設計と実験を行った。
著者
辛 振玉 藤原 大悟 羽沢 健作 野波 健蔵
出版者
一般社団法人日本機械学会
雑誌
日本機械学會論文集. C編 (ISSN:03875024)
巻号頁・発行日
vol.68, no.675, pp.3284-3291, 2002-11-25
被引用文献数
17

This paper proposes the model based control system design for autonomous flight and guidance control of Radio-Controlled Helicopter. RC Helicoper has been studied with fuzzy and neural network approach, but it is so difficult for unmodel based control to stabilize it. The system identification techniques and model tuning approach are applied for RC helicopter system to obtain the mathmetical model. In order to realize the full automatic controlled RC helicopter, we have designed the attitude controller and altitude controller with LQG based Kalman filter and trajectory controller with SMC (Sliding Mode Control) for RC helicopter. It has been clarified that the proposed scheme for attitude control, altitude control and hovering control are very useful by way of the simulations and experiments.