著者
橋本 良夫 斉藤 敏克
出版者
The Japan Society of Mechanical Engineers
雑誌
日本機械学会論文集 C編 (ISSN:03875024)
巻号頁・発行日
vol.69, no.687, pp.3029-3033, 2003

A method is proposed to analyze dynamic response of a rocket-launcher system at lift-off. In this paper, rocket-launcher system is modeled as finite element Bernoulli-Euler beams connected with two slippers which are modeled as linear springs. A beam element with a moving spring is devised to represent the rocket-launcher interaction. Coupled equations of motion with time-varying coefficients are derived and solved by using direct method such as the Wilson θ method to calculate the dynamic response of the system. To verify the validity of this method, dynamic response is calculated by using the data of M-3S rocket-launcher system. Two rocket models, rigid-body and elastic-body models, are used in this calculation. The numerical results obtained from two models are compared and discussed.
著者
堤 一郎
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.74, no.746, pp.2387-2395, 2008-10-25 (Released:2011-03-04)
参考文献数
17

Wooden carriage manufacture of Japanese Imperial Government Railway (J. I. G. R.) Works and Japanese young railway engineer cultivation in the Meiji period are described. In the start of J. I. G. R.'s transport business, 143 rolling stocks were imported from the U. K., and English railway engineers were employed. They cultivated Japanese young trainees through the construction of wooden carriages by themselves on the job training. A drawing of Adams bogie track with Munsell wheels, brief personal record of four English railway engineers and three Japanese young engineers were explained. Mechanical Engineering Heritage of four wooden carriages preserved in Japan are introduced, too.
著者
白國 紀行 谷村 正治 宮崎 文夫
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.72, no.716, pp.1021-1027, 2006-04-25 (Released:2011-03-04)
参考文献数
4

Among high-speed railway systems, the superconducting maglev train is an innovative transportation system, in which trains are levitated and driven at speeds of up to 550 km/h. But in case of quench of superconducting magnet, vehicles are forced to touch down on the guideway. For safe landing, we developed the new equipment named “Emergency Wheel”. Our process of development is as follows : (i) To know the maximum load for the landing, we simulated the electromagnetic power and dynamics of vehicles. (ii) Each element of emergency wheel was developed and tested in a factory. (iii) Quench tests were conducted on the Yamanashi Maglev Test Line and results showed a good accordance between simulation and test. Through the study and development of emergency wheel, we established a design method of safety equipment for Maglev.
著者
山田 健介 宮本 共生 臼井 清一
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.71, no.708, pp.2557-2562, 2005-08-25 (Released:2011-03-04)
参考文献数
8
被引用文献数
4 3

The paper presents a design and characteristics of a new holonomic omnidirectional moving vehicle, which simultaneous and independently controlled translational and rotational motions. The moving vehicle has four rubber balls instead of wheels. Each ball is driven by two rotating rollers. But the system has only four actuators. The kinematics of the moving vehicle is analyzed and the control algorithms are derived for the holonomic and omnidirectional moving vehicle. The experimental results show that the proposed new type of moving mechanism has good characteristics and the sensor on board is useful for autonomous moving under relatively large disturbance.
著者
山中 仁寛 中易 秀敏 三好 哲也 前田 多章
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.72, no.719, pp.2248-2256, 2006-07-25 (Released:2011-03-04)
参考文献数
17

A new method is proposed to measure the useful field of view (UFOV) when one can recognize the objects by visual task. Since the distance from fixation point to target mark is the strength of stimuli, the psychometric curve is utilized for UFOV by the statistical estimation by Probit and Staircase methods. An approximation by ellipse is also applied to represent the contour of the UFOV. The proposed method enables one to estimate the threshold of recognition with probability that means the UFOV with the detection probability. Therefore, it is proposed in this paper to determine the threshold in any direction from fixation point of the UFOV with visual task by psychometric curve. The availabilities of the proposed method are examined for accuracy and efficiency by the experiments.
著者
新宮 正弘 江口 清 山海 嘉之
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.76, no.772, pp.3630-3639, 2010
参考文献数
24
被引用文献数
1

Polio survivors with severe limb paralysis cannot move their limbs voluntarily because they have a significantly reduced number of motor neurons due to the poliovirus infection. There is a danger that their ability to control their neuromuscular system, in particular fundamental abilities such as balancing flexors and extensors in the neuromuscular system may decrease dramatically in the long-term. If such polio survivors could improve their ability to balance, it would be possible for them to use the "Robot Suit HAL" wearable movement support device. HAL anticipates its wearer's intended movements through the measurement of bioelectrical signals, and generates assistive torques to support their movements. This study proposes a biofeedback training method using visual information, with the objective of restoring motor functions using HAL. A biofeedback system that feeds-back bioelectrical signals visually was developed, and tested with a polio survivor. The polio survivor was able to adjust the balance of their muscular control through the proposed training method, and voluntary motion was recorded to a paralyzed knee using a single-joint type HAL. These results suggest that polio survivors who have been paralyzed for a long time may improve their ability to control their neuromuscular system by using the proposed training method.
著者
星川 秀利 藤本 浩志
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.69, no.680, pp.1080-1085, 2003-04-25 (Released:2008-02-26)
参考文献数
12

The purpose of this study is to investigate the influence of lower saddle height on the knee joint. Five healthy male pedal at 60 rpm against the work load of 100 and 200 W. Three saddle heights of 80, 90 and 100% of trochanteric leg height are selected in this study. During each trial, the position data of the right lower limb's joints by the video camera and the force data of the right pedal by the force sensor are measured. Using these data, the inverse dynamics analysis is done, and the following results are obtained. The peak link force acting on the knee joint and the peak knee extension moment do not indicate any change over the three saddle heights, however, the angles at their peak values shift to the knee flexion as the lower saddle height. These results indicate that the lower saddle would overload at the knee joint.
著者
藤本 浩志 加藤 一郎
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.61, no.582, pp.641-646, 1995-02-25 (Released:2008-02-26)
参考文献数
8
被引用文献数
1 1

This paper deals with the method of controlling an A/K prosthesis which allows disabled persons to ascend a staircase. Since conventional A/K prostheses are capable of only the function of walking on a level surface, disabled persons wearing conventional A/K prostheses have been compelled to walk on stairs with unnatural posture. The research study of developing powered A/K prostheses has the important themes of not only developing the mechanism of the prosthesis but also devising the controlling method. By measuring the axial forces acting on the socket ; which is the man-machine-interface, during walking, using the six axis force-moment sensor, the torque of a disabled side hip joint was calculated. We devised the control method using this torque as the control signal. Results of clinical walking experiments showed that a subject wearing the A/K prosthesis was able to walk with a joint angle pattern similar to that of unaffected persons. Furthermore, from the results of the inverse dynamics analysis, the subject was found to generate a similar torque pattern and power pattern at his disabled side hip joint. Thus the effectiveness of the controlling method proposed in this study was confirmed.
著者
小出 祐一 中川 正紀 福士 直己 石垣 博邦
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.73, no.725, pp.66-71, 2007-01-25 (Released:2011-03-04)
参考文献数
9
被引用文献数
1

In vibration design, we need to estimate the damping ratio to calculate the dynamic response of a structure. In particular, an estimation of its probability distribution is important to carry out so-called probabilistic design. For this paper, we developed an estimation method using the Bayesian approach to generate the probability distribution of the damping ratio from a vibration test with a small sample size. The Bayesian approach has special significance to engineering design, where available test data is invariably limited, for the approach can systematically incorporate subjective judgments based on experience or indirect information with observed data. We supposed that the probability distribution of the damping ratio has a normal distribution. Therefore, we applied the Bayesian approach to estimate unknown parameters of the distribution. In addition, we compared this method with a method of moments classified as a classical estimation and investigated the influence of sample size by conducting an evaluation test. With the results of our analysis, we came to the following conclusions. First, he true standard deviation of the damping ratio is less than 0.4, and the prior distribution of the standard deviation ranges between 0 and 0.5. (1) The estimated probability distributions determined by the Bayesian approach and the classical approach almost fully agree across more than 40 specimens. (2) The Bayesian approach provides good agreement, less than 10 percent error, with a true standard deviation for approximately 10 specimens. Even though the prior distribution of standard deviation ranges between 0 and 1.0, almost the same accuracy is obtained for approximately 10 specimens.
著者
斉藤 俊 千葉 洋三
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.64, no.623, pp.2389-2394, 1998-07-25 (Released:2008-02-26)
参考文献数
10

Two kinds of road racer bicycles are employed to research vibration characteristics of driving bicycles. After obtaing the natural frequencies and modes by vibration test in the non-driving state, practical driving tests are carried out. The acceleration of vibration in the middle of the handles and under the saddles are measured and the corresponding spectral density functions are calculated based on FFT method. The results show that in the driving bicycles, the dominant frequencies exist between 10 Hz and 50 Hz and the lower two modes in the non-driving state are excited.
著者
中村 友道 廣田 和生 友松 健一 高井 睦夫 岩瀬 敏彦 宇和川 誠一 班目 春樹 岩壺 卓三 齋藤 孝基
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.68, no.668, pp.1064-1072, 2002-04-25 (Released:2008-02-26)
参考文献数
7
被引用文献数
1

A partial but full-size mock-up test of practical steam-generator U-bend tubes in nuclear power plants has been carried out, where the test model has been set in a HFCF-123 fluid two-phase flow loop. U-bend tubes are supported with so-called "Anti-vibration Bars (AVB) ", which have two types of AVBs in Japan, 7-span type and 5-span one. Both types of AVBs have been examined and it is found that tubes with AVB supports shows no large amplitude vibration up to 150% flow rate to the practical condition. Basic data for the fluidelastic instability are obtained when some tubes have been set to be flexible at some contact points with AVBs.
著者
田中 裕久 大石 保徳
出版者
The Japan Society of Mechanical Engineers
雑誌
日本機械学会論文集 C編 (ISSN:03875024)
巻号頁・発行日
vol.65, no.637, pp.3804-3810, 1999

A double cavity half toroidal contimlously variable power transmission transmits input torque through a pair of variable units and changes its speed ratio by controlling attitude angels of four power rollers. One power roller among them is controlled by a hydraulic servomechanism and the others are followed it under the control principle of equal force transmission. Synchronization of four power rollers is guaranteed by safety wires, however nonlinearities of friction force on the control pistons or pressure delay in hydraulic lines due to air mix or pipe length cause instability of the speed ratio servomechanism through the safety wires. This paper focuses the relation between the synchronization and stability of the CVT by making bond graph analyses and experiments, and shows design guidelines on the stabilization of the double cavity half toroidal CVT.
著者
中山 信行 川本 広行
出版者
The Japan Society of Mechanical Engineers
雑誌
日本機械学会論文集 C編 (ISSN:03875024)
巻号頁・発行日
vol.70, no.691, pp.804-811, 2004
被引用文献数
6

Formation of magnetic bead chains in a magnetic field was numerically simulated with the Distinct Element Method in order to apply for improvements of a magnetic brush development system in electrophotography. Simulated chain configurations, length and slant angle. and dynamic chain forming process were compared to the experimental results. The 2-D calculation could not simulate quantitatively well the chain configurations and the process, because the magnetic interaction between beads was under estimated due to the neglect of the interaction force between three-dimensionally distributed beads. On the other hand, 3-D calculation showed good agreement with experiments and it is concluded that 3-D calculation is indispensable for the quantitative evaluation. It was also confirmed that chain configurations were determined approximately to minimize its total potential energy given by the sum of magnetic energy and gravitational energy.
著者
今村 信昭 吉成 聡志 金子 真
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.59, no.564, pp.2395-2400, 1993-08-25 (Released:2008-02-26)
参考文献数
14

A simple torque sensor for a tendon-driven manipulator is proposed. The finger joint torque around a drive pulley is proportional to the tension difference on both ends of the pulley. With a coupling mechanism between tendons, this tension difference can be measured directly without detecting individual tendon tensions. The tension differential-type torque (T.D.T.) sensor is based on this idea and is useful for compensating for friction existing in the transmission system of the manipulator. However, so far, the T.D.T. sensor needs at least one tension pulley to support a driving tendon. This paper shows that it is possible to design a T.D.T. sensor without any tension pulley maintaing its basic principle. A torque sensor installation on the movable link makes it possible to eliminate the tension pulley and downsize it.
著者
章国 光 古荘 純次
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.61, no.592, pp.4687-4695, 1995-12-25 (Released:2008-02-26)
参考文献数
11

Friction in joint driving systems constitutes an important source of nonlinearity that makes it difficult to achieve high-precision control. In this paper, a method of estimating friction is proposed, which requires a joint torque signal, armature current and motor angular velocity. Considering disturbance rejection, a position control method is proposed as follows. Vibration is restrained by bandpass joint torque feedback, and high-precision position control is realized by friction feedforward compensation. Assignment of pole distribution is employed to determine three control coefficients, and the effect of disturbance rejection is compared and evaluated for three kinds of pole distributions. Properties of the proposed control are discussed, and experimental results are also Presented.
著者
橋本 巨 石本 早霧
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.63, no.607, pp.723-731, 1997-03-25 (Released:2008-02-26)
参考文献数
20
被引用文献数
1 1

Elucidation of the vibration mechanism of winged insect from the viewpoint of bionic design might aid in development and design of the driving systems for small- or micro-size actuators, because some flying insects easily overcome scale effects through use of wing vibration and achieve flight with high robustness and speed under conditions of large air viscosity. The aim of this report is to describe a theoretical model of the dynamics of relatively large-size insect wings powered by the direct-flight-muscle and of the dynamics of small-size insect wings powered by the indirect-flight-muscle. Based on morphological consideration of these two types of insect wing dynamics, the equations of motion for the wings are formulated. In the model, the dry friction-type and van der Pol-type forces are employed to power the wings of direct-flight-muscle-type insects, and the periodic impulsive force is assumed to power the wings of indirect-flight-muscle-type insects. Applying the equations of motion to the wings of insects such as dragonflies and flies, the wing vibration is analyzed under various conditions. From the numerical results, the vibration mechanism of two types of flying insects' wings is clarified.
著者
小泉 孝之 辻内 伸好 松原 真己 松山 幸司 相川 将隆 大島 裕子
出版者
The Japan Society of Mechanical Engineers
雑誌
日本機械学会論文集 C編 (ISSN:03875024)
巻号頁・発行日
vol.77, no.777, pp.2018-2029, 2011
被引用文献数
1 4

Structure borne noise is dominant in vehicle interior noise as frequencies below approximately 300Hz. Spindle force is a critical factor in structure borne noise for vehicle interior noise. To research the vibration characteristic of a rolling tire is essential for prediction of spindle force. This paper describes vibration analysis of a tire on the static and operational condition. Firstly, the surface vibration velocities are measured in the operational condition to comprehend the vibration behavior of a rolling tire using the scanning Laser Doppler Vibrometers. Secondly, the tire vibration model based on the cylindrical shell theory is build up. The basic equation, including the effects of the initial tension and the Coriolis force due to rotation, is derived by thin rotating cylindrical shell model and Hamilton principal. The results of the experiment and the theoretical analysis for a rolling tire are presented. Consequently, it is found that same shape of traveling-wave modes occur for a rolling tire, and the excited frequency of forward wave is different from that of backward wave. Finally, it is revealed that whether the rotation effect have affect on the vibration characteristics of a rolling tire.
著者
山口 哲郎 仙波 卓弥
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.73, no.732, pp.2394-2400, 2007-08-25 (Released:2011-03-04)
参考文献数
10
被引用文献数
2

A high-speed microfabrication technique using a focused laser beam was developed. A conventional CAD/CAM system was used, and the beam was scanned mechanically by attaching both optical mirror arrays and a focal lens to the column of an ultraprecision machining center. The measured groove width and pocket depth obtained by grooving and pocket machining were used as the tool diameter and the axial depth of cut, respectively. Glasslike carbon with a laser beam absorptivity of over 80% and a hardness of 650 MHv was employed as a workpiece. It was verified through a machining test that pseudo-3-dimensional concave prisms can be fabricated by digging square pockets with different square sizes but the same pocket depth in the negative Z direction. Shifting the laser's focal point away from the work surface can decrease the depth of the square pocket, so that high-speed roughing by adjusting the focal point on to the work surface and highspeed finishing by shifting the focal point away from the work surface can be conducted.
著者
富岡 隆弘 瀧上 唯夫
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.70, no.696, pp.2419-2426, 2004-08-25 (Released:2011-03-04)
参考文献数
15
被引用文献数
3 2

This paper presents a method to suppress the vertical bending vibration of railway vehicle carbody by using carbody-truck (or bogie) interaction. It is shown from the running test result of an actual Shinkansen vehicle that the bending vibration can greatly be reduced when the rigidity of carbody-truck connecting elements in the longitudinal direction (i.e., rubber bush rigidity of traction links and anti-yaw dampers) Kx is set at the optimum value. The mechanism of the effect to reduce such vibration is analyzed theoretically. As a result, it is found that the truck frames and wheelsets act as dynamic vibration absorbers against the bending vibration of carbody. A formula to adjust Kx to its suitable value is derived. The accuracy and validity of the formula is evaluated numerically.
著者
木村 仁 遠藤 真美 小関 道彦 伊能 教夫
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.74, no.740, pp.806-813, 2008-04-25 (Released:2011-03-04)
参考文献数
17
被引用文献数
1

A phenomenon that passengers are getting sleepy is often found in running cars or trains. If a mechanism can reproduce this phenomenon, it is feasible to put insomnia patients or infants to sleep without any harmful effects. This will bring extreme benefit for insomnia patients or parents of babies. The purpose of this study is to elucidate the sleep-inducing factors of running cars or trains, and the final goal is to develop a machine which reproduces the environment to put people to sleep. For the first step of this study, we investigated the relationship between sleepiness and vibrations on several trains. The sleepability of each train is discussed by the ratio of sleeping passengers. According to the vibration analyses, the results suggest that comfortable vibration for sleep has mainly low-frequency (2 Hz) vibration with particular fluctuation. In addition, it is also guessed that low level jerks contribute the sleepability.