著者

景山 一郎 江本 浩二

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.565-570, 1995-02-25 (Released:2008-02-26)

参考文献数

5

被引用文献数

2 1

---

The shimmy that appears in two-wheeled vehicles has been regarded as a self-exited vibration, but this has yet to be clearly proven. Here, we provide experimental and theoretical analyses based on three experiments. It is found that the shimmy phenomenon can be clearly defined by the experimental analyses. It is impossible for previous theoretical models to describe the shimmy phenomenon. Therefore, we propose a new tire model which includes the dynamics of side force and self-aligning torque. From the results of the theoretical analyses, it is found that the model describes the shimmy phenomena not only qualitatively but also quantitatively. Furthermore we analyze the influence of the design parameters of the tire and their main influences on shimmy. Consequently, it is clarified that cornering stiffness, tire lateral and torsional rigidity, relaxation length of lateral displacement of contact patch, tire lateral damping and moment of inertia around the steering axis all have strong influences on shimmy.

著者

大塚 敏之 石谷 雅宏

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.66, no.652, pp.3962-3969, 2000-12-25 (Released:2008-02-26)

参考文献数

9

被引用文献数

1

---

This study applies differential game theory to simplified four-wheeled vehicle models. We describe the motions of two four-wheeled vehicles on plane as nonlinear systems and formulate receding-horizon differential game problems. Performance indexes of the differential games have a moving performance interval. The game optimal solution (minimax solution) is calculated by applying a real-time algorithm without successive approximation. Numerical results of pursuit-evasion and overtaking are reported and discussed.

著者

奥泉 信克 木村 康治

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.622, pp.1873-1881, 1998-06-25 (Released:2008-02-26)

参考文献数

14

---

Dynamic behavior of smooth hysteretic systems subjected to harmonic excitation is analyzed. Wen's differential equation model for hysteresis, which can be applied to a large class of hysteretic systems, is used. A piecewise power series expression for hysteresis, which was derived from Wen's model assuming a sinusoidal response and weak hysteresis in the previous paper, is extended to the case of the response expressed in terms of constant and higher harmonic components. The method of multiple scales is applied to the equation of motion with the extended piecewise power series terms and the second order approximate solution for the case of primary resonance is obtained. Phase plane trajectories and resonance curves obtained from the solution are compared with the results of numerical simulations and the second order averaging analysis in order to examine the validity of the present analysis.

著者

内山 寛信 櫛谷 義治 楠見 昌隆

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.612, pp.2731-2738, 1997-08-25 (Released:2008-02-26)

参考文献数

6

被引用文献数

1

---

As one of the manufacturing processes in the apparel industry, a fabric roll has to spread a piece of cloth smoothly on the working table in order to cut the cloth into parts. In this process, it is important to prevent creasing by adjusting the spreading speed of the cloth. However, the construction of a speed control system is difficult, because the tension acting on the spread cloth cannot be estimated. Accordingly, the shape of a hanging cloth-belt in the cloth spreading machine is determined by a estimated curve based on the catenary function. The coefficients of the curve are calculated by detecting the displacement of a representative point on the doth-belt. Using this estimated curve. the tension can be measured with a high accuracy without touching the cloth. In this paper. the accuracy of the calculated values by the estimated cloth curve and the dynamic behavior of the cloth-belt are discussed. A new speed control system with the estimation mechanism of tension was proposed, and good performance was confirmed.

著者

那須野 洋 清水 信行

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.724, pp.3728-3735, 2006-12-25 (Released:2011-08-16)

参考文献数

21

---

This paper is concerned with the development of an efficient algorithm for the numerical solution of the fractional differential equation (FDE). The numerical integration of the FDE requires significant computational cost, because the fractional convolution integral included in the fractional derivative, requires O(N2) operations for N points calculation. The kernel of the fractional integral has singularity and consequently excessive small time-step near the singularity is needed to secure the high precision in the numerical calculation. This difficulty is solved by means of a new computational procedure for fractional derivative by introducing the variable trasformation from the physical time to the power time which is newly defined in this paper. The proposed algorithm is used to solved the nonlinear FDE. Computational results are compared with those by the former method (Nasuno and Shimizu, JSME (C), 2006). The proposed method shows remarkably higher performance than the former one.

著者

那須野 洋 清水 信行 安野 拓也

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.1041-1048, 2006-04-25 (Released:2011-03-04)

参考文献数

9

被引用文献数

3 2

---

The experimantal study has been conducted for several years to investigate the nonlinear psudo-statical and dynamical behaviors of a viscoelastic body described by the fractional derivative law. Pre-stress due to pre-displacement induces higer damping capacity during sinusoidal excitation. In order to understand this behavior, nonlinear statical and dynamical models are considered. The authors establish and propose the appropriate models to describe the behavior of the fractional derivative viscoelastic body. The nonlinearity having second order term with respect to pre-displacement for pseudo-statical compressive displacement and the nonlinearity having exponential term with respect to pre-displacement for sinusoidal excitation are found to be appropriate to describe the viscoelastic damping coefficients. Some discussions on the values of the viscoelastic damping coefficients and how to model a unified force-displacement relation covering from lower to higher wide frequency range are given.

著者

丸茂 喜高 片山 硬

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.704, pp.1247-1253, 2005-04-25 (Released:2011-03-04)

参考文献数

5

被引用文献数

2 1

---

This study proposes an improved method for stabilizing straight running of two-wheeled vehicles. An analysis of the two-wheeled vehicle's vibration modes was completed using the Energy Flow Method, which calculates energy flow of external forces in each motion. Based on these results, we examined the control using steering torque as the control input. Controlling steering torque with rolling acceleration feedback increases wobble and weave mode stabilities. Wobble mode stability is increased by the external force concerning rolling motion. Weave mode stability is also increased by the phase lead of front tire side force in yawing motion. Using another variable as a feedback control signal, for example controlling steering torque with yaw rate feedback, increases only one mode's stability and destabilizes the other mode.

著者

細川 健治 佐藤 悠有 坂田 敏行

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.690, pp.440-444, 2004-02-25 (Released:2011-03-04)

参考文献数

7

---

The elastic parameters of skis are essential for simulation on skiing. Generally, the elastic parameters of skis have not been reported. Also, the elastic parameters of skis are difficult to determine by either theoretical and experimental approach. Therefore, an inverse analysis method to identify equivalent elastic parameters of skis is very important. In the identification method, mainly, the experimental modal analysis technique, the finite element method and the sensitivity analysis method are used. First, by applying the experimental modal analysis technique to a ski with free boundary conditions, natural frequencies and mode shapes are obtained. Secondly, from the obtained natural frequencies and mode shapes, the equivalent elastic parameters of the ski are identified numerically. Finally, to justify the application of this approach, the bending stiffness and twisting stiffness in longitudinal direction calculated by the obtained equivalent elastic parameters of the ski are compared with those obtained by the other experimental method.

著者

章 国光 武居 直行 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.65, no.636, pp.3226-3233, 1999-08-25 (Released:2008-02-26)

参考文献数

12

---

Flexibility in joint drive systems causes robot arm vibration. The conventional semi closed-loop control cannot provide a high servo stiffness and large bandwidth for industrial robots. To achieve a high speed and high precision control, it is important to reduce vibration of robot arm and effect of disturbance. For this purpose, state feedback control becomes more and more important in practice. In this paper, we present an analysis and design of state feedback control for two-inertia system. From the viewpoints of non-negative positional stiffness and internal feedback construction, the domain of pole assignment is analyzed. The effect of disturbance is compared and evaluated for three optimum pole assignments, and the worst case of disturbance is also introduced. It is shown that choice and design of optimum pole assignment are very important when considering the effect of disturbance.

著者

大山 忠夫 内田 清五

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.60, no.574, pp.2096-2102, 1994-06-25 (Released:2008-02-26)

参考文献数

6

被引用文献数

2 3

---

In order to investigate the behavior of adhesion force from a microslip region to a gross sliding one, we carried out experimental studies mainly under water lubrication with static and dynamic contact loads. Every repeated experiment up to gross sliding showed a decrease in the adhesion coefficient under water lubrication and the traction force in the gross sliding region showed unstable behavior. Furthermore, it was recognized that the measured adhesion force during gross sliding agreed well with the values calculated with sliding acceleration and moment of inertia of rollers. The adhesion force under dynamic load was less than that under static load.

著者

能島 裕介 小島 史男 久保田 直行

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.671, pp.2067-2073, 2002-07-25 (Released:2008-02-26)

参考文献数

16

被引用文献数

3 3

---

This paper is concerned with behavior acquisition of mobile robots based on multi-objective behavior coordination. Based on the concept of structured intelligence, the intelligence of a robot emerges from the interaction among simple functional mechanisms. The multio-bjective behavior coordination plays a role in integrating behavioral modules. A behavioral weight is assigned to each behavioral module represented by a fuzzy controller. To situate its action to the facing environment, the robot dynamically updates behavioral weights according to spatio-temporal context of the environment. The purpose of this paper is to discuss the effectiveness of the multi-objective behavior coordination through the behavior acquisition from the viewpoint of the structured intelligence.

著者

小松崎 俊彦 畑中 健介 岩田 佳雄

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.737, pp.75-82, 2008-01-25 (Released:2011-03-04)

参考文献数

14

被引用文献数

3 3

---

Recent advances in digital signal processors have facilitated the development of active noise control (ANC) technology where the various kinds of researches as well as applications have been studied. In general, the sound waves propagate spherically in three dimensional space. Simply constituting SISO system using ordinary loudspeaker as a control source may cause interfered sound field with both attenuated and amplified nodes exist. By placing number of microphones and control sources can improve the range of quiet zone and many researches have been dedicated to this end, yet still limitations on implementation and cost cannot be neglected. On the other hand, the recent development of high-directional loudspeakers based on new sound production theory known as 'parametric array effect' has allowed sound transmission to a narrow range of acoustic space like 'spotlight'. This peculiar characteristic can be implemented as one measure for improving active noise control scheme controlling acoustic field locally without adversely influencing vicinal space. In the present study, a new approach for active control of sound in free space is developed using high directional parametric loudspeaker as a control source. Experiments are performed for the active control of noise generated by single source located in space, where the noise is attenuated by a control source at error microphone which evaluates sound level. Both normal and the parametric loudspeakers are tested as control sources and results are compared based on measurement of interfered sound field around the evaluation point. It is known that the suggested ANC system can mitigate sound locally but cause less influence on sound field in circumferential space.

著者

小椋 優 林 憲玉 高西 淳夫

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.700, pp.3509-3515, 2004-12-25 (Released:2011-03-04)

参考文献数

12

被引用文献数

2 4

---

This paper describes a knee stretch walking for the biped robot having three degrees of freedom (DOF) in each ankle, one DOF in each knee, three DOF in each hip and two DOF in the waist. Firstly, the initial parameters, foot and waist trajectories and a knee joint trajectory of the supporting leg, are given. Secondly, the motion pattern of the swing leg is generated by inverse kinematics. Finally, the roll motion of the waist is used to avoid the singularity of the swing leg. Also, a compensatory motion algorithm is discussed in this paper, which cancels moments generated by the motion of the legs. Through stretch walking simulations, the effectiveness of the stretch walking pattern generation method is confirmed.

著者

清水 哲雄 小松 治男 馬田 俊雄 高橋 清 佐藤 正矩

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.2348-2353, 1998-07-25 (Released:2008-02-26)

参考文献数

3

被引用文献数

1

---

Understanding the spinning mechanism of an impacted golfball is an important factor in golf science and engineering. The rigid sphere model which considers the Coulomb-type slip friction presented independently by Daish and Kawamura (referred to here as the Daish-Kawamura model) seems to well explain the experimental results of golfball spinning. For a more general interpretation of the spin phenomenon, we attempted to modify this model by introducing a physical quantity called the "s parameter", which is defined as the ratio of the circumferential velocity of the ball to its centroid velocity. An experiment performed to verify the appropriateness of the new parameter introduction led to the following conclusions: The spin phenomenon in golf impact can be divided into two phases, in both of which the Daish-Kawamura model is effective. A method is described to evaluate the coefficient of slip friction under high sliding velocities, and the value is estimated as 0.07 for a slippery surface condition.

著者

伊坂 忠夫 Robert J. GREGOR 川村 貞夫

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.64, no.623, pp.2429-2436, 1998-07-25 (Released:2008-02-26)

参考文献数

20

被引用文献数

1 4

---

The purpose of this study is to derive the reasonable lifting movement from analysis of biomechanical characteristics of the snatch, back lift (BL) and leg lift (LL) in a skilled weightlifter. During the snatch lift, the differences between skilled and unskilled lifter appear in EMG and joint torque patterns. The skilled lifter utilizes the double knee bend technique and motor unit recruitment patterns in agonist and antagonist about joint might be reasonable to lift heavy weight. The present data suggest that skilled weightlifter has acquired the higher neuromuscular performance, which is required the control among the recruited muscles with regard to the tension and the timing of the coactivation and the contraction-relaxation. From comparison of BL and LL, it is suggested that BL has higher EMG activity and produces a much higher shear force about L 5/Sl joint which induces a low back injury. In case of LL, the shear force about L 5-Sl joint depends on the lifting posture. Moreover, it is revealed that the skilled weightlifter might have a lower shear force than unskilled person. From the experimental results, it is shown that the detailed instruction about lifting posture is needed to reduce the incidence of low back injury.

著者

石橋 彰 園田 計二 前之園 好爾

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.62, no.594, pp.721-728, 1996-02-25 (Released:2008-02-26)

参考文献数

8

被引用文献数

2 1

---

This paper derives new equations for calculating the efficiencies of differential gear drives using simple laws based on mechanics, When the new equations are used, the efficiency for speed reduction is lower than that for speed increase, in most cases. This is completely opposite to the case of the results obtained from the earlier equations. The reason for this is clearly shown by analyzing the power flows used for deriving the equations. It is found that the power flows used for deriving the earlier equations do not satisfy the boundary conditions due to an assumption which is unconsciously introduced in the process of deriving the equations. Numerical calculations are conducted and differences in the efficiencies are shown in the case of representative differential gear drives.

著者

水野 雅彦 酒井 英樹 大山 鋼造 磯村 吉高

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.711, pp.3208-3215, 2005-11-25 (Released:2011-03-04)

参考文献数

5

被引用文献数

2

---

The results of vehicle performance tests often vary depending on differences in the road surface temperature. It is believed that these changes can partially be attributed to the effect of tire surface temperature. The aim of this study is to develop a tire force model considering the dependence of tire surface temperature. The newly developed tire model is composed of two functions, the thermodynamic function that allows us to consider changes in the tire surface temperature and the force function that allows for the effects of tire surface temperature. The parameters of this model are identified using the measured data obtained with an indoor test facility. To prove the validity of the developed model, the surface temperature and the tire force values are predicted using this model. The simulation results agreed rather well with the experimental results.

著者

中川 智皓 竹原 昭一郎 須田 義大

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.75, no.749, pp.74-80, 2009-01-25 (Released:2017-06-09)

参考文献数

12

被引用文献数

4 2

---

In this research, the dynamic characteristics of a small wheel bicycle are investigated. The bicycle model is formulated by using multibody dynamics. Then, the stability of bicycles is analyzed by parametric study using the bicycle model. The effects of the parameters of tire diameter and head angle are examined by focusing on a small wheel bicycle. The straight-ahead stability and upstanding stability are evaluated at each parameter. The results show the tendency of stability at each parameter and the influential parameter to the small wheel bicycle is found. The driving experiment using the small wheel bicycle is performed. In the experiment, the stability of the small wheel bicycles with variable head angle is evaluated by the subjects. It is confirmed that varying head angle increases the stability of the small wheel bicycle. The results are corresponding with the simulation results and it is shown that the simulation captures the tendency of the stability and expresses the characteristics of the small wheel bicycle.

著者

原 敬 横川 隆一 甲斐 義弘

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.618, pp.604-609, 1998-02-25 (Released:2008-02-26)

参考文献数

12

被引用文献数

1 1

---

The purpose of this paper is to present a graphical method for evaluating task performance of a manipulator for a planar peg-in-hole assembly task. The manipulator has three revolute joints, including a compliant element, and performs the task in a plane. Further, an RCC (Remote Center Compliance) is mounted on the end-point of the manipulator. First, a force condition to avoid jamming on the chamfer is derived. A stiffness condition at the compliance center of the RCC is then obtained from the force condition. Under the stiffness condition, the manipulator can avoid the jamming on the chamfer. Second, a graphical method is proposed on the basis of the stiffness condition and a DMA (Dexterity Measure for Assembly) that was previously derived by the authors. Third, the method allows us to evaluate the task-performance of a manipulator (e.g. PUMA 560). Finally, the evaluation results show that the stiffness condition for avoidance of jamming on the chamfer is important in evaluating task-performance of a manipulator for a peg in-hole task.

著者

城越 教夫 日高 照晃

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.624, pp.3120-3127, 1998-08-25 (Released:2008-02-26)

参考文献数

5

被引用文献数

1 1

---

It is necessary to reduce gearing backlashes and bearing clearances at planet gears for the sake of minimizing the backlash of the planetary gear system for factory automation uses. However, the reducing backlash would further cause improper load distribution to each planet gear, and it would usually not be easy to keep smooth rotation of planetary gear system. To solve this problem this study experimentally investigated the influence of eccentricity of planet gears and the assembling condition on the load distribution of planet gears and the transmission error. It has revealed that there is each appropriate method to obtain better load distribution or smaller transmission error, respectively.