著者

平光 陽一 渡邊 武 西村 尚哉 村瀬 勝彦

出版者

一般社団法人 日本機械学会

雑誌

東海支部総会講演会講演論文集 2012.61 (ISSN:24242748)

巻号頁・発行日

pp._607-1_-_607-2_, 2012-03-15 (Released:2017-06-19)

著者

山根 清美 湯浅 皓太 伊藤 孝起 小砂 匡 竹村 幾史

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

pp.22-00198, (Released:2022-11-28)

参考文献数

10

---

We propose a method for solving differential equations implicitly using iterative calculations in spreadsheet software. This method uses difference equations by discretizing the coordinates of the independent variables with cells of spreadsheet for analysis. Thus, the equations are embedded in the cells performing substitution of grid point. In addition, the embedded equations are solved by Newton’s method, and the iterative function of the spreadsheet software is used in the calculation. This method can be applied even when the differential equation is discretized by an implicit solution method. Therefore, it can be applied to ordinary and partial differential equations of different types. The advantages of discretization using the implicit method (high computational accuracy, large time increments) are also presented in this paper. The analysis procedure is almost the same regardless of the type of equation. In this paper, as an example, a simple differential equation was analyzed using Microsoft Excel, a typical spreadsheet software, to illustrate the method. The results are also shown by the analysis of the gas lubrication equation.

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

木船 紘爾

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌 (ISSN:24242675)

巻号頁・発行日

vol.93, no.860, pp.611, 1990-07-05 (Released:2017-06-21)

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

福井 貴大 松川 宗一郎 福岡 泰宏

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 (ISSN:21879761)

巻号頁・発行日

vol.85, no.870, pp.18-00360, 2019 (Released:2019-02-25)

参考文献数

57

---

This study aims to suggest a method for achieving an autonomous gait transition according to speed for a four-legged robot pacing at medium speeds. Our quadruped robot is simply designed and applies a central pattern generator (CPG) for each leg. Each leg is controlled by a PD controller based on a rhythmic output from the CPG. The four CPGs are coupled, and a hard-wired CPG network is constructed to generate a default pace pattern. In addition, we apply feedback of the body tilt to the CPG as vestibular sensory feedback. As a result, our robot safely locomotes at various speeds by autonomously changing the gait from walking to pacing to rotary galloping according to speed, despite the fact that the walk and rotary gallop are not predefined. A factor that causes the gaits' emergence is considered the body oscillation that changes according to the speed. The body oscillation exhibits a double peak per leg frequency at low speeds, no peak at medium speeds, and a single peak at high speeds. The phase differences between the four legs are adjusted according to the body oscillation by feeding the body tilt back to the CPG. The gait transition is triggered only by the body tilt angle, we expect that the suggested method can be generally used for quadruped robots.

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

池田 健

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌 (ISSN:24242675)

巻号頁・発行日

vol.70, no.585, pp.1529-1537, 1967-10-05 (Released:2017-06-21)

著者

古賀 達蔵

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.46, no.411, pp.1280-1289, 1980-11-25 (Released:2008-02-21)

参考文献数

6

被引用文献数

2 3

---

周方向に閉じた薄肉弾性円筒かくについて, 古典かく理論の自由振動方程式および境界条件式から, 系統的な近似によって最小固有振動数を求める実用的な近似式を導く. 4)のとおりの境界条件の組合わせを検討し, 軸方向面内拘束条件のいかんによって五つの異なった特性方程式で分類されることを明らかにする. 一つは不伸長振動解を与え, ほかは軸線素ばりのたわみ振動の特性方程式と一致する.

著者

田原 誠 鈴木 智 野波 健蔵

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集C編 (ISSN:18848354)

巻号頁・発行日

vol.77, no.781, pp.3386-3397, 2011 (Released:2011-09-25)

参考文献数

19

被引用文献数

1

---

The attitude sensor mounted on unmanned systems is required high accuracy attitude under the dynamic acceleration environment for the autonomous attitude control. In order to estimate attitude by using a quaternion based on extended Kalman filter (EKF) , the attitude sensor detects a direction of the gravity by using a tri-axis accelerometer. However, accelerometers are usually sensitive to both the gravity and dynamic accelerations. In this paper, the dynamic accelerations are dealt with explicitly, and two types of algorithms are proposed. In the first approach, measured accelerations are filtered, and divided into the gravity and dynamic accelerations. Using only the gravity, EKF estimates high accuracy of attitude. This algorithm can be realized with relatively small amount of computation, and have a good effect under the short dynamic acceleration environment. The second approach demonstrates adequate performance with EKF which includes the dynamical model of accelerations. This paper shows a critical comparison of attitude estimation algorithms under the dynamic acceleration environment for the autonomous control of unmanned systems.

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

西川 一男 古川 浩二 河手 功 農沢 隆秀 辻 敏夫

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 (ISSN:21879761)

巻号頁・発行日

vol.80, no.816, pp.BMS0247, 2014 (Released:2014-08-25)

参考文献数

8

被引用文献数

1

---

In the study reported here, the operational characteristics of a human-gearshift lever system were experimentally analyzed in consideration of the mechanical properties of the human arm and related effects on muscle activity. The results highlighted three points in particular: (1) It is possible to determine positioning that facilitates operation as well as the operational direction of the gearshift lever based on force manipulability in consideration of human joint-torque characteristics; (2) subjects feel that handling is easier when arm muscle activities in push and pull operations are almost equal during translational lever movement; and (3) the gearshift lever operation speed and the force-stroke characteristics have a very significant effect on whether operation is favorable or poor. Comprehensive consideration of these results is expected to be useful in the design of a human-vehicle gearshift lever system.

著者

山形 与志樹 中村 仁也

出版者

一般社団法人 日本機械学会

雑誌

計算力学講演会講演論文集 2004.17 (ISSN:24242799)

巻号頁・発行日

pp.659-660, 2004-11-17 (Released:2017-06-19)

著者

酒井 英樹

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.82, no.843, pp.16-00314, 2016 (Released:2016-11-25)

参考文献数

15

---

The roll motion of the vehicle has an effect on the yaw natural frequency. Because the yaw natural frequency formula considering this effect is the solution to a quartic equation, the expression of the formula is thought to be complex and incomprehensible. Accordingly, a seemingly comprehensible approximate formula was suggested in the former paper. In this approximation process, it was assumed that the cornering forces of the front and rear wheels are generated simultaneously. On the other hand, a later report have indicated that the yaw resonance when the vehicle drives at a certain speed has a cornering forces phase difference of 90 degrees between the front and rear wheels. Therefore this paper formulates the yaw natural frequency and yaw damping ratio assuming the phase difference to be 90 degrees. As results of that, qualitatively, the design variables that dominate the characteristic equation are appropriately included in the yaw natural frequency and yaw damping ratio formulas, and quantitatively, the approximation error is reduced. Consequently, these formulas are believed to be more appropriate than the previously proposed formulas. These formulas indicate that, when the load distribution ratio of the front wheels becomes larger, the yaw natural frequency decreases and the yaw damping ratio increases. In addition, this paper also indicates the scope of these approximate formulas quantitatively.

著者

河原 遼太 小河原 加久治 新銀 秀徳

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.86, no.887, pp.19-00429, 2020 (Released:2020-07-25)

参考文献数

15

---

This paper proposes a method of airspeed measurement using ultrasonic waves for control of micro UAVs. Measurement by pitot tube sensor generally used for aircraft control does not show high resolution and responsiveness in low speed flight. The proposed method employs the phase difference method to overcome the drawback of low resolution in the measurement. The efficiency of this method is demonstrated through flight experiments to estimate the angle of attack and the angle of side slip of a micro UAV from measured airspeed.

著者

陳 俊百 倉鋪 圭太 大塚 真生 吉灘 裕

出版者

一般社団法人 日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集 2016 (ISSN:24243124)

巻号頁・発行日

pp.1A1-08a6, 2016 (Released:2017-06-19)

被引用文献数

1 1

---

Autonomous mobile robots have been an active research recently. Although laser range finder based navigation is known to work well in limited environment, expanding 3D geometric maps used in those methods to worldwide requires great effort. The same is true of maintaining them up-to-date. For this reason, we develop a visual navigation method using a topological map to reduce prior information and enhance scalability of the map. Topological maps only contain information about impressive places (i.e. intersections) and their linkage with roads. In the topological approach, the robot conducts three primal tasks: 1) road following between impressive places, 2) recognizing impressive places, and 3) taking action at impressive places (e. g., road selection). This paper proposes a visual place recognition method based on GIST descriptor and Support Vector Machine. The proposed method is evaluated at 13 point in outdoor walkways under several situations. As the result, the proposed method could identify all of 13 recognition points.

著者

秋山 悟

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌 (ISSN:24242675)

巻号頁・発行日

vol.111, no.1075, pp.468-469, 2008-06-05 (Released:2017-06-21)

被引用文献数

2 2

著者

秋山 悟

出版者

一般社団法人 日本機械学会

雑誌

交通・物流部門大会講演論文集 2009.18 (ISSN:24243175)

巻号頁・発行日

pp.53-56, 2009-12-02 (Released:2017-06-19)

被引用文献数

3 3