著者

下嶋 浩

出版者

東京工業大学

巻号頁・発行日

1972

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博士論文

著者

下嶋 浩平 小川 諭志 内藤 裕貴 Milton Orlando Valencia 清水 庸 細井、 文樹 宇賀 優作 石谷 学 Michael Gomez Selvaraj 大政 謙次

出版者

生態工学会

雑誌

Eco-Engineering (ISSN:13470485)

巻号頁・発行日

vol.29, no.1, pp.11-16, 2017-01-31 (Released:2017-02-01)

参考文献数

15

---

Remote sensing technology for monitoring plant trains has a huge potential to accelerate breeding process. In this paper, we have studied on remote sensing of using an unmanned aerial vehicle (UAV) system for plant traits phenotyping in rice. The images of rice canopy were taken by a RGB camera from the UAV at three growing stages; Vegetative (VG), Flowering (FW) and Grain filling (GF). Typical color indices (r, g, b, INT, VIG, L*, a*, b*, H) were calculated by image processing. Single regression analysis was conducted between rice plant traits (leaf area index (LAI), grain yield, above ground biomass, plant height, panicle length, grain filling rate, tiller number) and color indices. The index a* at FW and GF had close liner relationships with LAI (the coefficient of determination R2 > 0.70) and grain yield (R2 > 0.50). Moreover, a* and g at FW and GF showed high R2 with plant height and grain filling rate (R2 > 0.50). The R2 between grain yield and color indices increased above 0.5 for about 40% of models at three growing stages by multiple regression analysis. In particular, the models of H and INT and of H and L* at VG were closely related (R2 > 0.70). Our findings show the analysis of color images taken by UAV remote sensing is useful to assessing four rice traits; LAI, grain yield, plant height and grain filling rate at early stage, and especially more available for grain yield estimation.

著者

梶原 逸朗 山家 勝裕 下嶋 浩

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.626, pp.3839-3846, 1998-10-25

参考文献数

9

被引用文献数

1

---

Dynamics of multi-link manipulators are highly nonlinear and depend on the time varying configuration. This paper presents a method of gain scheduling which consists in designing an linear time invariant (LTI) controller for each operating point and in switching controller when the operating conditions change. Each LTI controller is designed based on LMI approach in which an optimization problem is defined as a mixed H_2/H_∞ control problem with pole placement. The performances of the force and the position controls are defined by the H_2 norm, and the robust stability according to gain scheduling is evaluated with the H_∞ norm and the pole placement of the closed-loop system. The effectiveness and the practicability of the proposed method are verified by both simulations and experiments with 2-link manipulator system.

著者

小池 関也 山家 勝裕 下嶋 浩

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.2094-2101, 1998-06

参考文献数

15

---

A hybrid control method for a flexible manipulator based on an angular velocity control is presented, which is applicable to curved constraint surfaces. The error of contact force is converted into a velocity vector according to the force/velocity conversion law which consideres both force respose characteristics and variational angular velocity with respect to normal direction of the surface. The velocity vector which is tangent to the constraint surface is calculated using the velocity control law. The desired velocity vector is obtained as a sum of the above two velocity vectors, and is converted into angular velocity vectors. A vibration control law is proposed to reduce overshoot of end point velocity response. The desired angular velocity vector is obtained as a sum of the above angular velocity vector and vibration control term. Motion and force controls without calculating inverse dynamics is performed using DC motors whose desired values are equal to the above desired angular velocity vectors. Computer simulations and experimental analyses are carried out to clarify the validity of the proposed method.

著者

下嶋 浩 松永 義弘 小池 関也 梶原 逸朗

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.633, pp.1849-1856, 1999-05

参考文献数

7

被引用文献数

2

---

An approach for feedback active noise control of a one dimensional duct with multiple control sources based on modal analysis is presented in this paper. Based on experimental modal analysis, the modal parameters of an acoustical system are derived from measured multiple frequency response functions. The state equation of the duct is described by the identified modal parameters. Considering eigenvectors of the acoustical system calculated by finite element method, control sources are located to the duct. A feedback active noise controller is designed based on mixed H_2/H_∞ problem in addition to H_∞ problem, preventing the increase in dimensions of the controllers. Simulations are carried out using the designed controllers. Moreover experiments are carried out using identified controllers based on modal analysis to reduce dimensions of the controllers. The desired performances are obtained by the presented approach.

著者

雉本 信哉 下嶋 浩 柴原 章宏

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.62, no.596, pp.1397-1402, 1996-04-25

参考文献数

10

被引用文献数

1

---

A new adaptive control algorithm in the frequency domain was proposed. This frequency domain approach is an alternative to the ordinary filtered-x least mean squares (LMS) algorithm in the time domain. A transfer characteristic of an acoustic path is identified adaptively in the frequency domain using the fast Fourier transform (FFT). The real-time control of the noise reduction in an L-formed duct model was carried out. A digital signal processor and a personal computer were used for the active noise control. The maximum noise reduction level of about 30 dB and the average reduction level of about 7 dB were obtained through the experiment. As a result, it was shown that this frequency domain adaptive algorithm has faster convergence compared to the ordinary filtered-x LMS algorithm.

著者

小池 関也 下嶋 浩

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.575, pp.p2323-2330, 1994-07

被引用文献数

2

---

This paper presents a simple hybrid method for controlling both the motion and contact force of a manipulator without calculating inverse dynamics. The contact force is converted into a velocity vector according to the force/velocity conversion law. The velocity vector which is tangent to the constraint surface is calculated by the velocity servo. The desired velocity vecotor is obtained as a sum of the above two velocity vectors. The desired axial velocity vector is calculated from the desired velocity vector using inverse Jacobian matrix. Motion and force control is performed using DC motors whose desired values are the above desired axial velocity vector. The stability of the motion control system is also considered.

著者

下嶋 浩 雉本 信哉 佐藤 治 前田 秀 斎藤 敦

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.562, pp.p1803-1808, 1993-06

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Motions of human arms are analyzed kinetically and kinematically with respect to smoothness. A kinematic arm model with 6 degrees of freedom is suggested and spatial motions are simulated considering the sum of the weighted square of joint displacements, which approximately equals kinetic energy of the whole arm. A low-pass filter is applied for smoothing the kinetic state variables, i. e. , displacement, velocity, and acceleration, and the smoothing transfomation is optimized from the aspect of characteristics of response and vibration. Such transformation is also applied to the human arm model, and the effects are investigated through simulations.

著者

小池 関也 小林 優揮 飯田 裕 下嶋 浩

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.67, no.654, pp.321-328, 2001-02-25

参考文献数

10

被引用文献数

2

---

This paper proposes an active noise controller applicable to a moving evaluation point in one dimensional acoustic field. A combined adaptive feedforward/feedback controller based on filtered-x LMS algorithm is proposed. The feedforward controller is utilized for the noise reduction, and the feedback controller is utilized for the reduction of howling, which occurs with use of acoustic reference signal at feedforward controller. For the sake of stable noise control under moving evaluation point, necessity for a real time identificator of transfer function of the error path, which uses a microphone fixed in the neighborhood of the control speaker, is shown. Stable noise reduction without howling is realized by using above combined controller and the real time identificator with use of acoustic reference signal aiming practical use. A straight duct is chosen as a one dimensional acoustic field. Computer simulations and experimental analyses are carried out to clarify the validity of the proposed controller.

著者

小池 関也 下嶋 浩 山家 勝裕

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.590, pp.3999-4006, 1995-10-25

参考文献数

16

被引用文献数

1

---

A simple method is presented for controlling the motion and gripping force in dual flexible manipulators without calculating inverse dynamics. The gripping force is converted into a velocity vector according to the proposed force/velocity conversion law considering the flexibility of the manipulator. The velocity vector of contact point is calculated from the velocity of the object. The desired velocity vector is obtained as a sum of the above two velocity vectors, and is converted into angular velocity vector considering defectional velocity of the flexible links. The desired angular velocity vector is obtained as a sum of the above angular velocity vector and strain feedback term. Coordinative control is performed using DC motors whose desired values are equal to the above desired angular velocity vector. The characteristics of gripping force response of control system is also considered. Computer simulations and experimental analyses are carried out to clarify the validity of the proposed method.

著者

丸山 剛生 柴山 憲文 竹内 博之 下嶋 浩 中原 凱文

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.616, pp.4224-4230, 1997-12-25

参考文献数

11

---

Equipment to measure the surface hardness of the human body has been designed for the purpose of estimating muscle generating force from the physiological view point. The surface hardness is defined as the reaction force of the body surface under predetermined thrust displacement. The sensor described here is suitable for analysis of human motion and multipoint measurements because of its compactness. From the results of experiments on elbow joints, a relationship was found between the measured hardness and the joint torque. The results also showed that body surface hardness was a function of the joint angle. Moreover, it was shown that muscle forces could be estimated by a neural network when the hardness and joint angle were given.

著者

小池 関也 小林 優揮 飯田 裕 下嶋 浩

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 = Transactions of the Japan Society of Mechanical Engineers. C (ISSN:03875024)

巻号頁・発行日

vol.67, no.660, pp.2521-2527, 2001-08-25

参考文献数

13

被引用文献数

2

---

A basic noise control system applicable to a moving evaluation point was proposed in the previous report, and its effectiveness was examined numerically and experimentally. Although the results showed that the proposed system is effective, it can only handle the case of slow evaluation point velocity. This restriction seemed to be due to the slow convergent speed of the adaptive filter. In this paper the cause of restriction is examined in detail, and an advanced control system is proposed. The features of the proposed system are as follows : 1) Improved feedback controller where main filter is less affected by the movement of the evaluation point. 2) Introduction of IIR filter together with the learning identification method to the error path identifier. The new system is examined both in simulation and experiment and shows great improvement compared with the basic model.

著者

佐藤 治 下嶋 浩 李 丁 長友 聖二

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.60, no.572, pp.p1344-1350, 1994-04

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Equations of motion of a closed-type manipulator are derived in consideration of characteristics of the step motors. Vibration control is achieved using two types of forcing functions. The first is the function of the pulse width modulation to avoid exciting resonance, and the second is the bang-bang control function on each step function. Dynamic characteristics of the system controlled by these method are analyzed theoretically and investigated experimentally.

著者

雉本 信哉 下嶋 浩

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.598, pp.2272-2277, 1996-06-25

参考文献数

7

---

In active noise control, the transfer characteristic of an acoustic feedback path has a considerable influence on the stability of the control system. When the acoustic system has a feedback path, the control system often causes unstable behavior called howling. An adaptive howling canceler designed to prevent thin howling is studied in this paper. This adaptive howling canceler estimates the acoustic feedback path and acts to suppress the howling. In this paper, the effect of this adaptive howling canceler was considered for two different adaptive noise control algorithms. One was the conventional filtered-x LMS (least mean squares) algorithm and the other was the frequency-domain adaptive algorithm proposed by the authors. From computer simulations, it was shown that the howling canceler works effectively with the filtered-x LMS algorithm. On the other hand, the control system became unstable with the frequency-domain adaptive algorithm. To alleviate this unstable behavior, variable output gain was considered. A good result was obtained with this variable gain.

著者

小池 関也 下嶋 浩 榎本 明夫

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.61, no.583, pp.1064-1071, 1995-03-25

参考文献数

16

---

This paper presents a simple method for controlling both the motion and contact force of a flexible manipulator without calculating inverse dynamics. The contact force is converted into a velocity vector according to the proposed force/velocity conversion law considering the flexibility of the manipulator. The velocity vector which is tangent to the constraint surface is calculated using velocity control law. The desired velocity vector is obtained as a sum of the above two velocity vectors, and is converted into angular velocity vectors considering deflectional velocity of the flexible links. The desired angular velocity vector is obtained as a sum of the above angular velocity vector and strain feedback term. Motion and force control is performed using DC motors whose desired values are the above desired angular velocity vectors. Computer simulations and experimental analyses are carried out to clarify the validity of the proposed method.

著者

雉本 信哉 下嶋 浩 田窪 崇行

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.60, no.571, pp.p850-855, 1994-03

被引用文献数

1

---

An approach for active noise control using structural vibration was proposed. No acoustic instruments such as loud speakers and microphones are necessary in this approach. The adaptive FIR filter using the LMS algorithm was used in the control system. Both a computer simulation and an experiment were carried out. The importance of using a howling canceler with the adaptive FIR filter was shown by the simulation. In the experiment, the vibration of the sidewalls of the duct was used for control. Good results were acquired using the simple controller.

著者

梶原 逸朗 福田 将直 下嶋 浩

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.621, pp.1668-1675, 1998-05

参考文献数

5

被引用文献数

5

---

Approach for modeling and feedback noise control of a one-dimensional duct based on experimental modal analysis and LMI is presented in this paper. The modal parameters of a coupled acoustical-structural system are derived from measured noise and vibration data. The state equation of the duct is described by the identified modal parameters. An active noise controller is designed based on LMI approach in which an optimization problem is defined as a mixed H_2/H_∞ control problem. The performances of the noise reduction and the robust stability are described with H_2 and H_∞ norms of the closed loop system, respectively. Frequency response shaping is performed by the presented approach with weighted modal matrix and frequency weighting functions. Simulations and experiments are carried out and the desired performances are obtained by the presented approach.

著者

雉本 信哉 下嶋 浩

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.589, pp.3581-3586, 1995-09-25

参考文献数

9

被引用文献数

4

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A new adaptive control algorithm in frequency domain was proposed. This frequency domain approach corresponds to the ordinary filtered-x least mean square (LMS) algorithm in discrete time domain. In this approach, the fast Fourier transform (FFT) was used for converting signals between frequency domain and discrete time domain. Since the computaion processes in these two domains are almost independent with each other, this algorithm can be realized effectively by using two processors. Computer simulations were carried out for investigating convergence characteristics of this approach. As the result of these simulations, it was shown that this algorithm has faster convergence with less computation comparing to the ordinary filtered-x LMS algorithm.