※一部利用できない機能があります
| 1.
論文 |
論文
|
福室, 允央 ; 大関, 健一郎 ; 斎藤, 正人 ; 葛, 徳梁 ; 村上, 岩範 ; 長屋, 幸助
概要:
application/pdf<br />Journal Article<br />A simple and stable energy-storage flywheel system with high temperature superconducting levitation is presented. In order to have stable levitation, a superconductor and a permanent magnet are
…
used, and 3 permanent magnets support the top of the shaft. In the part of drive system, 8-poles permanent magnet and 8 coils are used to cancel electromagnetic forces in the radial direction. An electromagnetic damper consisting of permanent magnet for levitation and 4 coils is presented which lies at both ends of the shaft. When the shaft vibrates in the direction perpendicular to the shaft axis, current flows in the damper coil. It generates the electromagnetic force. The force is in proportion to vibration frequencies of the shaft, so that the force behaves like damping forces. Using this system, a control like the sensorless control is performed. Experimental tests have been carried out for the system as just mentioned. It is clarified that our system has stable levitation, and vibrations are suppressed significantly.
続きを見る
|
||
| 2.
論文 |
論文
|
小島, 宏行 ; 羽廣, 憲一
概要:
application/pdf<br />Journal Article<br />In this paper, the residual vibration reduction method of a crane using the optimal trajectory planning is proposed, and the usefulness of the present residual vibration reduction method is
…
confirmed both numerically and experimentally. In the optimal trajectory planning, the velocity profile of the trolley is expressed with two fifth-order polynomials, and it is depicted by two parameters obtained by applying some conditions to the fifth-order polynomials. Then, the traiectory is expressed as a function of the chromosome using the two parameters as the genes of the genetic algorithm, and the optimal trajectory of the trolley is obtained by defining the fitness function for the residual vibrations of the load. Furthermore, the numerical calculations been carried out, and it is confirmed that the residual vibrations can be extremely reduced, and the experimental results agree well with the calculation results.
続きを見る
|
||
| 3.
論文 |
論文
|
小島, 宏行
概要:
application/pdf<br />Journal Article<br />This study is concerned with the trajectory planning method of a CP control flexible robot arm by using a genetic algorithm. The flexible robot arm consists of a first rigid link and a second
…
flexible link, and the desired trajectory is set to be a straight line. In the trajectory planning, the reference trajectory, as if the flexural displacement of the second flexible link is zero, is expressed by use of a cubic spline function, and the velocity profile in the direction of the desired trajectory is depicted using two fifth-order polynomial functions. The individual chromosome of the genetic algorithm is composed using the parameters of the cubic spline function and the fifth-order polynomial functions as the genes. Then, the fitness function of the individual chromosome for the residual vibration reduction and the trajectory tracking control is defined, and the trajectory planning algorithm is constructed using the genetic algorithm. Furthermore, the numerical calculations have been carried out, and it is confirmed that the residual vibrations can be remarkably reduced, and the trajectory error from the desired trajectory can be considerably reduced.
続きを見る
|
||
| 4.
論文 |
論文
|
Pranoto, Tjahjo ; 長屋, 幸助 ; 細田, 敦史
概要:
application/pdf<br />Journal Article<br />The purpose of this work is to develop a linear damper in the wing of the aircraft. Then it requires the following: (1) The damping force have to be large for low frequency because the vibration
…
frequency of the wing is small. (2) It works for small displacement, (3) Its size has to be small which can be stacked in the wing, and (4) Passive damper is desirable. This article presents a new type linear damper, which satisfies the conditions as just mentioned. The damper consists of a number of thin plates with slits. MR fluid is filled in the damper, so that magnetic fields freeze MR fluid. Resisting torque (friction torque) is generated when the plates slide due to the shear of slits of the plates. The damper works against the bending moment of the wing by responding its deflection. The damper is maintenance free, and it is one of passive dampers with a good durability.
続きを見る
|
||
| 5.
論文 |
論文
|
小島, 宏行 ; 戸塚, 輝成 ; 近藤, 厚哉
概要:
application/pdf<br />Journal Article<br />In this report, the rotation control system of the flexible robot arm is constructed with both the desired signal planning algorithm of the joint angle and the tracking controller. The tracking
…
controller consists of the PD controller and the disturbance observer. Then, the experiments of the rotation control of the flexible robot arm have been carried out. As the results, it is seen that the residual vibrations of the flexible robot arm can be remarkably reduced. Therefore, the usefulness of the present rotation control system of the flexible robot arm using the desired signal planning method of the joint angle and the disturbance observer is confirmed experimentally.
続きを見る
|
||
| 6.
論文 |
論文
|
小島, 宏行
概要:
application/pdf<br />Journal Article<br />In this report, first, the nonlinear equations of motion of a horizontal one-link flexible robot arm are obtained by use of the mode functions of a cantilever beam with a mass. Then, the algorithm
…
of the desired signal planning of the joint angle for the purpose of the reduction control of residual vibrations of the flexible robot arm is derived by use of the initial and final conditions of the flexural displacement of the flexible link and the constraint conditions of the desired signal of the joint angle during the acceleration and deceleration terms as well as the linearized equation of motion of the flexible robot arm. The rotation control system of the flexible robot arm is constructed with the desired signal planning for the joint angle and the PD controller. Furthermore, the numerical simulations of the rotation control of the flexible robot arm have been carried out, and it is confirmed that the residual vibrations of the flexible robot arm can be effectively reduced by the present desired signal planning for the joint angle.
続きを見る
|
||
| 7.
論文 |
論文
|
長屋, 幸助 ; 小林, 譲二 ; 今井, 勝仁
概要:
application/pdf<br />Journal Article<br />This paper presents a method of micro-vibration control of milling machine heads by use of vibration absorber. The principle used in the paper is different from usual absorbers. In the
…
present absorber, an auto-tuning vibration absorber is presented in which the absorber create anti-resonance state. When the anti-resonance is used, the damping has to be significantly small, so it is difficult to suppress higher modes. To suppress higher modes, the present article uses autotuning magnetic damper. It damps higher modes, but it also increase first modal vibration. Then a method of optimal auto tuning control is presented in which both principal and higher modal vibrations are suppressed. Experimental tests are carried out for a real milling machine, and cutting tests are also performed.
続きを見る
|
||
| 8.
論文 |
論文
|
長屋, 幸助 ; 小杉, 泰裕 ; 鈴木, 孝明 ; 村上, 岩範
概要:
application/pdf<br />Journal Article<br />A simple but stable non-contact high Tc superconducting levitation system with a vertical shaft has been presented. The system consists of a superconductor and permanent magnets. In the system,
…
only a lower end of the shaft is supported by a high Tc superconductor, and the other end is supported by two ordinary permanent magnets. Since the restoring force is small with respect to the radial direction the system becomes unstable when the force act in the radial direction, so it is difficult to drive the shaft by electromagnetic forces in using such as motors. Then, a driving system using electromagnets has been presented, in which the balanced forces act on two opposite sides of the disc type rotor in the axial direction. Since the system has no unbalance force from an analytical point of view, the rotor will be able to rotate without control. In the system, however, since there is the eccentricity between the center of rotation and magnetic center, so vibrations are generated. This study also presents an optimal control method of the vibrations. To validates the proposed system, and the control method, experimental tests have been carried out.
続きを見る
|
||
| 9.
論文 |
論文
|
長屋, 幸助 ; 塚越, 正人 ; 小杉, 泰裕 ; 村上, 雅人
概要:
application/pdf<br />Journal Article<br />The present article discusses a modeling and control of high-T_c superconducting levitation system. The paper first clarifies analytical expressions for obtaining nonlinear levitation force
…
given by the present author, then presents at vibration control method in which feedback currents involving frequency weights. In the method, an addition of a square of the displacement and currents in a frequency domain is taken as a cost function. Optimal coefficients of the transfer function of the controller are obtained by minimizing the cost function. Hence, the spillover instability due to the nonlinear vibration will be redriced. Numerical calculations have been carried out for some typical problems. To validate the present method, experimental tests also have been carried out.
続きを見る
|
||
| 10.
論文 |
論文
|
井開, 重男 ; 樫本, 弘 ; 大沢, 恵一 ; 長屋, 幸助
概要:
application/pdf<br />Journal Article<br />This paper presents an actuator with a sensor for controlling vibrations of machines. It consists of a voice coil type electromagnetic actuator connected to piezoelectric sensor and a coil spring.
…
The actuator is used for controlling a motor laid on the beam. The disturbance force due to the centrifugal force of the motor is detected by the sensor, and the force which is equivalent to the disturbance force is applied to the motor and the beam by the actuator. This implies that the disturbance force is canceled. The control technique as just mentioned has advantages because it reduces the vibration in the low frequency region, in addition, the actuator becomes compact, and the control force becomes small. But the control is insufficient for controlling the resonance peak. The PD control is available for reducing the resonance peak, but the displacement and velocity sensors are required. In the present article, a method of vibration control of disturbance cancellation combining the PD control is presented in which both the displacement and velocity sensors are not required. The analytical results for obtaining the control current and the response of both the motor and beam have been obtained. To validate the present actuator sensor system and the control method, experimental tests are carried out.
続きを見る
|
