著者
花房 秀郎 浅田 春比古
出版者
The Society of Instrument and Control Engineers
雑誌
計測自動制御学会論文集 (ISSN:04534654)
巻号頁・発行日
vol.12, no.5, pp.536-542, 1976-10-30 (Released:2009-03-27)
参考文献数
4
被引用文献数
1 2

It is desired that artificial fingers can grip various objects with a gripping suitable to their shapes. In this paper, we discuss the matching between the structure of artificial fingers and the shapes of objects. The gripping by a robot is regarded as the restriction of the objects by the fingers. The forces acting on the objects should be balanced for the gripping.First the finger forces depending on the structure of the artificial fingers and the shape of an object are analyzed. Second by introducing the potential function the stability of a gripping form is discussed. When the potential is relative minimum at a certain gripping form, the resultant of all the finger forces acts so as to keep the gripping for all of small deviations. The defined potential can be applied to decide the optimal gripping form and the design of an universal gripper.
著者
浅田 春比古
出版者
The Society of Instrument and Control Engineers
雑誌
計測自動制御学会論文集 (ISSN:04534654)
巻号頁・発行日
vol.19, no.6, pp.500-505, 1983-06-30 (Released:2009-03-27)
参考文献数
7
被引用文献数
1 6

Robot manipulators and mechanical arms have complicated behavior including interactions among multiple joints, nonlinear effects such as Coriolis and centrifugal forces, and varying inertia depending on the arm configuration. In this paper, a new approach to the geometrical representation of manipulator dynamics is presented. The inertia ellipsoid, which is used to represent dynamic characteristics of a single rigid body, is extended to a series of rigid bodies in order to represent the manipulator dynamics. The geometrical representation of the generalized inertia ellipsoid (GIE) represents the characteristics of the manipulator as a whole. One can understand the complicated inertia effect and nonlinearity of multi-degree-of-freedom motion by simply investigating the GIE configuration. In the latter half of the paper, the presented method is applied to aid the design of a mechanical arm, in which dimensions of an arm structure and its mass distribution are optimized through the evaluation and graphical representation of the arm dynamics.
著者
浅田 春比古
出版者
The Society of Instrument and Control Engineers
雑誌
計測自動制御学会論文集 (ISSN:04534654)
巻号頁・発行日
vol.22, no.8, pp.891-896, 1986-08-30 (Released:2009-03-27)
参考文献数
10
被引用文献数
1 1

In a direct-drive arm, motors are directly coupled to their arm linkages without reducers. This eliminates some defects of traditional gearing such as backlash, friction and deflection, and therfore enables the drive system to have improved control accuracy. The D.C. motors used for the direct-drive arm, however, have a significant amount of torque ripples and deadband, which limits the control accuracy, particularly for compliance and force control.In this paper, a method for the torque feedback control of a direct-drive joint is presented. The motor output torque is directly measured by a strain gage sensor built into the motor. It is found that closed loop torque control can compensate for the complicated nonlinearities and improve the overall control accuracy.First, the design of the torque sensor is presented. The effect of the structural vibration mode which results from the insertion of the flexible torque sensor is analysed, and a design method to place the natural frequency of this mode far above the operating frequencies is shown. Torque feedback control using the sensor is then discussed. The sensor design is verified experimentally, and the control performance using the direct torque feedback is evaluated.