著者

原田 祐志 浅野 文彦 田地 宏一 宇野 洋二

出版者

一般社団法人 日本ロボット学会

雑誌

日本ロボット学会誌 (ISSN:02891824)

巻号頁・発行日

vol.27, no.5, pp.575-582, 2009 (Released:2011-11-15)

参考文献数

9

被引用文献数

3 2

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We have applied a parametric excitation method to a kneed biped robot with semicircular feet and have shown that the robot can walk sustainably with only knee torque. A swing-leg of the kneed biped robot has similar mechanism to an acrobot, and many acrobots are controlled in inverse direction like ornithoid walking. These suggest that inverse bending of a knee restores more mechanical energy than forward bending, and hence, the ornithoid walking can be more efficient. In this paper, we first compare the forward bending with the inverse bending for a double pendulum, and show by numerical simulation that the mechanical energy of the inverse bending increases more than that of the forward bending like human walking. We then propose a parametric excitation based ornithoid gait for a kneed biped robot, and show sustainably walking by numerical simulation. Finally, we compare parametric excitation based ornithoid gait with parametric excitation based human gait, and we show that ornithoid gait is more efficeint.

著者

加藤 隆一 池田 隆 原田 祐志

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.83, no.852, pp.17-00109-17-00109, 2017 (Released:2017-08-25)

参考文献数

12

被引用文献数

1

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This paper investigates the free vibrations of double beams, consisting of upper and lower beams, which are discretely connected by N springs. In the theoretical analysis, the modal analysis approach is employed to determine the expressions for the natural frequencies and vibrational modes of the system. In the numerical calculation, two cases, Cases A and B, are examined. In Case A, the two beams are connected by a single spring, while in Case B they are connected by two springs. In Case A, when the two beams have identical materials and dimensions, as the spring constant K1 increases, the natural frequencies of the odd-order vibrational modes are constant because the two beams vibrate in phase in their vibrational modes and the connecting spring is not stretched. The natural frequencies of the even-order vibrational modes are increased with the increase of K1 because the two beams vibrate out of phase. When the spring is attached at the middle of the beams, the natural frequencies p4n-1 (n=1, 2, …) equal p4n. In addition, when K1 reaches the specific values K1,n in this case, a set of three natural frequencies satisfies p4n-2=p4n-1=p4n, and a magnitude relationship of the natural frequencies is switched when K1 crosses the value K1,n. In Case B, when two springs are attached in symmetry with respect to the midpoints of the beams, a set of two natural frequencies satisfies p2n=p2n+1 for the specific values of the spring constants even if the springs are not attached to the positions of the nodes of the independent beams. The validity of the theoretical analysis was confirmed by comparing the theoretical results with the results obtained by the FEM analysis for Case A.