Abstract
A method of motion control as well as shape optimization is proposed for the preliminary design of a suitlike flexible arm, which is composed of some variable-length and fixed-length beams. The large deformation, variable geometry and motion of the flexible structure are calculated by dynamic finite element analysis (FEA) using the step by step time integration method. A neural-networks-inverse-model, which learns nonlinear behaviour of the flexible structure, has been applied for the motion control as an inverse model of the flexible arm. For this geometrically nonlinear structure and time response problem, the optimum shape of the cross-section has been calculated under constraints of stress, stiffness and minimum weight with FEA and sensitivity analysis combined with fuzzy rules. This method has been applied for the design of a flexible arm, which simulates a process of lifting a human body and moving it. The calculated optimum shape has a much higher stiffness with decrease in weight in comparison with the initial shape. Moreover, the calculated motion agrees well with the one aimed for and the flexible arm reduces the impact force.
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Akasaki, F.; Shimojima, S.; Nishigaki, H.; Ishiyama, S. 1992: Large deformation analysis of flexible hose by dynamic finite element method.25th ISATA Symp., pp. 663–670
Ando, F.; Noritsugu, T.; Takaiwa, M.; Yamanaka, T. 1993: Application of rubber artificial muscle manipulator to rehabilitation aided robot (in Japanese).11th Annual Conf. of Robotics Society of Japan, pp. 993–996
Ishiyama, S.; Takagi, J.; Yamamoto, K.; Nishimura, T. 1988: Impact response of thin-walled frame structures.Int. J. Impact Engng. 7, 197–212
Meek, J.L. 1971:Matrix structural analysis. New York: McGraw-Hill
Wasserman, P.D. 1989:Neural computing theory and practice. Van Nostrand Reinhold
Yamakawa, H. 1993:Optimum design (in Japanese). Baifuu Kan
Yamamoto, K. 1994: Powered arm and leg for assisting nurse labor.Proc. 1st Asian Control Conf. (SICE)
Yamamoto, K.; Hyodo, K.; Yakou, T. 1995: Powered suit for assisting nurse labor (in Japanese).72-nd JSME Spring Annual Meeting, pp. 533–534
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Nishigaki, H., Kawashima, K. Motion control and shape optimization of a suitlike flexible arm. Structural Optimization 15, 163–171 (1998). https://doi.org/10.1007/BF01203527
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DOI: https://doi.org/10.1007/BF01203527