扁平气动人工肌肉的设计和分析

Design and Analysis of the Flat Pneumatic Artificial Muscle

传统的气动人工肌肉受结构和制造手段的限制,很难同时满足高收缩率、高收缩力和全柔性等应用需求。针对这些问题,本文基于约束层、收缩层与扁平气囊正交混合编织的工艺,提出了一种扁平编织型气动人工肌肉(扁肌)。通过建模分析了最小收缩层长度、收缩率以及扁肌最大厚度与气囊层数及气囊手指数量之间的关系,并通过数值拟合获得了收缩力的近似解析解。扁肌的各主要部件均采用激光切割而成,组装完成的扁肌质量仅为8.1 g,厚1.2 mm。收缩实验表明,扁肌在5%的收缩率下最大收缩力可达280 N,是其自重的3527倍。在0.5 kg的负载下最大收缩率42.8%,最大收缩速度1216.2 mm/s。迟滞实验表明,扁肌存在一定的位移迟滞,而力迟滞并不明显。在采用闭环控制时,扁肌对0.25 Hz的正弦信号具有良好的位置跟踪能力,最大位移误差2.5 mm。当频率为0.5 Hz时,受放气速度的影响,扁肌存在较大位移延迟。

Due to the limitations of structure and manufacturing process,it is difficult for the traditional pneumatic artificial muscle to meet the application requirements of high contraction ratio,high contraction force,and full flexibility.To solve these problems,a kind of flat pneumatic artificial muscle(flat muscle)is proposed based on the orthogonal hybrid weaving process of constrained layer,contraction layer,and flat balloon.The relationship among the minimum length and contraction ratio of the contraction layer,the maximum thickness of the flat muscle,the amount of flat balloon layers,and the amount of balloon fingers is analyzed by modeling,and the approximate analytical solution of the contraction force is obtained by the numerical fitting method.Main components of the flat muscle are made by the laser cutting process.The mass of the finished prototype is only 8.1 g with a thickness of 1.2 mm.The contraction experiments show that the maximum contraction force of the flat muscle can reach 280 N at a contraction ratio of 5%,which is 3527 times of its weight.Under the load of 0.5 kg,the maximum contraction ratio is 42.8%,and the maximum contraction speed is 1216.2 mm/s.Hysteresis experiments show that there exists some displacement hysteresis,but force hysteresis is not obvious.Using the closed-loop control method,the flat muscle has a good position tracking ability to the 0.25 Hz sinusoidal signal,and the maximum displacement error is 2.5 mm.When the frequency is 0.5 Hz,the flat muscle demonstrates a large displacement delay due to the deflation velocity.