基于SMA弹簧紧凑型柔性电机的设计与研制

Research on a Compact and Flexible Actuator Consisting of SMA Springs

介绍了一种基于SMA弹簧的紧凑型柔性电机结构。三只SMA弹簧偏心嵌入室温硫化的双组分硅胶棒中,弹簧与丝除在端部通过两个固定片连接外,其他部分可自由地相对运动。通过占空比可调的电流脉冲加热SMA弹簧,控制其收缩变形,可实现电机的柔性空间运行。这一低功耗、高功率重量比、可直接驱动的紧凑型柔性电机,可望在拟人机械手及其他微小型机器人系统中得到实用。本文分析了弹性棒在集中与分布载荷作用下的形变理论,对硅胶棒与SMA弹簧的关键参数进行了研究并详细推导了二者的设计过程。最后,进行了样机研制的工艺探讨并制作了样机,对样机进行的实验研究,验证了设计电机的性能。

A new structure of compact flexible actuator based on shape memory alloy （SMA） springs is first presented. Three SMA springs, which are trained to shrink as the phase transition occurs, are embedded off-axially and movably in silicone rubber rod solidified at room temperature. The spatial bending, which is accomplished through heating SMA springs by suitable current, can restore flexibly as soon as stopping heating. Thus, the compact, flexible, mechanical and electrical incorporation actuator is completed. Be provided with the merits such as high load-weight ratio, low energy dissipation and direct driving, the actuators can realize miniature configuration, simple drive and control and flexible movement pose synthetically. After analyzing equilibrium of elastic rod with distributed and concentrated loads, the parameters design process of the rod and SMA spring are deduced. Subsequently, the manufacture of the prototype is discussed in details. Finally, the experiments of the actuator proof fine qualities of the operation performances.