形状记忆合金丝驱动的柔性机械臂建模与实验

Modeling and experiment of flexible manipulator actuated by shape memory alloy wire

针对传统机械臂在水下特殊环境中柔性不能满足应用需求的问题,在分析章鱼腕生物学肌肉组织结构的基础上,设计形状记忆合金(SMA)丝驱动的柔性机械臂.建立柔性机械臂的力学模型、SMA丝的热力学模型和本构模型.通过实验研究不同驱动电压和脉宽调制(PWM)方波的占空比对SMA丝电阻和柔性机械臂弯曲角度的影响.实验结果表明,柔性机械臂能够实现连续的柔性弯曲运动,最大弯曲角度为60°,驱动电压、PWM占空比、SMA电阻和柔性机械臂弯曲角度关系的实验结果与理论分析结果吻合较好.

A flexible manipulator actuated by shape memory alloy(SMA)wires was designed based on the biological analysis of muscle structure in wrist of octopus in order to meet the requirement of the flexibility of robot manipulators when operated in complex underwater environment.The mechanical model of the flexible manipulator was constructed.Then the constitutive equation and the thermal model of embedded SMA wires were described.Actuating experiments were conducted on the influence of different driving voltages and duty ratio of pulse-width modulation(PWM)on the resistance of SMA wires and the bending angle of manipulator.The experimental results show that the flexible manipulator can complete continuous flexible bending motion with a maximum bending angle of 60 degree.Relationship between driving voltage,PWM ratio,resistance of SMA and the bending angle of flexible manipulator accorded with the theoretical analysis results.