This paper investigates the problem of the variable stiffness for a class of multisegment continuum manipulators. A simple design that mainly consists of two types of pneumatic muscle actuators (PMAs) is introduced to deal with the problem. To provide a detailed analysis, this characteristic of the variable stiffness is coupled with a mathematical analysis that is built upon the geometric mechanics and the performance testing of the stiffness in each PMA, thereby forming the stiffness model. Moreover, utilizing the simple design enables the continuum manipulator composed of two units to vary its stiffness independently from the angular position. In addition, using only the pressure variation of the PMAs in each unit, the dual-segment manipulator also has the capacity to implement independent unit locking. The experimental results further validate the expected performance of the proposed continuum manipulator.

本文研究了一类多段连续体机械手的变刚度问题。介绍了一种主要由两种类型的气动肌肉执行器（PMA）组成的简单设计。为了提供详细的分析，将可变刚度的这一特性与基于几何力学和每个PMA中刚度的性能测试的数学分析相结合，从而形成刚度模型。此外，利用简单的设计，由两个单元组成的连续操纵器可以独立于角位置改变其刚度。此外，仅使用每个单元中PMA的压力变化，双段操纵器还具有实现独立单元锁定的能力。