Tendon-driven continuum robots suffer from crosstalk of driving forces between sections, typically resulting in motion coupling between sections, which affects their motion accuracy and complicates the control strategies. To address these issues, this article proposes a mechanically designed variable-pitch flexible-screw-driven continuum robot (FSDCR) that enables motion decoupling between sections. The continuum section of the FSDCR comprises a series of orthogonally arranged vertebrae and is driven by customized variable-pitch flexible screws. The variable-pitch flexible screws apply driving forces and constraints to several threaded vertebrae in the continuum section, improving positioning accuracy and loading capacity. The flexible screws effectively balance the driving force and torque within one section through antagonistic torsional actuation, thereby achieving motion decoupling between sections. Characterization experiments have been conducted to compare the motion accuracy and load capacity of the variable-pitch FSDCR with those of the constant-pitch FSDCR. The results demonstrate that the variable-pitch FSDCR exhibits improved positioning accuracy, minimizing an average error of 0.79 mm (0.60% relative to its total length), which is 82.09% lower than that of the constant-pitch FSDCR. The load capacity of the variable-pitch FSDCR is enhanced by up to 129.09% compared with the constant-pitch FSDCR. Experiments on the motion decoupling performance of the FSDCR show that the maximum motion coupling error is 0.32 mm (0.24% relative to the section length). Additionally, the motion coupling error is minimally influenced by the rotational speed of the screw. Finally, a three-section FSDCR is constructed, and its load capacity and motion flexibility are demonstrated.

中文翻译：

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开发具有运动解耦能力的可变螺距柔性丝杠驱动连续体机器人 （FSDCR）。


肌腱驱动的连续体机器人受到截面之间驱动力串扰的影响，通常会导致截面之间的运动耦合，这会影响其运动精度并使控制策略复杂化。为了解决这些问题，本文提出了一种机械设计的可变螺距柔性丝杠驱动连续体机器人 （FSDCR），该机器人可实现各部分之间的运动解耦。FSDCR 的连续部分由一系列正交排列的椎骨组成，由定制的可变螺距柔性螺钉驱动。可变螺距柔性螺钉将驱动力和约束作用到连续截面中的多个螺纹椎骨，从而提高定位精度和负载能力。柔性螺钉通过拮抗扭转驱动有效地平衡一个截面内的驱动力和扭矩，从而实现截面之间的运动解耦。已经进行了表征实验，以比较可变螺距 FSDCR 与恒定螺距 FSDCR 的运动精度和负载能力。结果表明，可变间距 FSDCR 表现出更高的定位精度，将平均误差降低了 0.79 mm（相对于其总长度 0.60%），比恒定间距 FSDCR 低 82.09%。与恒定螺距 FSDCR 相比，可变螺距 FSDCR 的负载能力提高了 129.09%。对 FSDCR 运动解耦性能的实验表明，最大运动耦合误差为 0.32 mm（相对于截面长度为 0.24%）。此外，运动耦合误差受螺杆转速的影响最小。最后，构建了一个三段式 FSDCR，并展示了其负载能力和运动灵活性。