Abstract This paper analyzes the locomotion of a double screw-like robot composed of a right hand screw and a left hand screw attached via a rotating motor. Since the screws rotate in opposite directions, both screws produce propulsion in the same direction to advance. The advantage of this mechanism is that it can be used to crawl over deformable surfaces such as inside biological vessels and in granular media. We first develop a general analytical model of this double screw-like motion and describe its different modes of locomotion (raising-raising, raising-lowering, lowering-raising, lowering-lowering). We then use the model to determine the speed and forces acting on the robot as a function of the rotation speed, the screw geometry such as the diameter of the screw and its pitch, and the friction coefficient of the surface. The model is then used to evaluate the energy consumption of the locomotion and motor torques. The findings show that the surface forces acting on the two screws vary significantly if the coefficients of friction on each are different. The numerous new singular cases in which the screw forces can become infinite are discussed.

中文翻译：

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双螺杆爬行机器人的运动力学

摘要 本文分析了一个由右手螺杆和左手螺杆通过旋转电机连接的双螺杆式机器人的运动。由于螺杆以相反的方向旋转，因此两个螺杆产生相同方向的推进力以前进。这种机制的优点是它可用于在可变形表面上爬行，例如生物血管内部和颗粒介质。我们首先开发了这种双螺旋状运动的一般分析模型，并描述了它的不同运动模式（升-升、升-降、降-升、降-降）。然后，我们使用该模型来确定作用在机器人上的速度和力，作为旋转速度、螺杆几何形状（如螺杆直径及其螺距）以及表面摩擦系数的函数。然后使用该模型来评估运动和电机扭矩的能量消耗。研究结果表明，如果每个螺钉的摩擦系数不同，作用在两个螺钉上的表面力就会显着不同。讨论了许多新的奇异情况，在这些情况下，螺旋力可以变得无穷大。 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .