In this letter, an autonomous spiral stair climbing method for tracked vehicles using the reaction force from side walls has been proposed. Spiral stairs are one of the most difficult terrains for tracked vehicles because of their asymmetrical ground shape and small turning radius. Tracked vehicles are expected to be used in industrial plant inspection tasks, where robots should navigate on multiple floors by ascending the stairs. Spiral or curved stairs are installed as part of inspection passages for cylindrical facilities, such as boilers, chimneys, or large tanks. Previously, the authors have experimentally demonstrated that the wall-following motion is effective for stabilizing and accelerating spiral stair climbing. However, the complete automation of climbing motion or the analysis of why the same motion is generated even if a disturbance exists in the initial entry angle to the wall should be investigated. In this study, the authors developed an autonomous spiral stair climbing method using the wall reaction force and clarified the applicable limitations of this method using a geometrical model. Autonomous spiral stair climbing is realized by attaching passive wheels on its collision point and automating the motions of main tracks and sub-tracks. The geometrical model shows the expected trajectory of the robot on the spiral stairs, which suggests that the robot’ s rotation radius converges to a specific value; this is experimentally confirmed by measuring the robot's motion. The wall-following motion of robots is equivalent to human inspectors grasping handrails while climbing stairs. Through collisions with surrounding objects, motion is stabilized and certainty is guaranteed.

中文翻译：

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利用墙壁反作用力的履带车辆稳定自主螺旋爬楼梯

在这封信中，提出了一种利用侧壁反作用力的履带式车辆自主螺旋楼梯爬升方法。螺旋楼梯是履带车辆最困难的地形之一，因为它们的地面形状不对称，转弯半径小。履带式车辆有望用于工业工厂检查任务，其中机器人应通过爬楼梯在多个楼层上导航。螺旋或弯曲楼梯作为圆柱形设施（如锅炉、烟囱或大型储罐）的检查通道的一部分安装。此前，作者已经通过实验证明，墙体跟随运动对于稳定和加速螺旋楼梯攀爬是有效的。然而，应该调查爬升运动的完全自动化或分析为什么即使在初始进入墙壁的角度存在干扰也会产生相同的运动。在这项研究中，作者开发了一种利用墙壁反作用力的自主螺旋楼梯爬楼梯方法，并使用几何模型阐明了该方法的适用局限性。通过在其碰撞点上安装被动轮并使主轨道和子轨道的运动自动化来实现自主螺旋楼梯爬升。几何模型显示了机器人在螺旋楼梯上的预期轨迹，表明机器人的旋转半径收敛到一个特定值；这是通过测量机器人的运动实验证实的。机器人的跟墙运动相当于人类检查员在爬楼梯时抓住扶手。通过与周围物体的碰撞，运动得以稳定并保证确定性。