The dynamics of legged locomotion in heterogeneous terrain: universality in scattering and sensitivity to initial conditions
The dynamics of legged locomotion in heterogeneous terrain: universality in scattering and sensitivity to initial conditions
复制标题
异质地形中腿式运动的动力学：散射的普遍性和对初始条件的敏感性
DOI：
10.15607/rss.2015.xi.030
复制
发表时间：
2015
影响因子：
12.7
通讯作者：
D. Goldman
中科院分区：
文献类型：
--
作者：
Feifei Qian;D. Goldman
天然基质通常由不同大小的颗粒组成，从细沙到鹅卵石和巨砾。机器人运动在这样的异质基板上是复杂的，部分原因是由于大的力和运动学波动引入的异质性。为了系统地探索异质性如何影响运动，我们研究了一个六足机器人（15厘米，150克）在轨道上充满了101毫米的“沙子”，与一个更大的凸“巨石”的各种形状和粗糙度嵌入内的运动。我们调查如何存在的巨石影响机器人的轨迹。为此，我们开发了一个全自动地形创建系统，SCATTER（系统创建任意地形和测试探索机器人），以控制基底的初始条件，包括沙子压实，巨石分布和基底倾斜度。机器人的轨迹分析表明，与巨石的相互作用可以建模为具有吸引力和排斥力的散射体。根据在巨石上的接触位置，机器人在相互作用后将分散到不同的方向。一个单独的相互作用的轨迹敏感地依赖于初始条件，但值得注意的是，这种依赖性的散射角后的初始接触位置是普遍的在很宽的范围内的巨石属性。对于具有多个“散射体”的较大异质场，可以使用来自每个散射体的散射角的叠加来估计机器人的轨迹。这种散射叠加可以应用于各种复杂的地形，包括不同的几何形状，方向和纹理的异质性。我们的研究结果可以帮助发展的确定性和统计描述的机器人运动，控制和路径规划在复杂的地形。
Natural substrates are often composed of particulates of varying size, from fine sand to pebbles and boulders. Robot locomotion on such heterogeneous substrates is complicated in part due to large force and kinematic fluctuations introduced by heterogeneities. To systematically explore how heterogeneity affects locomotion, we study the movement of a hexapedal robot (15 cm, 150 g) in a trackway filled with ∼ 1 mm “sand”, with a larger convex “boulder” of various shape and roughness embedded within. We investigate how the presence of the boulder affects the robot’s trajectory. To do so we develop a fully-automated terrain creation system, the SCATTER (Systematic Creation of Arbitrary Terrain and Testing of Exploratory Robots), to control the initial conditions of the substrate, including sand compaction, boulder distribution, and substrate inclination. Analysis of the robot’s trajectory indicates that the interaction with a boulder can be modeled as a scatterer with attractive and repulsive features. Depending on the contact position on the boulder, the robot will be scattered to different directions after the interaction. The trajectory of an individual interaction depends sensitively on the initial conditions, but remarkably this dependence of scattering angle upon initial contact location is universal over a wide range of boulder properties. For a larger heterogeneous field with multiple “scatterers”, the trajectory of the robot can be estimated using a superposition of the scattering angles from each scatterer. This scattering superposition can be applied to a variety of complex terrains, including heterogeneities of different geometry, orientation, and texture. Our results can aid in development of both deterministic and statistical descriptions of robot locomotion, control and path planning in complex terrain.