Terrain geometry is, in general, non-smooth, non-linear, non-convex, and, if perceived through a robot-centric visual unit, appears partially occluded and noisy. This work presents the complete control pipeline capable of handling the aforementioned problems in real-time. We formulate a trajectory optimization problem that jointly optimizes over the base pose and footholds, subject to a heightmap. To avoid converging into undesirable local optima, we deploy a graduated optimization technique. We embed a compact, contact-force free stability criterion that is compatible with the non-flat ground formulation. Direct collocation is used as transcription method, resulting in a non-linear optimization problem that can be solved online in less than ten milliseconds. To increase robustness in the presence of external disturbances, we close the tracking loop with a momentum observer. Our experiments demonstrate stair climbing, walking on stepping stones, and over gaps, utilizing various dynamic gaits.
翻译:地形几何一般是非摩特、非线性、非线性、非线性,如果通过机器人中心视觉单位来观察,似乎部分隐蔽和吵闹。 这项工作展示了能够实时处理上述问题的完整控制管道。 我们设计了一个轨迹优化问题, 在有高度映射的情况下, 共同优化基座和足部。 为了避免混入不受欢迎的本地optima, 我们使用了一种分级优化技术。 我们安装了一个与非平板地面配制兼容的紧凑、 接触力自由的稳定标准。 直接合用作为抄录方法, 导致一个非线性优化问题, 可以在不到10毫秒的时间内在网上解决 。 为了在出现外部扰动时增强稳健性, 我们用动力观察者关闭跟踪环路 。 我们的实验展示了楼梯攀升、 踩脚石 和跨越缺口, 使用各种动态的格子 。