First steps toward formal controller synthesis for bipedal robots
First steps toward formal controller synthesis for bipedal robots
复制标题
双足机器人正式控制器综合的第一步
DOI：
10.1145/2728606.2728611
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
J. Grizzle
中科院分区：
文献类型：
--
作者：
A. Ames;P. Tabuada;Austin M. Jones;Wen;M. Rungger;B. Schürmann;Shishir N Y Kolathaya;J. Grizzle
双足机器人是复杂的信息物理系统（CPS）的主要例子。它们表现出许多使CPS的设计和验证如此困难的特征：混合动力学，每种模式下的大连续动力学（例如，10个或更多的状态变量），以及涉及对状态变量的非线性约束的非平凡规范。在本文中，我们提出了一个两步的方法来正式合成控制软件的双足机器人，以执行规格的设计，从而产生物理上可实现的稳定行走。在第一步中，我们设计输出和经典控制器驱动这些输出为零。所得到的控制系统的发展低维流形和所描述的混合零动态管理的剩余自由度。在第二步中，我们构建了一个抽象的混合零动态，用于合成控制器执行所需的规格，以满足全阶模型。我们的两个步骤的方法是一个系统的方式来减轻灾难的维数，阻碍了正式的合成技术复杂的CPS的适用性。我们的研究结果示出了与模拟显示如何合成控制器强制执行所有所需的规格，并提供了改进的性能相对于控制器，用于获得实验行走的双足机器人琥珀2。
Bipedal robots are prime examples of complex cyber-physical systems (CPS). They exhibit many of the features that make the design and verification of CPS so difficult: hybrid dynamics, large continuous dynamics in each mode (e.g., 10 or more state variables), and nontrivial specifications involving nonlinear constraints on the state variables. In this paper, we propose a two-step approach to formally synthesize control software for bipedal robots so as to enforce specifications by design and thereby generate physically realizable stable walking. In the first step, we design outputs and classical controllers driving these outputs to zero. The resulting controlled system evolves on a lower dimensional manifold and is described by the hybrid zero dynamics governing the remaining degrees of freedom. In the second step, we construct an abstraction of the hybrid zero dynamics that is used to synthesize a controller enforcing the desired specifications to be satisfied on the full order model. Our two step approach is a systematic way to mitigate the curse of dimensionality that hampers the applicability of formal synthesis techniques to complex CPS. Our results are illustrated with simulations showing how the synthesized controller enforces all the desired specifications and offers improved performance with respect to a controller that was utilized to obtain walking experimentally on the bipedal robot AMBER 2.