Paper Info
Title
First steps toward formal controller synthesis for bipedal robots
Abstract
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.
Year
DOI
Venue
2015
10.1145/2728606.2728611
HSCC
Field
DocType
Citations 
Prime (order theory),Control theory,Nonlinear system,Abstraction,Control theory,Curse of dimensionality,Control engineering,State variable,Engineering,Robot,Manifold
Conference
3
PageRank 
References 
Authors
0.40
23
7
Name
Order
Citations
PageRank
Aaron D. Ames11202136.68
Paulo Tabuada24281264.80
Bastian Schürmann3224.58
Wen-Loong Ma4256.05
Shishir Kolathaya5677.40
Matthias Rungger630.40
Jessy W. Grizzle730.40