Title
Hierarchical and Safe Motion Control for Cooperative Locomotion of Robotic Guide Dogs and Humans: A Hybrid Systems Approach
Abstract
This letter presents a hierarchical control strategy based on hybrid systems theory, nonlinear control, and safety-critical systems to enable cooperative locomotion of robotic guide dogs and visually impaired people. We address high-dimensional and complex hybrid dynamical models that represent collaborative locomotion. At the high level of the control scheme, local and nonlinear controllers, based on the virtual constraints approach, are designed to induce exponentially stable dynamic gaits. The local controller for the leash is assumed to be a nonlinear controller that keeps the human in a safe distance from the dog while following it. At the lower level, a real-time quadratic programming (QP) is solved for modifying the local controllers of the robot as well as the leash to avoid obstacles. In particular, the QP framework is set up based on control barrier functions (CBFs) to compute optimal control inputs that guarantee safety while being close to the local controllers. The stability of the complex periodic gaits is investigated through the Poincaré return map. To demonstrate the power of the analytical foundation, the control algorithms are transferred into an extensive numerical simulation of a complex model that represents cooperative locomotion of a quadrupedal robot, referred to as Vision 60, and a human model. The complex model has 16 continuous-time domains with 60 state variables and 20 control inputs.
Year
DOI
Venue
2020
10.1109/LRA.2019.2939719
international conference on robotics and automation
Keywords
Field
DocType
Dogs,Legged locomotion,Robot kinematics,Safety,Adaptation models
Control theory,Motion control,Mathematical optimization,Optimal control,Nonlinear control,Control theory,Exponential stability,Quadratic programming,Robot,Hybrid system,Mathematics
Journal
Volume
Issue
ISSN
5
1
2377-3766
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Kaveh Akbari Hamed1439.55
Vinay R. Kamidi202.70
Wen-Loong Ma3256.05
Alexander Leonessa49314.33
Aaron D. Ames51202136.68