Departmental Papers (ESE)

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We present a framework for detecting, identifying, and recovering within stride from faults and other leg contact disturbances encountered by a walking hexapedal robot. Detection is achieved by means of a software contactevent sensor with no additional sensing hardware beyond the commercial actuators’ standard shaft encoders. A simple finite state machine identifies disturbances as due either to an expected ground contact, a missing ground contact indicating leg fault, or an unexpected “wall” contact. Recovery proceeds as necessary by means of a recently developed topological gait transition coordinator. We demonstrate the efficacy of this system by presenting preliminary data arising from two reactive behaviors — wall avoidance and leg-break recovery. We believe that extensions of this framework will enable reactive behaviors allowing the robot to function with guarded autonomy under widely varying terrain and self-health conditions.

Document Type

Conference Paper

Subject Area

GRASP, Kodlab

Date of this Version



Suggested Citation:
Johnson, A.M., G.C. Haynes and D.E. Koditschek. (2010). "Disturbance Detection, Identification, and Recovery by Gait Transition in Legged Robots" 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems October 18-22, 2010, Taipei, Taiwan. pp. 5347-5353

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Legged Robots, Hexapods, Biologically Inspired, Fault Detection, Proprioception, Reactive Behaviors



Date Posted: 09 November 2010

This document has been peer reviewed.