Control of underactuated planar hexapedal pronking through a dynamically embedded SLIP monopod
Date
2010Source Title
2010 IEEE International Conference on Robotics and Automation
Print ISSN
1050-4729
Publisher
IEEE
Pages
4721 - 4727
Language
English
Type
Conference PaperItem Usage Stats
144
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Abstract
Pronking (aka. stotting) is a gait in which all legs are used in synchrony, resulting in long flight phases and large jumping heights that may potentially be useful for mobile robots on rough terrain. Robotic instantiations of this gait suffer from severe pitch instability either due to underactuation, or the lack of sufficient feedback. Nevertheless, the dynamic nature of this gait suggests that the Spring-Loaded Inverted Pendulum Model (SLIP), a very successful predictive model for both natural and robotic runners, would be a good basis for more robust and maneuverable robotic pronking. In this paper, we describe how "template-based control", a controller structure based on the embedding of a simple dynamical "template" within a more complex "anchor" system, can be used to achieve stable and controllable pronking for a planar, underactuated hexapod model. In this context, high-level control of the gait is regulated through speed and height commands to the SLIP template, while the embedding controller based on approximate inverse-dynamics and carefully designed passive dynamics ensures the stability of the remaining degrees of freedom. We show through extensive simulation experiments that unlike existing open-loop alternatives, the resulting control structure provides stability, explicit maneuverability and significant robustness against sensor and actuator noise. ©2010 IEEE.
Keywords
Approximate inverseControl structure
Controller structures
Degrees of freedom
Dynamic nature
Extensive simulations
Flight phasis
Open loops
Predictive models
Rough terrains
Sensor and actuators
Show through
Spring loaded inverted pendulums
Template-based
Under-actuation
Underactuated
Controllers
Robots
Robotics