Comparative Design, Scaling, and Control of Appendages for Inertial Reorientation
This work addresses the challenge of optimizing appendage design for aerial reorientation in robotics, representing an incremental advance in control and morphology integration.
The paper tackles the problem of designing actuated inertial appendages for planar aerial reorientation by developing a comparative framework and introducing the Inertial Reorientation template to link task constraints with body designs, concluding that tails offer the highest potential performance and demonstrating this with a physical retrofit on a RHex robot.
This paper develops a comparative framework for the design of actuated inertial appendages for planar, aerial reorientation. We define the Inertial Reorientation template, the simplest model of this behavior, and leverage its linear dynamics to reveal the design constraints linking a task with the body designs capable of completing it. As practicable inertial appendage designs lead to morphology that is generally more complex, we advance a notion of "anchoring" whereby a judicious choice of physical design in concert with an appropriate control policy yields a system whose closed loop dynamics are sufficiently captured by the template as to permit all further design to take place in its far simpler parameter space. This approach is effective and accurate over the diverse design spaces afforded by existing platforms, enabling performance comparison through the shared task space. We analyze examples from the literature and find advantages to each body type, but conclude that tails provide the highest potential performance for reasonable designs. Thus motivated, we build a physical example by retrofitting a tail to a RHex robot and present empirical evidence of its efficacy.