The next IPAB Workshop will take place on 25/06/2020 at 13:00 on Blackboard Collaborate. Steve Tonneau will be speaking.
Title: The "contact planning problem" for legged robots: A cardinality minimisation approach
Abstract: In order to move, legged animals and robots create contacts with their environment.
Reaching a desired position requires planning several steps ahead (literally): when, where and with which effector should the next contacts be created between the robot and the environment?
We call this issue the "contact planning problem". It is a high-dimensional, non-linear combinatorial problem of exponential complexity.
In this talk I will focus on the combinatorial aspect of legged locomotion.
First, I will argue that under simplifying assumptions, our combinatorial problem can be efficiently approximated as a convex quadratic program and thus solved trivially. This reformulation, which we called SL1M , allowed us to plan motions for the humanoid robot Talos and the quadruped Anymal with computation times up to 100 times faster than the state of the art.
The price to pay for this performance gain is to lose guarantees of optimality and sometimes even convergence to a feasible solution for the original problem.
The second part of the presentation will be more speculative. I will elaborate on the limitations of SL1M and suggest avenues of research to specifically address them.
 SL1M: Sparse L1-norm Minimization for contact planning on uneven terrain. Presented at ICRA 2020.