Embodiment

How do body mechanics and interactions with the environment produce behavior or reduce the work required of a controller? Covers passive movement, self-modeling and adaptation to bodily damage.

Body dynamics and regulation

  • Ultrastability and the Homeostat - When essential variables leave acceptable bounds, a second feedback process changes the system’s parameters. Ashby’s four-unit machine demonstrates adaptation through finding a stable configuration. Ashby 1960.
  • Braitenberg vehicles - Thought experiments construct increasingly elaborate behavior from simple mechanisms. They connect synthetic machines with psychological interpretations of behavior; the book’s vehicles are hypothetical constructions. Braitenberg 1984.
  • Passive dynamic walking - Leg geometry and mechanics support a stable walking cycle down a shallow slope without active control. Physical prototypes exploit gravity as the energy source and body dynamics as part of the control solution. McGeer 1990.
  • Soft robotic maze escape - An asymmetric elastomer ribbon turns and snaps away from obstacles, escaping tested mazes where symmetric designs become trapped. Body mechanics replace onboard control; the maze experiments use a 120°C heated surface. Zhao et al. 2023.

Body design and adaptation

  • Evolving virtual creatures - Genetic search jointly evolves articulated bodies and neural controllers in simulated physics. Swimming, walking, jumping and following emerge under researcher-specified fitness functions. Sims 1994; video.
  • Robot self-modeling - A four-legged robot tests actions that discriminate candidate models of its body, then uses a model to generate gaits. After a leg segment is removed, revised models support compensatory walking. Bongard et al. 2006.
  • Intelligent trial and error - A behavior map computed before deployment guides rapid adaptation after damage. Tests use a physical hexapod and a simulated arm; recovery reuses prior search rather than discovering all behaviors after injury. Cully et al. 2015.

Open questions

  • Which behavioral capacities survive changes in the body or environment beyond those used in design and training?
  • How much recovery comes from body dynamics, online inference or an externally computed repertoire?