This is the first demonstration of an artificially evolved soft robot developing a stiff skeleton in response to proprioceptive sensory information (material pressure). This adaptive mechanism (which we call stiffness plasticity) confers robustness in the face of a dynamic environment, allowing the robot to retain almost 40% of its fitness when exposed to a previously unseen environment where gravity is doubled.
Part of:
Corucci et al., "Evolutionary Developmental Soft Robotics As a Framework to Study Intelligence and Adaptive Behavior in Animals and Plants"
www.frontiersi...
Further details:
----------
A robot is evolved in an environment where the gravity acceleration is g=-9.81 m/s^2. Tested in that environment, it shows a suitable developmental program that tends to stiffen appendages that are subject to repeated mechanical load (red material is the stiffest possible material, blue the softest). This strategy is evolved, the proprioceptive information that are used as input for the developmental adaptation are selected by evolution, as well as the parameters of such developmental adaptation (adaptive rates).
Halfway during the lifetime of the individual gravity is doubled, and the robot is exposed to a never experienced gravity level of 2g. A broader developmental adaptation takes place, which causes two smaller lateral legs to stiffen as well as they interact with the ground due to the increased gravity. A stiff frame also forms all around the robot to better support and distribute the increased load. After a short transition period, this generalized adaptation enabled again locomotion (~40% of the original speed is regained). A suitable environment-mediated developmental program, found by evolution, is able to confer robustness in previously unseen environments.
To the best of our knowledge, this is the first time that adaptation phenomena similar to the Wolff's law of bones remodeling are artificially evolved in simulated soft bodied creatures.
3 окт 2024
