Morphological Computation

Read here about a theoretical topic in computational cognition that has a direct bearing on tensegrity robotics research.

Overview

Morphological computation refers to the phenomenon that computation can be obtained through interactions of physical form. Morphology, the physical form of a robot, biological creature, or sensor, affects how it may compute and assess its surroundings. The investigation of this relationship is called morphological computation. Tensegrity structures are a unique morphology which offers the opportunity to combine control mechanisms and structural components. This means that the study of morphological computation is relevant to tensegrity in general and tensegrity robotics in particular.

Discussion

This discussion is based on the work of Mark Khazanov, Julian Jocque and John Rieffel.

The fact that the morphology of a robot affects its control requirements has become increasingly evident in robotics. Not only does the morphology determine the behaviors that can be performed, but also the amount of control required for these behaviors. Particularly in systems where behavior is obtained through purely sensory-motor interactions of the body with the environment, the morphology is of prime importance. Nonetheless, even in other robotic systems, a relationship has been found to exist between morphology and control requirements, in that some morphologies yield themselves to being more easily controlled than others. This relationship was first observed and characterized by Pfeifer as the morphology and control trade-off, but the mechanisms underlying this relationship have been unclear.

Morphological computation, the phenomenon that computation can be obtained through interactions of physical form, elucidates a possible mechanism underlying this relationship. The fact that simple physical interactions give rise to computation indicates the theoretical possibility for the dynamics of the morphology to play a computational role in the system, and thereby to subsume part of the role of control. It thus serves the robotics designer to analyze the relationship between morphology and control, and guide the design of robots with reduced control requirements. This study examines robot morphology through the lens of the potential role in the morphology and control trade-off, which can be used as a basis to design robots with reduced control requirements.

Przemysław Robert Nowakowski suggests that such control mechanisms can be considered as a form of cognition, and morphological computation is a kind of embodied cognition, where "non-neural" or non-cognitive structural elements play a critical role in cognition. The integration of embodied and computational approaches to cognition requires that non-neural body parts be described as parts of a computing system, which realizes cognitive processing. Structural, non-cognitive body parts form part of a computational system, but they do not realize computation autonomously, only in connection with some kind of—even in the simplest form—central control system.

References and Links

Khazanov, Jocque and Rieffel: https://www.sciencedirect.com/science/article/pii/S0921889006000613