A review on locomotion robophysics: the study of movement at the intersection of robotics, soft matter and dynamical systems

Abstract

Discovery of fundamental principles which govern and limit effective locomotion (self-propulsion) is of intellectual interest and practical importance. Human technology has created robotic moving systems that excel in movement on and within environments of societal interest: paved roads, open air and water. However, such devices cannot yet robustly and efficiently navigate (as animals do) the enormous diversity of natural environments which might be of future interest for autonomous robots; examples include vertical surfaces like trees and cliffs, heterogeneous ground like desert rubble and brush, turbulent flows found near seashores, and deformable/flowable substrates like sand, mud and soil. In this review we argue for the creation of a physics of moving systems-a 'locomotion robophysics'-which we define as the pursuit of principles of self-generated motion. Robophysics can provide an important intellectual complement to the discipline of robotics, largely the domain of researchers from engineering and computer science. The essential idea is that we must complement the study of complex robots in complex situations with systematic study of simplified robotic devices in controlled laboratory settings and in simplified theoretical models. We must thus use the methods of physics to examine both locomotor successes and failures using parameter space exploration, systematic control, and techniques from dynamical systems. Using examples from our and others' research, we will discuss how such robophysical studies have begun to aid engineers in the creation of devices that have begun to achieve life-like locomotor abilities on and within complex environments, have inspired interesting physics questions in low dimensional dynamical systems, geometric mechanics and soft matter physics, and have been useful to develop models for biological locomotion in complex terrain. The rapidly decreasing cost of constructing robot models with easy access to significant computational power bodes well for scientists and engineers to engage in a discipline which can readily integrate experiment, theory and computation.

Power-Law Scaling of Early-Stage Forces during Granular Impact

“…[13] and many others [3,12,[14][15][16][17][18], the initial impact forces are consistently larger than expected from Poncelet drag or similar drag models, which is sometimes attributed [12] to a shock wave at impact [19]. These large forces are short lived but may be most important for determining damage to the grains and projectile [3,20] and for capturing the dynamics of a highly transient process like a jumping animal or robot [5,6]. However, there is currently no theory that captures these initial forces.…”

“…We find that the early-stage forces are inherently related to wave propagation, but the current theory of shocks in granular media cannot capture them, suggesting that a new theory is needed. The insensitivity of our results to many system details suggest that they may also apply to impacts into similar materials like foams and emulsions.High-speed impact by an intruder into a granular bed is a ubiquitous process with broad relevance in many disciplines, including ballistics [1-4], robotics [5,6], astrophysics [7], and earth science [8]. The forces exerted by the grains on the intruder are often described using Poncelet drag, which is dominated by a velocity-squared force with a nearly constant drag coefficient [9][10][11][12].…”

Implementation of Controlled Robot for Fire Detection and Extinguish to Closed Areas Based on Arduino

“…Mobile robots generally can move either by using wheeled mechanisms, like technology for vehicles, or by using articulated legs, the simplest of the biological approaches to locomotion [7]. In general, legged locomotion requires higher degrees of freedom when compared with wheeled locomotion and therefore greater mechanical complexity.in additi on to being simple; it is suitable very well to the flat ground.…”

When the goal is to generate a series of activities: A self-organized simulated robot arm

“…Abstracting from animal models, one may ask conversely to which extent compliant locomotion may be generated via self-organizing principles [10], that is in the absence of top-down control in the form of a central pattern generator. One talks in this context of 'embodiment' [11], when part of the computation generating locomotion is carried out by the elasto-mechanical properties of the constituting body [12]. For quadruped robots with legs that are independently controlled by single non-linear phase oscillators [13], it has been shown that the limb-specific sensorimotor feedback derived form pressure sensors leads to self-organized interlimb communications, with emerging gaits that correspond to walking, trotting and galloping [14].…”