A review on locomotion robophysics: the study of movement at the intersection of robotics, soft matter and dynamical systems (1602.04712v1)

Abstract: In this review we argue for the creation of a physics of moving systems -- a locomotion "robophysics" -- which we define as the pursuit of the discovery 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 study of complex robots in complex situations with systematic study of simplified robophysical devices in controlled laboratory settings and simplified theoretical models. We must thus use the methods of physics to examine successful and failed locomotion in simplified (abstracted) devices using parameter space exploration, systematic control, and techniques from dynamical systems. Using examples from our and other's research, we will discuss how such robophysical studies have begun to aid engineers in the creation of devices that begin 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 sophisticated 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.

• The paper establishes locomotion robophysics by showing that simplified robotic models can isolate core movement dynamics.
• The paper systematically explores environmental and control parameters through high-throughput experiments to map effective locomotion strategies.
• The paper integrates experimental findings with theory and geometric mechanics to propose robust, quantitative frameworks for optimizing motion in complex terrains.

An Expert Overview of Locomotion Robophysics

The paper "A review on locomotion robophysics" by Aguilar et al. provides a comprehensive analysis of the necessity for an interdisciplinary approach to studying self-propelled motion. This approach, termed "locomotion robophysics," integrates physics, engineering, and biology to address the challenges and complexities associated with locomotion in both natural and artificial systems. The authors assert the importance of employing simplified mechanical models and simulacra to complement complex robotic studies, aiming to discover universal principles governing effective movement across diverse environments.

Key Contributions and Findings

The paper emphasizes the importance of understanding locomotion through a physics-based framework, termed "robophysics," which employs the methodologies of experimental physics characterized by systematic experimentation and theoretical model development. Some of the vital contributions and analyses from the paper include:

1. Simplification for Insight:
   • The authors promote the approach of studying simplified robotic models in controlled environments to derive insights about complex movement. By leveraging these simplified models, researchers can effectively isolate and paper primary factors influencing locomotion without the interference of extraneous complexity inherent in full-scale robotic or biological systems.
2. Systematic Parameter Exploration:
   • A haLLMark of the robophysics approach outlined is the systematic variation of control and environmental parameters. This is achieved through high-throughput experimentation enabled by automation, allowing researchers to map out behaviors, successes, and failures systematically.
3. Integration of Theory and Experiment:
   • A significant focus is placed on the integration of theory, experiment, and computation. Using this trifecta, the authors advocate for a robust framework facilitating the understanding and potential control of complex locomotor phenomena seen across both biological and robotic entities.
4. Implications for Robotics and Biology:
   • The application of robophysical paper opens new opportunities in improving robotic mobility in unstructured and complicated terrains such as sandy slopes or granular substrates. Furthermore, insights gained extend to biological contexts, aiding in the understanding of locomotion in animals ranging from sidewinding snakes to locomotive strategies employed by sea turtles.
5. Geometric Mechanics as a Framework:
   • The authors explore the potential of geometric mechanics to serve as a "language" for robustly characterizing and predicting locomotive dynamics. This mathematical framework helps capture the essence of body shape changes and resultant motion, thereby providing a quantitative basis for gait optimization and control strategies.

Implications and Future Directions

The implications of this locomotion robophysics approach are broad and significant. Practically, this integrated, interdisciplinary methodology promises advancements in designing robots capable of navigating challenging and dynamic terrains, potentially surpassing the adaptability found in biological systems. Theoretically, it deepens our understanding of mobility, addressing foundational issues related to the robustness and adaptability of movement strategies across species and engineered systems alike.

The authors suggest further research into dynamically heterogeneous environments and advocate for continuous collaboration among physicists, biologists, and engineers. Investigation into wet granular systems, varied substrates, and collective dynamics in robotic systems are among the areas ripe for exploration. The robust integration of computational tools and experimental validation stands to further enhance the predictive power of models, serving as a critical feedback loop in advancing locological understanding and application.

In summary, this paper serves as a clarion call for a new disciplinary amalgamation, where robophysics not only aids in the comprehension of existing locomotion principles but also actively contributes to innovation and discovery in both synthetic and natural systems.