17 accepted papers
Recent advancements in soft actuators have enabled soft continuum swimming robots to achieve higher efficiency and more closely mimic the behaviors of real marine animals. However, optimizing the design and control of these soft continuum robots remains a significant challenge. In this paper, we pre
Miniature-legged robots are constrained by their onboard computation and control, thus motivating the need for simple, first-principles-based geometric models that connect <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">periodic actuation or gaits</i
Geometric motion planning offers effective and interpretable gait analysis and optimization tools for locomoting systems. However, due to the curse of dimensionality in coordinate optimization, a key component of geometric motion planning, it is almost infeasible to apply current geometric motion pl…
Inertia-dominated mechanical systems can achieve net displacement by 1) periodically changing their shape (known as kinematic gait) and 2) adjusting their inertia distribution to utilize the existing nonzero net momentum (known as momentum gait). Therefore, finding the gait that most effectively uti…
Discrete and periodic contact switching is a key characteristic of steady-state legged locomotion. This letter introduces a framework for modeling and analyzing this contact-switching behavior through the framework of geometric mechanics on a toy robot model that can make continuous limb swings and
A key problem in robotic locomotion is in finding optimal shape changes to effectively displace systems through the world. Variational techniques for gait optimization require estimates of body displacement per gait cycle; however, these estimates introduce error due to unincluded high order terms.…
The gaits of locomoting systems are typically designed to maximize some sort of efficiency, such as cost of transport or speed. Equally important is the ability to modulate such a gait to effect turning maneuvers. For drag-dominated systems, geometric mechanics provides an elegant and practical fram…
The complex dynamics of agile robotic legged locomotion requires motion planning to intelligently adjust footstep locations. Often, bipedal footstep and motion planning use mathematically simple models such as the linear inverted pendulum, instead of dynamically-rich models that do not have closed-f…
The Robotic locomotion community is interested in optimal gaits for control. Based on the optimization criterion, however, there could be a number of possible optimal gaits. For example, the optimal gait for maximizing displacement with respect to cost is quite different from the maximum displacemen…
In this letter, we describe an approach to achieve dynamic legged locomotion on physical robots which combines existing methods for control with reinforcement learning. Specifically, our goal is a control hierarchy in which highest-level behaviors are planned through reduced-order models, which desc
We propose a method to generate actuation plans for a reduced order, dynamic model of bipedal running. This method explicitly enforces robustness to ground uncertainty. The plan generated is not a fixed body trajectory that is aggressively stabilized: instead, the plan interacts with the passive dyn…
Frictional anisotropy, as produced by the directionality of scales in snake skin, is necessary to propel snakes across flat, hard surfaces. This work illustrates the design, fabrication, and testing of a snake-inspired skin based on kirigami techniques that, when attached to a soft snake robot, impr
Jumping spiders are capable of targeted jumps by using their front legs to guide the release of energy from their rear legs. In this paper, we present a simplified model of the jumping spider based on the anatomy of the real spider. The immediate goal of this model is to understand how the geometry
Snake robots can contact their environments along their whole bodies. This distributed contact makes them versatile and robust locomotors, but also makes controlling them a chal- lenging problem involving high-dimensional configuration spaces, with no direct way to break their motion down into âdr…
In this work, we use first principles of kinematics to provide a fundamental insight into mechanical power distribution within multi-actuator machines. Individual actuator powersânot their net sumâdetermine the efficiency and actuator size of a multi-joint machine. Net power delivered to the env…
The spring-mass locomotion paradigm is showing great promise as a template for agile and efficient robots. Efficiency and stability are enabled by the passive generation of locomotion patterns, rather than enforced by the control system. However, as leg designs develop more articulation and complexi…
A casting manipulator is a robot that launches a payload as a projectile then alters the ballistic trajectory by pulling on an attached tether. Prior work in casting manipulation has focused on applying impulses through the tether to place the payload at a specific location and then retract it. In t…