52 citations · 115 across the 20 of their papers we have counts for
28 papers
Learning to Exploit Passive Dynamics for Energy-Efficient Target Hopping of a Spring-Legged Quadcopter
Ruigang Chen, Qi Zhang, Zhicheng Zhong +3
Combining aerial thrust with spring-loaded hopping makes monopedal quadcopters promising for locomotion over complex terrain, but heuristic proportional-integral-derivative (PID) t…
Dynamics-Informed Reinforcement Learning for Agile and Energy-Efficient Locomotion of a Monopedal Hopping Quadcopter
Ruigang Chen, Qi Zhang, Zhicheng Zhong +3
Although aerial-legged robots offer combined agility and efficiency, controlling high-speed hopping under complex hybrid dynamics is challenging. Reinforcement Learning (RL) is pro…
Optimal control of a swimming robot based on Purcell's microswimmer model
Noam Berkovich Lahav, Oren Wiezel, Yizhar Or
Purcell's swimmer is a well-known planar model of a swimming microorganism, governed by low Reynolds number hydrodynamics, which is comprised of three rigid links connected by actu…
Dynamics, stability, and energy efficiency of an energy-recycling rimless wheel with spring-clutch legs
Tongchen Lin, Yanqiu Zheng, Chuhan Zhang +3
This paper proposes an energy-recycling rimless wheel with spring-clutch legs. The proposed mechanism uses a lockable clutch to store part of the impact-induced elastic energy afte…
Passive Vibration-Driven Locomotion
Anna Zigelman, Gilad Israel, Yizhar Or +1
We investigate a concept of passive, vibration-driven locomotion, in which a mechanical system achieves horizontal self-propulsion by resonantly harvesting energy from vertical env…
Sample Efficient Learning of Body-Environment Interaction of an Under-Actuated System
Zvi Chapnik, Yizhar Or, Shai Revzen
Geometric mechanics provides valuable insights into how biological and robotic systems use changes in shape to move by mechanically interacting with their environment. In high-fric…
Dynamics and multi-stability of a rotor-actuated Twistcar robot with passive steering joint
Anna Zigelman, Zitao Yu, Rom Levy +1
The nonlinear dynamics of many under-actuated wheeled platforms are governed by nonholonomic constraints of no-skid for passively rolling wheels, coupled with momentum balance. In…
Analysis and experiments of the dissipative Twistcar: direction reversal and asymptotic approximations
Rom Levy, Ari Dantus, Zitao Yu +1
Underactuated wheeled vehicles are commonly studied as nonholonomic systems with periodic actuation. Twistcar is a classical example inspired by a riding toy, which has been analyz…
Locomotion Dynamics of an Underactuated Three-Link Robotic Vehicle
Leonid Raz, Yizhar Or
The wheeled three-link snake robot is a well-known example of an underactuated system modelled using nonholonomic constraints, preventing lateral slippage (skid) of the wheels. A k…
Dynamics of Purcell-type microswimmers with active-elastic joints
Anna Zigelman, Gilad Ben Zvi, Yizhar Or
Purcell's planar three-link microswimmer is a classic model of swimming in low-Reynolds-number fluid, inspired by motion of flagellated microorganisms. Many works analyzed this mod…
Nonlinear dynamics and bifurcations of a planar undulating magnetic microswimmer
Jithu Paul, Yizhar Or, Oleg Gendelman
Swimming micro-organisms such as flagellated bacteria and sperm cells have fascinating locomotion capabilities. Inspired by their natural motion, there is an ongoing effort to deve…
Dynamics of reconfigurable straw-like elements
Dotan Ilssar, Michael Pukshansky, Yizhar Or +1
In this paper, we discuss the dynamic modeling of fluid-filled straw-like elements consisting of serially interconnected elastic frusta with both axisymmetric and antisymmetric deg…
Lamb-type solution and properties of unsteady Stokes equations
Itzhak Fouxon, Alexander Leshansky, Boris Rubinstein +1
We derive the general solution of the unsteady Stokes equations for an unbounded fluid in spherical polar coordinates, in both time and frequency domains. The solution is an expans…
Geometric analysis of gaits and optimal control for three-link kinematic swimmers
Oren Wiezel, Suresh Ramasamy, Nathan Justus +2
Many robotic systems locomote using gaits - periodic changes of internal shape, whose mechanical interaction with the robot's environment generate characteristic net displacements.…
Fluid-driven traveling waves in soft robots
Lior Salem, Amir D. Gat, Yizhar Or
Many marine creatures, gastropods, and earthworms generate continuous traveling waves in their bodies for locomotion within marine environments, complex surfaces, and inside narrow…
Viscous flow-fields in hyperelastic Chambers
Eran Ben-Haim, Dotan Ilssar, Yizhar Or +1
Viscous flows in hyperelastic chambers are relevant to many biological phenomena such as inhalation into the lung's acinar region and medical applications such as the inflation of…
Experimental Verification of Stability Theory for a Planar Rigid Body with Two Unilateral Frictional Contacts
Yizhar Or, Peter L. Varkonyi
Stability of equilibrium states in mechanical systems with multiple unilateral frictional contacts is an important practical requirement, with high relevance for robotic applicatio…
Dynamic Inchworm Crawling: Performance Analysis and Optimization of a Three-link Robot
Benny Gamus, Amir D. Gat, Yizhar Or
Inchworm crawling allows for both quasistatic and dynamic gaits at a wide range of actuation frequencies. This locomotion mechanism is common in nonskeletal animals and exploited e…
Understanding Legged Crawling for Soft-Robotics
Benny Gamus, Lior Salem, Amir D. Gat +1
Crawling is a common locomotion mechanism in soft robots and nonskeletal animals. In this work we propose modeling soft-robotic legged locomotion by approximating it with an equiva…
Leveraging viscous peeling in soft actuators and reconfigurable microchannel networks
Lior Salem, Benny Gamus, Yizhar Or +1
The research fields of microfluidics and soft robotics both involve complex small-scale internal channel networks, embedded within a solid structure. This work examines leveraging…
Single-Input Control of Multiple Fluid-Driven Elastic Actuators Via Interaction Between Bi-Stability and Viscosity
Eran Ben-Haim, Lior Salem, Yizhar Or +1
A leading concept in soft robotics actuation, as well as in microfluidics applications such as valves in lab-on-a-chip devices, is applying pressurized flow in cavities embedded wi…
Dynamic Walking on Slippery Surfaces: Demonstrating Stable Bipedal Gaits with Planned Ground Slippage
Wen-Loong Ma, Yizhar Or, Aaron D. Ames
Dynamic bipedal robot locomotion has achieved remarkable success due in part to recent advances in trajectory generation and nonlinear control for stabilization. A key assumption u…
Energy-optimal strokes for multi-link microswimmers: Purcell's loops and Taylor's waves reconciled
François Alouges, Antonio DeSimone, Laetitia Giraldi +2
Micron-scale swimmers move in the realm of negligible inertia, dominated by viscous drag forces. In this paper, we formulate the leading-order dynamics of a slender multi-link (N-l…
Inertial self-propulsion of spherical microswimmers by rotation-translation coupling
Itzhak Fouxon, Yizhar Or
We study swimming of small spherical particles who regulate fluid flow on their surface by applying tangential squirming strokes. We derive translational and rotational velocities…