Alexander S. Boxerbaum

Case Western Reserve University, Cleveland, Ohio, United States

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Publications (26)5.09 Total impact

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    ABSTRACT: In this work, we present a dynamic simulation of an earthworm-like robot moving in a pipe with radially symmetric Coulomb friction contact. Under these conditions, peristaltic locomotion is efficient if slip is minimized. We characterize ways to reduce slip-related losses in a constant-radius pipe. Using these principles, we can design controllers that can navigate pipes even with a narrowing in radius. We propose a stable heteroclinic channel controller that takes advantage of contact force feedback on each segment. In an example narrowing pipe, this controller loses 40% less energy to slip compared to the best-fit sine wave controller. The peristaltic locomotion with feedback also has greater speed and more consistent forward progress.
    Full-text · Article · Aug 2013 · Bioinspiration & Biomimetics
  • Alexander S. Boxerbaum · Kathryn A. Daltorio · Hillel J. Chiel · Roger D. Quinn
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    ABSTRACT: In this paper, we investigate control architectures that combine implicit models of behavior with ubiquitous sensory input, for soft hyper-redundant robots. Using a Wilson-Cowan neuronal model in a continuum arrangement that mirrors the arrangement of muscles in an earthworm, we can create a wide range of steady waves with descending signals. Here, we demonstrate how sensory feedback from individual segment strains can be used to modulate the behavior in desirable ways.
    No preview · Chapter · Jul 2012
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    ABSTRACT: Water and land mine detection performed on beaches and in turbulent surf-zone areas pose specific challenges to robot operation. A robot which is useful in the effort to disarm mined waterways must be capable of navigating rocky terrain, hard-packed wet sand and loose dry sand, and constantly changing underwater currents common to these environments. It is also preferable for them to be man-packable and have a large payload capacity for sensors. Studies of insect locomotion mechanisms, and their abstraction to specific movement principles, provides a framework for designing robots that can quickly adapt to varied terrain types. Based on recent success with beach environment autonomy and a new rugged waterproof robotic platform, we propose a new design that will fuse a range of insect-inspired passive mechanisms with active control strategies to seamlessly adapt to and traverse through a range of challenging environments both in and out of the water.
    No preview · Conference Paper · Jun 2012
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    Conference Paper: Worms, waves and robots
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    ABSTRACT: The Biologically Inspired Robotics group at Case Western Reserve University has developed several innovative designs for a new kind of robot that uses peristalsis, the method of locomotion used by earthworms. Unlike previous wormlike robots, our concept uses a continuously deformable outer mesh that interpolates the body position between discrete actuators. Here, we summarize our progress with this soft hyper-redundant robot.
    Full-text · Conference Paper · May 2012
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    ABSTRACT: Video submission to ICRA '12: "Worms, Waves, and Robots". Narrated. See associated short paper for further details: https://researchgate.net/publication/261416542 Please contact me for higher quality versions of this video or for any usage questions. Video file details: 2 min. 56 sec., 71.5 MB, 1280 x 720p, 29.97 fps, H.264 video, AAC stereo audio
    Full-text · Dataset · May 2012
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    Alexander S. Boxerbaum · Kendrick M. Shaw · Hillel J. Chiel · Roger D. Quinn
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    ABSTRACT: We have developed several innovative designs for a new kind of robot that uses a continuous wave of peristalsis for locomotion, the same method that earthworms use, and report on the first completed prototypes. This form of locomotion is particularly effective in constrained spaces, and although the motion has been understood for some time, it has rarely been effectively or accurately implemented in a robotic platform. As an alternative to robots with long segments, we present a technique using a braided mesh exterior to produce smooth waves of motion along the body of a worm-like robot. We also present a new analytical model of this motion and compare predicted robot velocity to a 2D simulation and a working prototype. Because constant-velocity peristaltic waves form due to accelerating and decelerating segments, it has been often assumed that this motion requires strong anisotropic ground friction. However, our analysis shows that with smooth, constant velocity waves, the forces that cause accelerations within the body sum to zero. Instead, transition timing between aerial and ground phases plays a critical role in the amount of slippage, and the final robot speed. The concept is highly scalable, and we present methods of construction at two different scales.
    Full-text · Article · Mar 2012 · The International Journal of Robotics Research
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    ABSTRACT: Surf-zone environments represent an extreme challenges to robot operation. A robot that autonomously navigates rocky terrain, constantly changing underwater currents, hard-packed moist sand and loose dry sand characterizing this environment, would have significant utility in a range of defence and civilian missions. The study of animal locomotion mechanisms can elucidate specific movement principles that can be applied to address these demands. In this work, we report on the design and optimization of a biologically inspired amphibious robot for deployment and operation in an ocean beach environment. We specifically report a new design fusing a range of insectinspired passive mechanisms with active autonomous control architectures to seamlessly adapt to and traverse a range of challenging substrates both in and out of the water, and the design and construction of SeaDog, a proof-of-concept amphibious robot built for navigating rocky or sandy beaches and turbulent surf zones. The robot incorporates a layered hull and chassis design that is integrated into a waterproof Explorer Case in order to provide a large, protected payload in an easy-to-carry package. It employs a rugged drivetrain with four wheel-legs and a unique tail design and actuation strategy to aid in climbing, swimming and stabilization. Several modes of terrestrial and aquatic locomotion are suggested and tested versus range of mobility metrics, including data obtained in simulation and hardware testing. A waterproofing strategy is also tested and discussed, providing a foundation for future generations of amphibious mobile robots.
    No preview · Article · Jan 2012
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    ABSTRACT: While soft-bodied animals have an extraordinarily diverse set of robust behaviors, soft-bodied robots have not yet achieved this flexiblity. In this paper, we explore controlling a truly continuously deformable structure with a CPG-like network. Our recently completed soft wormlike robot with a continuously deformable outer mesh, along with a continuum analysis of peristalsis, has suggested the neural control investigated here. We use a Wilson-Cowan neuronal model in a continuum arrangement that mirrors the arrangement of muscles in an earthworm. We show that such a system is well suited to incorporate sensory input and can create both rhythmic and nonrhythmic activity. The system can be controlled using straightforward descending signals whose effects are largely decoupled and can modulate the properties from CPG-like behaviors to static waves. This approach will be useful for designing robotic systems that express multiple adaptive behavioral modes.
    Full-text · Conference Paper · Sep 2011
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    ABSTRACT: Animal behavioral, physiological and neurobiological studies are providing a wealth of inspirational data for robot design and control. Several very different biologically inspired mobile robots will be reviewed. A robot called DIGbot is being developed that moves independent of the direction of gravity using Distributed Inward Gripping (DIG) as a rapid and robust attachment mechanism observed in climbing animals. DIGbot is an 18 degree of freedom hexapod with onboard power and control systems. Passive compliance in its feet, which is inspired by the flexible tarsus of the cockroach, increases the robustness of the adhesion strategy and enables DIGbot to execute large steps and stationary turns while walking on mesh screens. A Whegs™ robot, inspired by insect locomotion principles, is being developed that can be rapidly reconfigured between tracks and wheel-legs and carry GeoSystems Zipper Mast. The mechanisms that cause it to passively change its gait on irregular terrain have been integrated into its hubs for a compact and modular design. The robot is designed to move smoothly on moderately rugged terrain using its tracks and run on irregular terrain and stairs using its wheel-legs. We are also developing soft bodied robots that use peristalsis, the same method of locomotion earthworms use. We present a technique of using a braided mesh exterior to produce fluid waves of motion along the body of the robot that increase the robot's speed relative to previous designs. The concept is highly scalable, for endoscopes to water, oil or gas line inspection.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
    No preview · Article · May 2011
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    ABSTRACT: Animal behavioral, physiological and neurobiological studies are providing a wealth of inspirational data for robot design and control. Several very different biologically inspired mobile robots will be reviewed. A robot called DIGbot is being developed that moves independent of the direction of gravity using Distributed Inward Gripping (DIG) as a rapid and robust attachment mechanism observed in climbing animals. DIGbot is an 18 degree of freedom hexapod with onboard power and control systems. Passive compliance in its feet, which is inspired by the flexible tarsus of the cockroach, increases the robustness of the adhesion strategy and enables DIGbot to execute large steps and stationary turns while walking on mesh screens. A Whegs™ robot, inspired by insect locomotion principles, is being developed that can be rapidly reconfigured between tracks and wheel-legs and carry GeoSystems Zipper Mast. The mechanisms that cause it to passively change its gait on irregular terrain have been integrated into its hubs for a compact and modular design. The robot is designed to move smoothly on moderately rugged terrain using its tracks and run on irregular terrain and stairs using its wheel-legs. We are also developing soft bodied robots that use peristalsis, the same method of locomotion earthworms use. We present a technique of using a braided mesh exterior to produce fluid waves of motion along the body of the robot that increase the robot's speed relative to previous designs. The concept is highly scalable, for endoscopes to water, oil or gas line inspection.
    No preview · Article · May 2011 · Proceedings of SPIE - The International Society for Optical Engineering
  • M.J. Smith · A. Boxerbaum · G.L. Peterson · R.D. Quinn
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    ABSTRACT: When a camera is affixed on a dynamic mobile robot, image stabilization is the first step towards more complex analysis on the video feed. This paper presents a novel electronic image stabilization (EIS) algorithm for highly dynamic mobile robotic platforms. The algorithm combines optical flow motion parameter estimation with angular rate data provided by a strapdown inertial measurement unit (IMU). A discrete Kalman filter in feedforward configuration is used for optimal fusion of the two data sources. Performance evaluations are conducted using a simulated video truth model (capturing the effects of image translation, rotation, blurring, and moving objects), and live test data. Live data was collected from a camera and IMU affixed to the DAGSI Whegs mobile robotic platform as it navigated through a hallway. Template matching, feature detection, optical flow, and inertial measurement techniques are compared and analyzed to determine the most suitable algorithm for this specific type of image stabilization. Pyramidal Lucas-Kanade optical flow using Shi-Tomasi good features in combination with inertial measurement is the EIS algorithm found to be superior. In the presence of moving objects, fusion of inertial measurement reduces optical flow root-mean-squared (RMS) error in motion parameter estimates by 40%.
    No preview · Conference Paper · Nov 2010
  • Alexander S Boxerbaum · Hillel J Chiel · Roger D Quinn
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    ABSTRACT: We have developed several innovative designs for a new kind of robot that uses peristalsis for locomotion, the same method that earthworms use, and report on the first completed prototype (Fig. 1). This form of locomotion is particularly effective in constrained spaces, and although the motion has been understood for some time, it has rarely been effectively or accurately implemented in a robotic platform. We address some reasons for this, including some common misconceptions within the field. We present a technique using a braided mesh exterior to produce fluid waves of motion along the body of a worm-like robot. We also present a new analytical model of this motion and compare predicted robot velocity to a 2-D simulation. Unlike previous mathematical models of peristaltic motion, our model suggests that friction is not a limiting factor in robot speed, but only in acceleration. The concept is highly scalable, and we present methods of construction at two different scales.
    No preview · Conference Paper · Jun 2010
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    ABSTRACT: The capability of autonomous platforms to function on beaches and in the ocean surf-zone is critical for a wide range of military and civilian operations. Of particular importance is the ability to navigate autonomously through the rocky terrain, hard-packed moist sand, and loose dry sand characterizing this environment. The study of animal locomotion mechanisms can elucidate specific movement principles that can be applied to address these demands. In this work, we report the design, fabrication, control system development, simulation, and field testing of a biologically inspired autonomous robot for deployment and operation in an ocean beach environment. The robot successfully fuses a range of insect-inspired passive mechanisms with active autonomous control architectures to seamlessly adapt to and traverse through a range of challenging substrates.Field testing establishes the performance of the robot to navigate semi-rugged terrain in the surf-zone environment including soft to hard-packed sand, mild to medium inclines, and rocky terrain. Platform autonomy is shown to be effective for navigation and communication. The fusion of passive mechanisms and active control algorithms results in a robot with mobility comparable to a legged vehicle with a control system of comparable simplicity to a wheeled robot. Based on the success of this platform, we further introduce the design of a fully amphibious robot designed to extend its performance to completely undersea surroundings.
    No preview · Article · Mar 2010 · International Journal of Design & Nature and Ecodynamics
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    ABSTRACT: Surf zone environments pose extreme challenges to robot operation. A robot that could autonomously navigate through the rocky terrain, constantly changing underwater currents, hard-packed moist sand, and loose dry sand characterizing this environment, would have very significant utility for a range of defence and civilian missions. The study of animal locomotion mechanisms can elucidate specific movement principles that can be applied to address these demands. In this work, we report on the design and optimization of a biologically inspired autonomous robot for deployment and operation in an ocean beach environment. Based on recent success with beach environment autonomy and a new rugged waterproof robotic platform, we propose a new design that will fuse a range of insect-inspired passive mechanisms with active autonomous control architectures to seamlessly adapt to and traverse through a range of challenging substrates both in and out of the water.
    Full-text · Conference Paper · Aug 2009
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    Alexander Boxerbaum · Hillel Chiel · Roger Quinn
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    ABSTRACT: We have developed several innovative designs for a new kind of robot that uses peristalsis, the same method of locomotion earthworms use, and are currently building the first prototypes. This method of locomotion is particularly effective in constrained spaces, and although the motion has been understood for some time, it has never been effectively or accurately implemented in a robotic platform. We address the reasons for this, including some common misconceptions within the field, and present a technique of using a braided mesh exterior to produce fluid waves of motion along the body of the robot. The concept is highly scalable, and we present methods of construction at two different scales. We also present a concept for a robot specifically designed for pipe crawling, where it can take advantage of flowing fluid to locomote very efficiently, even upstream. A soft-bodied worm-like robot could find many uses in domestic and military applications, where it could be used for inspecting pipelines, patrolling or maintaining tortuous plumbing, for exploring complex underwater structures, or for search and rescue missions in piles of rubble. Miniaturized versions of worm-like robots could find multiple applications in medicine, such as endoscopy or angioplasty. A previous worm robot was developed using long braided pneumatic actuators (artificial muscles) in series (4). The robot moved much slower than expected. The power requirements were substantial and required an off-board pressurized air supply. Its unusually slow speed made us re-evaluate our understanding of peristaltic motion. We found that not only our robot, but all robots known to attempt peristaltic motion use an inappropriately crude approximation by using very long actuators with gaps between actuators. This is probably a direct result of the way peristaltic motion is explained in the literature, with large blocks illustrating differentially small muscle segments for the purpose of clarity. However, peristaltic motion is a wave of motion, and the better the approximation of this, the more "fluid" the motion. Our previous robot moved very slowly because this crude approximation of peristaltic motion causes the robot to slip when trying to move suddenly with each actuation. Combining this with the problems of power autonomy, it became clear that the solution required a radically new approach.
    Full-text · Article · Jan 2009
  • A.S. Boxerbaum · Julio Oro · Gilbert Peterson · R.D. Quinn
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    ABSTRACT: Current autonomous and semi-autonomous robotic platforms are limited to functioning in highly structured environments such as buildings and roads. Autonomous robots that could explore and navigate rugged terrain and highly unstructured environments such as collapsed buildings would have large dividends in civilian and military applications. In this work, we present the next generation of Whegstrade robots, DAGSI Whegstrade, which has been completed and extensively field tested. Several innovations have made the robot more rugged and well suited to autonomous operation. Specifically, an actively controlled, passively compliant body joint has been tested in three different modes of operation to judge the usefulness of the mechanism. A two-dimensional dynamic simulation of the robot has also been constructed, and has been used to study the effects of weight distribution on obstacle climbing and to investigate future autonomous climbing strategies. Moving the center of mass forward allowed the robot to climb taller obstacles. DAGSI Whegstrade can climb rectangular obstacles as tall as 2.19 times the length of a leg.
    No preview · Conference Paper · Oct 2008
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    ABSTRACT: We report the successful design and fabrication of an autonomous robot, dubbed the CASE/NPS Beach Whegstrade robot, capable of navigating the challenging terrain of the non-submersed surf-zone region based on abstracted biological inspiration. Abstracted biological inspiration attempts to distill salient biological principles and implement them using presently available technologies; its efficacy lies in the successful fusion of organic and inorganic architectures such that the proper level of influence of biology is established for optimum performance. The CASE/NPS Beach Whegstrade robot benefits from insect inspired mechanisms of locomotion for movement over challenging and different terrains. The robotpsilas mechanics are an integrated and essential part of its control system. It does not have, or need, sensors and control circuits to actively change its gait. Instead, its mechanics cause it to passively adapt its gait appropriately to very different terrains. Therefore, its motor control circuits are reduced to controlling broad directives of the robot. Its navigational system is a higher-level circuit that communicates desired speed and heading to the local control system. The confluence of active and passive control mechanisms in the robot have resulted in a system with the simplicity of a wheeled vehicle that nevertheless facilitates the mobility of a legged vehicle.
    No preview · Conference Paper · Oct 2008
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    ABSTRACT: Insects and geckos use claws and adhesive pads to negotiate both rough and smooth surfaces. Climbing robots have been designed to mimic various aspects of these and other biological systems to operate in specific vertical environments. Robots that adhere to the surface through suction cups, magnetic end-effectors, or adhesive pads can climb featureless, flat, or smoothly curved surfaces. Vortex-generating climbers do not require smooth surfaces. Robots have been designed with end-effectors that match specific features of the environment, such as peg-holes, handrails, climbing-wall footholds, and poles. Robots have also been fitted with insect-inspired spines to scale rough vertical surfaces.
    No preview · Conference Paper · Jun 2008
  • Alexander S. Boxerbaum · Julio Oro · Roger D. Quinn
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    ABSTRACT: DAGSI Whegs is the latest generation of full size Whegs robots. The robot is designed for collaborative work with the Air Force Institute of Technology (AFIT) in SLAM with active feature recognition. Whegs vehicles use abstracted biological principles to navigate over irregular and varied terrain with little or no low level control. Torsionally compliant devices in the drive train of each wheel-leg allow its gait to passively adapt when climbing large obstacles or steep inclines. Whegs is similar to the RHex line of robots that preceded Whegs in that the foot motion of all 6 legs is circular, but it differs in many aspects: 3 leg-spokes versus 1, 1 drive motor vs. 6, leg rotation for steering instead of skid steering, passive gait adaptation vs. active gait control, and Whegs has a body joint.
    No preview · Conference Paper · Jun 2008

  • No preview · Conference Paper · Jan 2008