spool
How does 3D printing work?
Technology Engineering How does 3D printing work? Rapid prototyping is a relatively simple process that can be scaled up or down. Breakthroughs, discoveries, and DIY tips sent every weekday. Since 3D printers debuted in the 1980s, the devices have been used to build meat, chocolate, human organs, clothing, cars, and houses . It's more mainstream than ever, and you can buy a machine for less than $200.
Educational SoftHand-A: Building an Anthropomorphic Hand with Soft Synergies using LEGO MINDSTORMS
Lepora, Jared K., Li, Haoran, Psomopoulou, Efi, Lepora, Nathan F.
Abstract-- This paper introduces an anthropomorphic robot hand built entirely using LEGO MINDSTORMS: the Educational SoftHand-A, a tendon-driven, highly-underactuated robot hand based on the Pisa/IIT SoftHand and related hands. T o be suitable for an educational context, the design is constrained to use only standard LEGO pieces with tests using common equipment available at home. The hand features dual motors driving an agonist/antagonist opposing pair of tendons on each finger, which are shown to result in reactive fine control. The finger motions are synchonized through soft synergies, implemented with a differential mechanism using clutch gears. Altogether, this design results in an anthropomorphic hand that can adaptively grasp a broad range of objects using a simple actuation and control mechanism. Since the hand can be constructed from LEGO pieces and uses state-of-the-art design concepts for robotic hands, it has the potential to educate and inspire children to learn about the frontiers of modern robotics.
Switch-based Independent Antagonist Actuation with a Single Motor for a Soft Exosuit
Vadeyar, Atharva, Varghese, Rejin John, Burdet, Etienne, Farina, Dario
The use of a cable-driven soft exosuit poses challenges with regards to the mechanical design of the actuation system, particularly when used for actuation along multiple degrees of freedom (DoF). The simplest general solution requires the use of two actuators to be capable of inducing movement along one DoF. However, this solution is not practical for the development of multi-joint exosuits. Reducing the number of actuators is a critical need in multi-DoF exosuits. We propose a switch-based mechanism to control an antagonist pair of cables such that it can actuate along any cable path geometry. The results showed that 298.24ms was needed for switching between cables. While this latency is relatively large, it can reduced in the future by a better choice of the motor used for actuation.
Modeling and parametric optimization of 3D tendon-sheath actuator system for upper limb soft exosuit
Yadav, Amit, Kumar, Nitesh, Surana, Shaurya, Ramasamy, Aravind, Pal, Abhishek Rudra, Santapuri, Sushma, Kumar, Lalan, Muthukrishnan, Suriya Prakash, Bhasin, Shubhendu, Roy, Sitikantha
This paper presents an analysis of parametric characterization of a motor driven tendon-sheath actuator system for use in upper limb augmentation for applications such as rehabilitation, therapy, and industrial automation. The double tendon sheath system, which uses two sets of cables (agonist and antagonist side) guided through a sheath, is considered to produce smooth and natural-looking movements of the arm. The exoskeleton is equipped with a single motor capable of controlling both the flexion and extension motions. One of the key challenges in the implementation of a double tendon sheath system is the possibility of slack in the tendon, which can impact the overall performance of the system. To address this issue, a robust mathematical model is developed and a comprehensive parametric study is carried out to determine the most effective strategies for overcoming the problem of slack and improving the transmission. The study suggests that incorporating a series spring into the system's tendon leads to a universally applicable design, eliminating the need for individual customization. The results also show that the slack in the tendon can be effectively controlled by changing the pretension, spring constant, and size and geometry of spool mounted on the axle of motor.
Stiffness Change for Reconfiguration of Inflated Beam Robots
Do, Brian H., Wu, Shuai, Zhao, Ruike Renee, Okamura, Allison M.
Active control of the shape of soft robots is challenging. Despite having an infinite number of passive degrees of freedom (DOFs), soft robots typically only have a few actively controllable DOFs, limited by the number of degrees of actuation (DOAs). The complexity of actuators restricts the number of DOAs that can be incorporated into soft robots. Active shape control is further complicated by the buckling of soft robots under compressive forces; this is particularly challenging for compliant continuum robots due to their long aspect ratios. In this work, we show how variable stiffness can enable shape control of soft robots by addressing these challenges. Dynamically changing the stiffness of sections along a compliant continuum robot can selectively "activate" discrete joints. By changing which joints are activated, the output of a single actuator can be reconfigured to actively control many different joints, thus decoupling the number of controllable DOFs from the number of DOAs. We demonstrate embedded positive pressure layer jamming as a simple method for stiffness change in inflated beam robots, its compatibility with growing robots, and its use as an "activating" technology. We experimentally characterize the stiffness change in a growing inflated beam robot and present finite element models which serve as guides for robot design and fabrication. We fabricate a multi-segment everting inflated beam robot and demonstrate how stiffness change is compatible with growth through tip eversion, enables an increase in workspace, and achieves new actuation patterns not possible without stiffening.
Enabling Under-Ice Geochemical Observations with a Size, Weight, and Power-Constrained Robot
Horowitz, Jess, Preston, Victoria, Michel, Anna P. M.
Estimates of greenhouse gas emissions from Arctic estuarine environments are dominated by in situ summer-time ice-free dissolved gas measurements due to the logistical ease of performing field observations in these conditions. Recent evidence in coastal Arctic environments, however, has demonstrated that dissolved methane (CH4) and carbon dioxide (CO2) are strongly seasonally variable, and at least one significant gas ventilation event occurs during the spring freshet. Whether the Arctic serves as a source or sink of greenhouse emissions has significant implications on modeling climate change and its feedback mechanisms. To enable higher resolution spatiotemporal measurements of dissolved gases in typically undersampled conditions, remotely operated vehicles (ROVs) can be used to extract near continuous water samples below ice before and during the spring freshet. Here, we present a size, weight, and power-constrained (SWAP) underwater vehicle (UV) and novel geochemical sampling system suitable for taking under-ice geochemical observations and demonstrate the proposed system in a field-analog setting for Arctic estuarine studies.
How to Deploy a 10-km Interferometric Radio Telescope on the Moon with Just Four Tethered Robots
McGarey, Patrick, Nesnas, Issa A., Rajguru, Adarsh, Bezkrovny, Matthew, Jamnejad, Vahraz, Lux, Jim, Sunada, Eric, Teitelbaum, Lawrence, Miller, Alexander, Squyres, Steve W., Hallinan, Gregg, Hegedus, Alex, Burns, Jack O.
The Far-side Array for Radio Science Investigations of the Dark ages and Exoplanets (FARSIDE) is a proposed mission concept to the lunar far side that seeks to deploy and operate an array of 128 dual-polarization, dipole antennas over a region of 100 square kilometers. The resulting interferometric radio telescope would provide unprecedented radio images of distant star systems, allowing for the investigation of faint radio signatures of coronal mass ejections and energetic particle events and could also lead to the detection of magnetospheres around exoplanets within their parent star's habitable zone. Simultaneously, FARSIDE would also measure the "Dark Ages" of the early Universe at a global 21-cm signal across a range of red shifts (z approximately 50-100). Each discrete antenna node in the array is connected to a central hub (located at the lander) via a communication and power tether. Nodes are driven by cold=operable electronics that continuously monitor an extremely wide-band of frequencies (200 kHz to 40 MHz), which surpass the capabilities of Earth-based telescopes by two orders of magnitude. Achieving this ground-breaking capability requires a robust deployment strategy on the lunar surface, which is feasible with existing, high TRL technologies (demonstrated or under active development) and is capable of delivery to the surface on next-generation commercial landers, such as Blue Origin's Blue Moon Lander. This paper presents an antenna packaging, placement, and surface deployment trade study that leverages recent advances in tethered mobile robots under development at NASA's Jet Propulsion Laboratory, which are used to deploy a flat, antenna-embedded, tape tether with optical communication and power transmission capabilities.
What are the latest artificial intelligence trends?
There is something so awe-inspiring and sublime about watching unmanned drones or flying cars or the stuff of dreams. Now, you don't need to worry as the future of Artificial Intelligence is here. From visors to Virtual Reality or Augmented Reality headsets to mechanized robots which would replace humans in the immediate future. One prominent example of the lure and reach that Artificial Technology has is that we grapple with it daily; we are oblivious to that fact. A restaurant in Indira Nagar in the hinterland of Bangalore is robot-centric wherein your food is served by this.
Meet the CHUGBOT: Robotic hand that can catch a beer and crush it could revolutionize prosthetics
Scientists have developed what could turn out to be the most lifelike robotic prosthetic hand yet. The technology, developed by researchers from Cornell University, takes a page from the machinery used in a car to give the robotic arm dexterity that's comparable to a human. And to demonstrate this, the hand was able to nimbly catch a can of beer and even crush it with remarkable strength. Researchers created a life-like robotic prosthetic hand that uses a'transmission' to allow it to alternate between strength and speed. The transmission, which they call an elastomeric passive transmission, is essentially a cylindrical spool with a'tendon' wrapped around it.