Goto

Collaborating Authors

 servo


Low-Cost Open-Source Ambidextrous Robotic Hand with 23 Direct-Drive servos for American Sign Language Alphabet

Amador, Kelvin Daniel Gonzalez

arXiv.org Artificial Intelligence

Accessible communication through sign language is vital for deaf communities, 1 yet robotic solutions are often costly and limited. This study presents VulcanV3, a low- 2 cost, open-source, 3D-printed ambidextrous robotic hand capable of reproducing the full 3 American Sign Language (ASL) alphabet (52 signs for right- and left-hand configurations). 4 The system employs 23 direct-drive servo actuators for precise finger and wrist movements, 5 controlled by an Arduino Mega with dual PCA9685 modules. Unlike most humanoid upper- 6 limb systems, which rarely employ direct-drive actuation, VulcanV3 achieves complete ASL 7 coverage with a reversible design. All CAD files and code are released under permissive 8 open-source licenses to enable replication. Empirical tests confirmed accurate reproduction 9 of all 52 ASL handshapes, while a participant study (n = 33) achieved 96.97% recognition 10 accuracy, improving to 98.78% after video demonstration. VulcanV3 advances assistive 11 robotics by combining affordability, full ASL coverage, and ambidexterity in an openly 12 shared platform, contributing to accessible communication technologies and inclusive 13 innovation.


Low-cost Real-world Implementation of the Swing-up Pendulum for Deep Reinforcement Learning Experiments

Böhm, Peter, Pounds, Pauline, Chapman, Archie C.

arXiv.org Artificial Intelligence

Deep reinforcement learning (DRL) has had success in virtual and simulated domains, but due to key differences between simulated and real-world environments, DRL-trained policies have had limited success in real-world applications. To assist researchers to bridge the \textit{sim-to-real gap}, in this paper, we describe a low-cost physical inverted pendulum apparatus and software environment for exploring sim-to-real DRL methods. In particular, the design of our apparatus enables detailed examination of the delays that arise in physical systems when sensing, communicating, learning, inferring and actuating. Moreover, we wish to improve access to educational systems, so our apparatus uses readily available materials and parts to reduce cost and logistical barriers. Our design shows how commercial, off-the-shelf electronics and electromechanical and sensor systems, combined with common metal extrusions, dowel and 3D printed couplings provide a pathway for affordable physical DRL apparatus. The physical apparatus is complemented with a simulated environment implemented using a high-fidelity physics engine and OpenAI Gym interface.


WHERE-Bot: a Wheel-less Helical-ring Everting Robot Capable of Omnidirectional Locomotion

Feng, Siyuan, Yan, Dengfeng, Liu, Jin, Han, Haotong, Kühl, Alexandra, Li, Shuguang

arXiv.org Artificial Intelligence

Compared to conventional wheeled transportation systems designed for flat surfaces, soft robots exhibit exceptional adaptability to various terrains, enabling stable movement in complex environments. However, due to the risk of collision with obstacles and barriers, most soft robots rely on sensors for navigation in unstructured environments with uncertain boundaries. In this work, we present the WHERE-Bot, a wheel-less everting soft robot capable of omnidirectional locomotion. Our WHERE-Bot can navigate through unstructured environments by leveraging its structural and motion advantages rather than relying on sensors for boundary detection. By configuring a spring toy ``Slinky'' into a loop shape, the WHERE-Bot performs multiple rotational motions: spiral-rotating along the hub circumference, self-rotating around the hub's center, and orbiting around a certain point. The robot's trajectories can be reprogrammed by actively altering its mass distribution. The WHERE-Bot shows significant potential for boundary exploration in unstructured environments.

  Country:
  Genre: Research Report (0.50)
  Industry: Energy > Oil & Gas (0.46)

A Decapod Robot with Rotary Bellows-Enclosed Soft Transmissions

He, Yiming, Wang, Yuchen, Zhang, Yunjia, Li, Shuguang

arXiv.org Artificial Intelligence

Soft crawling robots exhibit efficient locomotion across various terrains and demonstrate robustness to diverse environmental conditions. Here, we propose a valveless soft-legged robot that integrates a pair of rotary bellows-enclosed soft transmission systems (R-BESTS). The proposed R-BESTS can directly transmit the servo rotation into leg swing motion. A timing belt controls the pair of R-BESTS to maintain synchronous rotation in opposite phases, realizing alternating tripod gaits of walking and turning. We explored several designs to understand the role of a reinforcement skeleton in twisting the R-BESTS' input bellows units. The bending sequences of the robot legs are controlled through structural design for the output bellows units. Finally, we demonstrate untethered locomotion with the soft robotic decapod. Experimental results show that our robot can walk at 1.75 centimeters per second (0.07 body length per second) for 90 min, turn with a 15-centimeter (0.6 BL) radius, carry a payload of 200 g, and adapt to different terrains.

  Country: Asia > China (0.15)
  Genre: Research Report > New Finding (0.48)
  Industry:

Camber-changing flapping hydrofoils for efficient and environmental-safe water propulsion system

Romanello, Luca, Hohaus, Leonard, Schmitt, David-Marian, Kovac, Mirko, Armanini, Sophie F.

arXiv.org Artificial Intelligence

This research introduces a novel hydrofoil-based propulsion framework for unmanned aquatic robots, inspired by the undulating locomotion observed in select aquatic species. The proposed system incorporates a camber-modulating mechanism to enhance hydrofoil propulsive force generation and eventually efficiency. Through dynamic simulations, we validate the effectiveness of the camber-adjusting hydrofoil compared to a symmetric counterpart. The results demonstrate a significant improvement in horizontal thrust, emphasizing the potential of the cambering approach to enhance propulsive performance. Additionally, a prototype flipper design is presented, featuring individual control of heave and pitch motions, as well as a camber-adjustment mechanism. The integrated system not only provides efficient water-based propulsion but also offers the capacity for generating vertical forces during take-off maneuvers for seaplanes. The design is tailored to harness wave energy, contributing to the exploration of alternative energy resources. This work advances the understanding of bionic oscillatory principles for aquatic robots and provides a foundation for future developments in environmentally safe and agile underwater exploration.


Three-dimensional geometric resolution of the inverse kinematics of a 7 degree of freedom articulated arm

González, Antonio Losada

arXiv.org Artificial Intelligence

This work presents a three-dimensional geometric resolution method to calculate the complete inverse kinematics of a 7-degree-of-freedom articulated arm, including the hand itself. The method is classified as an analytical method with geometric solution, since it obtains a precise solution in a closed number of steps, converting the inverse kinematic problem into a three-dimensional geometric model. To simplify the problem, the kinematic decoupling method is used, so that the position of the wrist is calculated independently on one hand with information on the orientation of the hand, and the angles of the rest of the arm are calculated from the wrist.


Hybrid Continuum-Eversion Robot: Precise Navigation and Decontamination in Nuclear Environments using Vine Robot

Al-Dubooni, Mohammed, Wong, Cuebong, Althoefer, Kaspar

arXiv.org Artificial Intelligence

Soft growing vine robots show great potential for navigation and decontamination tasks in the nuclear industry. This paper introduces a novel hybrid continuum-eversion robot designed to address certain challenges in relation to navigating and operating within pipe networks and enclosed remote vessels. The hybrid robot combines the flexibility of a soft eversion robot with the precision of a continuum robot at its tip, allowing for controlled steering and movement in hard to access and/or complex environments. The design enables the delivery of sensors, liquids, and aerosols to remote areas, supporting remote decontamination activities. This paper outlines the design and construction of the robot and the methods by which it achieves selective steering. We also include a comprehensive review of current related work in eversion robotics, as well as other steering devices and actuators currently under research, which underpin this novel active steering approach. This is followed by an experimental evaluation that demonstrates the robot's real-world capabilities in delivering liquids and aerosols to remote locations. The experiments reveal successful outcomes, with over 95% success in precision spraying tests. The paper concludes by discussing future work alongside limitations in the current design, ultimately showcasing its potential as a solution for remote decontamination operations in the nuclear industry.


Designing a Hair-Clip Inspired Bistable Mechanism for Soft Fish Robots

Xiong, Zechen, Lipson, Hod

arXiv.org Artificial Intelligence

The Hair clip mechanism (HCM) is an in-plane prestressed bistable mechanism proposed in our previous research [1]~[5] to enhance the functionality of soft robotics. HCMs have several advantages, such as high rigidity, high mobility, good repeatability, and design and fabrication simplicity, compared to existing soft and compliant robotics. Using our experience with fish robots, this work delves into designing a novel HCM robotic propulsion system made from PETG plastic, carbon fiber-reinforced plastic (CFRP), and steel. Detailed derivation and verification of the HCM theory are given, and the influence of key parameters like dimensions, material types, and servo motor specifications are summarized. The designing algorithm offers insight into HCM robotics. It enables us to search for suitable components, operate robots at a desired frequency, and achieve high-frequency and high-speed undulatory swimming for fish robots.


CarbonFish -- A Bistable Underactuated Compliant Fish Robot capable of High Frequency Undulation

Xiong, Zechen, Lipson, Hod

arXiv.org Artificial Intelligence

When juxtaposed with conventional soft and compliant robotic systems, HCMs exhibit pronounced rigidity, augmented mobility, reproducible repeatability, and an effective design and fabrication paradigm. In this research, we investigate the feasibility of utilizing carbon fiber-reinforced plastic (CFRP) as the foundational material for an HCM-based fish robot, herein referred to as "CarbonFish." Our objective centers on realizing high-frequency undulatory motion, thereby laying the groundwork for accelerated aquatic locomotion in subsequent models. We proffer an exhaustive design and fabrication schema underpinned by mathematical principles. Preliminary evaluations of our single-actuated CarbonFish have evidenced an undulation frequency approaching 10 Hz, suggesting its potential to outperform other biologically inspired aquatic entities as well as real fish. Keywords: soft fish robot, compliant mechanism, bistability, undulation swimming Main Text Introduction Soft and compliant robotics represents an advancing domain in robotics research, emphasizing the design and development of robots utilizing soft and deformable materials.


HASHI: Highly Adaptable Seafood Handling Instrument for Manipulation in Industrial Settings

Allison, Austin, Hanson, Nathaniel, Wicke, Sebastian, Padır, Taşkın

arXiv.org Artificial Intelligence

The seafood processing industry provides fertile ground for robotics to impact the future-of-work from multiple perspectives including productivity, worker safety, and quality of work life. The robotics research challenge is the realization of flexible and reliable manipulation of soft, deformable, slippery, spiky and scaly objects. In this paper, we propose a novel robot end effector, called HASHI, that employs chopstick-like appendages for precise and dexterous manipulation. This gripper is capable of in-hand manipulation by rotating its two constituent sticks relative to each other and offers control of objects in all three axes of rotation by imitating human use of chopsticks. HASHI delicately positions and orients food through embedded 6-axis force-torque sensors. We derive and validate the kinematic model for HASHI, as well as demonstrate grip force and torque readings from the sensorization of each chopstick. We also evaluate the versatility of HASHI through grasping trials of a variety of real and simulated food items with varying geometry, weight, and firmness.