A Genderless Coupling Mechanism With Six-Degrees-of-Freedom Misalignment Capability for Modular Self-Reconfigurable Robots

2016 ◽  
Vol 8 (6) ◽  
Author(s):  
Wael Saab ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Degrees Of Freedom ◽  
High Strength ◽  
Robotic Systems ◽  
Critical Element ◽  
Coupling Mechanism ◽  
Six Degrees Of Freedom ◽  
Reconfigurable Robots ◽  
Docking Mechanism ◽  
Fail Safe ◽  
Coupling Mechanisms

Abstract This paper presents the design and integration of a genderless coupling mechanism for modular self-reconfigurable mobile robots. Modular self-reconfigurable mobile robotic systems consist of a number of self-sufficient modules that interconnect via coupling mechanisms and adopt different configurations to modify locomotion and/or manipulation capabilities. Coupling mechanisms are a critical element of these robotic systems. This paper focuses on a docking mechanism called GHEFT: a Genderless, High-strength, Efficient, Fail-safe, and high misalignment Tolerant coupling mechanism that aids self-reconfiguration. GHEFT provides a high strength and energy efficient connection using nonback drivable actuation with optimized clamping profiles that tolerate translational and angular misalignments. It also enables engagement/disengagement without gender restrictions in the presence of one-sided malfunction. The detailed design of the proposed mechanism is presented, including optimization of the clamping profile geometries. Experimental validation of misalignment tolerances and achievable clamping forces and torques is performed to demonstrate the strength, efficiency, and fail-safe capabilities of the proposed mechanism, and these results are compared to reported results of some of the existing coupling mechanisms.

A review of coupling mechanism designs for modular reconfigurable robots

Robotica ◽  
2018 ◽  
Vol 37 (2) ◽  
pp. 378-403 ◽  
Author(s):  
Wael Saab ◽  
Peter Racioppo ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Robotic Systems ◽  
Coupling Mechanism ◽  
Crucial Importance ◽  
Uncertain Environments ◽  
Reconfigurable Robots ◽  
Starting Point ◽  
Challenges And Opportunities ◽  
Robotic Platforms ◽  
Coupling Mechanisms ◽  
Reconfigurable Robotics

SUMMARYWith the increasing demands for versatile robotic platforms capable of performing a variety of tasks in diverse and uncertain environments, the needs for adaptable robotic structures have been on the rise. These requirements have led to the development of modular reconfigurable robotic systems that are composed of a numerous self-sufficient modules. Each module is capable of establishing rigid connections between multiple modules to form new structures that enable new functionalities. This allows the system to adapt to unknown tasks and environments. In such structures, coupling between modules is of crucial importance to the overall functionality of the system. Over the last two decades, researchers in the field of modular reconfigurable robotics have developed novel coupling mechanisms intended to establish rigid and robust connections, while enhancing system autonomy and reconfigurability. In this paper, we review research contributions related to robotic coupling mechanism designs, with the aim of outlining current progress and identifying key challenges and opportunities that lay ahead. By presenting notable design approaches to coupling mechanisms and the most relevant efforts at addressing the challenges of sensorization, misalignment tolerance, and autonomous reconfiguration, we hope to provide a useful starting point for further research into the field of modular reconfigurable robotics and other applications of robotic coupling.

Development of a Novel Coupling Mechanism for Modular Self-Reconfigurable Mobile Robots

2015 ◽  
Author(s):  
Wael Saab ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Mobile Robots ◽  
Scale Up ◽  
High Strength ◽  
Design Parameters ◽  
Coupling Mechanism ◽  
Dynamic Simulations ◽  
Challenging Tasks ◽  
Application Requirements ◽  
Fail Safe ◽  
Coupling Mechanisms

This paper presents the development of a novel coupling mechanism for modular self-reconfigurable mobile robots. Modular self-reconfigurable mobile robotic systems consist of a large number of self-sufficient modules that can transform into various configurations. One of the most challenging tasks in this field is designing a reliable and flexible coupling mechanism that physically connects modules to form larger and more articulated structures to scale up locomotion and manipulation functions. In this research we propose GHEFT: a Genderless, High strength, Efficient, Fail-safe, and high misalignment Tolerant coupling mechanism that aids the process of self-reconfiguration, and self-repair. Many existing coupling mechanisms fail to possess these crucial design features. The proposed mechanism ensures an efficient and high strength connection due to non-back drivable actuation and specially designed clamping profiles that enables modules to tolerate large misalignments and engage/disengage without gender restrictions in the presence of one-sided malfunction; thus, increasing both the versatility and robustness of the entire robotic system. In this paper, misalignment analysis is performed to formulate simple relations based on clamping profile design parameters to achieve specific misalignment tolerances based on application requirements. These formulations are used to compute maximum misalignment tolerances. Dynamic simulations are then performed to determine maximum misalignment tolerance capabilities and verify computed tolerances.

Controlling Modular Reconfigurable Robots With Handheld Smart Devices

2011 ◽  
Author(s):  
David Ko ◽  
Nalaka Kahawatte ◽  
Harry H. Cheng
Keyword(s):  
Graphical User Interface ◽  
Degrees Of Freedom ◽  
Robotic Systems ◽  
Effective Control ◽  
Smart Devices ◽  
Modular Robots ◽  
Reconfigurable Robots ◽  
Processing Power ◽  
Static Data ◽  
Remote Controller

Highly reconfigurable modular robots face unique teleoperation challenges due to their geometry, configurability, high number of degrees of freedom and complexity. Current methodology for controlling reconfigurable modular robots typically use gait tables to control the modules. Gait tables are static data structures and do not readily support realtime teleoperation. Teleoperation techniques for traditional wheeled, flying, or submerged robots typically use a set of joysticks to control the robots. However, these traditional methods of robot teleoperation are not suitable for reconfigurable modular robotic systems which may have dozens of controllable degrees of freedom. This research shows that modern cell phones serve as highly effective control platforms for modular robots because of their programmability, flexibility, wireless communication capabilities, and increased processing power. As a result of this research, a versatile Graphical User Interface, a set of libraries and tools have been developed which even a novice robotics enthusiast can use to easily program their mobile phones to control their hobby project. These libraries will be beneficial in any situation where it is effective for the operator to use an off-the-shelf, relatively inexpensive, hand-held mobile phone as a remote controller rather than a considerably heavy and bulky remote controllers which are popular today. Several usage examples and experiments are presented which demonstrate the controller’s ability to effectively control a modular robot to perform a series of complex gaits and poses, as well as navigating a module through an obstacle course.

Design and Simulation of Ground Test Platform for Microsatellite Docking Mechanism

2011 ◽  
Vol 188 ◽  
pp. 671-674
Author(s):  
Yi Nan Lai ◽  
M.J. Zhao ◽  
Y. Dai ◽  
M.Z. Lai ◽  
X. Lai
Keyword(s):  
Mechanical Properties ◽  
Degrees Of Freedom ◽  
Dynamics Simulation ◽  
Collision Process ◽  
Working Process ◽  
Flexible Coupling ◽  
Six Degrees Of Freedom ◽  
Test Platform ◽  
Docking Mechanism ◽  
Ground Test

According to the requirements of the ground demonstration test for small-sized docking mechanism, a set of ground test platform was designed, which can simulate the weightless environment of space and provide six degrees of freedom for the docking mechanism. This paper elaborated the structure and working process of the test platform, and used the way of rigid-flexible coupling to analysis the test platform in dynamics simulation by ADAMS. The mechanical properties of the platform’s key parts during the collision process were obtained

Kinematics and Interfacing of ModRED: A Self-Healing Capable, 4DOF Modular Self-Reconfigurable Robot

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
S. G. M. Hossain ◽  
Carl A. Nelson ◽  
Khoa D. Chu ◽  
Prithviraj Dasgupta
Keyword(s):  
Degrees Of Freedom ◽  
Singularity Analysis ◽  
Self Healing ◽  
Modular Robot ◽  
Reconfigurable Robots ◽  
Docking Mechanism ◽  
Rotary Plate ◽  
Working Principle ◽  
Kinematic Transformations ◽  
Forward Kinematic

Modular self-reconfigurable robots (MSRs) are systems which rely on modularity for maneuvering over unstructured terrains, while having the ability to complete multiple assigned functions in a distributed way. An MSR should be equipped with robust and efficient docking interfaces to ensure enhanced autonomy and self-reconfiguration ability. Genderless docking is a necessary criterion to maintain homogeneity of the robot modules. This also enables self-healing of a modular robot system in the case of a failed module. The mechanism needs to be compact and lightweight and at the same time have sufficient strength to transfer loads from other connected modules. This research focuses on the design of a modular robot with four degrees of freedom (4DOF) per module and with the goal of achieving higher workspace flexibility and self-healing capability. To explain the working principle of the robot, forward kinematic transformations were derived and workspace and singularity analysis were performed. In addition, to address the issues of interfacing, a rotary plate genderless single-sided docking mechanism—RoGenSiD—was developed. The design methodology included considerations for minimal space and weight as well as for fault tolerance. As a result, this docking mechanism is applicable for multifaceted docking in lattice-type, chain-type, or hybrid-type MSR systems. Several locomotion gaits were proposed and bench-top testing validated the system performance in terms of self-healing capability and generation of locomotion gaits.

Disturbance Response of Two-Link Underactuated Serial-Link Chains

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Ravi Balasubramanian ◽  
Joseph T. Belter ◽  
Aaron M. Dollar
Keyword(s):  
Degrees Of Freedom ◽  
External Disturbance ◽  
Contact Forces ◽  
Coupling Mechanism ◽  
Robotic Hands ◽  
External Disturbances ◽  
Serial Link ◽  
Disturbance Response ◽  
Actuation Mode ◽  
Coupling Mechanisms

In an attempt to improve the performance of underactuated robotic hands in grasping, we investigate the influence of the underlying coupling mechanism on the robustness of underactuated hands to external disturbance. The coupling mechanisms used in underactuated mechanisms can be divided into two main classes based on the self-adaptive transmission used to route actuation to the degrees of freedom, namely single-acting and double-acting transmissions. The kinematic coupling constraint is always active in double-acting mechanisms, while there are specific combinations of external disturbances and mechanism parameters that render the constraint inactive in single-acting mechanisms. This paper identifies unique behaviors in terms of mechanism reconfiguration and variation in grasping contact forces that result from the underactuated hand’s response to external disturbance forces and show that these behaviors are a function of the coupling mechanism, actuation mode, and contact constraints. We then present an analysis of how these behaviors influence grasping ability of the hand and discuss implications for underactuated hand design and operation.

A Parallel Reconfigurable Robot with Six Degrees of Freedom

2012 ◽  
Vol 162 ◽  
pp. 204-213 ◽  
Author(s):  
Calin Vaida ◽  
Nicolae Plitea ◽  
Dorin Lese ◽  
Doina Liana Pisla
Keyword(s):  
Degrees Of Freedom ◽  
Robotic Systems ◽  
Manufacturing Costs ◽  
Six Degrees Of Freedom ◽  
Reachable Workspace ◽  
Development Times ◽  
New Type ◽  
Reconfigurable Robot ◽  
6 Degrees Of Freedom ◽  
Workspace Representation

Shorter development times, wide variety of products and manufacturing costs optimization lead towards the development of a new type of robots that are more flexible and adaptable to all these changes. The idea of reconfiguration is thus born, many studies being focused on enlarging and improving this concept. Reconfigurable robotic systems are those that can change their geometry, their mobility degree and be default, their workspace and their applicability. This paper presents a 6 degrees of freedom (DOF) reconfigurable robot, entitled RECROB, its kinematics and possible reconfigurations with different DOFs. Based on the analysis of structure two possible configurations are identified, one of them being modeled and simulated. The paper ends with the reachable workspace representation, conclusions and applicability of such a robot.

Simultanous Mapping and Localization of Rescue Environments (Gleichzeitiges Kartieren und Lokalisieren von Rescue-Umgebungen)

2005 ◽  
Vol 47 (5) ◽  
Author(s):  
Hartmut Surmann ◽  
Kai Pervölz ◽  
Andreas Nüchter ◽  
Kai Lingemann ◽  
Joachim Hertzberg ◽  
...  
Keyword(s):  
Mobile Robot ◽  
Degrees Of Freedom ◽  
Urban Setting ◽  
Robotic Systems ◽  
Six Degrees Of Freedom ◽  
Rescue Robot ◽  
Rescue Workers ◽  
Robot Systems ◽  
A Site ◽  
Remote Inspection

SummaryDeploying rescue workers in an urban setting is often a perilous, time-, power-, and force-consuming job, and robot systems to assist in this effort are needed. A fundamental task for rescuer is to localize and salvage injured persons. To this end, robotic systems are used for mapping a site and for remote inspection of suspicious objects. The mobile robot Kurt3D is the first rescue robot that is capable of mapping its environment in 3D and self localize in all six degrees of freedom, i. e., considering its

Design of a Four-DOF Modular Self-Reconfigurable Robot With Novel Gaits

2011 ◽  
Author(s):  
Khoa D. Chu ◽  
S. G. M. Hossain ◽  
Carl A. Nelson
Keyword(s):  
Degrees Of Freedom ◽  
Radio Communication ◽  
Reconfigurable Robots ◽  
Docking Mechanism ◽  
Reconfigurable Robot ◽  
Kinematic Transformations ◽  
A Chain ◽  
The Individual ◽  
Forward Kinematic ◽  
Chain Type

Throughout the modern age, exploration of the unknown has been an attractive pursuit to seekers of knowledge. One of the primary frontiers for exploration today involves planetary and lunar environments. Exploration in these environments can involve many different types of tasks in a broad range of environmental conditions. Modular Self-Reconfigurable Robots (MSRs) would be beneficial for completing these tasks in unstructured environments, while having the ability to complete multiple assigned functions. Since payload is a critical concern, a lighter and more dexterous MSR is preferable. This research focuses on the design of a robot that has these qualities. A chain-type modular robot with four degrees of freedom per module has been designed with the goal of reducing weight and size while increasing range of motion. Forward kinematic transformations were derived to analyze the available workspace provided by the MSR. Radio communication and proximity sensing ability were provided in the individual MSR modules to locate each other. The modules are designed to maneuver independently using their individual navigation capability as well as connect to each other by means of a docking mechanism. Locomotion gaits for such multi-module robot chains are also described.

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