Configuration analysis of a reconfigurable Rubik's snake robot

2018 ◽  
Vol 233 (9) ◽  
pp. 3137-3154 ◽  
Author(s):  
Jinguo Liu ◽  
Xin Zhang ◽  
Ketao Zhang ◽  
Jian S Dai ◽  
Shujun Li ◽  
...  
Keyword(s):  
Robotic Systems ◽  
Modular Robots ◽  
Digital Code ◽  
Snake Robot ◽  
Target Configuration ◽  
Working Space ◽  
Core Content ◽  
Configuration Representation ◽  
Motion Sequence

Versatility and adaptability are the most prominent advantages of reconfigurable modular robotic systems. Unlike integrated robotic systems, reconfigurable modular robots can be rearranged to adapt to unpredictable environments. This paper presents a novel reconfigurable modular robot inspired by the Rubik's snake toy. For this reconfigurable Rubik's snake robot, the special feature is that it can work as not only a mechanism but also as a reconfigurable structure. In this paper, the configuration analysis is the core content. The concept of valid configurations is proposed to describe valid, controllable, and non-interference configurations. The configuration analysis theories are introduced in accordance with the configuration representation, the isomorphism analysis, the interference analysis, and the motion sequence analysis. Here, the configuration representation is proposed to define the position and orientation of two modules by using the adjacency matrix and the binary digital code, respectively. The equivalent digital code and the configuration ring are used to distinguish the same or symmetric configurations for the open and closed isomorphism configurations, respectively. Meanwhile, a case study is conducted to verify the effectiveness of the isomorphism analysis. Furthermore, the working space interference method is introduced to detect the interference issue in the process of forming target configurations. To accomplish a target configuration properly, the motion sequence matrix is defined to describe the motion sequence for achieving a target configuration. Finally, an experiment on the configuration transformation is demonstrated to verify the rationality and correctness of the theories of configuration analysis.

Module Design and Functionally Non-Isomorphic Configurations of the Hex-DMR II System

2016 ◽  
Vol 8 (5) ◽  
Author(s):  
Joshua D. Davis ◽  
Yunuscan Sevimli ◽  
Baxter R. Eldridge ◽  
Gregory S. Chirikjian
Keyword(s):  
Low Cost ◽  
Robotic Systems ◽  
Modular Robots ◽  
Design Constraints ◽  
Module Design ◽  
The Past ◽  
New Novel ◽  
Operational Capabilities ◽  
Mapping Task

Modular robots have captured the interest of the robotics community over the past several years. In particular, many modular robotic systems are reconfigurable, robust against faults, and low-cost due to mass production of a small number of different homogeneous modules. Faults in these systems are normally tolerated through redundancy or corrected by discarding damaged modules, which reduces the operational capabilities of the robot. To overcome these difficulties, we previously developed and discussed the general design constraints of a heterogeneous modular robotic system (Hex-DMR II) capable of autonomous team repair and diagnosis. In this paper, we discuss the design of each module, in detail, and present a new, novel elevator module. Then, we introduce a forestlike structure that enumerates every non-isomorphic, functional agent configuration of our system. Finally, we present a case study contrasting the kinematics and power consumption of two particular configurations during a mapping task.

Module Design and Functionally Non-Isomorphic Configurations of the Hex-DMR II System

2015 ◽  
Author(s):  
Joshua D. Davis ◽  
Yunuscan Sevimli ◽  
Baxter R. Eldridge ◽  
Gregory S. Chirikjian
Keyword(s):  
Low Cost ◽  
Robotic Systems ◽  
Modular Robots ◽  
Design Constraints ◽  
Module Design ◽  
The Past ◽  
New Novel ◽  
Operational Capabilities ◽  
Mapping Task

Modular robots have sustained the interest of the robotics community over the past several years. In particular, many modular robotic systems are reconfigurable, robust against faults, and low-cost due to mass production of a small number of homogeneous modules. Faults in these systems are normally tolerated through redundancy or corrected by discarding damaged modules which reduces the operational capabilities of the robot. To overcome these difficulties, we developed and discussed the general design constraints of a heterogeneous modular robotic system (Hex-DMR II) capable of autonomous team repair and diagnosis. In this paper, we discuss the design of each module, in detail, and present a new, novel elevator module. Then, we introduce a forest-like structure that enumerates every non-isomorphic, functional agent configuration of our system. Finally, we present a case study contrasting the kinematics and power consumption of two particular configurations during a mapping task.

Complete Accessibility of Oscillations in Robotic Systems by Orthogonal Projections

1990 ◽  
Vol 112 (2) ◽  
pp. 194-202 ◽  
Author(s):  
Sabri Tosunoglu ◽  
Shyng-Her Lin ◽  
Delbert Tesar
Keyword(s):  
Current Practice ◽  
Industrial Robot ◽  
Robotic Systems ◽  
Orthogonal Projections ◽  
Small Oscillations ◽  
Robotic Arms ◽  
Driven System ◽  
System Equations ◽  
Six Degree Of Freedom

The current practice of controller development for flexible robotic systems generally focuses on one-link robotic arms and is valid for small oscillations. This work addresses the control of n-link, serial, spatial robotic systems modeled with m1 joint and m2 link flexibilities such that n≥m1+m2. System compliance is modeled by local springs and nonactuated prismatic and revolute type pseudo joints. The coupled, nonlinear, error-driven system equations are derived for the complete model without linearization or neglecting certain terms. For this system, the complete accessibility of vibrations is studied by orthogonal projections. It is shown that under some configurations of a robotic system, the induced oscillations may not be accessible to the controller. Given accessibility, the controller developed in this work assures the global asymptotic stability of the system. Example numerical simulations are presented based on the model of a six-degree-of-freedom Cincinnati Milacron T3-776 industrial robot. One example models the system compliance in four joints, while another case study simulates four lateral link oscillations. These examples show that this controller, even under inaccurate payload description, eliminates the oscillations while tracking desired trajectories.

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.

Autonomous Docking of Hybrid-Wheeled Modular Robots with an Integrated Active Genderless Docking Mechanism

2021 ◽  
pp. 1-36
Author(s):  
Shubhdildeep S. Sohal ◽  
Bijo Sebastian ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Visual Servoing ◽  
Mechanical Design ◽  
Low Cost ◽  
Image Plane ◽  
Robotic Systems ◽  
Modular Robots ◽  
Tracking Accuracy ◽  
Drive Mechanism ◽  
Docking Mechanism ◽  
Autonomous Docking

Abstract This paper presents a self-reconfigurable modular robot with an integrated 2-DOF active docking mechanism. Active docking in modular robotic systems has received a lot of interest recently as it allows small versatile robotic systems to coalesce and achieve the structural benefits of large systems. This feature enables reconfigurable modular robotic systems to bridge the gap between small agile systems and larger robotic systems. The proposed self-reconfigurable mobile robot design exhibits dual mobility using a tracked drive mechanism for longitudinal locomotion and a wheeled drive mechanism for lateral locomotion. The 2-DOF docking interface allows for efficient docking while tolerating misalignments. To aid autonomous docking, visual marker-based tracking is used to detect and re-position the source robot relative to the target robot. The tracked features are then used in Image-Based Visual Servoing to bring the robots close enough for the docking procedure. The hybrid-tracking algorithm allows eliminating external pixelated noise in the image plane resulting in higher tracking accuracy along with faster frame update on a low-cost onboard computational device. This paper presents the overall mechanical design and the integration details of the modular robotic module with the docking mechanism. An overview of the autonomous tracking and docking algorithm is presented along-with a proof-of-concept real world demonstration of the autonomous docking and self-reconfigurability. Experimental results to validate the robustness of the proposed tracking method, as well as the reliability of the autonomous docking procedure, are also presented.

scholarly journals Smart and Modular

2011 ◽  
Vol 133 (09) ◽  
pp. 48-51
Author(s):  
Harry H. Cheng ◽  
Graham Ryland ◽  
David Ko ◽  
Kevin Gucwa ◽  
Stephen Nestinger
Keyword(s):  
Degrees Of Freedom ◽  
Robotic System ◽  
Search And Rescue ◽  
Degree Of Freedom ◽  
Robotic Systems ◽  
Modular Robots ◽  
Modular Robot ◽  
Modular Systems ◽  
The Past ◽  
Three Degrees Of Freedom

This article discusses the advantages of a modular robot that can reassemble itself for different tasks. Modular robots are composed of multiple, linked modules. Although individual modules can move on their own, the greatest advantage of modular systems is their structural reconfigurability. Modules can be combined and assembled to form configurations for specific tasks and then reassembled to suit other tasks. Modular robotic systems are also very well suited for dynamic and unpredictable application areas such as search and rescue operations. Modular robots can be reconfigured to suit various situations. Quite a number of modular robotic system prototypes have been developed and studied in the past, each containing unique geometries and capabilities. In some systems, a module only has one degree of freedom. In order to exhibit practical functionality, multiple interconnected modules are required. Other modular robotic systems use more complicated modules with two or three degrees of freedom. However, in most of these systems, a single module is incapable of certain fundamental locomotive behaviors, such as turning.

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