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.

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.

RoGenSiD: A Rotary Plate Genderless Single-Sided Docking Mechanism for Modular Self-Reconfigurable Robots

2013 ◽  
Author(s):  
S. G. M. Hossain ◽  
Carl A. Nelson ◽  
Prithviraj Dasgupta
Keyword(s):  
Design Methodology ◽  
Self Healing ◽  
Robot System ◽  
Reconfigurable Robots ◽  
Docking Mechanism ◽  
Rotary Plate ◽  
Reconfigurable Robot ◽  
Multiple Robot ◽  
Sufficient Strength ◽  
Chain Type

Docking mechanisms are an integral part of modular self-reconfigurable robot (MSR) systems, allowing multiple robot modules to attach to each other. 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. RoGenSiD is a rotary-plate genderless single sided docking mechanism that was designed to perform robustly and efficiently considering its application in unstructured terrains. The design methodology followed design for manufacture (DFM) and design for assembly (DFA) guidelines as well as considerations for minimal space and weight. As a result, this docking mechanism is applicable for multi-faceted docking in lattice-type, chain-type, or hybrid MSR systems. Bench-top testing validated the system performance.

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.

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.

scholarly journals Optimum Seeking of Redundant Actuators for M-RCM 3-UPU Parallel Mechanism

2020 ◽  
Author(s):  
Chen Zhao ◽  
Jingke Song ◽  
Xuechan Chen ◽  
Ziming Chen ◽  
Huafeng Ding
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Singularity Analysis ◽  
Universal Joint ◽  
Prismatic Joint ◽  
Transmission Index ◽  
Redundant Actuators ◽  
Force Transmissibility ◽  
Singular Configuration

Abstract This paper focuses on a 2R1T 3-UPU (U for universal joint and P for prismatic joint) parallel mechanism (PM) with two rotational and one translational (2R1T) degrees of freedom (DOFs) and the ability of multiple remote centers of motion (M-RCM). The singularity analysis based on the indexes of motion/force transmissibility and constraint shows that this PM has transmission singularity, constraint singularity, mixed singularity and limb singularity. To solve these singularproblems, the quantifiable redundancy transmission index (RTI) and the redundancy constraint index (RCI) are proposed for optimum seeking of redundant actuators for this PM. Then the appropriate redundant actuators are selected and the working scheme for redundant actuators near the corresponding singular configuration are given to help the PM go through the singularity.

Singularity analysis of a 7-DOF spatial hybrid manipulator for medical surgery

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sameer Gupta ◽  
Ekta Singla ◽  
Sanjeev Soni ◽  
Ashish Singla
Keyword(s):  
Degrees Of Freedom ◽  
Closed Loop ◽  
Singularity Analysis ◽  
Medical Surgery ◽  
Natural Motion ◽  
Hybrid Manipulator ◽  
Contour Plots ◽  
Kinematic Singularities ◽  
And Control ◽  
Optimal Configurations

Abstract This paper presents the singularity analysis of a 7-degrees of freedom (DOF) hybrid manipulator consisting of a closed-loop within it. From the past studies, it is well-known that the kinematic singularities play a significant role in the design and control of robotic manipulators. Kinematic singularities pose two-fold effects – first, they can induce the loss of one or more DOF of the manipulator and cause infinite joint rates at that particular joint, and second, they help to determine the trajectory or zone with high mechanical advantage. In current work, a 7-DOF hybrid manipulator is considered which is being developed at Council Of Scientific And Industrial Research–Central Scientific Instruments Organisation (CSIR–CSIO) Chandigarh to assist a surgeon during a medical-surgical task. To emulate the natural motion of a surgeon, the challenging configuration with redundant DOF is utilized. Jacobian has been computed analytically and analyzed at each instantaneous configuration with the evaluation of manipulability. Effect of a closed loop in the hybrid configurations is focused at, and utilizing the contour plots, good and worst working zones are identified in the workspace of the manipulator. The verification and validation of best and worst manipulability points (singularities) are done with the help of genetic algorithms, to determine locally and globally optimal configurations. Finally, on the basis of the singularity analysis, the present work concludes with few guidelines to the surgeon about the best and worst working zones for surgical tasks.

Quantum genetic algorithm to evolve controllers for self-reconfigurable modular robots

2020 ◽  
Vol 17 (3) ◽  
pp. 427-435
Author(s):  
Mohamed Khalil Mezghiche ◽  
Noureddine Djedi
Keyword(s):  
Genetic Algorithms ◽  
Degrees Of Freedom ◽  
Optimization Problems ◽  
The Self ◽  
Modular Robots ◽  
Modular Robot ◽  
Adaptive Locomotion ◽  
Content Type ◽  
Quantum Genetic Algorithm ◽  
Neural Controllers

Purpose The purpose of this study is to explore using real-observation quantum genetic algorithms (RQGAs) to evolve neural controllers that are capable of controlling a self-reconfigurable modular robot in an adaptive locomotion task. Design/methodology/approach Quantum-inspired genetic algorithms (QGAs) have shown their superiority against conventional genetic algorithms in numerous challenging applications in recent years. The authors have experimented with several QGAs variants and real-observation QGA achieved the best results in solving numerical optimization problems. The modular robot used in this study is a hybrid simulated robot; each module has two degrees of freedom and four connecting faces. The modular robot also possesses self-reconfiguration and self-mobile capabilities. Findings The authors have conducted several experiments using different robot configurations ranging from a single module configuration to test the self-mobile property to several disconnected modules configuration to examine self-reconfiguration, as well as snake, quadruped and rolling track configurations. The results demonstrate that the robot was able to perform self-reconfiguration and produce stable gaits in all test scenarios. Originality/value The artificial neural controllers evolved using the real-observation QGA were able to control the self-reconfigurable modular robot in the adaptive locomotion task efficiently.

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.

Two-Point Floating Clamping Device Based on Fixed Cylinder with Double-Piston and Toggle-Lever Force Amplifier

2011 ◽  
Vol 201-203 ◽  
pp. 2220-2223 ◽  
Author(s):  
Guang Ju Si ◽  
Kang Min Zhong ◽  
Jun Peng Jia
Keyword(s):  
Degrees Of Freedom ◽  
Clamping Force ◽  
Compact Structure ◽  
Mechanical Calculation ◽  
Working Principle ◽  
Working Status ◽  
Clamping Device ◽  
Fixed Cylinder ◽  
Vibration Noise

Two-point floating clamping device, widely used in manufacturing field, can effectively ensure the same clamping force on different workpieces or different surfaces in one workpiece. But due to the application of unitary suspended articulated cylinder, traditional two-point floating devices have disadvantages such as poor working status, great impaction, vibration and noise. A kind of innovatively designed two-point floating clamping devices, with rigidly fixed cylinder replacing unitary suspended articulated cylinder, is presented in this paper. To solve the problem of insufficient degrees of freedom, three different methods are applied. This device has significant advantages in compact structure, small impaction and vibration noise. Moreover, the working principle and mechanical calculation formulas are presented in this paper, which is instructive to the industrial field.

scholarly journals Analytical inverse kinematics for 5-DOF humanoid manipulator under arbitrarily specified unconstrained orientation of end-effector

Robotica ◽  
2014 ◽  
Vol 33 (4) ◽  
pp. 747-767 ◽  
Author(s):  
Masayuki Shimizu
Keyword(s):  
Analytical Method ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Singularity Analysis ◽  
Inverse Kinematic ◽  
Inverse Kinematic Problem ◽  
Target Orientation ◽  
End Effector ◽  
Position And Orientation

SUMMARYThis paper proposes an analytical method of solving the inverse kinematic problem for a humanoid manipulator with five degrees-of-freedom (DOF) under the condition that the target orientation of the manipulator's end-effector is not constrained around an axis fixed with respect to the environment. Since the number of the joints is less than six, the inverse kinematic problem cannot be solved for arbitrarily specified position and orientation of the end-effector. To cope with the problem, a generalized unconstrained orientation is introduced in this paper. In addition, this paper conducts the singularity analysis to identify all singular conditions.

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