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

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.

Geophysics ◽  
1946 ◽  
Vol 11 (3) ◽  
pp. 335-349
Author(s):  
E. E. Rosaire

Premium technological discovery volume is that achieved in excess of the volume to be anticipated on the basis of price alone and which can be attributed solely to technological advance. Three degrees of freedom, area, method, and objective, are recognized for the prospector, and these are fixed by choice in any prospecting venture. Continued operation with these three degrees fixed inevitably leads to diminishing returns and, finally, to marginal operations wherein price becomes the primary motivation. Under such conditions in the past, unfixing even one degree of freedom has led to marked surges in the discovery rate, i.e., to premium technological discovery. Such discovery surges have occurred more than once in the same petroleum province and, not infrequently, the magnitude of the surge has increased rather than decreased with time. Considerations are presented for a return to premium technological discovery within the United States. Such a return for the method now in most general use, the reflection seismograph, can be expected to follow from unfixing the area degree of freedom through initiating prospecting along the continental shelf. However, such a return for prospecting as a whole, and probably of even greater magnitude, can be anticipated to follow from unfixing the method degree of freedom through widespread application of novelty in prospecting methods.


1969 ◽  
Vol 59 (4) ◽  
pp. 1591-1598
Author(s):  
G. A. McLennan

Abstract An exact method is developed to eliminate the accelerometer error in dynamic response calculations for damped multi-degree of freedom systems. It is shown that the exact responses of a system can be obtained from the approximate responses which are conventionally calculated from an accelerogram. Response calculations were performed for two typical systems with three degrees of freedom for an assumed pseudo-earthquake. The results showed that the approximate responses may contain large errors, and that the correction developed effectively eliminates these errors.


2001 ◽  
Author(s):  
A. Khanicheh ◽  
A. Tehranian ◽  
A. Meghdari ◽  
M. S. Sadeghipour

Abstract This paper presents the kinematics and dynamic modeling of a three-link (3-DOF) underwater manipulator where the effects of hydrodynamic forces are investigated. In our investigation, drag and added mass coefficients are not considered as constants. In contrast, the drag coefficient is a variable with respect to all relative parameters. Experiments were conducted to validate the hydrodynamic model for a one degree-of-freedom manipulator up to a three degrees-of-freedom manipulator. Finally, the numerical and experimental results are compared and thoroughly discussed.


Author(s):  
David Ko ◽  
Nalaka Kahawatte ◽  
Harry H. Cheng

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.


2012 ◽  
Vol 619 ◽  
pp. 325-328
Author(s):  
You Jun Huang ◽  
Ze Lun Li ◽  
Zhi Cheng Huang

A teaching robot with three degree of freedom is designed. The three degrees of freedom are: waist rotation, lifting and stretching of the arm and opening and closing of the gripper. The designs of the main components are: a mobile chassis, parallel rails, horizontal rails and manipulator. The teaching robot designed has the features of low cost, easy to regulation, good repeatability and it has good promotion and application prospects in the field of teaching.


2021 ◽  
Author(s):  
Shiyi Zhang ◽  
Joseph Wang ◽  
Kenshi Hayashi ◽  
Fumihiro Sassa

Abstract Low-invasive soft robotic techniques can potentially be used for developing next-generation body–machine interfaces. Most soft robots require complicated fabrication processes involving 3D printing and bonding/assembling. In this letter, we describe a monolithic soft microrobot fabrication process for the mass production of soft film robots with a complex structure by simple 2D processing of a robotic actuator film. The 45 μg/mm^2 lightweight film robot can be driven at a voltage of CMOS compatible 5 V with 0.15 mm^-1 large curvature changes; it can generate a force 5.7 times greater than its self-weight. In a durability test, actuation could be carried out over 8000 times without degradation. To further demonstrate this technique, three types of film robots with multiple degrees of freedom and moving illuminator robot were fabricated. This technique can easily integrate various electrical circuits developed in the past to robotic systems and can be used for developing advanced wearable sensing devices; It can be called “Kinetic electronics.”


2020 ◽  
Vol 17 (3) ◽  
pp. 427-435
Author(s):  
Mohamed Khalil Mezghiche ◽  
Noureddine Djedi

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.


Author(s):  
David Ko ◽  
Harry H. Cheng

A new method of controlling and optimizing robotic gaits for a modular robotic system is presented in this paper. A robotic gait is implemented on a robotic system consisting of three Mobot modules for a total of twelve degrees of freedom using a Fourier series representation for the periodic motion of each joint. The gait implementation allows robotic modules to perform synchronized gaits with little or no communication with each other making it scalable to increasing numbers of modules. The coefficients of the Fourier series are optimized by a genetic algorithm to find gaits which move the robot cluster quickly and efficiently across flat terrain. Simulated and experimental results show that the optimized gaits can have over twice as much speed as randomly generated gaits.


2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Mark L. Guckert ◽  
Michael D. Naish

Spherical joints have evolved into a critical component of many robotic systems, often used to provide dexterity at the wrist of a manipulator. In this work, a novel 3 degree of freedom spherical joint is proposed, actuated by tendons that run along the surface of the sphere. The joint is mechanically simple and avoids mechanical singularities. The kinematics and mechanics of the joint are modeled and used to develop both open- and closed-loop control systems. Simulated and experimental assessment of the joint performance demonstrates that it can be successfully controlled in 3 degrees of freedom. It is expected that the joint will be a useful option in the development of emerging robotic applications, particularly those requiring miniaturization.


1985 ◽  
Vol 107 (4) ◽  
pp. 308-315 ◽  
Author(s):  
S. N. Singh ◽  
A. A. Schy

Using an inversion approach we derive a control law for trajectory following of robotic systems. A servocompensator is used around the inner decoupled loop for robustness to uncertainty in the system. These results are applied to trajectory control of a three-degrees-of-freedom robot arm and control laws Cθ and CH for joint angle and position trajectory following, respectively, are derived. Digital simulation results are presented to show the rapid trajectory following capability of the controller in spite of payload uncertainty.


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