scholarly journals An Electromechanical Pendulum Robot Arm in Action: Dynamics and Control

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
A. Notué Kadjie ◽  
P. R. Nwagoum Tuwa ◽  
Paul Woafo

The authors numerically investigate the dynamics and control of an electromechanical robot arm consisting of a pendulum coupled to an electrical circuit via an electromagnetic mechanism. The analysis of the dynamical behavior of the electromechanical device powered by a sinusoidal power source is carried out when the effects of the loads on the arm are neglected. It is found that the device exhibits period-n T oscillations and high amplitude oscillations when the electric current is at its smallest value. The specific case which considers the effects of the impulsive contact force caused by an external load mass pushed by the arm is also studied. It is found that the amplitude of the impulse force generates several behaviors such as jump of amplitude and distortions of the mechanical vibration and electrical signal. For more efficient functioning of the device, both piezoelectric and adaptive backstepping controls are applied on the system. It is found that the control strategies are able to mitigate the signal distortion and restore the dynamical behavior to its normal state or reduce the effects of perturbations such as a short time variation of one component or when the robot system is subject to noises.

2010 ◽  
Vol 37-38 ◽  
pp. 1433-1436 ◽  
Author(s):  
Yan Qing Wang ◽  
Gao Yan Zhong ◽  
Yong Biao Chang ◽  
Guo Xin Liu

In this paper, the existing research and key technologies of 4-DOF parallel robot are reviewed, i.e., mechanism, kinematics, singularity, workspace, dexterity, dynamics and control. Most of them are focused on mechanism and kinematics. The study in dynamics and control is relatively rare and not mature in practice, especially in how to optimize the control strategies to improve its performance. Finally, the research trend and unsolved problem of 4-DOF parallel robot is described.


2018 ◽  
Vol 449 ◽  
pp. 35-52 ◽  
Author(s):  
Andrew L. Krause ◽  
Lawrence Kurowski ◽  
Kamran Yawar ◽  
Robert A. Van Gorder

Author(s):  
John T. Cameron ◽  
Sean Brennan

This work presents results of an initial investigation into models and control strategies suitable to prevent vehicle rollover due to untripped driving maneuvers. Outside of industry, the study of vehicle rollover inclusive of both experimental validation and practical controller design is limited. The researcher interested in initiating study on rollover dynamics and control is left with the challenging task of identifying suitable vehicle models from the literature, comparing these models with experimental results, and determining suitable parameters for the models. This work addresses these issues via experimental testing of published models. Parameter estimation data based on model fits is presented, with commentary given on the validity of different methods. Experimental results are then presented and compared to the output predicted by the various models in both the time and frequency domain in order to provide a foundation for future work.


2021 ◽  
Vol 15 (5) ◽  
pp. e0009449
Author(s):  
Maylis Layan ◽  
Simon Dellicour ◽  
Guy Baele ◽  
Simon Cauchemez ◽  
Hervé Bourhy

Background Rabies is a fatal yet vaccine-preventable disease. In the last two decades, domestic dog populations have been shown to constitute the predominant reservoir of rabies in developing countries, causing 99% of human rabies cases. Despite substantial control efforts, dog rabies is still widely endemic and is spreading across previously rabies-free areas. Developing a detailed understanding of dog rabies dynamics and the impact of vaccination is essential to optimize existing control strategies and developing new ones. In this scoping review, we aimed at disentangling the respective contributions of mathematical models and phylodynamic approaches to advancing the understanding of rabies dynamics and control in domestic dog populations. We also addressed the methodological limitations of both approaches and the remaining issues related to studying rabies spread and how this could be applied to rabies control. Methodology/principal findings We reviewed how mathematical modelling of disease dynamics and phylodynamics have been developed and used to characterize dog rabies dynamics and control. Through a detailed search of the PubMed, Web of Science, and Scopus databases, we identified a total of n = 59 relevant studies using mathematical models (n = 30), phylodynamic inference (n = 22) and interdisciplinary approaches (n = 7). We found that despite often relying on scarce rabies epidemiological data, mathematical models investigated multiple aspects of rabies dynamics and control. These models confirmed the overwhelming efficacy of massive dog vaccination campaigns in all settings and unraveled the role of dog population structure and frequent introductions in dog rabies maintenance. Phylodynamic approaches successfully disentangled the evolutionary and environmental determinants of rabies dispersal and consistently reported support for the role of reintroduction events and human-mediated transportation over long distances in the maintenance of rabies in endemic areas. Potential biases in data collection still need to be properly accounted for in most of these analyses. Finally, interdisciplinary studies were determined to provide the most comprehensive assessments through hypothesis generation and testing. They also represent new avenues, especially concerning the reconstruction of local transmission chains or clusters through data integration. Conclusions/significance Despite advances in rabies knowledge, substantial uncertainty remains regarding the mechanisms of local spread, the role of wildlife in dog rabies maintenance, and the impact of community behavior on the efficacy of control strategies including vaccination of dogs. Future integrative approaches that use phylodynamic analyses and mechanistic models within a single framework could take full advantage of not only viral sequences but also additional epidemiological information as well as dog ecology data to refine our understanding of rabies spread and control. This would represent a significant improvement on past studies and a promising opportunity for canine rabies research in the frame of the One Health concept that aims to achieve better public health outcomes through cross-sector collaboration.


Author(s):  
Hartiny Kahar ◽  
Dirk Söffker

Abstract In this paper, the dynamical behavior of a nonlinear mechanical system is considered, namely an inverted flexible pendulum excited in its base by a cart driven by a motor. In this experimental procedure, the chaotic motion of the pendulum tip was identified, in combination with a specific range of parameters. Time-frequency energy analysis is performed to be used for modeling the transition between the equilibria of the chaotic systems. Controlling the chaotic behavior of the system is realized using impulsive control method, where additive impulses are injected into the system, designed with specific impulses energy content at a specific frequency band. The experimental results are presented and discussed in detail, concentrating on how the designed impulses have to be injected to affect the system, specifically the transition between states of equilibria. The results from this experimental modeling procedure show that both additive impulse design and frequency filtering of the injected additive impulses are able to stimulate the equilibrium shift and therefore to control the chaotic behavior of the system.


Robotica ◽  
2005 ◽  
Vol 23 (4) ◽  
pp. 515-520 ◽  
Author(s):  
Rafael Kelly ◽  
Sebastian Dormido ◽  
Carmen Monroy ◽  
Elizabeth Díaz

Control systems of robot manipulators offer many challenges in education where the students must learn robot dynamics and control structures, and understand relations between the control parameters and the systems performance. Interactive simulation is aimed at improving the understanding of and intuition for the abstract parts of the control of robot courses. This paper presents an application of interactive simulation to teach control systems of robots. The application considers a nonlinear robot arm and two control modules: position control and motion control. Students can directly manipulate graphical representation of the systems such as a choice among seven control structures, controller gains, and desired trajectories, and obtain instant feedback on the effects. These features make the interactive learning tool stimulating and of high pedagogical value.


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