scholarly journals Construcción y control de posición de un prototipo de brazo robótico de dos grados de libertad

2012 ◽  
pp. 92-101
Author(s):  
Oscar Darío Zabaleta Laverde
Keyword(s):  
Degrees Of Freedom ◽  
Robotic Arm ◽  
Pid Controllers ◽  
Tuning Method ◽  
Dc Motors ◽  
Starting Point ◽  
Reaction Curve ◽  
Physical Construction ◽  
Made In

La construcción física y el control electrónico del brazo robótico de dos grados de libertad, tiene como punto de partida la aproximación del sistema a las dinámicas de plantas de primer orden, donde a partir de la caracterización de la curva de reacción o comportamiento del brazo robótico, es posible la implementación de controladores PID con el método de sintonización de Ziegler y Nichols, que es sencillo y efectivo para el buen desempeño del prototipo expuesto en el presente artículo. En cuanto a la construcción del brazo robótico, es necesario resaltar el diseño y la implementacióndel acondicionamiento que requieren los actuadores del prototipo (Motorreductores DC) y los sensores que requiere el brazo (encoders de cuadratura), ya que deben ir acordescon el diseño y la construcción mecánica del brazo robótico, cuya estructura está elaborada en resina que se caracteriza por ser un material liviano y resistente al deterioro.Es necesario resaltar el acople de dos motores DC a la estructura mecánica del brazo robótico, cuya ubicación es indispensable para su correcta movilidad. Palabras claveBrazo robótico, controlador PID, lazo abierto y cerrado, actuadores y sensores. AbstractThe physical construction and electronic control of the robotic arm of two degrees of freedom has as a starting point the approach of the system to the plants dynamics of first order, where from the characterization of reaction curve or behavior of the robotic arm is possible the implementation of PID controllers with Ziegler and Nichols tuning method, that is simple and effective for the good performance of the prototype presented in this article. With regard to the construction of the robotic arm, it is necessary to highlight the design and implementation of the conditioning that requires the actuators of prototype (DC gearmotors) and sensors which requires the arm (squaring encoders), inasmuch as they must be consistent with the design and the mechanical constructionof the robotic arm, whose structure is made in resin that is characterized as a lighter material and resistant to decay.It is necessary to highlight the docking of two DC motors to the mechanical structure of the robotic arm, whose location is essential for its proper mobility.KeywordsRobotic arm, PID controller, open and closed loop, actuators and sensors. 

Tuning Fractional Order Proportional Integral Controllers for Time Delayed Systems With a Fractional Pole

2011 ◽  
Author(s):  
Hadi Malek ◽  
Ying Luo ◽  
YangQuan Chen
Keyword(s):  
Time Delay ◽  
Fractional Order ◽  
Model Systems ◽  
Delay Model ◽  
Delayed Systems ◽  
First Order ◽  
Tuning Method ◽  
Starting Point ◽  
Reaction Curve ◽  
Pi Controllers

First order plus time delay model is widely used to model systems with S-shaped reaction curve. Its generalized form is the use of a single fractional pole to replace the first order (single-time constant) model, which is believed to better characterize the reaction curve. Using time delayed system model with a fractional pole as the starting point, in this paper, designing fractional order controllers for this class of fractional order systems is investigated. The novelty of this paper is on designing the integer order PID and fractional order PI and [PI] controllers for these class of systems. The simulation and lab experimental results are both included to illustrate the effectiveness of the proposed tuning method. By comparing the results of PID controller, fractional order PI and [PI] controllers, the advantages of the fractional order controller are clearly demonstrated in the case of controlling the single fractional pole plants with constant time delay.

Bioactivity of Marine Natural Product Xyloketals

2020 ◽  
Vol 17 ◽  
Author(s):  
Biswajit Panda ◽  
Amal Kumar Gooyee
Keyword(s):  
Natural Products ◽  
Marine Natural Product ◽  
Ischemic Brain Injury ◽  
Ischemic Brain ◽  
Activity Inhibition ◽  
Life Saving ◽  
Behavior Suppression ◽  
Major Emphasis ◽  
Made In

: Oceans can play a major role in supplying life-saving medicines in the world in future. Although considerable progress has been made in finding new medicines from marine sources, large efforts are still necessary to examine such molecules for clinical applications. Xyloketals are an important group of natural products with various powerful and prominent bioactivities such as inhibition of acetylcholine esterase, antioxidant activity, inhibition of L-calcium channels, radicalscavenging behavior, suppression of cell proliferation, reduction of neonatal hypoxic-ischemic brain injury, etc. This review describes the isolation and structural characterization of all xyloketal natural products giving major emphasis on their bioactivity.

The Development of a Myoelectric Training Tool for Above-Elbow Amputees

2012 ◽  
Vol 6 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Michael R Dawson ◽  
Farbod Fahimi ◽  
Jason P Carey
Keyword(s):  
Degrees Of Freedom ◽  
Learning Task ◽  
Robotic Arm ◽  
Signal Acquisition ◽  
Myoelectric Prosthesis ◽  
Training Tool ◽  
Myoelectric Prostheses ◽  
Training Systems ◽  
Targeted Muscle Reinnervation

The objective of above-elbow myoelectric prostheses is to reestablish the functionality of missing limbs and increase the quality of life of amputees. By using electromyography (EMG) electrodes attached to the surface of the skin, amputees are able to control motors in myoelectric prostheses by voluntarily contracting the muscles of their residual limb. This work describes the development of an inexpensive myoelectric training tool (MTT) designed to help upper limb amputees learn how to use myoelectric technology in advance of receiving their actual myoelectric prosthesis. The training tool consists of a physical and simulated robotic arm, signal acquisition hardware, controller software, and a graphical user interface. The MTT improves over earlier training systems by allowing a targeted muscle reinnervation (TMR) patient to control up to two degrees of freedom simultaneously. The training tool has also been designed to function as a research prototype for novel myoelectric controllers. A preliminary experiment was performed in order to evaluate the effectiveness of the MTT as a learning tool and to identify any issues with the system. Five able-bodied participants performed a motor-learning task using the EMG controlled robotic arm with the goal of moving five balls from one box to another as quickly as possible. The results indicate that the subjects improved their skill in myoelectric control over the course of the trials. A usability survey was administered to the subjects after their trials. Results from the survey showed that the shoulder degree of freedom was the most difficult to control.

Characterization of Auditory Disability and Its Relation to the Resilience

2018 ◽  
Vol 5 (2) ◽  
pp. 15
Author(s):  
Bibian Bibeca Bumbila García ◽  
Hernán Andrés Cedeño Cedeño ◽  
Tatiana Moreira Chica ◽  
Yaritza Rossana Parrales Ríos
Keyword(s):  
Social Integration ◽  
Conceptual Analysis ◽  
Disabled People ◽  
Disabled Students ◽  
Hearing Disability ◽  
Technical University ◽  
The Relationship ◽  
Made In

The objective of the work is to establish the characterization of the auditory disability and its relationship with resilience at the Technical University of Manabí. The article shows a conceptual analysis related to the inclusion and social integration of disabled students. Based on the fact that the person with disabilities grows and develops in the same way as that of people without disabilities and what usually happens is that disabled people are rejected and discriminated against based on a prefabricated and erroneous conceptualization of these people. The results associated with the application of the SV-RES test prepared by the researchers are shown (Saavedra & Villalta, 2008b). Characterization of the auditory deficit is made in the students, and the limitations that derive from it are pointed out. We analyze the particularities related to communication with students who have a hearing disability and resilience in this type of student, where some personal highlights that in this sense constitute an example of resilience. Finally, the results related to the study of the relationship between students' hearing disability and the level of resilience dimensions are shown.

scholarly journals High-Order Filtered PID Controller Tuning Based on Magnitude Optimum

Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1340
Author(s):  
Damir Vrančić ◽  
Mikuláš Huba
Keyword(s):  
A Priori ◽  
Higher Order ◽  
Process Models ◽  
Pid Controllers ◽  
Tuning Method ◽  
Output Noise ◽  
Pid Controller Tuning ◽  
Output Time ◽  
Tuning Methods ◽  
Measured Input

The paper presents a tuning method for PID controllers with higher-order derivatives and higher-order controller filters (HO-PID), where the controller and filter orders can be arbitrarily chosen by the user. The controller and filter parameters are tuned according to the magnitude optimum criteria and the specified noise gain of the controller. The advantages of the proposed approach are twofold. First, all parameters can be obtained from the process transfer function or from the measured input and output time responses of the process as the steady-state changes. Second, the a priori defined controller noise gain limits the amount of HO-PID output noise. Therefore, the method can be successfully applied in practice. The work shows that the HO-PID controllers can significantly improve the control performance of various process models compared to the standard PID controllers. Of course, the increased efficiency is limited by the selected noise gain. The proposed tuning method is illustrated on several process models and compared with two other tuning methods for higher-order controllers.

scholarly journals A Modified 2-DOF Control Framework and GA Based Intelligent Tuning of PID Controllers

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 423
Author(s):  
Gun-Baek So
Keyword(s):  
Disturbance Rejection ◽  
Pid Controller ◽  
Weighting Function ◽  
Pid Controllers ◽  
Set Point ◽  
Tuning Method ◽  
Point Tracking ◽  
Load Disturbance ◽  
Control Framework ◽  
Feedforward Controller

Although a controller is well-tuned for set-point tracking, it shows poor control results for load disturbance rejection and vice versa. In this paper, a modified two-degree-of-freedom (2-DOF) control framework to solve this problem is proposed, and an optimal tuning method for the pa-rameters of each proportional integral derivative (PID) controller is discussed. The unique feature of the proposed scheme is that a feedforward controller is embedded in the parallel control structure to improve set-point tracking performance. This feedforward controller and the standard PID con-troller are combined to create a new set-point weighted PID controller with a set-point weighting function. Therefore, in this study, two controllers are used: a set-point weighted PID controller for set-point tracking and a conventional PID controller for load disturbance rejection. The parameters included in the two controllers are tuned separately to improve set-point tracking and load dis-turbance rejection performances, respectively. Each controller is optimally tuned by genetic algo-rithm (GA) in terms of minimizing the IAE performance index, and what is special at this time is that it also tunes the set-point weighting parameter simultaneously. The simulation results performed on four virtual processes verify that the proposed method shows better performance in set-point tracking and load disturbance rejection than those of the other methods.

Quel corpus pour l’étude du dialecte niçois ?

2021 ◽  
Vol 137 (2) ◽  
pp. 344-361
Author(s):  
Philippe Del Giudice
Keyword(s):  
Middle Ages ◽  
Written Language ◽  
Linguistic Features ◽  
Descriptive Grammar ◽  
Written Production ◽  
Starting Point ◽  
Social Use ◽  
Over Time ◽  
Made In ◽  
Do So

Abstract A new project has just been launched to write a synchronic, descriptive grammar of Niçois, the Occitan dialect of Nice. In this article, I define the corpus of the research. To do so, I first review written production from the Middle Ages to the present. I then analyze the linguistic features of Niçois over time, in order to determine the precise starting point of the current language state. But because of reinforced normativism and the decreasing social use of Niçois among the educated population, written language after WWII became artificial and does not really correspond to recordings made in the field. The corpus will thus be composed of writings from the 1820’s to WWII and recordings from the last few decades.

scholarly journals Drug delivery applications of poly-γ-glutamic acid

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Olalekan A. Balogun-Agbaje ◽  
Olubusola A. Odeniyi ◽  
Michael A. Odeniyi
Keyword(s):  
Drug Delivery ◽  
Glutamic Acid ◽  
Site Characterization ◽  
Fermentation Medium ◽  
Production Optimization ◽  
Main Body ◽  
Crucial Step ◽  
Drug Delivery Application ◽  
Made In

Abstract Background Poly-γ-glutamic acid (γ-PGA) is a biopolymer of microbial origin, consisting of repeating units of l-glutamic acid and/or D-glutamic acid. The biopolymer has found use in the fields of agriculture, food, wastewater, and medicine, owing to its non-toxic, biodegradable, and biocompatible properties. Due to its biodegradability, γ-PGA is being tipped to dislodge synthetic plastics in drug delivery application. High cost of production, relative to plastics, is however a clog in the wheel of achieving this. Main body of abstract This review looked at the production, nanoparticles fabrication, and drug delivery application of γ-PGA. γ-PGA production optimization by modifying the fermentation medium to tailor towards the production of desirable polymer at reduced cost and techniques for the formulation of γ-PGA nanoparticle as well as its characterization were discussed. This review also evaluated the application of γ-PGA and its nanoparticles in the delivery of drugs to action site. Characterization of γ-PGA and its nanoparticles is a crucial step towards determining the applicability of the biopolymer. γ-PGA has been used in the delivery of active agents to action sites. Conclusion This review highlights some of the efforts that have been made in the appraisal of γ-PGA and its nanoparticles for drug delivery. γ-PGA is a candidate for future extensive use in drug delivery.

scholarly journals Mass Spectrometry-Based Proteomic Characterization of Cutaneous Melanoma Ectosomes Reveals the Presence of Cancer-Related Molecules

2020 ◽  
Vol 21 (8) ◽  
pp. 2934 ◽  
Author(s):  
Magdalena Surman ◽  
Sylwia Kędracka-Krok ◽  
Dorota Hoja-Łukowicz ◽  
Urszula Jankowska ◽  
Anna Drożdż ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Protein Content ◽  
Cell Lines ◽  
Cutaneous Melanoma ◽  
Epithelial Mesenchymal Transition ◽  
Mesenchymal Transition ◽  
Starting Point ◽  
Novel Biomarkers

Cutaneous melanoma (CM) is an aggressive type of skin cancer for which effective biomarkers are still needed. Recently, the protein content of extracellular vesicles (ectosomes and exosomes) became increasingly investigated in terms of its functional role in CM and as a source of novel biomarkers; however, the data concerning the proteome of CM-derived ectosomes is very limited. We used the shotgun nanoLC–MS/MS approach to the profile protein content of ectosomes from primary (WM115, WM793) and metastatic (WM266-4, WM1205Lu) CM cell lines. Additionally, the effect exerted by CM ectosomes on recipient cells was assessed in terms of cell proliferation (Alamar Blue assay) and migratory properties (wound healing assay). All cell lines secreted heterogeneous populations of ectosomes enriched in the common set of proteins. A total of 1507 unique proteins were identified, with many of them involved in cancer cell proliferation, migration, escape from apoptosis, epithelial–mesenchymal transition and angiogenesis. Isolated ectosomes increased proliferation and motility of recipient cells, likely due to the ectosomal transfer of different cancer-promoting molecules. Taken together, these results confirm the significant role of ectosomes in several biological processes leading to CM development and progression, and might be used as a starting point for further studies exploring their diagnostic and prognostic potential.

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