Acevedo, Mario
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Preferred name
Acevedo, Mario
Official Name
Acevedo Alvarado, Mario
Alternative Name
macevedo
Main Affiliation
Scopus Author ID
55183765000
Researcher ID
JMX-0350-2023

Research Output
Now showing 1 - 10 of 31
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Optimum Balancing of the Four-Bar Linkage Using Fully Cartesian Coordinates

2019 , Acevedo, Mario , Orvañanos-Guerrero, María T. , Velázquez, Ramiro , Haro-Sandoval, Eduardo

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Gradient Descent-Based Optimization Method of a Four-Bar Mechanism Using Fully Cartesian Coordinates

2019 , Orvañanos-Guerrero, María T. , Sánchez-Gómez, Claudia , Mariano Rivera , Acevedo, Mario , Velázquez, Ramiro

Machine vibrations often occur due to dynamic unbalance inducing wear, fatigue, and noise that limit the potential of many machines. Dynamic balancing is a main concern in mechanism and machine theory as it allows designers to limit the transmission of vibrations to the frames and base of machines. This work introduces a novel method for representing a four-bar mechanism with the use of Fully Cartesian coordinates and a simple definition of the shaking force (ShF) and the shaking moment (ShM) equations. A simplified version of Projected Gradient Descent is used to minimize the ShF and ShM functions with the aim of balancing the system. The multi-objective optimization problem was solved using a linear combination of the objectives. A comprehensive analysis of the partial derivatives, volumes, and relations between area and thickness of the counterweights is used to define whether the allowed optimization boundaries should be changed in case the mechanical conditions of the mechanism permit it. A comparison between Pareto fronts is used to determine the impact that each counterweight has on the mechanism’s balancing. In this way, it is possible to determine which counterweights can be eliminated according to the importance of the static balance (ShF), dynamic balance (ShM), or both. The results of this methodology when using three counterweights reduces the ShF and ShM by 99.70% and 28.69%, respectively when importance is given to the static balancing and by 83.99% and 8.47%, respectively, when importance is focused on dynamic balancing. Even when further reducing the number of counterweights, the ShF and ShM can be decreased satisfactorily.

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Design and Evaluation of an Eye Disease Simulator

2015 , Velázquez, Ramiro , Varona, Jorge , Rodrigo, P. M. , Haro-Sandoval, Eduardo , Acevedo, Mario

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A hybrid fuzzy-molecular controller enhanced with evolutionary algorithms: A case study in a one-leg mechanism

2019 , Ponce, Hiram , Acevedo, Mario , Esparza-Duran, Noel

Intelligent control systems are able to work well in uncertain nonlinear systems, mainly for: changes in the operating point, presence of environmental noise and disturbances, uncertainty in sensor measurements, miscalibration, uncertain model plant, and others. For instance, fuzzy controllers have been widely studied and applied. Recently, artificial organic controllers (AOC) have been proposed as an ensemble of fuzzy logic and artificial hydrocarbon networks. However, a weakness in AOC is the lack of training methods for tuning parameters for desired output responses in control. In this regard, this paper aims to introduce an evolutionary optimization method, i.e. particle swarm optimization, for tuning artificial organic controllers. Three objectives are proposed for automatic tuning of AOC: overall error, steady-state error and settling time of output response. The proposed methodology is implemented in the well-known cart-pole system. Also, the proposed method is applied on a one-leg unstable mechanism as case study. Results validate that automatic tuning of AOC over simulation systems can achieve suitable output responses with minimal overall error, steady-state error and settling time. © 2019 The Franklin Institute. Journal of the Franklin Institute, Elsevier Ltd.

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Dynamic Balancing Conditions of Planar Parallel Manipulators

2015 , Acevedo, Mario , Reyes, José María

Force and moment balancing (dynamic balancing) of rigid body linkages with constant mass links is a traditional but still very active area of research in machine dynamics and robotics. The shaking force and the shaking moment caused by all moving links can be reduced in different ways but all having a common difficulty named to derive the so-called balancing conditions, that in general can be cumbersome. In this article a novel method to find the dynamic balancing conditions based on the use of Natural Coordinates is introduced. The method is direct, efficient, and easy to automate through the application of a computer algebra system. It can be used to obtain the shaking force and the shaking moment balancing conditions for planar and spatial mechanisms.

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Design of Reactionless Mechanisms with Counter-Rotary Counter-Masses

2016 , Acevedo, Mario

In this chapter a new method to find the force and moment balancing conditions based on Natural Coordinates is introduced. The method is simple and can be highly automated, it is very prone to be used in combination with a system for the manipulation of symbolic expressions. These conditions can be interpreted and used for the creation of dynamic balanced linkages by design. The application of the method is demonstrated through the dynamic balancing of a simple pendulum (open-loop linkage) and a general four-bar mechanism (closedloop linkage), particularly by the design of counter-rotary counter-masses applying optimization. The resulting designs are presented and their virtual prototypes simulated using a general multibody dynamics simulation software (ADAMS), specifying the resulting geometry (dimensions), shaking force, shaking moment, and driving torque. © Springer International Publishing Switzerland 2016.

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Neural network-driven interpretability analysis for evaluating compressive stress in polymer foams

2024 , Rodríguez-Sánchez, Alejandro E. , Plascencia Mora, Héctor , Acevedo, Mario

This research presents a method to analyze how neural network models, applied to Expanded Polypropylene and Expanded Polystyrene foams, predict their compressive stress responses. By using SHAP values and Partial Dependence Plots, the study elucidates the models’ decision-making processes. It focuses on three main features for both materials: density, loading rate, and strain, with an additional feature concerning loading and unloading for Expanded Polystyrene foam. The findings highlight that increased density and loading rate are closely correlated with higher compressive responses, and strain emerges as the most influential factor for the response of both materials. Partial Dependence Plots reveal a linear relationship with density, whereas other variables demonstrate non-linear relationships. These results validate the use of neural networks in analyzing material behavior, showing that the models’ outputs are in line with empirical observations. In conclusion, as presented, the integration of interpretability tools with neural network models offers a robust method for material response analysis, contributing to a deeper understanding of material science.

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An Alternative Method for Shaking Force Balancing of the 3RRR PPM through Acceleration Control of the Center of Mass

2020 , Acevedo, Mario , Orvañanos-Guerrero, María T. , Velázquez, Ramiro , Vigen Arakelian

The problem of shaking force balancing of robotic manipulators, which allows the elimination or substantial reduction of the variable force transmitted to the fixed frame, has been traditionally solved by optimal mass redistribution of the moving links. The resulting configurations have been achieved by adding counterweights, by adding auxiliary structures or, by modifying the form of the links from the early design phase. This leads to an increase in the mass of the elements of the mechanism, which in turn leads to an increment of the torque transmitted to the base (the shaking moment) and of the driving torque. Thus, a balancing method that avoids the increment in mass is very desirable. In this article, the reduction of the shaking force of robotic manipulators is proposed by the optimal trajectory planning of the common center of mass of the system, which is carried out by “bang-bang” profile. This allows a considerable reduction in shaking forces without requiring counterweights, additional structures, or changes in form. The method, already presented in the literature, is resumed in this case using a direct and easy to automate modeling technique based on fully Cartesian coordinates. This permits to express the common center of mass, the shaking force, and the shaking moment of the manipulator as simple analytic expressions. The suggested modeling procedure and balancing technique are illustrated through the balancing of the 3RRR planar parallel manipulator (PPM). Results from computer simulations are reported.

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A dynamics simulation of a 3-DOF parallel manipulator

2004 , Acevedo, Mario

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Efficient Balancing Optimization of a Simplified Slider-Crank Mechanism

2020 , Orvañanos-Guerrero, María T. , Acevedo, Mario , Nicola Ivan Giannoccaro , Paolo Visconti , Sánchez-Gómez, Claudia , Velázquez, Ramiro

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