REVISTA DE CIENCIAS TECNOLÓGICAS

Tracking control of a wheeled mobile robot in a velocity field with obstacle avoidance

Luis Arturo García — 2023-10-25

Non-holonomic vehicles, that is, vehicles with movement constraints or unable to follow any desired path, are used in a wide range of activities, both in everyday life and in industrial environments. This paper presents a navigation strategy for unicycle-type vehicles based on velocity potential fields. The validation of the navigation strategy was carried out using numerical simulation and experiments on the test platform. The results obtained demonstrate that the studied method fulfills the assigned task.

Analysis of thermodynamics properties correlations for saturated and superheated water applied in absorption refrigeration cycles

José Luis Rodríguez Muñoz — 2023-10-02

This paper compares the thermodynamic properties, of saturated and superheated water, computed with proposed correlations of two groups of authors versus those obtained by the IAPWS. Besides, the COP of an absorption refrigeration cycle using as working pair, is estimated, for different effectiveness of the solution heat exchanger, using such correlations. The results show that there is a good agreement between both correlations proposed in comparison with the IAPWS formulations. When the correlations are used to compute the COP of the cycle, those correlations proposed by one of the two groups of authors estimate it very well, being the maximum deviation when the cycle operates at of solution heat exchanger effectiveness; while if the proposed correlations by the other group of authors are used, the deviation is almost constant averaging . Finally, the advantage of using the correlations proposed by both authors, in comparison with those obtained by the IAPWS formulations, is that these result from simple polynomials correlations (n≤6), which makes them easier to program, as well as their possible implementation as a computational tool for the calculation of water properties in the analysis and simulation of absorption refrigeration systems.

Adjust operating conditions of an in-made house horizontal hydraulic press for a 90° cold bending process

Hugo Estrada-Pimentel — 2023-11-30

During the cold-bending process, the tooling suffers considerable damage due to excess pressure. This also causes the machines to break down, causing problems in the precision and quality of the metal parts formed. The precision depends on the operating conditions of the press, the tooling employed, and the elastic recovery effect of the material. This study determines the working conditions for a made-in-house horizontal hydraulic press through an experimental design (DOE). This research carried out the V-forming to 90° (ISO 2768-1) of a hot-rolled carbon steel plate, considering pressure, piston permanence time, and recovery factor (Kr). The experimental and statistical analysis ensures accurate forming while the work pressure decreases by 17% and 33%, respectively, regarding the maximum. This reduction will delay the appearance of fatigue damage and have the operating parameters well established; in turn, it will be possible to design tools according to commercial standards.

Wheelchair automation using electromyographic signals obtained from facial movements

Jesús García García — 2023-10-13

Tetraplegia is a disease that can be caused by different factors, whether congenital or accidental, limiting people to live without being able to move both the lower and upper extremities. The present work shows the development of a prototype of a wheelchair for quadriplegics controlled by facial movements, this in order to give the patient independence and improve their emotional state by not requiring help to carry out the task of moving the chair. For the implementation of the prototype, an electronic circuit for analog acquisition, amplification and filtering of electromyography (EMG) signals was designed and built, which provides a signal corresponding to the degree of movement of the facial muscles. Subsequently, the signal obtained from the analog base board is digitized and processed with the help of an ATmega328p microcontroller, where additional filtering is performed and the movement made from the signals obtained is determined. This information is sent via Bluetooth connection to a second ATmega328p microcontroller in the physical prototype of the wheelchair. With the information of the action on the wheelchair's microcontroller, the conditioning of the signal is carried out to control the motors that will carry out the corresponding movement. Finally, a mobile application was designed and implemented to control the prototype through buttons, with the idea that a person responsible for the user of the chair can take control if necessary. As a result, the system was implemented on a basic commercial wheelchair, where the motors and a transmission by bands were adapted to generate the movement, this allowed basic control through facial movement and through the mobile application, however, the EMG system requires to be calibrated for different users. As future work, it is proposed to modify the transmission of the prototype and allow an automatic calibration to be applied regardless of the user.

Generative design applied to the design of an automobile brake pedal

Christian Enrique Nava Alcantar — 2023-11-19

The present work proposes the use of generative design for the modeling of an automobile brake pedal, generating a functional, safe and light design proposal; reducing as much as possible the amount of material, but keeping a good mechanical resistance. For this research, use was made of the generative design module of the Autodesk Fusion 360^® CAD software. This software employs a series of algorithms and the parameters defined by the user, and based on this, generate a series of pedal design proposals. As a result of the research, two brake pedal proposals were obtained. The finite element analysis (FEM) showed mechanical stresses up to 86.07 % below the ultimate stress of the manufacturing material (aluminum 6061-T4). Additionally, safety factor of up to 4.8 and a reduction in pedal mass of up to 16.67% were obtained. The results showed that generative design is a good tool to explore new ideas and concepts that promote innovation in automotive design, achieving functional, resistant and low material consumption designs.

Automation of inoculation in culture media for the microbiology laboratory

Pablo Jonatán Flores Medina — 2023-11-09

The clinical laboratories belonging to the health system in Mexico are among the most discriminated departments due to factors such as sources of financing, as it requires strong administrative management, as well as the dependence on vast infrastructure, material, and human resources. Pneumonia, a disease that can be detected in a subclinical stage, is the 2nd cause of death from respiratory infections in Mexico and is, in turn, the 7th cause of death in the country. For the early diagnosis of diseases caused by microorganisms such as the one just mentioned, laboratory tests are performed, including inoculation in culture media for the proliferation of said microorganisms, however, the techniques used are manual, delaying technological progress. applied in terms of automation, which would allow better workflows with fewer resources. A great challenge in automating the process is cross-contamination that occurs at the time of inoculation, as well as decontamination and sterilization after sowing. Considering this, the model of a device that performs the microbiological culture process automatically was developed, emphasizing the variables involved to avoid cross-contamination and sterilization of the areas, comparing various decontamination techniques, the ones that best fit us are through exposure to UV light, since we avoid the malfunction of electronic components due to temperature.

Taguchi method for parameter optimization in the numerical simulation stage for the injection molding process

Elva Lilia Reynoso Jardón — 2023-10-24

This paper proposes the use Taguchi method for parameter optimization in the numerical simulation stage for the injection molding process to reduce the total displacement of the product. The variables of melting temperature, cooling time, filling time, and holding time were identified. The use of Taguchi's design of experiments of three levels and five factors is proposed, which adds up to a total of 27 iterations of the experiment. The signal-to-noise analysis determined that the two most influential parameters in the decrease of displacement were melting temperature and pressure maintenance time. After the analysis of the variance and the interpretation of signal graphs, two experiments were proposed whose values demonstrated an improvement of 27 % (5.0349 mm) and 31.43 % (4.7485 mm), respectively, compared to the control values (6.9252 mm). Using Taguchi and SolidWorks plastic, it was possible to reduce the variation of deformation and the detection of the main variables that affect the filling process of the part by applying the proposed method.

Voice communication module for automotive instrument panel indicators based on virtual assistant open-source solution - Mycroft AI

Ricardo Hernández Mejía — 2023-10-04

This work was originated from the increasing interest in several industries to implement voice based virtual assistant solutions powered by the Natural Language Processing field of study. This work is focused on the automotive industry Human Machine Interface related products, specifically the Instrument Panel. Nowadays people are constantly using virtual assistants like Google Assistant, Alexa, Cortana or Siri on their electronic devices. Furthermore, 31% of cars have a built-in virtual assistant, for example Ford uses Alexa, Mercedes-Benz and Hyundai use Google Assistant, BMW and Nissan use Cortana, GM uses IBM Watson, Honda uses Hana and Toyota uses YUI. Apart from the proprietary solutions described earlier, there are also contemporary open-source generic solutions available on the market, such as Mycroft AI which stands out from other technologies due to ready to deploy, well documented, simple installation on a Linux PC or RPI SoC, and simple execution. This paper presents a way to use Mycroft AI as an alternative to add artificial intelligence-based voice assistance to applications in the automotive domain. The voice communication module presented here drives notifications related to three different entities: seat belt, fuel level and battery level, all of them are telltales present in any automotive Instrument Panel. Since the Mycroft AI design approach is based on Human Centered Design (HCD), the voice communication module presented here provides real user experience (UX) based design. As a conclusion, Mycroft AI demonstrates great potential as an alternative to add voice assistance to automotive industry Human Machine Interface related products. About future work, due to the fact that Mycroft AI is based on Python, there are many possibilities for connecting and expanding the voice communication module by using countless Python libraries in order to import and process any type of information, in any format or source, for example the information from communication technologies like CAN, LIN, Ethernet, MOST, GPS or any other device or technology in order to create comprehensive automotive solutions.

Strength-to-weight ratio assessment of a cotton-glass fibers hybrid composite beam

Manuel Secundino Delgado — 2023-11-22

In this work, the strength-to-weight ratio on I-beam of a cotton-glass fibers hybrid composite (64% cotton fibers and 36% glass fibers) was assessed. Numerical simulations were carried out under flexural loads and a flexural test were carried out using a Shimadzu AG-X plus 100kN testing machine. The results showed that it is possible to obtain an optimized geometry within the beam through the strategic removal of material zones without compromising the structural integrity. Furthermore, the flexural test on the composite beam showed a higher value in the strength/weight ratio (44) compared to the optimized 6061-T6 aluminum beam (39.65); this behavior can be explained because fiber-reinforced composites are generally less dense compared to metals, and to the distribution of cotton and glass fibers within the beam.

Evaluation of the effectiveness of PCA and ICA in improving muscle movement recognition from raw EMG signals

Jose Alejandro Amezquita Garcia — 2023-10-06

In the last decade, the development of classification models through machine learning for the control of multifunctional prosthetic devices has been increasing. Electromyography (EMG) are recordings produced by muscle fibers naturally when performing movements; if modeled, they could play a more active role in this type of control. These signals are used to control devices/applications. The problem with these models is the stochastic nature of the signal, the variability between subjects and the inherent cross-communication that makes them inaccurate when faced with a high number of movements. The stochastic nature and variability of the signal are already widely studied, however, there are still no definitive results that describe generalizable movement classification models. Here, two databases available on the CapgMyo network and the Ninapro project are studied, their characteristics are evaluated, with the objective of investigating the variability of the muscle signal between subjects, the factors that modify it and how the use of analysis affects principal components (PCA) and independent component analysis (ICA) to EMG information in classification models. A comparison was made between the results in terms of recognition percentages of classic machine learning methods such as linear discriminant analysis (LDA) and quadratic analysis (QDA) using transformation techniques to new spaces introducing the possibility of performing a dimensionality reduction. with PCA and ICA, algorithms usually used to solve problems such as blind source separation (BSS), which is applicable to the phenomenon presented in muscle signals and their acquisition through surface electrodes. The results can be evaluated through the recognition percentage of the classification models created, these show that for raw EMG signals the PCA and ICA methods are useful to perform a reduction in the dimensionality of the data without providing a significant increase in the recognition percentages. It was shown that the recognition percentages in the classification of movements for the Capgmyo database were higher thanks to the characteristics that define it, a higher recognition percentage was obtained ranging from 72.5% to 87.9% with QDA, and 82.8% to 90% for QDA with PCA. The main contribution is the evaluation of the effectiveness of algorithms such as PCA and ICA in machine learning tasks with raw EMG data. Future work is to lay the foundations to reduce the effects of cross-communication in EMG recordings.

Management of public and fiscal policies for the energy transition and sustainable development in Mexico

María Eliazar Raygoza-Limón — 2023-10-06

One of the biggest problems facing the population worldwide is global warming, mainly derived from the anthropogenic footprint. The excessive increase in actions that impact the environment such as public transportation, the use of fossil fuels, industry, etc., have unbalanced ecosystems. The measures and actions to mitigate the environmental impact have not been enough, this has disturbed the United Nations Organization (UN), which has taken a series of international measures such as the proposal of 17 objectives that help to safeguard different large social. Among the goals for 2030 is what is relevant to "clean energy". To align with these strategies, Mexico must take concrete and efficient actions; these actions must be established through the strict elaboration of public policies, which manage to integrate different scientific and technological areas, with timely participation of the different actors involved. The proposal of this document is the integration of public policies together with fiscal and energy policies that contribute to common objectives, through different actions such as energy efficiencies and increasing the participation of renewable energies in the country's energy matrix. Mexico has currently stopped some strategies planned in previous government periods, which have been stopping an energy transition that manages to establish an optimal use of infrastructure and develop a plan that allows the diversification of the energy matrix with the incorporation of renewable energy sources to reduce the use of fossil fuels, which have a share of more than 70% causing various damages to the environment and health. The execution of the proposed strategy required the integration and commitment of the different actors involved, due to the complex nature of the public policy formulation process, the authors propose working with a quality regulatory framework and monitoring the different governmental changes in the country.

Biomedical data transfer system with low consumption communication protocols

Víctor Becerra Tapia — 2023-11-09

In the field of medical care, hospitals face numerous challenges in effectively managing biomedical data. This can lead to a decrease in the efficiency of care, as not all institutions have efficient methods for managing such data. In addition to personal data, physiological constants, such as heart rate and oxygen levels, need to be constantly monitored in order to detect any changes. However, obtaining this data from different instruments and ensuring its constant recording can be problematic. To address these challenges, a system based on the Internet of Things (IoT) has been developed. This system utilizes sensors connected to ESP32 cards, which are in constant communication, to obtain physiological constants and other relevant data. A prototype has been designed, which includes sensors placed on the wrist to measure three physiological constants. The MAX30102 pulse sensor is used to measure blood oxygenation and heart rate. This sensor can be placed on the fingers, lobe, or wrist to obtain accurate readings. Additionally, the MLX90614 sensor is used for temperature acquisition. All the data collected by these sensors is managed by an ESP32 card, which acquires the information and sends it for further use. They employ communication protocols that enable the simultaneous reading of multiple sensors for the parallel monitoring of more than one patient, a capability not addressed in current prehospital care systems. To ensure constant monitoring of physiological constants, a master-slave configuration is utilized. Each slave module collects information from individual patients and sends it to a master card. The data is encrypted during transmission. These devices can be used in various healthcare settings, including prehospital care, and can be carried by the patients themselves. The collected data is then transmitted to a central system using the MQTT protocol. A master ESP32, connected to a Raspberry Pi 4, acts as the main console, where the data is centralized. Once the data is in the MQTT broker, it can be accessed and analyzed from various devices for traceability purposes. Real-time data recording is achieved by utilizing Google services, specifically Firebase, which stores the data in a database.

Modeling of thermoelectric systems for energy harvesting in biological environments

Martha Alexandra Gómez Caraveo — 2023-11-14

In recent years, the trend in the emerging development of autonomous and portable biosensors has led to the search for new materials, as well as the design of new structures that can efficiently generate their own energy with high performance to ensure long-term energy supply, eliminating the use of external sources. Among the most studied are triboelectric, piezoelectric, thermoelectric, and pyroelectric materials, which have shown greater biocompatibility with the physiological parameters of the human body for energy harvesting. This paper proposes to illustrate the systematic process in a finite element simulation software of the bismuth telluride (Bi₂Te₃) material, considered one of the most efficient in thermoelectric energy generation. Simulations implemented in COMSOL Multiphysics^Ⓡ demonstrate the correlation between the physical-mechanical design of the structures and energy efficiency, allowing the determination of the crucial features and parameters for future development. The results demonstrate the power generated by the material according to the surface temperature gradient of the human body for each of the designed structures.

Design and implementation process of a pico-hydro power generation system for teaching and training

Josefa Morales Morales — 2023-11-30

In Mexico the development of remote laboratories is incipient, in 2020 the National Council of Humanities, Sciences, and Technologies (CONAHCYT) created a network of virtual laboratories with nine of its public research centers in order to create a virtual space that enables the development of experimental and research activities in a distance modality. However, access to virtual laboratories is limited only to its members, and the platforms are still under development. With this motivation, this article presents a multi-institutional project for the design, development, and implementation of a pico-hydraulic system for small-scale power generation for teaching and training purposes with the aim of responding to the current need for distance or virtual teaching of practical knowledge due to the coronavirus disease (COVID‑19) caused by the SARS-CoV-2 virus. For the development of the system, technological innovation tools (QFD, TRIZ) were used, with which the design requirements were obtained considering the users (students and teachers) and the renewable energy-related competence of the curricula. Finally, the satisfaction of the users (students and teachers) with the use of the designed system shows the advantage of including it as part of the practical activities of the subjects to improve the development of power generation, transformation, and transmission system projects.

Study of waste generation polystyrene based in Misantla, Veracruz from the circular economy

Romeo García Cruz — 2023-11-06

Recently, the excessive generation of plastic waste and its inadequate management have represented a problem worldwide. Petrochemical plastics, which account for 80% of the world's total plastic use, are the main pollutants. With the growth of the population and its needs, the generation of polystyrene waste increases considerably. Expanded polystyrene (EPS) has a very low recycling rate; it is estimated that, of 125 thousand tons generated annually in Mexico, only 0.1% is recycled. The objective of this project is to obtain a preliminary diagnosis on the generation of EPS waste in the city of Misantla, Ver., which allows its post-consumer use as recycled raw material, under a circular economy approach. The methodological proposal for the development of this research was defined in the following steps: (1) characterization of the participating actors, from the Circular Economy approach; (2) identification of businesses that generate polystyrene as waste; (3) determination of the type of polystyrene generated; (4) estimation of the quantities of waste generated; (5) analysis in comparison with the generation of other types of waste; (6) generation of post-consumer use strategies. According to the 2019 Economic Census, in Misantla the economic sector with the largest number of economic units in the municipality is retail, where it is located, the sale of food in small establishments or street stores, these agents being identified as the main generators of polystyrene waste. A survey was applied to 96 companies, mainly in the food sector. The results of these surveys show that these establishments mainly use disposable products made of expanded polystyrene such as plates and cups, and that, in some cases, the use of disposable polystyrene products such as containers and spoons was identified. With the information collected, it is concluded that the use of disposable products generates approximately 765 kilograms of EPS waste. Unlike plastic waste, misinformation about the recycling of EPS, the lack of strategies for its collection and post-consumer use, as well as the lack of awareness for its recycling, give way to it ending up in final disposal sites, continuing with the trend framed in different investigations that maintain that its final destination is incineration. After the diagnosis, there is a concrete vision of the generation of polystyrene waste and future work is given in the generation and implementation of strategies that allow the use of post-consumer unicel for its return to the value chain.

Design and development of hydraulic clamping device for broaching process

Jorge Alberto Morales Martínez — 2023-11-08

A hydraulic clamping device was developed for the broaching process of Brackets used in automotive braking systems, which allows reducing the variation of the cutting process by improving the clamping system and thereby limiting the deformation of the piece after having been processed. With this concept of device, it is possible to improve the conditions of the production process such as: cutting speed, cycle time reduction, operation performance, scrap cost reduction, and downtime reduction due to process over-adjustment and change over. Additionally, the development of a part detection system was made that allows capturing when a part is not correctly placed in the device before starting the cutting cycle, with this it is possible to detect failures in the process that represent a risk to the operation. During the design stage, a simulation of the machining process was carried out in extreme conditions and ideal conditions to measure the deformation of the part and with this obtain the appropriate cutting parameters for the implementation of the clamping device. For the validation of the model, a Cpk and Ppk process ability study was carried out (according to customer requirements) to assess that the new process is efficient and is under control.

Sustainable practices for the efficient use of green energy in Ciudad Juárez SMEs

Georgina Elizabeth Riosvelasco Monroy — 2023-11-03

Carbon emissions have been increasing due to economic growth and development. Fossil-based energy is one of the main factors of environmental pollution. In Mexico, 77.24% of fossil-based energy is from stationary source combustion, 15.7% from industry processes and commercial activities, 6.64% from mobile sources, and 0.05% from agriculture and livestock activities. Specifically, manufacturing operations use 33.4%, of the total consumption of electricity and natural gas. Because the production of green energy is from naturally regenerating sources and does not emit greenhouse gases or compounds, decreases the environmental impact, and because they are able to apply to manufacturing operations, it is pertinent the efforts in this sense. The article presents the PRISMA 2020 as a methodology for searching between distinct databases and current research with the objective of identifying variables and their measurements so micro, small, and mid-size enterprises in Ciudad Juarez, Chihuahua, Mexico can develop collaboration strategies towards a sustainable manufacturing environment. The literature review resulted in the identification of six green energy indicators and their measurements.