Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
Browse
Search Results
- Statistical process control of path-planning algorithms for robots based on visual feedback(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2023-06-14) Sandoval Gaytan, Bryan Daniel; Vázquez Hurtado, Carlos; puemcuervo, emipsanchez; Rodríguez Padilla, Ma. Consuelo; Cuan Urquizo, Enrique; School of Engineering and Sciences; Campus Monterrey; Román Flores, ArmandoThis work presents an analysis of the effects of implementing curves generated by B-Spline and Catmull-Rom splines on a path-planning algorithm for a 6-axis robot. The objective of this project is to validate the use of path-planning algorithms based on curve fitting by splines to maintain a Process Capability Ratio CpK of at least 1.33. The project serves as a first approach to building a working alternative for an edge-grinding system for glass workpieces produced in the automotive industry. The current manufacturing process is done by a CNC machine, but it lacks the flexibility needed to keep up with the changing market needs generated by Industry 4.0. The setup built consisted of a Cognex In-Sight camera as a Vision System to detect and recognize the shape of the workpieces used, MATLAB to filter, process, and apply the curve fitting algorithms to the detected points to generate a tool path, and a UR5 robot to handle the workpiece, using a dial indicator tool as a remote TCP to measure the offset between the expected and the actual position of the robot. A Design of Experiments was done to determine what was the best combination of parameters that approximated the measurements better to the expected value and reduced the variance in the data. The results showed in the vast majority that the splines were capable of maintaining the position of the robot within the ± 0.4 mm tolerance requirements, however, a tolerance of ± 1 mm was chosen to assure the expected Process Capability Ratio CpK, as it is still a good tolerance range accepted for these types of applications. The variance of the measurements was different depending on the combination of parameters used, however, the best combination found was a Catmull-Rom spline and distance between points of 2 mm, and the process was capable of maintaining a CpK of 1.34. These results show that the program and installation developed are able to keep good positioning for the robot in the different paths generated.
- A comparison of cautious learning procedures in statistical process monitoring(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2023) Ibarra Tovar, Alain; Víctor Gustavo, Tercero Gómez; emimmayorquin; Cordero Franco, Álvaro Eduardo; School of Engineering and Sciences; Campus Monterrey; Garza Venegas, Jorge ArturoStatistical process control relies heavily on control charts to gather insights of operational processes and assess their performance. The construction of effective control charts rest on accurate estimations of its parameters, mean and variance when observations are normal. This is a challenge often encountered in real-world applications, and parameters have to be estimated. Various authors have proposed solutions to this challenge by augmenting control limits to ensure a minimum level of performance. Nonetheless, increasing control limits diminish the power of a chart to detect changes. Addressing this trade-off, cautious learning procedures have been introduced to mitigate the impact of imprecise parameter estimates. Cautious Learning is a method which seeks to use the data of the process itself with the objective of increasing the precision of the estimates, making use of certain criteria to select useful information, these criteria vary according to the author. Several authors have presented their proposal, each has its advantages and limitations. This research systematically assesses the effectiveness of such learning procedures when applied to control charts for location, specifically those following CUSUM approaches.
- A phase I nonparametric shewhart-type chart based on sequential normal scores(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-06-15) Hernández Zamudio, Guillermo; TERCERO GOMEZ, VICTOR GUSTAVO;;2256718; Tercero Gómez, Víctor Gustavo; tolmquevedo, emipsanchez; School of Engineering and Sciences; Campus Monterrey; Conover, William JayNonparametric statistical methods are gaining importance in industrial process monitoring due to their robustness to the underlying distribution of the data, a common situation when dealing with real industrial processes. Control charts are regularly used to monitor the behavior of a system over time, often assuming a normal distribution, thus, the exactness of results obtained relies on the truthfulness of given assumptions. Nonparametric solutions based on permutations are limited to deal with small samples due to the computational complexity. Approaches based on rank transformations have shown relatively great power, however, their use in the analysis of series, such as control chart monitoring, involves re-ranking calculations that might become too complex when facing large data flows. This can be avoided by restricting the incorporation of new data into the analysis at the expense of losing power. Sequential rank transformations have shown attractive properties in terms of power and computational complexity, and the normal scores variant has reduced the analytical complexity extending its applicability by adapting parametric approaches that assume normality. This thesis proposes the use of sequential normal scores (SNS) for industrial process monitoring and compares its performance over a wide variety of practical situations and other nonparametric alternatives. The performance showed robustness over different distributions, in terms of the Empirical Alarm Probability (EAP), and an increase in power as new observations were incorporated in the analysis.