One of the topics of greatest attention in mobile robotics is related to the location and mapping of a robot in a given environment and the other, associated with the selection of the devices or sensors necessary to acquire as much external information as possible for the generation of a global map. The purpose of this article is to propose the integration between a caterpillar-type land mobile robot, SLAM tasks with LiDAR devices and the use of stereo vision through the ZED camera for the generation of a 2D global map and the tracking of the movement of the mobile robot using the MATLAB® software. The experiment consists of performing different detection tests to determine distances and track the position of mobile robot in a structured environment indoors, to observe the behavior of the mobile platform and determine the error in the measurements. The results obtained show that the integrated devices satisfactorily fulfill the tasks established in controlled conditions and in indoor environments, obtaining error percentages lower than 1 and 4% for the case of the LiDAR and the ZED camera respectively. An alternative was developed that solves one of the most common problems of mobile robotics in recent years and, additionally, this solution allows the possibility of merging other types of sensors such as inertial systems, encoders, GPS, among others, in order to improve the applications in the area and the quality of the information acquired from abroad.

Recently, there has been a huge increase in the different ways to manufacture polymer-based sensors. Methods like additive manufacturing, microfluidic preparation, and brush painting are just a few examples of new approaches designed to improve sensor features like self-healing, higher sensitivity, reduced drift over time, and lower hysteresis. That being said, we believe there is still a lot of potential to boost the performance of current sensors by applying modeling, classification, and machine learning techniques. With this approach, final sensor users may benefit from inexpensive computational methods instead of dealing with the already mentioned manufacturing routes. In this study, a total of 96 specimens of two commercial brands of Force Sensing Resistors (FSRs) were characterized under the error metrics of drift and hysteresis; the characterization was performed at multiple input voltages in a tailored test bench. It was found that the output voltage at null force (V_{o_null}) of a given specimen is inversely correlated with its drift error, and, consequently, it is possible to predict the sensor’s performance by performing inexpensive electrical measurements on the sensor before deploying it to the final application. Hysteresis error was also studied in regard to V_{o_null} readings; nonetheless, a relationship between V_{o_null} and hysteresis was not found. However, a classification rule base on k-means clustering method was implemented; the clustering allowed us to distinguish in advance between sensors with high and low hysteresis by relying solely on V_{o_null} readings; the method was successfully implemented on Peratech SP200 sensors, but it could be applied to Interlink FSR402 sensors. With the aim of providing a comprehensive insight of the experimental data, the theoretical foundations of FSRs are also presented and correlated with the introduced modeling/classification techniques.

The purpose of this report is to explain the design and implementation process of a PID controller with a lead network to control the tilt angle of an aerodynamic rocker. For this, the mathematical model of the plant was built and the physical and electrical parameters that characterize the plant were identified experimentally. By linearizing the model around a defined operating point, the transfer function of the system was obtained, which was validated by means of simulations in MATLAB®-Simulink. With this, the PID controller and the lead network were designed considering the performance and robustness requirements. Subsequently, the plant was physically built, and the control system was implemented in a Microchip® brand PIC18 microcontroller. Finally, tests were carried out on the physical implementation to verify the performance and robustness attained. As a result, a controller was obtained whose implementation is fast, has a good follow-up to a wide range of references, rejects disturbances, and is robust to changes in the plant. It is concluded that the implementation in the proposed microcontroller was successful and other researchers are invited to experiment with this project in different ways. Los cultivos hidropónicos reducen el consumo de agua y permiten la preservación del suelo al evitar el uso de fungicidas y pesticidas, que a la vez pueden resultar dañinos para la salud del ser humano. Para controlar el ambiente interior de dichos cultivos en invernadero, es necesario considerar las variables físicas como el nivel y pH del fluido, la temperatura y la humedad relativa del aire, cuyos valores deben ajustarse para permitir la supervivencia y garantizar el correcto crecimiento de las plantas. Este artículo presenta el desarrollo del prototipo del sistema Hidropomatic, un sistema semiautomático para el control y monitoreo web de cultivos hidropónicos de espinacas, en donde se preservan la humedad relativa y temperatura del ambiente de las plantas y se mantiene constante el nivel de fluido nutritivo. Las variables se controlan mediante el uso de humidificador y deshumidificador para la humedad relativa, calefactor y ventilador para la temperatura y una bomba de agua para el nivel de fluido, todo ello en un ambiente tipo invernadero. El sistema posee una alta versatilidad debido a que puede utilizarse en cualquier sistema operativo, ya sea en dispositivos móviles o en computadoras con conexión a internet, desde el cual es posible controlar el cultivo de espinacas con acciones como inicio y paradas de manera remota, monitoreo del estado de sensores y actuadores en campo, con un consumo de recursos computacionales reducido.