M. F. Santos

Design of angular PID controllers for quadcopters built with low cost equipment

This work presents the modeling and practical control design of an UAV (Unmanned Aerial Vehicle) based on a quadcopter type. The PID controllers were set for angular position stability (roll and pitch) and yaw speed. The PID gains were designed based on the Saturation Constraints and Performance and Root-Locus technique. The prototype was built with low cost equipment, with satisfactory practical results, producing the expected behavior, allowing safe flight conditions and reliability. The adopted control validation parameters were; peak time (Tp), settling time (Ts) and the percentage overshoot (%UP).

A multiple kernel classification approach based on a Quadratic Successive Geometric Segmentation methodology with a fault diagnosis case

This work presents a new approach for solving classification and learning problems. The Successive Geometric Segmentation technique is applied to encapsulate large datasets by using a series of Oriented Bounding Hyper Box (OBHBs). Each OBHB is obtained through linear separation analysis and each one represents a specific region in a patterns solution space. Also, each OBHB can be seen as a data abstraction layer and be considered as an individual Kernel. Thus, it is possible by applying a quadratic discriminant function, to assemble a set of nonlinear surfaces separating each desirable pattern. This approach allows working with large datasets using high speed linear analysis tools and yet providing a very accurate non-linear classifier as final result. The methodology was tested using the UCI Machine Learning repository and a Power Transformer Fault Diagnosis real scenario problem. The results were compared with different approaches provided by literature and, finally, the potential and further applications of the methodology were also discussed.

Control of level systems by arduino via PC platform

Nowadays, a great variety of industrial processes has an extreme necessity of improving the quality of controlled tanks level, due to the fact that this type of control and process is widely found in the industrial environment. The objective of this work consists to create a tank system, aiming to represent in small scale an industrial level process, seeking exemplify applications, modes of use and control techniques. Firstly, there is the need to identify the system response of the open-loop to be adjusted the best controller, in accordance with the best method of tuning. As control platform, Arduino microcontroller was used to establish a serial communication with a PC workstation. The results were quite satisfactory considering its functionality in industrial systems, represented in small scale.

Case study: Level system control performed with LPC2148 microcontroller via PC platform

This paper aims to show the development and methodology of PI controllers, tuning by Ant Colony Optimization (ACO). It is an optimized technique that uses other methods for this purpose, based on metaheuristic. Which solves the problem of the traveling salesman, among others. The PI controller has two parameters that must be determined to start the process control. The ACO technique is used to optimize these constants. In this work will be presented the steps needed to identify and tune a First Order Delay Time (FODT) system and create an ant colony optimization method, through a supervisory system developed in Java programming language. The applicability of this PI tuning technique depends on the knowledge of the desired response. In this work, it is essential that the process of optimization provides the shortest possible settling time response, and no (or almost no) overshoot.

Anti wind-up techniques applied to real tank level system performed by PI controllers

PI controller is still the most used control algorithm in industry. This can be explained by its robustness and easy implementation. However, the presence of overshoot (inherent characteristic of the integral action) could prejudice its use. Considering the presence of such an effect, the main objective of this paper is to present the outcome of seven principal methodologies to compensate the integral action through a real level tank system. The results obtained showed the extreme necessity to compensate the integral action when using PI controller. For control loop audit, non-intrusive performance indexes were used, like IAE, ITAE, ISE and ITSE.

Modeling and control of one DOF arm controlled by brushless motor: A first class experimental case

Automation systems, as well as process control, has played a key role in the industry nowadays. For good system performance, it is necessary that mathematical model is closest to the real model, which is detailed in this work. The objective of this study is to present a modeling (considering the viscous friction), stability analysis and simple PID controller tuning using as an example, an arm with one Degree Of Freedom (DOF), actuated by a brushless motor. Taking this into account, this work can be useful in robotics area as a first class experimental case. The measurement will be performed by gyroscope and accelerometer sensors built for Arduino. The control will be based on space states modeling and stability analysis made from the portrait phase, considering the system nonlinearities. Finally, the controller implementation results are presented using the physical system.