Study of Intelligent Control Techniques Applied to a Stirring Tank with Heat Exchanger

This work presents a study and evaluation of intelligent control techniques applied to the problem of temperature control of a stirring tank with heat exchanger. This problem is represented by the example provided and documented by MathWorks in MATLAB/Simulink software, called Heatex. The intelligent techniques used are Fuzzy Logic Controller (FLC), Fuzzy Cognitive Maps (FCM), Artificial Neural Networks (ANN) and the combination of these. The proportional-integral (PI) controller provided in the Heatex example is considered as a reference basis during the evaluation of the intelligent control techniques in different test scenarios. The metrics Integral of Absolute Error (IAE) and Integral Time-weighted Absolute Error (ITAE), as well as the parameters overshoot percentage and settling time are the criteria used to evaluate the control techniques performance

Construction of an Instrumentation Kit for Identification and Control of DC Motors

This paper presents the development of an instrumentation kit of voltage and current measurement for identification of the dynamic model and control of direct current (DC) motors. In the methodology for the parameters identification is used the responses of input voltage and current, and angular velocity of the DC motor. The validation of the obtained dynamic model is done through the comparison of the simulated and experimental responses, and the application of a control system based on state feedback and complete eigenstructure assignment (tracking system). The responses are compared through the normalized root-mean-square error criterion

Control of a Modified Ball and Beam System Using Tracking System in Real Time with a DC Motor as an Actuator

This paper presents amodified ball and beam system, with the intention of realizing a test bed, to study new control techniques in real-time.The ball and beam system consists of a ball over a long beam where the control objective is to stabilizethe position of the ball on the beam by changing the angular position of the beam.In this paper, the ball of the conventional system is replaced by a cart with an embedded microcontroller, enabling the use of a linear encoder as position sensor and allowing to transmit the position via RF (Radio Frequency). The mathematical model of the ball and beam is obtained through the equations of Newton-Euler and the equations were linearized. The system is controlled using the hardware-in-the-loop technique with MATLAB/Simulink.It is applied a tracking control system with entire eigenstructure assignment to control the position of the cart. The actuator used is a DC motor, and a PID(proportional, integral and derivative) control is used to perform the angular position control of beam.The simulation results and the experimental results are compared to validate the mathematical model. The results obtained were satisfactory with adequate accuracy

Inverse Kinematics and Trajectory Planning Analysis of a Robotic Manipulator

In this work, we pretended to show and compare three methodologies used to solve the inverse kinematics of a 3 DOF robotic manipulator. The approaches are the algebraic method through Matlabreg; solve function, Genetic Algorithms (GAs), Artificial Neural Networks (ANNs). Another aspect considered is the trajectory planning of the manipulator, which allows the user to control the desired movement in the joint space. We compare polynomials of third, fourth and fifth orders for the solution of the chosen coordinates. The results show that the ANN method presented best results due to its configuration to show only feasible joint values, as also do the GA. In the trajectory planning the analysis lead to the fifth-order polynomial, which showed the smoothest solution

Parameters Identification of a Direct Current Motor Using the Trust Region Algorithm

In this paper, the trust region algorithm was used to identify the parameters of the dynamic model of a permanent magnet direct current (PMDC) motor, using the MATLAB/Simulink Parameter Estimation tool. The objective was to estimate the parameters applying the square wave, pseudo-random binary sequence (PRBS) and random signals in the motor excitation. The obtained models were evaluated in open and closed loop, where a speed control project was applied using the entire eigenstructure assignment. The error between the simulated and real curves of velocity and current were evaluated by means of the normalized root mean squared error (NRMSE)

Virtual Prototyping, Identification and Control of a Twin Rotor with 3DOF

This paper presents a methodology for identification of the physical characteristics, generation of the mathematical model through virtual prototyping and control of the didactic plant of a twin rotor. In the identification of the physical characteristics, the centers of mass and moments of inertia of the twin rotor parts were identified separately, by means of an easel designed for such task. Still in the identification of the physical characteristics, the equation that relates the applied voltage in the direct current motor with the thrust force produced by the propellers was obtained. The mathematical model of the twin rotor was obtained by means of the identification of the physical characteristics allied to the virtual prototyping with the aid of ADAMS and SolidWorks software. The implemented control system uses state feedback and complete eigenstructure assignment. The ease and usefulness of the proposed methodology was presented through the plant instrumentation, simulation and control in MATLAB/Simulink environment

Robust stability of Markov jump linear systems through randomized evaluations

The paper presents a method for checking the robust mean square stability of continuous-time Markov jump linear systems. The robustness arises in the analysis due to the assumption that the Markovian transition probability matrix is partially known. The corresponding infinite-dimensional robust stability problem, difficult to solve, is then converted into a probabilistic problem, amenable to the numerical viewpoint, taking advantage of the randomized (scenario) approach. The paper shows examples-including a real-time electronic-circuit application-for which the results from the literature fail to determine the robust stability but the randomized approach gives a positive answer346287294CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo88881.030423/2013-01304856/2007-003/06736-

Shaking Table Attached to Magnetorheological Damper: Simulation and Experiments for Structural Engineering

This paper details how to construct a small-scale shaking table attached to a magnetorheological (MR) damper. The motivation for this construction relies on the increasing interest in modeling the dynamics of MR dampers—MR dampers have been used in structures for safety reasons. To model the MR damper, we use the so-called ‘Dahl model’, which is useful to represent systems with a hysteresis. The Dahl model, validated through experimental data collected in a laboratory, was combined with a linear model to represent a two-story building. This two-story building model allows us to simulate the dynamics of that building when its floors are attached to MR dampers. By doing so, we can assess—through simulation—to what extent MR dampers can protect structures from vibrations. Using data from the ‘El Centro’ earthquake (1940), we can conclude that MR dampers have the potential to reduce the impact of earthquakes upon structures. This finding emphasizes the potential benefits of MR dampers for the safety of structures, which is a conclusion taken from the apparatus detailed in this paper

Low-cost dual-axis solar tracker with photovoltaic energy processing for education

Converting the sunlight into electricity has gained the world’s agenda—institutions and individuals have been relying on solar technology more than ever. Still, few workers are qualified to face the increasing demand for solar technology—the high cost of photovoltaic solar technology impedes the creation of more educational programs to qualify more people. To help foster photovoltaic engineering education, we show how to construct a low-cost photovoltaic kit for education. This paper documents the steps necessary to build a low-cost solar tracker and how to process the energy it generates. The equipment has a total cost of about US$ 720. This paper emphasizes the necessary features a solar tracker must have, such as collecting and processing photovoltaic energy, in an optimal way. Using real-time data, we have identified a linear system to represent the dynamics of the sun-tracker equipment. This linear model feeds the algorithm that controls the sun-tracker. Experimental data confirm the effectiveness of the designed solar tracker equipment for extracting the maximum amount of photovoltaic energy—the data indicate an improved energy efficiency of about 32%. The proposed equipment requires only low-cost spare parts, a clear benefit for the education on photovoltaics.Peer ReviewedPostprint (author's final draft