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Authors
Abstract(s)
Os acidentes envolvendo tombamento de veículos agrícolas, em especial os tratores e
moto 4, são muito comuns e apresentam alto índice de fatalidade devido às características destes
veículos e do seu ambiente de utilização. O objetivo principal desta dissertação consiste na
criação de um sistema de alerta ao condutor, com base num modelo de estabilidade dinâmica
do veículo (a escolher e validar). Para tal, foram estudados diversos modelos matemáticos de
estabilidade e métodos para a obtenção das variáveis necessárias (centro de gravidade,
momentos de inércia e ângulos críticos) para criação do modelo do veículo. Para a determinação
do índice de estabilidade, que é um valor adimensional para caracterizar se o veículo está estável
ou em não, é necessário conhecer em tempo real as acelerações lineares e as velocidades
angulares do veículo. Nesse sentido, foi criado um sistema de monitorização e aquisição de
dados utilizando uma unidade de medição inercial (IMU) e um programa em linguagem Python
com uma interface gráfica do utilizador (GUI). De modo a obter um ambiente controlado, os
ensaios foram inicialmente realizados com um veículo à escala. Os algoritmos de estabilidade
e o sistema de monitorização e aquisição de dados foram validados, utilizando o veículo à
escala, num plano inclinado ajustável onde um obstáculo simula um evento de instabilidade
dinâmica. Os resultados obtidos demonstram que o sistema implementado consegue prever a
iminência do tombamento.
ABSTRACT: Accidents involving the overturning of agriculture vehicles, especially tractors e ATVs, are quite common and have a high fatality rate due to those vehicle’s characteristics and their work environment. The aim of this thesis consists in the creation of an alert system to the operator, based on a dynamic stability model of the vehicle. To this end, several mathematical models of stability and methods to obtain the necessary variables (center of mass, moment f inertia and critical angles) were reviewed to create the vehicle’s model. For the determination of the stability index, it’s necessary to know in real time the linear accelerations and angular velocities of the vehicle. To this end, a system for data monitoring and acquisition was developed, using an inertial measuring unit (IMU) and a program developed in the Python language with a graphical user interface (GUI). To obtain a controlled environment, the tests were initially conducted with a reduced scale model of the vehicle. The stability algorithm and the data monitoring and acquisition system were validated, using the vehicle in an adjustable inclination plane where an obstacle was placed to simulate an event of dynamic instability. The results obtained demonstrate that the implemented system can predict the imminence of the overturning.
ABSTRACT: Accidents involving the overturning of agriculture vehicles, especially tractors e ATVs, are quite common and have a high fatality rate due to those vehicle’s characteristics and their work environment. The aim of this thesis consists in the creation of an alert system to the operator, based on a dynamic stability model of the vehicle. To this end, several mathematical models of stability and methods to obtain the necessary variables (center of mass, moment f inertia and critical angles) were reviewed to create the vehicle’s model. For the determination of the stability index, it’s necessary to know in real time the linear accelerations and angular velocities of the vehicle. To this end, a system for data monitoring and acquisition was developed, using an inertial measuring unit (IMU) and a program developed in the Python language with a graphical user interface (GUI). To obtain a controlled environment, the tests were initially conducted with a reduced scale model of the vehicle. The stability algorithm and the data monitoring and acquisition system were validated, using the vehicle in an adjustable inclination plane where an obstacle was placed to simulate an event of dynamic instability. The results obtained demonstrate that the implemented system can predict the imminence of the overturning.
Description
Keywords
Tratores Veículos agrícolas Estabilidade de veículos Estabilidade dinâmica Prevenção de acidentes IMU