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Abstract(s)
Desde a invenção da bicicleta como meio de transporte até à sua utilização em grande escala, tem aparecido diferentes soluções para as tornar mais seguras e cómodas. Uma das principais formas para conseguir com que sejam cómodas e seguras é integrar um sistema de suspensão.
Nos últimos anos, com o aumento da sua utilização, desde o lazer ao desporto de alta competição, acompanhada dos progressos na tecnologia, fez suscitar um grande interesse nos sistemas de suspensão, ativos e semi-ativos, dado que permitem adaptar a sua dureza às condições do terreno e à forma de condução.
Este tipo de suspensões permitem melhorar o conforto do passageiro, aumentando a estabilidade e absorção das vibrações transmitidas pelos pneus. Assim sendo, além de aumentar a segurança, desempenho e conforto do ciclista, ajudam a melhorar a estabilidade em todo o tipo de circunstâncias.
Desenvolvido em pareceria com investigadores de engenharia mecânica, este projeto tem como principal objetivo desenvolver um protótipo de forma a investigar e aprofundar conhecimentos sobre as suspensões semi-ativas, mais concretamente sobre os amortecedores magneto-reológicos, estudando o seu comportamento e como permitem uma melhoria nas prestações dinâmicas do sistema.
Através de vários sensores estrategicamente posicionados, estudou-se o comportamento da nova suspensão (adaptada com um amortecedor magneto-reológico), obtendo uma variedade de dados em diferentes tipos de pisos, declives e velocidades, que permitiram compreender o desempenho do sistema para cada uma das situações.
Com a análise dos dados recolhidos com o protótipo completamente montado, e ainda que, com controlo da suspensão em malha aberta, foi possível encontrar os níveis de rigidez adequados para aplicar ao amortecedor em cada uma das situações. Após a realização deste estudo, verificou-se que o controlo em malha aberta não é o mais eficiente, sendo um objetivo de trabalho futuro a realização do controlo em malha fechada, justificando-se um estudo mais aprofundado.
Since the invention of the bicycle as a means of transportation, and given its use on a large scale, different solutions have appeared to make it safer and more comfortable for users. One of the most common approaches applied with the purpose of the bicycle be more comfortable and safe at the same time, is to integrate a suspension system. In the past years with the increase in its use, from recreational to top-level sport, together with the advances in technology, it raised a lot of interest in suspension systems, active and semi-active, as they make possible to adapt its hardness to the ground conditions and cycling style. Such suspensions allow improvement in the rider comfort, increasing the stability and absorption of the vibrations transmitted by the tires. Therefore, in addition to increasing safety, comfort and cycling performance, they help improve stability in all types of circumstances. Developed in partnership with researchers in mechanical engineering, this project aims to develop a prototype to research and increase knowledge of the semi-active suspensions, more particularly on the magneto-rheological dampers, studying their behaviour and how they allow an improvement in the dynamic performance of the system. Through several sensors strategically placed, it is studied the behaviour of the new suspension, obtaining a variety of data in different types of floors, slopes and speeds, which allowed to understand the system’s performance for each situation. With the analysis of the collected data using the prototype fully assembled, even with the suspension control in open loop, it was possible to find the levels of rigidity appropriated to apply to the damper in each situation. After this study it was found that the control in open loop is not the most efficient approach, being proposed as future work to perform the closed loop, being justified a deeper study to be carried out in the future.
Since the invention of the bicycle as a means of transportation, and given its use on a large scale, different solutions have appeared to make it safer and more comfortable for users. One of the most common approaches applied with the purpose of the bicycle be more comfortable and safe at the same time, is to integrate a suspension system. In the past years with the increase in its use, from recreational to top-level sport, together with the advances in technology, it raised a lot of interest in suspension systems, active and semi-active, as they make possible to adapt its hardness to the ground conditions and cycling style. Such suspensions allow improvement in the rider comfort, increasing the stability and absorption of the vibrations transmitted by the tires. Therefore, in addition to increasing safety, comfort and cycling performance, they help improve stability in all types of circumstances. Developed in partnership with researchers in mechanical engineering, this project aims to develop a prototype to research and increase knowledge of the semi-active suspensions, more particularly on the magneto-rheological dampers, studying their behaviour and how they allow an improvement in the dynamic performance of the system. Through several sensors strategically placed, it is studied the behaviour of the new suspension, obtaining a variety of data in different types of floors, slopes and speeds, which allowed to understand the system’s performance for each situation. With the analysis of the collected data using the prototype fully assembled, even with the suspension control in open loop, it was possible to find the levels of rigidity appropriated to apply to the damper in each situation. After this study it was found that the control in open loop is not the most efficient approach, being proposed as future work to perform the closed loop, being justified a deeper study to be carried out in the future.
Description
Keywords
Amortecedor MR Bicicleta com sensores Acelerómetro Análise de conforto LVDT (Transformador Diferencial Variável Linear) Célula de carga