A carregar...
Publicação
Desenvolvimento de uma Plataforma Stewart como Suporte Inercial Aplicado a uma Embarcação
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 8.86 MB | Adobe PDF |
Orientador(es)
Resumo(s)
Todos os anos, graças às condições adversas do oceano, são causadas perdas monetárias
significantes devido ao adiamento de operações marítimas. Para além disto, por causa de
condições de segurança precárias ocorrem acidentes que poderiam ser evitados através
de uma estabilização mais correta de estruturas em ambientes offshore.
Este trabalho apresenta o desenvolvimento de uma plataforma Stewart de 3 elos, pro-
jetada para integração em embarcações, com o objetivo de estabilizar sistemas, mantendo
o plano superior nivelado, ao compensar movimentos causados por ondas marítimas. Foi
estudada a cinemática inversa destes equipamentos para determinar os comprimentos ne-
cessários dos atuadores para alcançar as orientações desejadas. Foi também desenvolvido
um ambiente de simulação para estudar as implicações de um design de 3 elos em vez
de 6. Foram construídos 3 protótipos ao longo desta tese, com cada iteração corrigindo
problemas como o sobreaquecimento dos primeiros atuadores e falhas de estabilização,
sobretudo através da projeção de componentes impressos em 3D. Os sensores MPU9250
e HR-S04 foram integrados no sistema, após a sua devida calibração e processamento de
sinal, incluindo um filtro complementar e filtro de média móvel. O algoritmo de controlo
foi implementado num Arduino UNO, que ao utilizar as leituras dos sensores, determina
os outputs de controlo para o movimento correto dos atuadores lineares.
Os resultados obtidos em testes de resposta a perturbações apresentam erros steady-
state de 2, 63◦ e 3, 64◦ para os valores de roll e pitch respetivamente, sendo este erro
representativo da diferença entre os ângulos de estabilização da plataforma antes e depois
de uma perturbação.
Trabalho futuro deverá incluir a integração de motores mais rápidos, e deverão ser
exploradas as integrações de estratégias de controlo mais sofisticadas.
Every year, significant financial losses occur due to the postponement of maritime opera- tions caused by the adverse conditions of the ocean. Additionally, accidents resulting from unsafe conditions, which could be prevented through better stabilization of structures in offshore environments, are a frequent occurrence. This work presents the development of a three-legged Stewart platform designed for integration into vessels, with the goal of stabilizing systems by keeping the top plane level, compensating for movements caused by ocean waves. The inverse kinematics of these systems were studied to determine the necessary actuator lengths to achieve the desired orientations. A simulation environment was also developed to study the implications of a three-legged design versus a six-legged one. Three prototypes were built throughout this thesis, with each iteration addressing issues such as overheating of the initial actuators and stabilization failures, particularly through the design of 3D-printed components. The MPU9250 and HR-S04 sensors were integrated into the system, following proper calibration and signal processing, including a complementary filter and moving average filter. The control algorithm was implemented on an Arduino UNO, which, using the sensor readings, determines the control outputs for the correct movement of the linear actuators. The results obtained from disturbance response tests show steady-state errors of 2.63◦ and 3.64◦ for roll and pitch, respectively. This error represents the difference between the platform’s stabilization angles before and after a disturbance. Future work should include integrating faster motors and exploring more sophisticated control strategies.
Every year, significant financial losses occur due to the postponement of maritime opera- tions caused by the adverse conditions of the ocean. Additionally, accidents resulting from unsafe conditions, which could be prevented through better stabilization of structures in offshore environments, are a frequent occurrence. This work presents the development of a three-legged Stewart platform designed for integration into vessels, with the goal of stabilizing systems by keeping the top plane level, compensating for movements caused by ocean waves. The inverse kinematics of these systems were studied to determine the necessary actuator lengths to achieve the desired orientations. A simulation environment was also developed to study the implications of a three-legged design versus a six-legged one. Three prototypes were built throughout this thesis, with each iteration addressing issues such as overheating of the initial actuators and stabilization failures, particularly through the design of 3D-printed components. The MPU9250 and HR-S04 sensors were integrated into the system, following proper calibration and signal processing, including a complementary filter and moving average filter. The control algorithm was implemented on an Arduino UNO, which, using the sensor readings, determines the control outputs for the correct movement of the linear actuators. The results obtained from disturbance response tests show steady-state errors of 2.63◦ and 3.64◦ for roll and pitch, respectively. This error represents the difference between the platform’s stabilization angles before and after a disturbance. Future work should include integrating faster motors and exploring more sophisticated control strategies.
Descrição
Palavras-chave
plataforma Stewart compensação de ondas cinemática inversa controlo atuadores