Compensação dinâmica em cames

Abstract

iii iv AGRADECIMENTOSAo Prof. Dr. Álvaro Costa Neto, mais do que orientador, um companheiro e amigo de longa data.Aos colegas de departamento, professores e funcionários, pela amizade, companheirismo e colaboração.Ao CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) pela bolsa de estudos que deu suporte ao desenvolvimento da maior parte deste trabalho na Katholieke Universiteit Leuven na Bélgica.Ao Prof. Dr. Joris De Schutter pela orientação, pelo apoio, pela compreensão e por todo o suporte durante toda minha estadia na Bélgica.Aos professores, funcionários e colegas do PMA, departamento onde desenvolvi boa parte de meu trabalho na Bélgica. In a cam-follower system the dynamics of the follower-train mechanism cause an actual motion which deviates from the desired one. This effect can be compensated by taking into account the inverse dynamic model of the followertrain in the design of the cam motion law. By considering a constant cam velocity, the follower-train has linear dynamics. However, due to the varying transmission ratio, and due to other nonlinear effects, the whole drive train is a nonlinear system, and nonlinear procedures should be used to fit a motion law.A theoretical analysis with only the linear feed-forward compensation, supported by simulation results, has shown the potential of this approach, at least in the case of simple follower-train dynamics: a considerable reduction of the motion error, and a good robustness with respect to errors in the estimated resonance frequency and damping ratio of the follower-train. Experiments with a small driving servomotor, as expected, show different results, due to the non-constant angular velocity. The observed cam angular velocity ripple is then taken into account to design a complete nonlinear feedforward motion law.