Técnicas avanzadas de control para la mejora de la precisión y velocidad en las plataformas de nanoposicionamiento

Resumen

The term nanopositioning refers to the controlled movement of objects with nanoscale accuracy, which means almost atomic resolution. Such resolution has application in many areas, both in pure and applied science. Two examples are the biological research and the use of atomic microscopy, and the industrial applications such as the design of hard disks drives and the design of new high-density semiconductor systems. In any case, regardless of the application, the controlled movement at nanometric scale involves to solve many issues of different nature: random external perturbations, residual vibrations of the mechanical structures, and non-linear dynamics caused by the actuators employed to move the system. This thesis explains several control techniques used to solve these issues and to allow accurate movements in a wide range of frequencies. Therefore, the specifications of the currently existing control schemes applied to nanopositioning are improved. More specifically, we have developed control techniques to increase the bandwidth of the system, thus allowing faster operation speeds in microscopy applications. We have developed techniques to compensate the delay of the system, thus allowing to use of cheaper control electronics with less computing power. And finally, we have developed techniques to allow the real-time estimation of the parameters of the system, thus allowing to re-tune the parameters of the control scheme when the operation conditions change, so that the robustness of the system is increased.