Positioning accuracy improvement of a vision-based optical fiber alignment stage powered by a Piezo-Actuator

Optical fiber communication has become mainstream in wired communication due to its low attenuation, low cost, and high bandwidth. However, optical fiber is light and thin, which makes the coupling procedure between fibers and optoelectronic components very complex and difficult. To maintain high transmission quality, it is imperative to develop a high-precision alignment technique for optical fiber fabrication. In this paper, a vision-based optical fiber alignment stage powered by a piezo-actuator (PEA) is proposed. The tracking performance of PEA is limited due to its inherent hysteretic nonlinearity and time varying parameters. In order to cope with this problem, a feedforward compensator based on a cerebellar model articulation controller (CMAC) combined with a PI feedback controller is developed to eliminate the effects of hysteresis. Multi-rate control is used to deal with the vision latency problem. Experimental results show that the proposed approach shows satisfactory performance.