Optical signal detection of foreign fibers based on H_∞ filter

To solve the problem of the difficulty in detecting foreign fibers in textile enterprises,a technical solution was put forward,in which a single green modulated light and three silicon photocells regularly arrayed were adopted.It can detect foreign fibers and yarn faults by means of contrasting the reflection and transmission signals received by the silicon photocells and analyzing the color and diameter changes of yarn.A mathematical model was established,and the simulation experiment was made based on H∞ filter using software MatLab.The results proved that the algorithm is more sensitive to signal singularity of the surface brightness signal and the diameter signal of yarn,and can also track the color change on a percentage scale.It is further confirmed that the scheme of detecting foreign fibers and yarn faults is feasible,and the H∞ filter algorithm can effectively improve the detection precision of yarn faults such as color change and heavy and thin fiber.