SBIR-STTR Award

Interferometric Fiber Optic Gyro (IFOG) optical fiber coil windings are precision level windings between flanges. To make these windings insensitive to thermal gradients across the wound pack, the innermost wound layers is at the center of the measurement path fiber coil. Alternate pairs of subsequent layers are drawn from lengths of fiber on opposite sides of the center innermost layer. This arrangement causes any thermal gradient present in the coil structure to be symmetrical about the center of the fiber loop, with the result that measurement errors from the two halves of the loop cancel one another. Although the principle is sound, such windings are difficult to realize in practice, because the alternating layer pair geometry tends to introduce winding flaws which degrade precision and make reliable production of the winding difficult. Optelecom has devised proprietary methods of level winding between flanges which facilitate maintaining the required precision. We propose to show how these proprietary winding techniques will lead to a low manufacturing cost IFOG coil winding implementation. In Phase I, we propose to demonstrate the winding implementation using prototype machinery. In Phase II, we plan to develop a winding machine capable of making 1,000 coils per year. Anticipated benefits/potential commercial applications - winding cost alone for IFOG coils is presently $1,000 per axis or more. This is the single largest cost element of IFOG systems. If successful, the proposed work could reduce winding cost to less than $200.00 per axis. IFOG units will have widespread military applications. In addition, certain commercial applications such as use for industrial robotics and recreational marine navigation will become feasible.Key words: fiber optic gyro coils, fiber coil winding machinery.

Interferometric fiber optic gyro (IFOG) optical fiber coil windings are precision level windings between flanges. To make these windings insensitive to thermal gradients across the wound pack, the innermost wound layers is at the center of the measurement path fiber coil. Alternate pairs of subsequent layers are drawn from lengths of fiber on opposite sides of the center innermost layer. This arrangement causes any thermal gradient present in the coil structure to be symmetrical about the center of the fiber loop, with the result that measurement errors from the two halves of the loop cancel one another. Although the principle is sound, such windings are difficult to realize in practice, because the alternating layer pair geometry tends to introduce winding flaws which degrade precision and make reliable production of the winding difficult. Opetelcom has devised and tested proprietary methods of level winding between flanges which facilitate maintaining the required precision. In phase i we demonstrated that winding techniques can be successfully applied to producing full precision windings with the alternate layer pair winding geometry using a winding station adapted from one of our high speed fiber payout winders. Phase i technical success is indicative that the prospects are good for successful development of winding equipment for low cost ifog coil winding. In phase ii we plan to develop a winding machine capable of making 1,000 coils per year. Anticipated benefits/potential commercial applications - winding cost alone for ifog coils is presently $500 per axis or more. This is disproportionate to the degree of complexity of the winding task. One of our phase ii goals is to reduce winding cost to less than $200 per 1km coil. Ifog units will have widespread military applications. In addition, certain commercial applications such as use for industrial robotics and recreational marine navigation will become feasible when the cost is reduced.

Keywords:
Fiber Optic Gyro Coils, Fiber Coil Winding Machinery.