System analysis and design of a low-cost micromechanical seeker system

Abstract

Precision guided targeting systems have been in use by the U.S. military for the last half-century. The desire for high targeting accuracies while maintaining minimal collateral damage has driven the implementation of guidance systems on a myriad of different platforms. Current seeker systems using global positioning system (GPS)-aided technology offer good accuracy, but are limited by an adversary's signal jamming capabilities and the dynamic nature of the military target environment. Furthermore, ultra-accurate inertial measurement units (IMU) that serve as stand-alone guidance systems are very expensive and offer no terminal guidance enhancement. As a result, it is cost prohibitive to equip some platforms with precision guidance capability. The demand for high accuracy at low cost has prompted substantial recent development of micro-electromechanical systems (MEMS) IMU's and optical focal plane arrays (FPA). The resulting decreasing device size and production costs coupled with higher unit performance have created opportunities for implementing seeker-enabled systems on platforms previously deemed impractical. As a result, the author proposes a design methodology to develop a low-cost system while satisfying stringent performance requirements. The methodology is developed within the context of a strap-down seeker system for tactical applications. The design tenets of the optical sensor, the inertial sensor, and projectile flight dynamics were analyzed in-depth for the specific scenario. The results of each analysis were combined to formulate a proposed system.

(cont.) The system was then modeled to produce system miss distance estimates for differing engagement situations. The system demonstrated 3[sigma] miss distance estimates that were less than the maximum allowable error in each case. The system cost was tabulated and a production price was approximated. Using current technology and pricing information for the main components, the analysis shows that a system with a 3[sigma] miss distance of 0.801 m could be built for a unit price in the range of $11,730 -$19,550, depending on production costs. Design limitations are discussed, as well as strategies to improve the analysis for future consideration.