Decentralized Estimation Algorithms for Formation Flying Spacecraft
Philip A. Ferguson, Jonathan P. How · AIAA Guidance, Navigation, and Control Conference and Exhibit · 2003
Future formatiC flyi g mi ssi ons are bei g planned for fleets of spacecrafti n MEO, GEO, and beyond where relati e navi29)9L usi ng GPS wi7 ei9 er be i possi ble ori nsu#ci9 t. To extend fleet es ti ati7 for these scenar i# , local ran gi g devi9( on each vehi cle are bei g consi dered to replace or augment the avai lable GPS measurements. Provi ded that the fleet provi des a good measurement geometry, these addi ti onal local rangi ng measurements can substanti allyi mprove the esti mator accuracy. Many of the mi ssi ons ofi nteresti n thi s work requi re large fleets to achi( e th ei sci2 ce goals. Thus, algorio m i di stri buti7 becomes a necessi ty due to the large amounts of d tr i uted data and computatiL al load li i#726 s. However, local rangi g measurement augmentatiC s are i nherently nonli near and couple the states of each vehi clei n the fleet, whi ch compli cate the process of decentrali2C g the es ti ator, often requi ri ngi7C ati e techni ques. A key stepi n developi g fleet esti mati on routi nesi s to determi ne the communi cati on and computati on requi rements for each esti - mator. Th i paper presents several es ti ator archi tectures and associ9CL algorig ms for es ti ati g the fleet state, and then compares the resulti g performance, computati3 , and communi cati9 requ i ements. The resultsi ndi cate that the decentrali6( reduced-order filters presented provi e near op ti al es ti ati7 results whi7 us i g m i i al amounts of communi cati7 and computatiL . Embeddi ng these reduced-order es ti ators wi th i the hi] archi c archi tecture presented permi( scali g of the relati e navi2)9C) to very large fleets. # To appear at eAIAAGuidance,Navigation,andControlConference,August2003 usetts Institute of TechV logy, [email protected] # Senior Member AIA...