This　paper　addresses　a　method　of　dynamically　estimating　relative　pose　between　two　rigid　bodies　from　four　corresponding　point　sets　during　motion　in　applications　such　as　visual　servoing　and　metrology　for　intelligent　manufacturing.　Instead　of　tracking　each　body　individually　relative　to　a　camera,　the　underlying　problem　is　how　to　track　two　bodies　simultaneously　and　accurately.　For　this　reason,　the　proposed　method　directly　assigns　the　relative　pose　and　motion　as　a　state　estimate.　Further,　an　observation　model　is　formulated　in　such　a　way　that　the　state　estimate　is　mapped　to　the　observed　point　sets　of　two　bodies.　Since　this　observation　model　is　nonlinear,　an　analytical　expression　of　linearization　is　derived　and　state　estimation　by　iterative　extended　Kalman　filters　(IEKF)　is　adapted　to　reduce　the　linearization　errors.　The　proposed　approach　is　implemented　in　simulations　of　position-based　visual　servoing　and　validated　experimentally　on　a　robotic　riveting　system　for　aircraft　automated　assembly.　©　2015　IEEE.