Patent ID: 6978965

Claim:
A target tracking device for target tracking missiles comprising an electro-optical seeker assembly ( 16 ) mounted in a missile structure ( 10 ) through gimbals ( 18 , 22 ), said seeker assembly responding to target radiation and providing target deviation signals, and actuator means ( 36 , 38 ) for causing said seeker assembly ( 16 ) to track the target, said actuator means being controlled by said target deviation signals wherein: (a) said electro-optical seeker assembly ( 16 ) is pivotally mounted in said missile structure ( 10 ) about a roll axis ( 24 ) and a pitch axis ( 20 ) only, said pitch axis being orthogonal to said roll axis ( 24 ), (b) first and second pick-off means ( 28 , 34 ) are provided for picking off angles of rotation of said seeker assembly ( 16 ) about said roll and pitch axes ( 24 and 20 , respectively), said first and second pick-off means ( 28 , 34 ) providing pick-off signals, (c) structure-fixed inertial sensor means ( 48 ) are provided for measuring the angular rates about three mutually orthogonal axes and providing angular rate signals, (d) said target deviation signals from said seeker assembly ( 16 ), said pick-off signals from said pick-off means ( 28 , 34 ) and said angular rate signals from said inertial sensor means ( 48 ) are applied to a computer ( 76 ), which is programmed to define a seeker reference system with three degrees of freedom, said seeker reference system being de-coupled from movements of the missile and the seeker assembly ( 16 ), having a roll movement which is zero, and which is caused to track a target detected by said seeker assembly ( 16 ), and (e) said computer ( 76 ), in addition, has means ( 80 ) for generating positioning commands for said actuator means ( 36 , 38 ) depending on the position of said seeker reference system.