Remote object position and orientation locator

Claim 1

Apparatus for determining the position and orientation of a remote object relative to a reference coordinate frame comprising: a plurality of radiating means having orthogonal components (41, 42, 43) centered about the origin of the reference coordinate frame; means (30) for applying to the plurality of radiating means electrical signals which generate a plurality of electromagnetic fields, the electromagnetic fields being distinguishable from one another; a plurality of receiving means disposed on said remote object, said receiving means having orthogonal components (22, 23, 24) for detecting and measuring components of the electromagnetic fields; and analyzing means (50) associated with the receiving means for converting the received components of the electromagnetic fields into remote object position and orientation relative to the reference coordinate frame with at most two ambiguous combinations of orientation and position, the analyzing means operating open loop with respect to the radiating means; characterized in that one of the said pluralities consists of only two orthogonal components and the other consists of three components; that the apparatus is adapted for operation in a region in which the far-field components of the electromagnetic fields are substantially greater in magnitude than the near-field components; and that the orientation is determined by a method which includes obtaining from the received components two of three vectors representative of the orientation of the remote object and deriving the third vector by forming the cross product of the two known vectors.