US 4,298,874 A · Method and apparatus for tracking objects

Abstract

Two spaced bodies, each including at least two independently oriented radiating antennas, are in communication with each other by such means as an electromagnetic field. The first body receives radiation transmitted from the second body and establishes the pointing angles to the second body with respect to the first body coordinate reference frame. The field received by the first body can include information defining the second body's pointing angles to the first body with respect to the second body's coordinate reference frame and the relative roll about their mutually aligned pointing axis. These pointing angles and relative roll are sufficient for determining the orientation of the first body relative to the second body. The second body receives radiation transmitted from the first body and establishes the pointing angles to the first body with respect to the second body. Analogously, radiation received by the second body can include information defining the first body's pointing angles with respect to the first body coordinate reference frame to the second body and the relative roll between their mutually aligned pointing axes. As before, this information is sufficient for the second body to determine its orientation relative to the first body. Distance between the two bodies can be determined by phase-locking techniques, thus providing the capability of a full six-degree-of-freedom measurement system. A third body, known and defined in the coordinate frame of the first body, can be defined at the second body with respect to the frame of the second body. That is, information is transmitted from the first body and received at the second body which establishes a vector from the second body to the third body thus defining the location of the third body at the second body.

Claims70

Dependent claims

Apparatus for determining a pointing angle to a first body from a second body comprising:

at least two independently oriented first body radiating means coupled to said first body and defining a first reference coordinate frame;
a first means for applying to said first body radiating means first actuating signals for producing a first field radiated in response to said first signals oscillating along a first line of generation and characterizing a first body pointing angle of a first pointing vector with respect to said first reference frame, said first field having receivable components characterized in that at said second body one direction in said first field has unique characteristics with respect to all other directions in said first field;
at least two independently oriented second body receiving means coupled to said second body and defining a second reference coordinate frame for detecting and measuring the receivable components of said first field;
and
a second body analyzing means coupled to said second body receiving means for converting said first field components into a second body pointing angle, from said second body to said first body, relative to said second reference coordinate frame.

2 more elements

Apparatus for determining second body pointing angles to a first body from a second body comprising:

independently oriented first body radiating means coupled to said first body and defining a first reference coordinate frame;
a first means for applying to said first body radiating means first actuating signals for radiating first field components rotating in a plane denoted a first plane of rotation and characterizing a first field, said first field having receivable components characterized in that, at said second body, one direction in said first field has unique characteristics with respect to all other directions in said first field and for at least partially characterizing the relative roll angle about an axis between said first and second bodies;
independently oriented second body receiving means coupled to said second body and defining a second reference coordinate frame for detecting and measuring the spatial components of said first field;
and
a second body analyzing means coupled to said second body receiving means for using said first field components to determine second body pointing angles, from said second body to said first body, relative to said second reference coordinate frame and for determining the relative roll angle about said axis.

2 more elements

Apparatus for determining the direction and roll angle between first and second bodies relative to one another, each body having a coordinate reference frame, said apparatus comprising:

means for radiating a first field from said first body, said first field having components receivable at said second body from which said second body:
(a) can determine the direction to the first body with respect to the second body coordinate frame;
(b) can define the relative roll angle between said first body and said second body about said direction;
means at said second body for receiving said first field, said receiving means including:
(a) means for determining the direction to the first body with respect to the second body coordinate frame;
(b) means for defining the relative roll angle between said first body and said second body about said direction;
means for radiating a second field from said second body, said second field having components receivable at said first body from which said first body:
(a) can determine the direction to the second body with respect to the first body coordinate frame;
(b) can define the relative roll angle between said second body and said first body about said direction;
means at said first body for receiving said second field, said receiving means including:
(a) means for determining the direction to the second body with respect to the first body coordinate frame;
and
(b) means for defining the relative roll angle between said second body and said first body about said direction.

10 more elements

Apparatus for determining the direction between and relative orientation of a second body relative to a first body, each body having a coordinate reference frame, said apparatus comprising:

means for radiating a first vector field from said first body, the frequency of said field being such that the ratio of the wavelength to the distance separating said bodies results in far-field reception characteristics at said second body, each cycle of said first field having components receivable at said second body and processable to produce at said second body at least five independent measurements from which said second body:
(a) can compute the direction to the first body with respect to the second body coordinate reference frame;
and
(b) can compute the rotation of said first body coordinate reference frame with respect to said second body coordinate reference frame;
means at said second body:
(a) for receiving and processing said first field to produce said five independent measurements;
(b) for computing the direction to the first body with respect to the second body coordinate reference frame, said direction computing means utilizing the far-field characteristics of said field;
and
(c) for computing the rotation of said first body coordinate reference frame with respect to said second body reference frame.

6 more elements

Apparatus for determining the direction between and relative orientation of first and second bodies relative to one another, each body having a coordinate reference frame, said apparatus comprising:

means for radiating a first field from said first body, each cycle of said first field having components receivable at said second body and processable to produce at said second body at least five independent measurements from which said second body:
(a) can compute the direction to the first body with respect to the second body coordinate reference frame;
and
(b) can compute the rotation of said first body coordinate reference frame with respect to said second body coordinate reference frame;
means at said second body:
(a) for receiving and processsing said first field to produce said five independent measurements;
(b) for computing the direction to the first body with respect to the second body coordinate reference frame;
and
(c) for computing the rotation of said first body coordinate reference frame with respect to said second body coordinate reference frame;
means for radiating a second field from said second body, each cycle of said second field having components receivable at said first body and processable to produce at said first body at least five independent measurements from which said first body:
(a) can compute the direction to the second body with respect to the first body coordinate reference frame;
and
(b) can compute the rotation of said second body coordinate reference frame with respect to said first body coordinate reference frame;
means at said first body:
(a) for receiving and processing said second field to produce said five independent measurements;
(b) for computing the direction to the second body with respect to the first body coordinate reference frame;
and
(c) for computing the rotation of said second body coordinate reference frame with respect to said first body coordinate reference frame.

15 more elements

Apparatus for determining a second body object vector from a second body to a remote object, said apparatus including a first body, said first and second bodies having coordinate reference frames, said first body having a priori knowledge of the angles and magnitude of a first body object vector between the first body and the object, said apparatus comprising:

means for radiating a first field from said first body, said first field having components receivable at said second body from which said second body:
(a) can determine the direction to the first body with respect to the second body coordinate frame;
(b) can define the relative roll angle between said first body and said second body about said direction;
means at said second body for receiving said field, said receiving means including:
(a) means for determining the direction to the first body with respect to the second body coordinate frame;
(b) means for defining the relative roll angle between said first body and said second body about said direction;
means for radiating a second field from said second body, said second field having components receivable at said first body from which said first body can determine the direction to the second body with respect to the first body coordinate frame;
means at said first body for receiving said field, said receiving means including means for determining the direction to the second body with respect to the first body coordinate frame;
means at said first body for determining the distance between said first body and said second body, said distance along with said direction to the second body establishing a reference vector between said first and second bodies;
means at said first body for determining a third vector, said third vector being the third side of a vector triangle including said reference vector and said first body object vector, the direction of said third vector being determined relative to said first body coordinate reference frame;
means for establishing at said first body a pseudo coordinate reference frame, said pseudo frame having one of its axes defined by said third vector and being displaced from said first body coordinate reference frame through a series of two angles;
means for transmitting to said second body from said first body:
(a) the direction to the second body from the first body relative to said pseudo frame;
and
(b) the magnitude of said third vector.

12 more elements

A process for determining the direction and roll angle between first and second bodies relative to one another, each body having a coordinate reference frame, said process comprising the steps of:

radiating a first vector field from said first body, said first field having components receivable at said second body from which said second body:
(a) can determine the direction to the first body with respect to the second body coordinate frame;
(b) can define the relative roll angle between said first body and said second body about said direction;
receiving said first field at said second body and:
(a) determining the direction to the first body with respect to the second body coordinate frame;
(b) defining the relative roll angle between said first body and said second body about said direction;
radiating a second vector field from said second body, said second field having components receivable at said first body from which said first body:
(a) can determine the direction to the second body with respect to the first body coordinate frame;
(b) can define the relative roll angle between said second body and said first body about said direction;
receiving said second field at said first body and:
(a) determining the direction to the second body with respect to the first body coordinate frame;
and
(b) defining the relative roll angle between said second body and said first body about said direction.

10 more elements

A process for determining the direction between and the relative orientation of first and second bodies relative to one another, each body having a coordinate reference frame, said process comprising the steps of:

radiating a first vector field from said first body, each cycle of said first field having components receivable at said second body and processable to produce at said second body at least five independent measurements from which said second body:
(a) can compute the direction to the first body with respect to the second body coordinate reference frame;
and
(b) can compute the rotation of said first body coordinate reference frame with respect to said second body coordinate reference frame;
receiving and processing said first field at said second body to produce said five independent measurements;
computing at said second body the direction to the first body with respect to the second body coordinate reference frame;
and
computing at said second body the rotation of said first body coordinate reference frame with respect to said second body coordinate reference frame;
radiating a second vector field from said second body, each cycle of said second field having components receivable at said first body and processable to produce at said first body at least five independent measurements from which said first body:
(a) can compute the direction to the second body with respect to the first body coordinate reference frame;
and
(b) can compute the rotation of said second body coordinate reference frame with respect to said first body coordinate reference frame;
receiving and processing said second field at said first field to produce said five independent measurements;
computing at said first body the direction to the second body with respect to the first body coordinate reference frame;
and
computing at the first body the rotation of said second body coordinate reference frame with respect to said first body coordinate reference frame.

13 more elements

Dependencies are inferred from the claim text.

Method and apparatus for tracking objects

Life of this patent

Method and apparatus for tracking objects

Life of this patent

Abstract

Claims70