Method for determination of head position relative to rectangular axes for observer equipped with head-mounted module

• US 8,786,846 B2
• Filed: 07/05/2012
• Issued: 07/22/2014
• Est. Priority Date: 07/05/2012
• Status: Expired due to Fees

• Current Assignee: Efros, Alexander, Iokhvidson, Simon, Lvovskiy, Matvey, Sofya Volfson
• Original Assignee: Efros, Alexander, Iokhvidson, Simon, Lvovskiy, Matvey, Sofya Volfson
• Inventors: Lvovskiy, Matvey, Efros, Alexander, Volfson, Sofya, Iokhvidson, Simon
• Primary Examiner(s): JOHNSON, ALLISON WALTHALL
• Application Number:
  US13/507,492
• Publication Number:
  US 20140009367A1
• Time in Patent Office: 747 Days
• Field of Search: 345/8, 348/E13.051, 382/103, 356/139.03
• US Class Current: 356/139.03
• CPC Class Codes: F41G 3/225 Helmet sighting systems
• CPC Class Codes: G01S 17/875 for determining attitude
• CPC Class Codes: G01S 5/163 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49
• CPC Class Codes: G02B 27/017 Head mounted

Abstract

Method is proposed of angular coordinates determination for observer'"'"'s head relative to three mutually perpendicular axes of fixed (or tied to an object) coordinate system OXYZ (angle of roll, azimuth, elevation angle) by use of measuring system based on light-sensitive sensor with collimating lens fixed relative to coordinate system and LED lasers installed on head-mounted module HMM. Measuring device registers angular coordinates of narrow pencils of rays formed by LED lasers and provides determination of observer'"'"'s head angular coordinates in real-time. Three angles of HMM can be determined by proposed method while no less than two LED lasers are in lens field of view with angle Δ of set value and direction included between their axes. To provide specified measurement range of observer'"'"'s head angles exceeding lens field of view LED lasers matrix is installed on HMM containing LED lasers allocated in several horizontal and vertical lines.

Claims

1. A method for determination of angular coordinates of the head for an observer equipped with a head-mounted module (HMM) relative to fixed rectangular axes OXYZ the method comprising:

determining vertical and horizontal angular coordinates of the observer'"'"'s head in real-time relative to fixed horizontal axis OZ and fixed vertical axis OY using a first emitter and a device for measuring angular coordinates of the first emitter, wherein the first emitter is installed on the HMM and emits a narrow pencil of rays and the device for measuring angular coordinates is stationary relative to the fixed rectangular axes OXYZ wherein the device for measuring angular coordinates comprises a TV camera (TVC) provided with a lens generating a dot pattern of emitter light rays in a plane of a light-sensitive sensor, an optic axis of the lens is parallel to the axis OX, the plane of the light-sensitive sensor is parallel to the vertical plane YOZ, and

values of horizontal and vertical angular coordinates of the first emitter are unambiguously connected with values of linear coordinates of the corresponding dot pattern of light rays of the first emitter in the plane of the light-sensitive sensor;

and determining a value of a roll angular coordinate of the observer'"'"'s head in real-time using a second emitter, wherein a roll angular coordinate is an angle of rotation relative to the third axis OX, the second emitter is installed on the HMM in addition to the first emitter and is turned by a specified angle relative to the first, the value of the roll angular coordinate relative to the axis OX is defined by the arcsine of the difference of vertical angular coordinates of the first and second emitters divided by the value of the specified angle and values of the horizontal and vertical angular coordinates of the first and second emitters are unambiguously connected with values of linear coordinates of corresponding dot patterns of light rays of the first and second emitters in the plane of the light-sensitive sensor, whereas in order to provide the required angular ranges exceeding the TVC angular field of view when measuring the horizontal and vertical angles of observer'"'"'s head rotation an emitter matrix is installed on the head-mounted module HMM with emitters allocated so that they form several horizontal and vertical lines with specified spacing between the emitters and each of the emitters is turned by the specified angle relative to the next emitters,

wherein in order to provide continuous processing when measuring the angular coordinates of the observer'"'"'s head within a full range of angles, when one emitter from the first and second emitters currently being used to determine angular coordinates of the observer'"'"'s head is coming up to any border of the TVC'"'"'s field of view horizontally, then the one emitter is switched off and simultaneously a next horizontal emitter located in the TVC'"'"'s field of view is switched on; and

when one emitter from the first and second emitters currently being used to determine angular coordinates of the observer'"'"'s head is coming up to any border of the TVC'"'"'s field of view vertically, then the one emitter is switched off and simultaneously a next vertical emitter located in the TVC'"'"'s field of view is switched on.

2. A method for determination of angular coordinates of the head for an observer equipped with a head-mounted module (HMM) relative to fixed rectangular axes OXYZ, the method comprising:

determining vertical and horizontal angular coordinates of the observer'"'"'s head in real-time relative to fixed horizontal axis OZ and fixed vertical axis OY using a first emitter and a device for measuring angular coordinates of the first emitter, wherein the first emitter is installed on the HMM and emits a narrow pencil of rays and the device for measuring angular coordinates is stationary relative to the fixed rectangular axes OXYZ, wherein the device for measuring angular coordinates comprises a TV camera (TVC) provided with a lens generating a dot pattern of emitter light rays in a plane of a light-sensitive sensor, an optic axis of the lens is parallel to the axis OX, the plane of the light-sensitive sensor is parallel to the vertical plane YOZ, and

values of horizontal and vertical angular coordinates of the first emitter are unambiguously connected with values of linear coordinates of the corresponding dot pattern of light rays of the first emitter in the plane of the light-sensitive sensor;

and determining a value of a roll angular coordinate of the observer'"'"'s head in real-time using a second emitter, wherein a roll angular coordinate is an angle of rotation relative to the third axis OX, the second emitter is installed on the HMM in addition to the first emitter and is turned by a specified angle relative to the first, the value of the roll angular coordinate relative to the axis OX is defined by the arcsine of the difference of vertical angular coordinates of the first and second emitters divided by the value of the specified angle and values of the horizontal and vertical angular coordinates of the first and second emitters are unambiguously connected with values of linear coordinates of corresponding dot patterns of light rays of the first and second emitters in the plane of the light-sensitive sensor,

wherein in order to extend a range of allowable linear movements of the HMM relative to the stationary TVC in the horizontal direction, a plane-parallel plate PL is installed in front of the lens, the PL made of optical glass or acrylic that consists of a set of flat light-dividing components glued together creating a plurality of mutually parallel slanted beam splitters that are vertically oriented.

3. The method of claim 2, wherein in order to extend a range of allowable linear movements of the HMM relative to the stationary TVC in the vertical direction, a second PL is installed in front of the first PL, the second PL made of optical glass or acrylic that consists of a set of flat light dividing components glued together creating a plurality of mutually parallel slanted beam splitters that are horizontally oriented.

4. The method of claim 3 whereas in the first and second PL the beam splitters are inclined towards the input and output facets of the PLs at an angle, ensuring the fulfillment of the conditions of total reflection of rays for the even reflections from input and output facets.

5. The method of claim 4 whereas in order to improve the efficiency of lens operation with the first and second PL the lens entrance pupil is of a square form and the size of the square is equal to doubled product of value of the PL thickness and cotangent of angle of inclination of beam splitters towards the input and output facets of the PLs.