High speed well surveying and land navigation

• US 4,920,655 A
• Filed: 11/07/1988
• Issued: 05/01/1990
• Est. Priority Date: 07/30/1984
• Status: Expired due to Term

• Current Assignee: Applied Technologies Associates, Inc.
• Original Assignee: Applied Technologies Associates, Inc.
• Inventors: Van Steenwyk, Donald H.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Fulton, Christopher
• Application Number:
  US07/267,551
• Time in Patent Office: 540 Days
• Field of Search: 33/775, 33/333, 33/304, 33/318, 33/313, 33/312, 33/324, 33/302, 33/303
• US Class Current: 33/304
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism
• CPC Class Codes: G01C 21/166 Mechanical, construction or arrangement details of inertial navigation systems
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems

Abstract

Land vehicle navigation apparatus combining an inertial angular rate sensor having a sensitive axis, with an inertial acceleration or tilt sensor having at least two sensitive axes, these sensitive axes having a known relationship to the inertial angular rate sensor'"'"'s sensitive axis. Also provided is circuitry to accept from an external source an initial input valve (or self initialization, by rotary multiple positioning) of the vehicle'"'"'s azimuthal orientation angles, roll, pitch, and azimuth, with respect to an Earth-fixed coordinate set as the land vehicle travels over the Earth surface. Changes to the azimuth angle during travel are determined by integration of the output of the inertial angular rate sensor.

Claims

1. In a land vehicle navigation apparatus, the combination with the vehicle comprising

(a) inertial angular rate sensor means having a sensitive axis,

(b) inertial acceleration or tilt sensor means having at least two sensitive axes, said sensitive axes being arranged to be nominally located at the vehicle in a plane parallel to the Earth'"'"'s surface,

(c) a rotary drive operatively connected to said (a) means to rotate said (a) means about an axis extending generally at the vehicle in a plane parallel to the Earth'"'"'s surface,

(d) circuitry operatively connected with said (a) and (b) sensor means to determine three vehicle orientation angles, roll, pitch, and azimuth, with respect to an Earth-fixed coordinate set at a first location, and to also determine said three vehicle orientation angles as the land vehicle travels over the Earth'"'"'s surface wherein changes to said azimuth angle during travel are determined by integration of the output of said (a) sensor means,

(e) said (a) and (b) means and said (c) drive being carried by the vehicle, having support means on which the vehicle travels over the Earth'"'"'s surface,

(f) at least one of said (a) and (b) sensitive axes being canted.

2. In a land vehicle navigation apparatus, the combination for use with the vehicle comprising:

(a) inertial angular rate sensor means having a sensitive axis,

(b) inertial acceleration or tilt sensor means having at least two sensitive axes, said sensitive axes being arranged to be nominally located at the vehicle in a plane parallel to the Earth'"'"'s surface,

(c) a rotary drive operatively connected to said (a) and (b) means to rotate said (a) and (b) means about an axis extending generally at the vehicle in a plane parallel to the Earth'"'"'s surface,

(d) circuitry operatively connected with said (a) and (b) sensor means to determine three vehicle orientation angles, roll, pitch, and azimuth, with respect to an Earth-fixed coordinate set at a first location, and to also determine said three vehicle orientation angles as the land vehicle travels over the Earth surface wherein changes to said azimuth angle during travel are determined by integration of the output of said (a) sensor means,

(e) said (a) and (b) means, and said (c) drive and (d) circuitry being carried by the vehicle, which has support means on which the vehicle travels over the Earth'"'"'s surface,

(f) at least one of said (a) and (b) sensitive axes being canted.

3. In the method of operating land vehicle navigation apparatus which includes:

(i) inertial angular rate sensor means having a sensitive axis,

(ii) inertial acceleration or tilt sensor means having at least two sensitive axes, said sensitive axes being nominally orthogonal to said inertial angular rate sensor'"'"'s sensitive axis,

(iii) means to accept from an external source an initial value of the vehicle'"'"'s azimuthal orientation angle with respect to an Earth-fixed coordinate set, and

(iv) circuitry operatively connected with said (i) and (ii) sensor means and said (iii) input acceptance means to determine three vehicle orientation angles, roll, pitch, and azimuth, with respect to an Earth-fixed coordinate set as the land vehicle travels over the Earth'"'"'s surface, and wherein changes to said azimuth angle during travel are determined by integration of the output of said (a) sensor means,

the steps that include;

(a) operating the inertial angular rate sensing and the inertial acceleration sensing means and their associated computational, electronic circuitry, and power supply means at a first location on the land, in a land vehicle,

(b) determining from the inertial acceleration means output signals the two vehicle orientation angles about Earth-fixed level axis that are the vehicle pitch and roll angles at the first location,

(c) generating and accepting an external input to define the initial vehicle orientation angle about an Earth-fixed vertical axis to establish the vehicle azimuth angle at the first location, and

(d) then continuously determining the three vehicle orientation angles roll, pitch and azimuth as the vehicle moves over the surface of the earth by processing the outputs of the inertial acceleration sensing means to measure the vehicle roll and pitch angles and by integrating the output of the inertial angular rate sensor to measure changes in vehicle azimuth since the initial value, and

(e) combining the output of an external distance measurement sensor with the vehicle orientation angle data obtained in (d) to compute land-vehicle position.

4. In the method of operating land vehicle navigation apparatus which includes:

(a'"'"') inertial angular rate sensor means having a sensitive axis,

(b'"'"') inertial acceleration or tilt sensor means having at least two sensitive axis, said sensitive axes being arranged to be normally located at the vehicle in a plate parallel to the Earth'"'"'s surface,

(c'"'"') a rotary drive operatively connected to said (a'"'"') and (b'"'"') means to rotate said (a'"'"') and (b'"'"') means about an axis extending generally and the vehicle in a plate parallel to the Earth'"'"'s surface,

(d'"'"') circuitry operatively connected with said (a'"'"') and (b'"'"') sensor means to determine three vehicle orientation angles, roll, pitch, and azimuth, with respect to an Earth-fixed coordinate set at a first location, and to also determine said three vehicle orientation angles as the land vehicle travels over the Earth surface wherein changes to said azimuth angle during travel are determined by integration of the output of said (a'"'"') sensor means, the steps that include;

(a) operating the inertial angular rate sensor and the inertial acceleration sensing means and their associated computational, electronic circuitry, and power supply means at a first location on the land, in a land vehicle,

(b) said operating as in (a) carried out to self-determine all three of the vehicle orientation angles (roll, pitch and heading) so as to initialize vehicle azimuth angle at said first location,

(c) then continuously determining the three vehicle orientation angles roll, pitch and azimuth as the vehicle moves over the surface of the earth by processing the outputs of the inertial acceleration sensing means to measure the vehicle roll and pitch angles and by integrating the output of the inertial angular rate sensor to measure changes in vehicle azimuth since the initial value, and

(e) combining the output of an external distance measurement sensor with the vehicle orientation angle data obtained in (d'"'"') to compute land-vehicle position.

5. In the method of operating land navigation apparatus that includes a vehicle and

(a) inertial angular rate sensor means having a sensitive axis,

(b) inertial acceleration or tilt sensor means having at least two sensitive axes, said sensitive axes being nominally orthogonal to said inertial angular rate sensor'"'"'s sensitive axis,

(c) means to accept from an external source an initial value of the vehicle'"'"'s azimuthal orientation angle with respect to an Earth-fixed coordinate set, and

(d) circuitry operatively connected with said (a) and (b) sensor means and said (c) input acceptance means to determine three vehicle orientation angles, roll, pitch, and azimuth, with respect to an Earth-fixed coordinate set as the land vehicle travels over the Earth'"'"'s surface, and wherein changes to said azimuth angle during travel are determined by integration of the output of said (a) sensor means,

(e) and a land vehicle supporting said (a) and (b) means, and having support means on which the vehicle travels over the Earth'"'"'s surface,

the steps that include

(i) stopping the vehicle periodically,

(ii) observing any erroneous indicated rate-of change of vehicle azimuth angle,

(iii) observing the magnitude and direction of corrections that would reduce any observed erroneous rate to a level acceptable to the operator,

(iv) in-putting said correction to the apparatus, and

(v) continuing vehicle travel.

6. In the method of operation land or water vehicle navigation apparatus that includes a vehicle and

(a) inertial angular rate sensor means having a sensitive axis,

(b) inertial acceleration or tilt sensor means having at least two sensitive axes, said sensitive axes being arranged to be nominally located at the vehicle in a plane parallel to the Earth'"'"'s surface,

(c) a rotary drive operatively connected to said (a) means to rotate said (a) means about an axis extending generally at the vehicle in a plane parallel to the Earth'"'"'s surface,

(d) circuitry operatively connected with said (a) and (b) sensor means to determine three vehicle orientation angles, roll, pitch, and azimuth, with respect to an Earth-fixed coordinate set at a first location, and to also determine said three vehicle orientation angles as the land vehicle travels over the Earth surface wherein changes to said azimuth angle during travel are determined by integration of the output of said (a) sensor means,

(e) said (a) and (b) means and said (c) drive being carried by the vehicle, having support means on which the vehicle travels over the Earth'"'"'s surface, the steps that include

(i) stopping the vehicle periodically,

(ii) observing any erroneous indicated rate-of change of vehicle azimuth angle,

(iii) observing the magnitude and direction of corrections that would reduce any observed erroneous rate to a level acceptable to the operator,

(iv) in-putting said connection to the apparatus, and

(v) continuing vehicle travel.