Cantilevered manipulator for autonomous non-contact scanning of natural surfaces for the deployment of landmine detectors

• US 6,333,631 B1
• Filed: 03/08/1999
• Issued: 12/25/2001
• Est. Priority Date: 03/08/1999
• Status: Expired due to Term

• Current Assignee: Her Majesty The Queen As Represented By The Minister of National Defence of Her Majesty's Canadian Government
• Original Assignee: Her Majesty The Queen As Represented By The Minister of National Defence of Her Majesty's Canadian Government
• Inventors: Russell, Kevin, Das, Yogadish, Kircanski, Nenad, Goldenberg, Andrew
• Primary Examiner(s): Brown, Glenn W.
• Assistant Examiner(s): ZAVERI, SUBHASH
• Application Number:
  US09/263,060
• Time in Patent Office: 1,023 Days
• Field of Search: 324/326, 324/329, 324/337, 324/345, 376/154, 376/159, 250/392
• US Class Current: 324/326
• CPC Class Codes: F41H 11/12 Means for clearing land minefields; Systems specially adapted for detection of landmines
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat

Abstract

Apparatus and method is provided for performing detailed mine detection over variable terrain. An articulated robotic scanner comprises an articulated arm mounted to any vehicle such as a robot. One or more mine detectors mounted at the end of the arm. The arm operates autonomously to repetitively sweep the mine detector in ever forward advancing side-to-side arcs over the terrain. The vehicle can operate autonomously or be tele-operated. The position of the mine detector is monitored and known with respect to a known coordinate system. Sensors measure their position relative to the ground and relative to known co-ordinates of the mine detector. A controller determines the relative position of the ground and the mine detector and dynamically adjusts the mine detector'"'"'s position to maintain a constant separation over variable terrain without ever contacting the ground or objects thereon.

Claims

1. A mine-detecting apparatus supported from a vehicle which traverses the ground comprising:

(a) first support member having a proximal end pivotally connected to the vehicle and a distal end supporting a mine detector which is moved over the ground;

(b) a first robotic actuator connected to the first support member and having at least two rotational axes for enabling up-and-down and side-to-side panning movement of the mine detector by pivoting the first support member;

(c) one or more ground sensors for dynamically determining the spacing of the mine detector from the ground as it moves over the ground;

(d) a second support member having a proximal end pivotally supported by the vehicle and a distal end for supporting the sensors;

(e) a second robotic actuator connected to the second support member and having at least one rotational axis for enabling positioning of the sensors relative to the moving mine detector by pivoting the second support member; and

(f) a controller connected to the first robotic actuator for instructing the first robotic actuator to adjust the first support member so as to dynamically space the mine detector an optimal spacing from the ground as it moves over the ground and connected to the second robotic actuator for instructing the second robotic actuator to pivot the second support arm to position the sensors vertically with respect the ground in advance of the mine detector.

2. The apparatus as recited in claim 1 wherein the first robotic actuator comprises:

(a) a first pan pivot located between the first support member and the vehicle and having a first pan actuator for panning the first support member; and

(b) a tilt pivot located between the first support member and the vehicle and having tilt actuator for tilting the first support member.

3. The apparatus as recited in claim 2 wherein the range-finding sensors comprise both a laser and ultrasonic range-finders.

4. The apparatus as recited in claim 1 wherein the sensors comprise:

(a) one or more range-finding sensors positioned at known three dimensional coordinates relative to the mine detector, said range-finding sensors being directed toward the ground ahead of the mine detector movement for determining values of the distance of the ground from said range-finding sensors; and

(b) one or more sensors for determining values of the three dimensional coordinates of the mine detector so that the controller can establish measures of the spacing between the detector and the ground over which the mine detector is moving.

5. The apparatus as recited in claim 4 wherein the one or more range-finding sensors comprise a laser range-finder.

6. The apparatus as recited in claim 4 wherein the second robotic actuator comprises a second pan pivot located between the second support member and the vehicle, and a second pan actuator for panning the second support member.

7. The apparatus as recited in claim 6 wherein the second pan actuator pans the second support member so as to re-position the one or more range-finding sensors and direct them at the ground ahead of the mine detector.

8. The apparatus as recited in claim 6 wherein the proximal end of the second member is connected to the first support member so that the second support member is moveable with the first support member.

9. The apparatus as recited in claim 8 wherein the second pan actuator pans the second support member so as to re-position the one or more range-finding sensors and direct them at the ground ahead of the mine detector.

10. The apparatus as recited in claim 9 wherein the one or more range-finding sensors comprise a laser range-finder.

11. The apparatus as recited in claim 9 wherein the one or more range-finding sensors comprise a laser range-finder.

12. The apparatus as recited in claim 1 wherein the vehicle is remote controlled.

13. The apparatus as recited in claim 1 wherein the mine detector is a ground penetrating radar detector.

14. The apparatus as recited in claim 1 wherein the mine detector is a metal detector.

15. The apparatus of claim 14 further comprising:

a pivot located between the distal end of the first member and the detector;

a third actuator located at the proximal end of the first member; and

a non-metallic parallelogram linkage between the actuator and the pivot for tilting the metal detector.

16. A method for detecting mines in or on the ground comprising:

providing a vehicle having a first articulated member supported therefrom, the first articulated member having a mine detector mounted at a distal end;

continuously determining the spacing between the mine detector and the ground;

panning the first articulated member and mine detector laterally from side to side without contacting the ground to scan an arcuate region;

adjusting the position of the mine detector so as to space the mine detector an optimal distance from the ground; and

advancing the vehicle as necessary to scan a new arcuate region.

17. The method as recited in claim 16 wherein the spacing between the mine detector and the ground is determined by

determining the spacing between the ground and one or more range-finding sensors;

establishing the coordinates of the one or more range-finding sensors in a coordinate system and therefore establishing the location of the ground in the coordinate system;

establishing the coordinates of the mine detector in the coordinate system; and

determining the distance between the mine detector and the ground knowing the relative coordinates of the ground and the coordinates of the mine detector.

18. The method as recited in claim 17 wherein the one or more range-finding sensors are located remote from the mine detector.

19. The method as recited in claim 16 wherein the spacing between the mine detector and the ground is determined by

providing a second articulated member supported by the vehicle and one or more range-finding sensors being mounted at a distal end so that the one or more range-finding sensors may be panned in an arc substantially the same as that of the mine detector;

panning the second articulate member so that the one or more range-finding sensors determine the distance to the ground ahead of the panning mine detector;

establishing the coordinates of the one or more range-finding sensors and the ground in a coordinate system;

establishing the coordinates of the mine detector in the coordinate system; and

determining the distance between the mine detector and the ground knowing the coordinates of the ground and the coordinates of the mine detector.

20. Apparatus for panning a detector over and spaced form undulating ground surfaces, the detector having a predetermined optimal spacing from the ground, the apparatus comprising:

(a) a first support member having an articulated proximal end supported from a vehicle and a distal end supporting the detector which is moved over the ground;

a first robotic actuator associated with the first support member and having at least two rotational axes for enabling up-and-down and side-to-side panning movement of the detector;

one or more sensors for dynamically determining the spacing of the detector from the ground as it moves over the ground;

a second support member having a proximal end supported by the vehicle and a distal end for supporting the sensors;

a second robotic actuator associated with the second support member and having at least one rotational axis for enabling positioning of the sensors relative to the moving detector; and

a controller for instructing the first robotic actuator to adjust the first support member so as to dynamically space the mine detector at the optimal spacing from the ground as it moves over the ground and for instructing the second robotic actuator to adjust the second support arm to position the sensors in advance of the detector.

21. The apparatus of claim 20 further comprising:

a pivot located between the distal end of the first member and the detector.

22. The apparatus of claim 21 wherein the detector is a metal detector further comprising:

a third actuator located at the proximal end of the first member; and

a non-metallic parallelogram linkage between the actuator and the pivot for pivoting the detector.