Distance tracking control system for single pass topographical mapping

• US 6,563,130 B2
• Filed: 05/10/2002
• Issued: 05/13/2003
• Est. Priority Date: 10/21/1998
• Status: Expired due to Fees

• Current Assignee: Canadian Space Agency (Government of Canada)
• Original Assignee: Canadian Space Agency (Government of Canada)
• Inventors: Dworkowski, Robert, Wojcik, Peter
• Primary Examiner(s): Allen, Stephone B.
• Application Number:
  US10/144,238
• Publication Number:
  US 20020190230A1
• Time in Patent Office: 368 Days
• Field of Search: 250/559.33, 250/559.38, 219/121.6, 219/121.79, 219/121.82, 340/619, 356/602, 356/609, 356/623, 356/624, 356/152.2, 356/139.1, 702/158, 702/166
• US Class Current: 250/559.33
• CPC Class Codes: B23K 26/048 by controlling the distance between laser head and workpiece
• CPC Class Codes: B25J 9/1694 characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion
• CPC Class Codes: G01S 17/46 Indirect determination of position data
• CPC Class Codes: G05B 2219/37423 Distance, gap between tool and surface sensor
• CPC Class Codes: G05B 2219/40562 Position and orientation of end effector, teach probe, track them
• CPC Class Codes: G05B 2219/40623 Track position of end effector by laser beam

Abstract

A distance tracking control system, for use with a working member such as a robotic head, includes a non-contact distance sensor for sensing a distance of the working member from a surface. An actuator is provided for making positional adjustments of the working member in response to changes in the distance sensed by the non-contact distance sensor. A controller is connected to the distance sensor and the actuator. The controller receives data from the non-contact distance sensor and then sends signals to the actuator to make positional adjustments of the working member.

Claims

1. A distance tracking control system, comprising:

a non-contact distance sensor for sensing a distance of a movable working member from a surface;

an actuator for making positional adjustments of the working member in response to changes in the distance sensed by the non-contact distance sensor;

a controller connected to the distance sensor and the actuator, the controller receiving data from the non-contact distance sensor and then sending signals to the actuator to make positional adjustments of the working member; and

the non-contact distance sensor being one of a single sensor mounted on an arm which sweeps a portion of the surface adjacent to the working member to provide data from which the controller calculates a topographical map, and an array of sensors which blanket a portion of the surface adjacent to the working member to provide data from which the controller calculates a topographical map.

2. A distance tracking control system, comprising:

a non-contact distance sensor for sensing a distance of a movable working member from a surface, the non-contact distance sensor being a single sensor mounted on a rotating arm that orbits the working member;

an actuator for making positional adjustments of the working member in response to changes in the distance sensed by the non-contact distance sensor; and

a controller connected to the distance sensor and the actuator, wherein the controller uses data from the non-contact distance sensor to calculate a topographical map of the surface covered within an axis of rotation of the single sensor mounted on the rotating arm and then sends signals to the actuator to make positional adjustments of the working member.

3. A distance tracking control system, comprising:

a non-contact distance sensor for sensing a distance of a movable working member from a surface, wherein the non-contact distance sensor is a single sensor mounted on a steerable arm that sweeps a portion of the surface adjacent to the working member with the positioning of the arm being adjustable according to the future direction of movement of the working member;

an actuator for making positional adjustments of the working member in response to changes in the distance sensed by the non-contact distance sensor; and

a controller connected to the distance sensor and the actuator, the controller steering the arm to modify the position of the single sensor, using data from the non-contact distance sensor to calculate a topographical profile of the surface along a trajectory of the working member and then sending signals to the actuator to make positional adjustments of the working member.

4. A distance tracking control system, comprising:

a non-contact distance sensor for sensing a distance of a movable working member from a surface, the non-contact distance sensor being an array of sensors, the array of sensors being arranged in a linear scanning array to blanket a portion of the surface in advance of the working member;

an actuator for making positional adjustments of the working member in response to changes in the distance sensed by the non-contact distance sensor; and

a controller connected to the distance sensor and the actuator, the controller using data from the non-contact distance sensor to calculate a topographical map of the surface covered within the array of sensors, and then sending signals to the actuator to make positional adjustments of the working member.

5. A distance tracking control system, comprising:

a non-contact distance sensor for sensing a distance of a movable working member from a surface, the non-contact distance sensor being an array of sensors, the array of sensors being arranged in a circumferential scanning array to blanket a portion of the surface around the working member;

an actuator for making positional adjustments of the working member in response to changes in the distance sensed by the non-contact distance sensor; and

a controller connected to the distance sensor and the actuator, the controller using data from the non-contact distance sensor to calculate a topographical map of the surface covered within the array of sensors, and then sending signals to the actuator to make positional adjustments of the working member.

6. A distance tracking control system, comprising:

at least one transmitting source having a known relationship to a movable working member, the at least one transmitting source emitting an energy beam onto a surface;

at least one non-contact distance sensor for sensing a distance of the working member from the surface, the non-contact distance sensor receiving reflected energy from the energy beam, the at least one non-contact distance sensor being a circumferential sensing array of sensors positioned around the working member;

an actuator for making positional adjustments of the working member in response to changes in the distance sensed by the distance sensor; and

a controller connected to the non-contact distance sensor and the actuator, the controller receiving data regarding the reflected energy beam from the at least one receiving source, the controller using the data and the known relationship of the at least one transmitting source to the working member to calculate a topographical map of the surface covered within the array of sensors, and then sending signals to the actuator to make positional adjustments of the working member.

7. The distance tracking control system as defined in claim 6, wherein the non-contact distance sensor senses magnetic fields.

8. The distance tracking control system as defined in claim 6, wherein the non-contact distance sensor senses changes in capacitance.

9. The distance tracking control system as defined in claim 6, wherein the non-contact distance sensor senses light.

10. The distance tracking control system as defined in claim 9, wherein the light is emitted from a laser beam.

11. The distance tracking control system as defined in claim 6, wherein the non-contact distance sensor senses sound.

12. The distance tracking control system as defined in claim 11, wherein the sound is ultrasonic.

13. The distance tracking control system as defined in claim 6, wherein the controller adjusts the speed of the working member as it moves along the surface to ensure the movement of the actuator can be made in sufficient time to avoid a collision with obstructions on the surface.

14. The distance tracking control system as defined in claim 6, wherein the energy beam is a light source.

15. The distance tracking control system as defined in claim 14, wherein the light source is a low energy light beam collimated through a first lens focused upon the surface such that a light spot is projected upon the surface.

16. The distance tracking control system as defined in claim 15, wherein the at least one non-contact sensor is a position sensitive light sensor receiving light from a receiving lens focused upon the light spot on the surface, such that a reflected light spot is projected upon the position sensitive light sensor.

17. The distance tracking control system as defined in claim 6, wherein there is an array of transmitting sources.

18. The distance tracking control system as defined in claim 6, wherein the controller performs distance calculations between the working member and the surface based upon an elapsed time from the emitting of the energy beam by the at least one transmitting source to the receiving of reflected energy from the energy beam by the at least one non-contact distance sensor.

19. The distance tracking control system as defined in claim 6, wherein the controller performs distance calculations between the working member and the surface based upon variations in the angle at which reflected energy from the energy beam emitted by the at least one transmitting source strikes the at least one non-contact distance sensor.

20. The distance tracking control system as defined in claim 6, wherein the controller performs distance calculations between the working member and the surface based upon a phase shift between the energy beam emitted by the at least one transmitting source and the reflected energy from the energy beam received by the at least one non-contact distance sensor.