Automated position locator for a height sensor in a dispensing system

Patent metadata

Field	Value
Publication number	US-8944001-B2
Application number	US-201313769605-A
Country	US
Kind code	B2
Filing date	Feb 18, 2013
Priority date	Feb 18, 2013
Publication date	Feb 3, 2015
Grant date	Feb 3, 2015

Abstract

Apparatus and methods of determining a position of a height sensor in a dispensing system. The dispensing system includes a dispenser, height sensor, camera, and a calibration device configured to receive a signal from the height sensor. The calibration device may include an optical sensor that generates an alignment signal in response to receiving light from the height sensor and/or a fiducial that causes the height sensor to generate the alignment signal in response to a detected height change. The alignment signal is used to automatically determine the position at which the height sensor is aligned with the calibration device. The position of the height sensor relative to a camera is determined by aligning the camera with the calibration device and recording its position. The recorded coordinates of the camera are compared to the coordinates of the height sensor when the height sensor is automatically aligned with the calibration device.

First claim

What is claimed is:

1. An apparatus for dispensing a material onto a substrate, the apparatus comprising:
a height sensor configured to emit electromagnetic radiation;
a camera having a fixed spatial position relative to the height sensor;
a dispensing valve configured to dispense the material on the substrate;
a positioner configured to support the height sensor, the camera, and the dispensing valve and to move the height sensor, the camera, and the dispensing valve as an assembly relative to the substrate;
a controller in communication with the positioner, the height sensor, the camera, and the dispensing valve; and
a service station including an optical sensor in communication with the controller, the optical sensor configured to receive the electromagnetic radiation emitted from the height sensor and to generate an alignment signal that is communicated to the controller when the electromagnetic radiation is received by the optical sensor,
wherein the alignment signal indicates that the electromagnetic radiation from the height sensor is aligned with the optical sensor, and the controller is configured to determine a first offset vector between the camera and the height sensor.

2. The apparatus of claim 1 wherein the height sensor includes a laser and the electromagnetic radiation is a light beam.

3. The apparatus of claim 2 wherein the positioner is configured to move the assembly in a plane to a first position in which the optical sensor receives the light beam emitted from the height sensor and a second position in which the optical sensor is aligned with a predefined location in a field of view of the camera.

4. The apparatus of claim 3 wherein the service station includes a surface facing toward the height sensor and a fiducial mark on the surface adjacent to the optical sensor, and the positioner is configured to move the assembly in a plane to a first position in which the optical sensor receives the light beam emitted from the height sensor and a second position in which the fiducial mark is aligned with a predefined location in a field of view of the camera.

5. The apparatus of claim 3 wherein the service station includes a surface facing toward the height sensor and an opening in the surface, the optical sensor is positioned inside the opening, and the positioner is configured to move the assembly in a plane to a first position in which the optical sensor receives the light beam emitted from the height sensor and a second position in which the opening is aligned with a predefined location in a field of view of the camera.

6. The apparatus of claim 1 wherein the positioner is configured to move the assembly in a plane relative to the optical sensor to a first position in which the optical sensor generates the alignment signal and a second position in which the optical sensor is aligned with a predefined location in a field of view of the camera.

7. The apparatus of claim 6 wherein the controller is configured to receive a first set of coordinates in the plane from the positioner when the assembly is located at the first position, to receive a second set of coordinates in the plane from the positioner when the assembly is located at the second position, and to compute the first offset vector in the plane for the height sensor relative to the camera from the first and second sets of coordinates.

8. The apparatus of claim 7 wherein the service station includes a surface facing toward the height sensor and a dispensing area, and the controller is configured to cause the positioner to move the assembly in the plane to a third position in which the dispensing valve can dispense an amount of the material on the dispensing area and a fourth position in which the amount of the material is aligned with the predefined location in the field of view of the camera.

9. The apparatus of claim 8 wherein the controller is configured to receive a third set of coordinates from the positioner when the assembly is located at the third position, to receive a fourth set of coordinates from the positioner when the assembly is located at the fourth position, to compute a second offset vector in the plane for the dispensing valve relative to the camera from the third and fourth sets of coordinates, and to compute a third offset vector in the plane for the height sensor relative to the dispensing valve from the first and second offset vectors.

10. An apparatus for dispensing a material onto a substrate, the apparatus comprising:
a height sensor configured to emit electromagnetic radiation;
a camera having a fixed spatial position relative to the height sensor;
a dispensing valve configured to dispense the material on the substrate;
a positioner configured to support the height sensor, the camera, and the dispensing valve and to move the height sensor, the camera, and the dispensing valve as an assembly relative to the substrate;
a controller in communication with the positioner, the height sensor, the camera, and the dispensing valve; and
a service station including a surface configured to receive the electromagnetic radiation emitted from the height sensor and a fiducial feature on the surface, and the height sensor is configured to generate an alignment signal in response to detecting a change in a reflected portion of the light beam caused by the fiducial feature, and the height sensor is configured to communicate the alignment signal from the height sensor to the controller,
wherein the alignment signal indicates that the electromagnetic radiation from the height sensor is aligned with the fiducial feature, and the controller is configured to determine a first offset vector between the camera and the height sensor.

11. The apparatus of claim 10 wherein the fiducial feature includes an edge defining a step height change perceivable by the height sensor, and the alignment signal is generated when the height sensor detects the change in the reflected portion as the light beam crosses the edge.

12. The apparatus of claim 10 wherein the fiducial feature includes an aperture in the surface and an edge surrounding the aperture, the edge defines a step height change perceivable by the height sensor, and the alignment signal is generated when the height sensor detects the change in the reflected portion as the light beam crosses the edge.

13. The apparatus of claim 10 wherein the height sensor includes a laser and the electromagnetic radiation is a light beam.

14. The apparatus of claim 10 wherein the positioner is configured to move the assembly in a plane relative to the surface to a first position in which the alignment signal is generated by the fiducial feature and a second position in which the calibration device is aligned with a predefined location in a field of view of the camera.

15. The apparatus of claim 14 wherein the controller is configured to receive a first set of coordinates in the plane from the positioner when the assembly is located at the first position, to receive a second set of coordinates in the plane from the positioner when the assembly is located at the second position, and to compute the first offset vector in the plane for the height sensor relative to the camera from the first and second sets of coordinates.

16. The apparatus of claim 15 wherein the service station includes a dispensing area, and the controller is configured to cause the positioner to move the assembly in the plane to a third position in which the dispensing valve can dispense an amount of the material on the dispensing area and a fourth position in which the amount of the material is aligned with the pred

Assignees

• Nordson Corp

Inventors

• Suriawidjaja Floriana
• Weston Todd S

Classifications

• G01B11/0608

  Height gauges · CPC title

• B05B12/124 Primary

  responsive to distance between spray apparatus and target · CPC title

• Y10T29/49

  Method of mechanical manufacture · CPC title

• G01B11/026 Primary

  by measuring distance between sensor and object (G01B11/0608 takes precedence) · CPC title

• B05C11/00 Primary

  Component parts, details or accessories not specifically provided for in groups B05C1/00 - B05C9/00 (means for manipulating or holding work B05C13/00; enclosures for apparatus, booths B05C15/00; spray booths B05B16/00) · CPC title