Machine Vision Calibration Procedure

Table of Contents

Step-by-step Procedure

The following steps need to be performed every time a new cartridge type is introduced to the system.

  1. Go to the Camera Calibration page, from the “Calibration” drop-down list on the left panel of the Vape-Jet web interface.
    1. Open the Vape-Jet door.
    2. Click the “Loading Position” button from the right side panel, and place a tray of cartridges, pods, or capsules onto the filling platform.
    3. Gently tamp the tops of the cartridges or pods with your hand to ensure they are all close to the same height in the foam. Close the door.
    4. Use the “Concentric Jogger” to move the platform under the camera, such that a cartridge, pod, or capsule is directly underneath.
    5. Click the video display to select the Machine Vision Camera.
    6. Carefully adjust the “Camera Focus” slider to bring the topmost feature of the cartridge, pod, or capsule into sharp focus. Most 510-style cartridges or pods will be focused directly on the center post as it is the highest point of these styles; bottom-filled cartridges have shorter center posts and so focus will be on the outer edge of the cartridge tank, similarly to capsules.
  2. Calibration logic for traditional 510-style cartridges:
    1. From the “Configuration” page, fill out the “Cartridge Info” section with manufacturer, type, part numbers (must contain text, can’t be only numbers), and make sure the “Pod Type Cartridges” toggle is in the leftmost position to select for cartridges.
    2. From the “Camera” page under the “Calibration” drop down, adjust the “Camera Focus” slider to focus on center post.
    3. Click “Inner Circle Calibration”.
    4. Set “Maximum Circle Radius” and “Minimum Circle Radius” sliders to be within about 3-10 of each other, such that a solid lock can be found on the center post.
    5. Adjust “Detection Filter 1” and “Detection Filter 2” sliders to only lock on the center post when in frame.
    6. Adjust the “Inverse Ratio of the Accumulator Resolution to the Image Resolution” (IRARIR for short) slider to between 1.0 and 2.5.
    7. Click the “Outer Circle Detection” tab, then click “Enable Outer Circle Detection” and follow logic of steps 2b-2e to identify the outermost circle of the cartridge tank, with IRARIR set to between 3.5 and 7.5.
    8. Click “Calibrate Optical Scalers” and wait for the routine to complete.
    9. Click the gear symbol in the upper right to open the “Configurations” window; fill out “Configuration Name” and “Configuration Description”, then click “Save New”, and “X” or “Close” out of the window.
  3. Calibration logic for Pod style cartridges:
    1. From the “Configuration” page, fill out the “Cartridge Info” section with manufacturer, type, part numbers (must contain text, can’t be only numbers), and make sure the “Pod Type Cartridges” toggle is in the rightmost position to select for pods.
    2. From the “Camera” page under the “Calibration” drop down, adjust the “Camera Focus” slider to focus on center post.
    3. Click “Inner Circle Calibration”.
    4. Set “Maximum Circle Radius” and “Minimum Circle Radius” sliders to be within about 3-10 of each other, such that a solid lock can be found on the center post.
    5. Adjust “Detection Filter 1” and “Detection Filter 2” sliders to only lock on the center post when in frame.
    6. Adjust the “Inverse Ratio of the Accumulator Resolution to the Image Resolution” (IRARIR for short) slider to between 1.0 and 2.5.
    7. Click “Calibrate Optical Scalers” and wait for the routine to complete.
    8. Click the gear symbol in the upper right to open the “Configurations” window; fill out “Configuration Name” and “Configuration Description”, then click “Save New”, and “X” or “Close” out of the window.
  4. Calibration logic for bottom-fill 510-style cartridges:
    1. From the “Configuration” page, fill out the “Cartridge Info” section with manufacturer, type, part numbers (must contain text, can’t be only numbers), and make sure the “Pod Type Cartridges” toggle is in the leftmost position to select for cartridges.
    2. From the “Camera” page under the “Calibration” drop down, adjust the “Camera Focus” slider to focus on the outer circle of the cartridge tank.
    3. Click “Inner Circle Calibration”.
    4. Set “Maximum Circle Radius” and “Minimum Circle Radius” sliders to be within about 3-10 of each other, such that a solid lock can be found on the outermost circle of the cartridge tank.
    5. Adjust “Detection Filter 1” and “Detection Filter 2” sliders to only lock on the outermost circumference when in frame.
    6. Adjust the “Inverse Ratio of the Accumulator Resolution to the Image Resolution” (IRARIR for short) slider to between 3 and 7.5.
    7. Click “Calibrate Optical Scalers” and wait for the routine to complete.
    8. Click the gear symbol in the upper right to open the “Configurations” window; fill out “Configuration Name” and “Configuration Description”, then click “Save New”, and “X” or “Close” out of the window.
  5. Calibration logic for capsules:
    1. From the “Configuration” page, fill out the “Cartridge Info” section with manufacturer, type, part numbers (must contain text, can’t be only numbers), and make sure the “Pod Type Cartridges” toggle is in the leftmost position to select for cartridges.
    2. From the “Camera” page under the “Calibration” drop down, adjust the “Camera Focus” slider to focus on the circle of the capsule.
    3. Click “Inner Circle Calibration”.
    4. Set “Maximum Circle Radius” and “Minimum Circle Radius” sliders to be within about 3-10 of each other, such that a solid lock can be found on the capsule.
    5. Adjust “Detection Filter 1” and “Detection Filter 2” sliders to only lock on the circumference of the capsule when in frame.
    6. Adjust the “Inverse Ratio of the Accumulator Resolution to the Image Resolution” (IRARIR for short) slider to between 1 and 7.5.
    7. Click “Calibrate Optical Scalers” and wait for the routine to complete.
    8. Click the gear symbol in the upper right to open the “Configurations” window; fill out “Configuration Name” and “Configuration Description”, then click “Save New”, and “X” or “Close” out of the window.

Detailed Explanation of Calibration Parameters

Camera Focus

Should be set to sharp focus on the feature closest to the camera lens. Having a sharp focus is crucial to the Machine Vision Alignment system, as distances cannot be measured accurately without a well defined, sharp image.

Image 1: Focused on center post at Camera Focus = 58.8mm (shown off center for contrast)

Image 2: Not focused on center post at Camera Focus = 56.4mm

Minimum Circle Radius

Should be set such that the Machine Vision Alignment (MVA) system can identify the circle of interest, e.g. the center post for traditional cartridges and some pods, or the outside circumference of bottom-filled cartridges or of open capsules.

Image 3: the Minimum Circle Radius is set too high at 38, the green MVA circle jumps around the center post and cannot lock on.

Image 4: the Minimum Circle Radius is set too low at 30, the green MVA circle has a stable lock, but on the inner diameter of the center post. The MVA circle will not find a lock if set much lower as seen in Images 1 and 2.

Image 5: the Minimum Circle Radius is set to 34 resulting in a mostly stable MVA lock on the outer diameter of the center post.

Maximum Circle Radius

Should be set to be higher than Minimum Circle Radius, in order to improve the MVA lock on the circle of interest.

Image 6: the Maximum Circle Radius is too large, the MVA lock fluctuates between the center post and outer tank diameter.

Image 7: the Maximum Circle Radius is set to 38, resulting in a better MVA lock than was seen in Image 5 with a value of 50.

Detection Filter 1 and 2

Should be set such that the MVA can lock onto the post when centered or towards the edge of the image, whilst not locking when no part of the post is visible.

Image 8: Detection Filter 2 is set too high since the MVA cannot lock on when the post is clearly visible at the center of the image.

Image 9: Conversely if the center post is not visible in the image and Detection 2 is too low, then the MVA will get false locks sporadically which will result in misalignment.

Image 10: Adjusting both filters such that the MVA gets solid true locks and no off-center false locks is the purpose of these parameters.

IRARIR

Should be high enough to get a steady lock on the cartridge circle, but not so high that the circle doesn’t move with the cartridge when performing small jog operations. Lower values are used to maintain lock on smaller diameter circles, while higher values are used to maintain lock on larger diameter circles.

ALERT: If the accumulator threshold is set too high, the system may never lock to the center post close enough to finish alignment.

Calibrate Optical Scalers

This is an automated routine that should be run after the MVA has been properly calibrated by adjusting the above parameters. This routine will determine the scale of movements made by the MVA during the alignment process, i.e. how much off center the image is and how much to move to center it. If the Optical Scalers are incorrect, then the MVA will “hunt” for a lock taking several moves or more; the ideal behavior is to find center lock 1 or 2 moves after the align routine begins.