Vacuum Part Detection

When picking up parts with the LumenPnP, it’s important to verify that a part has been successfully picked. While the bottom camera can confirm this visually, using the LumenPnP's vacuum sensors provides a faster way to detect a successful pick.

How Vacuum Part Detection Works

When a part is picked up, it seals the nozzle opening, causing an increase in vacuum pressure within the pneumatic line. This change in pressure is measured by the vacuum sensors, and OpenPnP uses this data to determine whether a part has been successfully picked. With the nozzle tip covered, if the vacuum sensor value falls within the Vacuum Range low and high values, OpenPnP considers the part "picked".

Each nozzle has a different vacuum reading due to variations in nozzle tip size. The exact numbers aren’t critical as long as you understand how to set the high and low values correctly and adjust them accordingly.

Disabling Vacuum Detection is an Option

Vacuum Part detection is not required to use the LumenPnP because the bottom camera checks for a part before placing anyway. If you'd like to disable this feature, it's just a matter of setting "Measurement Method" to "None" on the relevant nozzle tip. Don't forget to Apply your settings and save your configuration before moving on. Machine Setup > Nozzle Tips > Reference Nozzle Tip N## > Part detection tab > Measurement Method > None

Setting Up Vacuum Part Detection for Nozzle: N1

Select the correct nozzle to control.
- In the bottom left of OpenPnP, select Nozzle: N1 - N045 (Head:H1) from the machine controls dropdown.
Confirm the correct nozzle tip is installed.
- Ensure that the N045 nozzle tip is securely attached to Nozzle: N1 (left toolhead).
Position Nozzle: N1 for Accurate Readings.
- Navigate to Machine Setup > Cameras > OpenPnPCaptureCamera Bottom > Position tab
- Click the Position the tool over the center of the location button.
- This brings the nozzle: N1 to the same Z height as the datum board, ensuring more consistent readings for the following steps.
Open the Part Detection Settings.
- Navigate to Machine Setup > Nozzle Tips > ReferenceNozzleTip N045 > Part Detection.
Measure the Vacuum Pressure.
- In Machine Controls, navigate to the Actuators tab.
- Select H1:VAC1 to open the vacuum pressure window.
- Click On to activate the pump and valve.
- Click Read. A value will appear in the Read Value box. This represents the vacuum pressure when the Nozzle: N1 is uncovered.
- Take note of this number. We will need it later.
Measure the Vacuum Pressure with a Sealed Nozzle.
- Cover the nozzle tip completely with your fingertip.
- Click Read again. This represents the vacuum pressure when a part is picked, or "covered".
- Take note of the new value. We will also need it later.
- Click Off to deactivate the pump and valve.
- Close the H1:VAC1 vacuum pressure window.
Calculate the Detection Threshold.
- Find the midpoint between the uncovered and covered values. For example:
  - Uncovered: 220
  - Covered: 200
  - Midpoint: 210 → Enter this as the High Value.
- Enter the calculated midpoint value into the Vacuum Range High Value field for the N045 nozzle tip.
- Ensure the Low Value is at least 10-20 units lower than the "Midpoint" reading. The default low value is 220, but if your readings are close to this number (like the example above), you may need to lower it further to avoid false detections. If your Midpoint value is 210, setting the Low Value to 190 (or lower) is a good starting point.
Caution

The difference between uncovered and covered readings may be small, but even a single-digit change can indicate a successful pick. Nozzle sizes affect these readings, so expect variations between nozzles.

1. Apply and Save * Click Apply in the lower right corner to save your changes to the N045 nozzle tip.

* Save your OpenPnP configuration now. File > Save Configuration.

Setting Up Vacuum Part Detection for Nozzle: N2

Select the correct nozzle to control.
- In the bottom left of OpenPnP, select Nozzle: N2 - N24 (Head:H1) from the machine controls dropdown.
Confirm the correct nozzle tip is installed.
- Ensure that the N24 nozzle tip is securely attached to Nozzle: N2(right toolhead).
Position Nozzle: N2 for Accurate Readings.
- Navigate to Machine Setup > Cameras > OpenPnPCaptureCamera Bottom > Position tab
- Click the Position the tool over the center of the location button.
- This brings the Nozzle: N2 to the same Z height as the datum board, ensuring more consistent readings for the following steps.
Open the Part Detection tab.
- Navigate to Machine Setup > Nozzle Tips > ReferenceNozzleTip N24 > Part Detection.
Measure the Vacuum Pressure.
- In Machine Controls, navigate to the Actuators tab.
- Select H1:VAC2 to open the vacuum pressure window.
- Click On to activate the pump and valve.
- Click Read. A value will appear in the Read Value box. This represents the vacuum pressure when Nozzle: N2 is uncovered.
- Take note of this number. We will need it later.
Measure the Vacuum Pressure with a Sealed Nozzle.
- Cover the nozzle tip completely with your fingertip.
- Click Read again. This represents the vacuum pressure when a part is picked, or "covered".
- Take note of the new value. We will also need it later.
- Click Off to deactivate the pump and valve.
- Close the H1:VAC2 vacuum pressure window.
Calculate the Detection Threshold.
1. Find the midpoint between the uncovered and covered values. For example:
  - Uncovered: 230
  - Covered: 200
  - Midpoint: 215 → Enter this as the High Value.
2. Enter the calculated midpoint value into the Vacuum Range High Value field for the N24 nozzle tip.
3. Ensure the Low Value is at least 10-20 units lower than the "Midpoint" reading. The default low value is 220, but if your readings are close to this number(like the example above), you may need to lower it further to avoid false detections. If your Midpoint value is 215, setting the Low Value to 195 (or lower) is a good starting point.
Don't forget

The difference between uncovered and covered readings may be small, but even a single-digit change can indicate a successful pick. Nozzle sizes affect these readings, so expect variations between nozzles.
Apply and Save
- Click Apply in the lower right corner to save your changes to the N24 nozzle tip.
- Save your OpenPnP configuration now. File > Save Configuration.

Next Steps

Next is Running Your First Job.