Vision: several cameras on one device

Last updated

License feature: Machine Vision

Some parts cannot be judged from one side — a label on top and a date code on the side, or a connector only visible from an angle. A vision device can have up to four cameras, and one verdict covers all of them.

Adding a camera

1. On the Vision page, press Add camera in the camera card. A tab appears, named Camera 2, set to Uploaded test image.
2. Give it a Camera name (up to 60 characters) such as "Side", pick its Camera type and fill in its address or URL.
3. On each tool that should use it, set Looks through to that camera and draw the tool's region again on its picture.
4. Save.

Add camera disappears once there are four. The bin icon beside Camera name ("Remove this camera — its tools move to the first camera") removes the camera shown.

The rules

• Each camera has its own settings: name, type, address or test image, and its own scale — two cameras at different working distances never share millimeters per pixel.
• Each tool looks through one camera, chosen with Looks through. A tool with no choice made looks through the first camera, which is what every inspection written before there were several cameras does.
• Every camera the program uses is grabbed at once for each inspection, so the pictures describe the same part at the same moment. A camera no tool in the running program uses is not grabbed.
• pass is true only when the judged tools on every camera pass.
• A camera that gives no picture fails its own tools with the reason ("No image from Side: Camera returned HTTP 503"); the tools on the other cameras are still judged, and the combined verdict fails. On the page the missing picture reads "No picture from Side: …".
• The device only connects when every camera answers. At connection it grabs from all cameras; one missing camera leaves the device disconnected with "No image from Side (…)".
• A region follows a locator on the same camera only. Positions in one camera's picture say nothing about where a part is in another's. Following a locator on another camera fails with "… is on a different camera. A tool can only follow a locator looking through the same camera."
• Changing a tool's camera clears its region (it was drawn on the other picture) and its locator.
• Selecting a tool shows its camera's picture. The camera tabs switch the picture without changing the tool, for setting another camera's scale. Drawing a region is disabled while the picture shown is not the selected tool's camera.
• Kept failed images show every camera side by side, labeled with the camera name, in one file.
• Removing a camera moves its tools to the first camera.
• Only the first camera's address is copied to the device's address on the Devices page.
• Processing time adds up. Two cameras at 5 MP each on a Pi double the decode and tool time; check last_run_ms.

See also

• Machine Vision
• Vision: cameras and connection
• Vision: pattern match, fixturing and gauges
• Vision: failed-part images and the Camera widget