Pattern verification (waypoint database)

Starting from Pally version 3.0 it is possible - and also highly recommended - to verify all patterns with the corresponding Pally calibration, and store the robot trajectory as an evidence of a successful testing.

Understanding Pattern verification

To ensure the pattern can be palletized, it has to be physically tested on the actual robot setup at least once. The robot should be able to build full pallet(s) from one or two pick positions, according to the current setup:

• If both left and right pallets are enabled, both must be tested, and

• If both primary and secondary pick positions are enabled, both must be tested.

Pattern verification is normally part of the factory acceptance test process that cannot be skipped. Without a complete test, operators who don't have access to the robot program and pallet pattern structures won't be able to keep the system running in production.

In addition, on the UR robots it is possible to create multiple URP programs and multiple installations on the same robot, and load the corresponding program for the specific use case. For example, if a robot is regularly transferred between multiple production lines, each line can have its own URP program with a specific Pally calibration that fits for the given production line. To ensure the system works properly, every pattern has to be verified using the URP and installation it will be used with.

Even if a pattern is fully verified on one specific Pally setup, it may fail completely on another setup, e.g. when the conveyor location is different. To be able to detect such issues, the program keeps a copy of the Pally setup and compares it with the current setup automatically. A warning is given to the user in case a difference in calibration is detected and the pattern verification state becomes invalid.

Pattern verification best practice

When starting with a brand new pattern, the program stores the robot trajectory - including waypoints and lifting column positions - for each position that has been palletized successfully. Once the trajectory is stored in the path storage database, it will be reused for subsequent pallets. This is done automatically without user interaction.

The pattern is considered verified if it is possible to palletize a full pallet on both pallet positions, but there are some special cases to be considered, especially when palletizing partial pallets using multi-pick.

The program may not be able to palletize fewer boxes than specified by the maxGrip settings. For example, when all positions are normally double-picked, but the operator requests a partial pallet with 1 box only, there is no guarantee that the robot can single-pick and has enough reach to perform the operation. To ensure this is possible, we recommend testing a full pallet with all single picks in addition to normal testing. The program will store the robot trajectories for both multi- and single-pick cases as an evidence of a successful testing.

To perform a new verification, the path storage database can be reset and generated again at any time, as long as the Active Plan option is valid.

Check pattern verification status

To see the current status, follow the steps below:

• Open the program and select the Pally program node.

• Go to Advanced / Verified patterns.

• Make sure the robot is ON. (This step is necessary due to technical limitations.)

• Press the “TEST” button.

The URCap will show an overview of the verification status of all available patterns according to the current path panning and calibration settings. The pattern verification status can be one of the following:

Open	Offline path storage is not available or not valid for this pattern.
Open	Partly tested with other calibration parameters. Cached waypoints may require further testing with another URP program.
Open	Fully tested with other calibration parameters.  Cached waypoints can't be used with this URP program, but may be used with another one.
Open	Partly tested with this calibration. (Test in progress?)  Cached waypoints will be used where available, but further testing is needed.
Open	Fully tested with other path planning parameters.  Cached waypoints will be used by this URP program for all box positions.
Open	Fully tested with the current path planning parameters. Cached waypoints will be used by this URP program for all box positions.
Open	Manually confirmed. Cached waypoints will be used by this URP program where available.

Press the "Show details" button to get more information about the pattern status.

Press the “Mark as Verified” button to mark the pattern verified even though not all box positions have been tested. This can be used for testing purposes and as a workaround in Dual Product mode where some combinations of pick- and pallet positions that won’t be used cannot be tested.

Press the "Reset selected" button to clear the waypoint database for the selected pattern and allow the palletizer program to store waypoints again next time the pattern is being palletized.