Warning

You are reading the documentation for an older Pickit release (3.1). Documentation for the latest release (3.4) can be found here.

Picking

Pickit is not only about detecting objects, but also about being able to pick them. While the Detection page is concerned with what to detect, the Picking page is concerned with everything that revolves around how to pick a detected object: From which points can it be picked? With which tool? Is the pick collision-free?

Tip

You can learn about the main ideas behind how to pick by watching this video tutorial.

Robot tool model

Pickit allows to model the robot tool that is used for picking. The tool model is useful for visually confirming the correct location of a pick point, and can also be used to prevent collisions between the tool and the bin, or other obstacles.

Pick points

A pick point represents where an object can be picked by the robot. It is specified as a position and orientation relative to the object, where the robot Tool Center Point (TCP) should move to perform a pick. What constitutes a good pick point depends on both the gripping device and the object to be picked.

Pick strategy

Once pick points are specified, there are a number of options that influence how objects are picked.

• Object ordering: When multiple objects are detected, object ordering determines the order in which they should be picked.

• Preferred pick point orientation: Pick points can have flexibility in how they are oriented. This flexibility can be used to favor pick orientations that are easier and faster to reach by the robot (e.g. less wrist motion).

• Limit the robot workspace such that picks are more likely to result in reachable robot motions:

  • Maximum robot flange tilt: Limits the robot flange orientation such that it is not too tilted at the pick point.

  • Minimum distance between robot flange and ROI: Limits the robot flange position such that it respects a minimum lateral distance from the bin walls, at the pick point.

• Temporarily avoid unpicked objects: This prevents repeatedly failing to pick the same object, and contributes to more consistent cycle times.

Collision prevention

In constrained picking scenarios like bin picking, it is important to prevent the robot tool from colliding with the bin or other obstacles. By modelling the robot tool and the obstacles in the picking area, Pickit is able to select pick points that prevent unwanted collisions.