Practical use case: Pick and place using a SCL gripper

Pick and place operations are quite common in the industry. They are often used in high-volume manufacturing. Let's see how we can implement one with nothing but a generic robotic operation and a set of SCL scripts. The scripts control the flow of parts as well as the gripper behavior. What's left for the robot is motion and signaling. Pretty basic but this makes it a good candidate for a post.

The setup:

1. a robot arm

2. a generic robotic operation

3. a gripper

4. a part

5. a part source component

6. a part target component

The robot picks a part appearance from the source and moves it to the target following its path. When the robot approaches the first location a new part appearance is generated at the source. When the robot is at the first location the part appearance at the source is gripped by the gripper and the part appearance at the target is destroyed. When the robot is at the last location the gripper releases the part appearance.

Then the cycle repeats itself over and over again.

The robot code simply moves the arm and notifies the scripts for the events of interest.

The scripts react on these events by using the related study signals:

The gripper code simply attaches/detaches the part appearance to the gripper by using the build-in SCL gripper functions. The rising/falling edge triggers ensure that the functions will be called once at pick/place position.

The part source component simply creates a part appearance upon request.

The part target component simply destroys the part appearances upon request:

Here is the final result:

You may ask: Why is this important?

Well: Flexibility and customization.

With the scripts you define the material flow and also the gripper's behavior. Imagine the situation where some parts appearances are considered defective and should not be gripped. You add an 'if' statement in the gripper's script and they won't be gripped. Also there might be emergency situations where part appearances should not be generated. It is easy - just skip the calls to CREATE_PART_APPEARANCE.

In other words scripts can be easily adapted to your needs.

This enables automation.

See you later!