How-to: Simple pick and place
Pick and place applications are a fundamental part of daily proceedings in so many applications and industries. In this blog post, we are going to be guiding you through a simple pick and place program.
Creating a simple pick and place program:
We want to first create a starting waypoint where we know the gripper will not collide with any object, this is done by clicking the waypoint button in the basic tab. It will create a move node with a waypoint in it.
From the move node, we can adjust they type of move we want (joint move (movej), linear (movel), or linear with blends (movep)) and adjust speeds and accelerations.
We will just leave it at the default settings for this program.
Next, click on waypoint_1.
To set the waypoint, press set waypoint:
You can move the robot into the desired position using either the freedrive mode or by using the directional arrows you see on-screen. Freedrive mode can be activated on screen using the freedrive button or by using the freedrive button on the back of the teach pendant. This allows you to manually move the robot into position.
Once the robot is in the desired position, you can press OK (green tick) and the waypoint will be saved. You can also rename it in the waypoint node - this is useful for troubleshooting later on. We will call our starting position ‘home’.
We then want to open the gripper, ready to pick the object. To do this, we go to the URCap tab in the program and select gripper. This will add a gripper move command to the program. Then click on edit action and tell the gripper to move to the fully open position and click save. You can also adjust the speed and force with which you want to move if necessary.
We then want to add another move, to go to the object. For this, we're going to add a movej to go to a point above the object, then a movel to move the fingers of the gripper around the object. We then want to add another gripper move command to close the grippers around the object. It should look like this:
Next, we want the robot to move the object to its desired position. We can do this by simply adding another move command, we may need multiple waypoints depending on where you want to move to. In this case, we will use three waypoints: one to retract it from where it currently is and help avoid a collision, another to move it above the desired position, and a final one to move it into the final position.
Finally, we want to get the gripper to open to drop off the object. We do this again with the gripper move command.
The program will loop infinitely in its current state - we can also add a halt command to stop the program running after one loop.
If required, much more functionality can be added to the program to make this far more advanced, such as force moves, object detection and if and else statements. In addition to this, there is the option of communicating with a multiple digital and analogue inputs and outputs.
We hope this quick How-to has given you food for thought for when it comes to creating your pick and place program. Happy picking! ...(and placing)