# place parts on 1 conveyor with 3 robots

• Hi!

PLease take a look on the attached pic. I have planned this robot line. 3 robots places parts on conveyor with different cyle time. How can I instruct the last 2 robots to place parts on the conveyor only if it has empty place on it? Any solution is good for me. If I think well line tracking system is not enough.

The first reply will got a beer:-)

## Images

• Hi!

If you know:

1. The velocity of the conveyor
2. Where the robot will place the object
3. A signal to indicate to the other robot when it place the object..

You should calculate/derteminate if there is something or not on the conveyor.

• Put a laser upstream on the conveyor and another downstream. Any time an object passes the upstream laser, a flag turns on and stays on until the downstream laser detects the object leaving. Program so the robot will not interact with the conveyor while the flag is on.

• I suggest a mix of soft and hard tracking.

Laser break sensors (like you'd see at a checkout at the grocery store) are unbelievably cheap so you'll want to throw that down before each robot.

Grab a free robot input for each (just use the simple digital IO).

Hook an encoder on one of the tensioning bearings for the conveyor.

Have a register count every so many ticks of the conveyor's encoder (you'll have to adjust this according to the distance between the robots, just sort of wing it and test it with some objects after).

Grab a free position register and while one laser detects an object, it *measures* its length by the number of ticks of the conveyor. For the first robot, it places it in the first element. It actually doesn't matter how many millimetres a tick is, just be sure you won't overflow a variable with ticks before it leaves the robot's reach.

Every so many ticks of the conveyor (BGLOGIC) the number shifts to the next position register element.

First robot deals with PR[#,1] and PR[#,2], second robot deals with 3 and 4, and so on. 6th position register doesn't shift, just gets overwritten because the robots won't care anymore about objects down stream. You could technically send that info to something down stream so it knows what to expect.

You'd run it and figure out how many ticks each robot is capable of reaching, and how many ticks your longest objects represent.

If a robot has an object ready to load, it checks to see if its upstream pr element has free space. It then picks one up and loads it into the downstream pr element when time is right (in ticks of the conveyor)

If your objects significantly differ in size, you could instead measure the gaps between the objects on the bed, to ensure a perfect fit.