Decision-taking robots make automation more flexible
05 December 2012
An automation system in which machines and robots make their own decisions and adapt to external circumstances continue to work, even when something goes wrong.
Automation Scientists Fredrik Danielsson and Bo Svensson at University West in Sweden have demonstrated that this works in reality. The tests are performed on an automated production line which contains three robots, two metal cutting machines, a transportation system, a material handling system and a measuring station.
Normally automated production of this kind functions just as long as nothing goes wrong. This is because the system is hierarchical. The master control system gives orders about what should be done. Only when the control system is told that the order has been completed, is the next order placed.
“A single error somewhere makes everything stop. For example, if a piece of sheet metal is damaged an operator has so take it out and then reset and restart everything,” says Bo Svensson.
In Fredrik Danielsson’s and Bo Svensson's new model, all robots and machines work independently. Each robot, conveyor and machine is equipped with an agent, a small intelligent program that does not require signals from a master control system to act.
“The agents know what neighbours they should communicate with and make small local decisions,” says Fredrik Danielsson.
An agent is triggered by what is happening next to it. The start signal for a machine may be that someone puts a piece of sheet metal in it. Then it knows that it must drill. Things do not have to happen in a certain order. If the sheet metal is lost the system continues to work with other sheets. The operator can also insert a new part in the middle of the flow without disturbing the system.
It may take up to a year to create a traditional automation system and it is very difficult, time consuming and expensive to adapt it to changing demands. In an agent configuration, however, you can easily insert and remove both equipment and operators. And it can produce an array of product variants, as it is easily reprogrammed.
Agents are automatically generated in minutes by the software 'P-SOP' developed by Fredrik Danielsson and Bo Svensson. The operator gives P-SOP instructions, in the form of a PowerPoint sketch, of how the system should work.
“Then he presses a button and P-SOP spits out a bunch of small agents for different machines. I think this may be the next big step in automation,” says Fredrik Danielsson.