Robots make the coins go round downunder

If you visit the Royal Australian Mint you will see a very busy, large, orange Kuka Titan robot, tipping coin blanks for delivery to the presses, tipping finished coins for packing into boxes and impressing visitors.

Dale Rogers, project manager for the Materials Handling and Warehousing Project (MHWP) at the Mint, said that until this year the materials and warehousing functions were carried out in a very manual fashion with very little technology bar Microsoft Excel.

A store-man and an operating supervisor would communicate to each other about when blanks were required upstairs and when finished coins were needed to be taken downstairs. It was a repetitive, day-long process. Information was harvested off the press by a person with a clipboard. That data would entered on an Excel spreadsheet for the production director or manager to review in order to make strategic decisions on the mix of coins to manufacture.

This process has been completely overhauled by Australis Engineering, the family-owned, local company that won the $7.4 million tender.

The star of the new system is definitely the Kuka Titan robot, visible to visitors from the foyer. But it also works with new Automated Guided Vehicles (AGVs), a bucket elevator system, surge hoppers and a vision counting system; all of which are underpinned and managed by an MES (Manufacturing Execution System).

Check out the Royal Australian Mint's Kuka Titan Robot in action in our slideshow.

The robot is the same as that used by Isuzu to build trucks, so it is well-used to hard work.

“When we purchased the robot it was the largest industrial robot in the world, but that has apparently recently been surpassed. [I think there is] a bit of a robot weight and capacity war going on right now between two different manufacturers,” Rogers said.

The new automated MHWP system is end-to-end. It starts and finishes at the basement dock. Staff in the dock unload blank coins onto a conveyor, the starting point of the materials handling system.

From there, the pallet of blanks in drums are barcode scanned and metadata is attached to each drum. An AGV then takes the drum from the basement and puts it in to storage. At the same time, the MES is monitoring production on the ground floor. Every evening, a night schedule runs which ensures that all of the finished goods from that day are taken to the new vault and new blanks are brought from storage in the basement, up the lift to the coin hold.

When the press runs out of blanks, the system automatically calls up the MES. The Kuka Titan robot takes delivery and decants the blanks in to the new vision counting system.

The vision counting system is a CCTV camera connected to a computer, which counts the blanks on the conveyor belt. The camera can count 15,000 blanks per minute and the blanks are then placed in the bucket elevator and delivered to the designated press.

“As the physical material travels though the process, the metadata is also traveling,” said Rogers. “The MES is constantly monitoring and managing those materials.

“Back at the Titan robot, the AGV picks up the drums that are used to decant the blanks into the vision counter and takes it back to the designated press. That helps us track our metadata and audit materials.”

The drum then goes back to the Titan robot, which decants it for a final time into large or small cardboard boxes, as required. An AGV takes the finished goods and puts them back in the vault. The next day, another AGV places the goods in an outwards bound area, ready for a store person to pick the order.

An added advantage of the new process is that 80 per cent of the Mint's customers were happy to change packaging style and receive coins in drums instead of cardboard boxes.

“We have reduced our cardboard consumption and have been able to re-use a material that used to go to waste (the empty drums). We're pretty excited that we have been able to adopt a more holistic packaging practice as a result of the new system,” Rogers said.

The new system also ensures that customers who order 200,000 coins receive 200,000 coins.

“It might be that some coins are wasted when they come off the press because there is a cracked die or another process problem. So that particular drum might end up with an odd number. In such cases, the drum [with an odd number] will be taken back to the robot, which decants the coins to be re-counted into another drum,” Rogers said.

Despite the robot stealing the limelight, the real heart of the new system is the MES, which runs on standard networked computers.

“Our whole production system is networked with Ethernet cabling and IP communications. We have remote I/O in the field, so if a valve or motor needs to run, the command is delivered across the Ethernet to the remote I/O, which then processes an output or accepts an input through a sensor.”

One of the major challenges in the project, according to Rogers, was in achieving a balance between automation and control and ensuring user friendliness.

“People have had to change their work habits because the system is thoroughly integrated from end-to-end, but at the same time we've tried to design it to be as friendly to the existing processes as possible,” he said.

“As you can imagine, everything is a degree of compromise. When we make the system more user friendly to existing methods it takes a little away from the initial vision of automation that inspired us initially. It is a real balancing act.”

Overall, the project has been very successful in meeting the objectives: reducing occupational health and safety (OHS) issues, increasing security and increasing productivity.

By removing human-operated fork lifts, the Mint has removed a huge OHS liability, according to Rogers.

“We are finding that the AGVs are much safer and more reliable. Robots are never affected by having a bad night with the baby and falling asleep at the wheel. They are extremely accurate and they always do the same task in the same way.”

Rogers admits to a few robot collisions early in the implementation — the only problem experienced so far and one that was inadvertently caused by the accuracy he praises.

“We have had a few incidents where, the weight of the goods placed on the racking caused the it to settle. The next time the AGV tried to load something into the rack, it tried to load it at, say, 1500mm off the floor. But the racking was now at 1480mm, which caused some problems,” he said.

“We are finding that the accuracy of the robots is more than that of our other systems and we need to adapt to that accuracy.”

Rogers also points out that the Titan robot is also incredibly accurate, despite appearing slow.

“When the robot bends down to pick up a drum, it comes very close to the bottom of the drum and appears to just stop and wait. A lot of visitors wonder what it is doing, but if you look very closely, it is actually moving its gripper to the left and right very slowly,” he said.

“The drum has come on a pallet, so it might not be exactly in the same position all the time. The robot sensors on its gripper can determine the center of the drum.”

Copyright © 2009 IDG Communications, Inc.

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