Resolving Four Unexpected Challenges of Mobile Robots

Autonomous mobile robots (AMRs) and automated guided vehicles (AGVs) can provide a flexible, efficient automation solution for machine shops. RMS, a medical device manufacturer, successfully integrated Staubli’s HelMo system, which consists of a mobile robotic arm mounted on an AGV base, into the production of medical devices. By tending as many as eight machines, HelMo has helped RMS save space and reduce automation costs in its pacing business unit. However, as the company discovered, the flexibility of such autonomous systems also introduced new challenges, requiring adjustments to ensure smooth operation.

Transcript

Julia Hider: Autonomous mobile robots, or AMRs and automated guided vehicles or AGVs have many potential uses in a machine shop. From tending machine tools to delivering new cutting tools, to moving away full chip bins. Autonomous robots’ ability to move around a facility means they can handle more machines than traditional fixed robots and take up less space.

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Medical manufacturer RMS dreamed of finding a fully integrated, autonomous machine tending robot for years. It finally found a solution in the HelMo system from Staubli.

HelMo consists of an industrial robotic arm mounted on top of an AGV base. It follows a pre-programed path around its cell, using three area scanners to detect any obstacles and stop it if necessary. The scanners can also slow or stop the speed of the robotic arm if it detects people nearby.

RMS uses the HelMo to tend Robodrills that machine high volume medical parts. The Helmo can tend as many as eight machines. And during manned shifts, two operators for every four machine tools flip parts from the first operation to the second operation. It also runs lights out between second and first shifts, giving the shop three more hours of unattended machining time.

According to RMS, the HelMo is cheaper than having a plug and play automation system at every machine tool. It also saves space, a key consideration for a shop with 850 machine tools and more on order.

But as RMS has learned, the benefits come with trade offs. Its flexibility meant that RMS had to solve problems as they arose in order to get the system working perfectly.

Each machine that the HelMo tends has these three studs. When the robot comes up to the machine, it scans them. And that helps the robot orient itself so it knows where it is in space, so it can begin loading and unloading. But these studs are strategically located on the machine so it can be serviced without removing them, because if the studs are removed and they aren't put back in the exact same place, that causes problems with orientation.

The team also redesigned the locating stud on its fixtures, so that these flats are always in the same position because that's what the robot grabs onto when it moves the fixtures.

The HelMo has three sensors, two on the back and one on the front. And the RMS team eventually realized that these sensors can pick up oil mist from the machines and that was affecting the navigation. So they've since had to install more mist collectors to help mitigate that issue.

One of the simplest issues they had to troubleshoot was these air hoses. People will leave them all over, on and around the machine tool, but that would cause problems with the robot's navigation. So now everybody hangs up the air hoses on a hook.

Robots and Autonomy Correspondent

Julia Hider

Julia Hider graduated from Ohio State University in 2014 with a B.A. in journalism, and joined Gardner Business Media as an assistant editor with Modern Machine Shop in 2017. She has served as an editor on several Gardner Business Media brands, including Production Machining and Additive Manufacturing Media. She is currently a senior editor for Modern Machine Shop and covering robotics for all Gardner Business Media brands.