Treat your industrial robot counterparts with some respect! Moving through tight spaces at high speed, these machines can seriously injure anyone who gets in their way. That’s why, to prevent injury they are usually kept in expensive, space-consuming cages.
In the last few years, however, a different type of robot has emerged – one that doesn’t need caging to keep factory workers safe. These are known as collaborative robots or cobots. The name comes from their ability to work directly with or alongside human factory workers in a shared workspace.
Cobots are a newer form of robotics technology. When used in the right kind of application they offer a host of benefits, but they have limitations too. Understanding these strengths and weaknesses is the key to successful deployment.
Robot-Human Collaboration at its Finest
The cobots getting the most attention are those that are power-and-force-limited (PFL). They are designed to stop immediately if they come into contact with anything, such as a human worker. Start ups and well established brands alike are creating cobots to take on a plethora of different tasks and responsibilities. In the field, they are typically light duty arms intended for small payload, lower precision, short reach applications.
Not to be left behind, established robotics companies have brought out their own versions. These bulkier yet stronger offerings have the same collaborative capabilities but in more industrial packages.
An alternative approach to robot-human collaboration is through advanced safety controls. These use area sensors to detect the presence of humans and fast-acting brakes to prevent robot arm-human collisions.
The third type of collaborative robot is those that are mobile. Unlike automated guided vehicles (AGV), these are able to navigate autonomously through crowded and unpredictable environments. Mobile cobots are finding use in warehouse and material delivery applications.
Benefits of Using Cobots
Forward-thinking manufacturing companies are exploring the potential of cobots for many reasons. Chief among these are:
- Enable partial automation – a cobot can handle repetitive parts of a task while the human concentrates on those aspects needing more skill, precision and judgement.
- Need less floor space – cages are eliminated, often along with complex conveyor or pallet systems for part feeding and removal.
- Protect workers from repetitive motions – repeated movements like twisting can cause long-lasting injury and monotony leads to mistakes. Letting a cobot handle these aspects of a task improves working conditions for the human and reduces costs.
- Deployment speed – small and light PFL cobots can be taught a motion path by leading or guiding rather than programming. This lets an engineer or technician get one running in just a few hours.
- Lower cost – while cobots are not much less expensive than similar-sized conventional robots, eliminating guarding and conveyors significantly lowers the total cost of implementation.
Robot buyers and users are mostly interested in three main aspects of performance: speed, payload and accuracy. Most cobots are inferior to similarly-sized traditional robots in each regard. They tend to have lower maximum movement speeds, lower payload limits and lower precision. In some cases this makes them the wrong tool to use. In other situations the engineering teams may need to reconfigure a process or equipment to accommodate the capabilities of a cobot.
Cobots are being put to work in factories, warehouses and laboratories. Sometimes they work directly with a human worker via partial automation and other times they work independently. Here are a few of the more interesting applications.
- Press brake tending – picking sheet metal parts and holding them while the tooling closes to make the bend or bends. This improves safety by keeping fingers away from pinch points.
- Inspection – cobots in vehicle assembly carry cameras to measure panel gaps and identify mismatch.
- Packaging – placing packages into cartons, inserting interlayer sheets or adding instruction leaflets.
- Assembly – cobots are taking care of simple part placement tasks, leaving human coworkers to handle the more difficult or challenging aspects of assembly.
- Sealant dispensing – in one automotive example, a cobot loads glass into a fixture where a second robot applies sealant. When the application is complete the cobot then unloads the fixture.
The Automation Shift is Coming
Factories and manufacturing methods continue to evolve. Thirty years ago it was rare to see a robot, but today these machines are commonplace. A new revolution is underway. Industry 4.0 and the Industrial Internet of Things (IIoT) are ushering-in an era of connectivity and data. In parallel, other advanced technologies, such as cobots, are simplifying and streamlining operations. Expect a lot more automation in the factory of the future, and far fewer barriers to getting things done.