|Evolution of Robotics||What are Cobots?||Cobot Safety and Risk Factors||Implications for Workers||Types of Cobots & Applications|
Collaborative robots, nicknamed cobots, are the more accessible, approachable descendants of traditional industrial robots. They’re smaller, less expensive, and, thanks to intuitive software, easier for non-experts to program. Built-in safety features expand types of jobs they can accomplish and perform complex operations side-by-side with human workers. They can even be reprogrammed to switch between tasks in the same facility, making them flexible and cost-effective. It’s time for manufacturers who thought robotic automation was out of reach to revisit that assumption. Is a cobot right for your company after all? Read on for the facts you need to decide.
What do you imagine when you think about robots in manufacturing? There was a time when industrial robots fit the stereotypical image of a towering mechanical arm, perhaps equipped with a welding tool or pincer, enclosed in a fenced area. Most likely that machine was doing a job considered dangerous or physically prohibitive for human workers, and it was definitely working at a distance from them, in isolation.
Early manufacturing robots were made for fixed use, designed to make one part or to complete one task until that part or job no longer was needed. Then it was time to get a new machine. The capital investment and physical space required for such dedicated machinery put early robots out of reach for all but the largest industrial companies.
Things have been evolving continuously ever since the first robots were introduced in automotive, aerospace, and packaging/shipping facilities.
To be sure, large-scale industrial robots still exist and are in use around the world today. But designs and capabilities have continued to change. Today, thanks to advances in controls and actuators, safety features, sensors, and computing power (not to mention shrinking component sizes and costs), new types of robots are capable of working near and with human coworkers in a wider range of settings. Consider the following:
Traditional industrial robots are built and programmed to do a single task at a distance from workers on the manufacturing or assembly floor. Common types include articulated arms, wheeled mobile robots, and gantry/rectilinear models, and they are often used to process large batches of single items: welding, drilling, spray application (paint, adhesive), transporting items across an area, loading and unloading heavy items. They are large, heavy, fast, and very strong, all of which make them hazardous to humans and require them to be surrounded by fencing or other barriers. Because they operate independently of the people around them, traditional industrial robots work in parallel, not in collaboration.
In contrast, a cobot is, according to its patent (US5952796A), "an apparatus and method for direct physical interaction between a person and a general-purpose manipulator controlled by a computer.” The key words here are direct physical interaction.
Collaboration is defined less by the task performed than by the features of the robot that make it safe and helpful for working side by side with humans. Machine and person can work on the same task, assembly, object, or activity at the same time in the same physical area, such as a work cell, station, or work bench.
There are several types of collaborative robot available “off-the-shelf,” which means there are options to suit a range of needs. Most cobots can also be customized and integrated into manufacturing production systems with accessories and tools like vision cameras, suction cup grippers, and welding tips (check out this example from Universal Robots on the right). Gone are the days when the only option for a robotic arm was to build a large, dedicated machine from scratch.
In stark contrast to older-style robots, bolted to the floor in a cage, collaborative models can be mobile multitaskers. They’re small and lightweight, able to be moved around the manufacturing floor or facility. Once in their new destination, easy and intuitive GUIs allow operators to quickly switch between tasks. Many models can also be programmed for new operations by hand guiding the arm through steps at the point of need. This flexibility is helpful for small and medium-size manufacturers, especially those in high-mix/low-volume and just-in-time (JIT) settings.
Cobots come in a range of sizes, payload capabilities, maximum reach distances, and operating speeds. Most are compact: small enough to mount on a workbench or sturdy cart. Larger models can mount to the floor (or ceiling, or wall, depending on the application). Payload limits are generally between about 3 and 16 kg (6.6 to 35.3 pounds), though FANUC has developed one that can lift up to 35 kg (just over 77 pounds). Typical reach ranges from 500 mm (19.7 inches) to 900 mm (35.4 inches). Where traditional industrial arms can move as fast as 3 meters/sec or more, most cobots have a maximum of speed of 1.5 m/s, though they’re usually operated at 1 m/s or less, depending on the proximity to human coworkers. Many also use six-axis motion, allowing for sophisticated movement around and between other equipment.
Another distinguishing feature cobots share is built-in controls to enhance safe operation. These include programmable settings to create “zones” of faster or slower speeds, collision avoidance, and sensors that stop the machine when a hand or other object enters an unanticipated area. (We’ll cover details about safety features in the next section.)
Along with safety, ergonomics can be improved with a cobot assistant. This is especially relevant as workers age, lose dexterity, and feel effects of standing, lifting, or twisting earlier in a shift. It also offers options to broaden the range of abilities and skills needed to perform a job, such as programming the robotic arm to do a task, making adjustments to settings based on computer data, or performing a job while seated. With these capabilities you can grow your manufacturing workforce.
Rather than removing human workers from jobs entirely, cobots usually integrate into the portions of a process that are repetitive or dull enough to risk errors or injury. Their small size and dexterous movement mean they make great assistants for tasks with small parts or intricate placement – the types of jobs humans do at workbenches and on the manufacturing floor. Examples include:
As accessories and technology evolve, applications are growing in other industries such as agriculture, food service, medical and more. With each new way of using cobot technology, the tasks that make up a person’s job will change, but there will remain aspects of the work that are not done by automation equipment. Universal Robots provides several examples of this collaborative work in action on their website, including this injection molding machine tending example on the left.
A final difference to consider between traditional industrial robots and their cobot cousins involves return on investment (ROI). Cobots are less expensive than their large-scale industrial cousins because they’re smaller and often require less technical expertise and time to install, deploy, and maintain. Many models cost under $40,000, though there will likely be additional costs for tools, accessories, or grippers for customizing it to the task at hand. Another initial investment may be the choice to work with an automation integrator to help efficiently integrate it into your manufacturing processes.
It’s possible to see the direct impact of the cobot within a period of months. For example, when a cobot increases your hourly production rate, results may include higher sales or the ability to fill larger orders. As a result, your revenue increases, which helps directly offset the cost of the new equipment and accompanying expenses. Indirect influences on ROI include reduced downtime due to worker fatigue or injury, opportunities to review existing workflows for inefficiencies, and, identifying additional work cells or departments in which to redeploy the cobot. All of these contribute to time and monetary savings and to ROI.
Collaborative robots are often billed as “inherently safe.” This usually refers to the built-in safety features most collaborative robot designs have that make them more safe than traditional factory robots. The focus is generally on how these robots can be used without caging or fencing or include rounded edges and corners.
ISO 10218 provides general information for robot designers and manufacturers in creating robots that can work safely with humans. More specific guidelines have been provided in ISO Technical Specification 15066, which was updated in 2016 to reflect the state of the art and current technology.
ISO/TS 15066 describes four major capabilities that render a robot collaborative in terms of ensuring human safety:
“One of the central ideas behind ISO/TS 15066 is that if contact between robots and humans is allowed, and incidental contact does occur, then that contact shall not result in pain or injury,” notes an article on risk assessment from Engineering.com. Part of this means defining pain and injury, as well as identifying safe maximum operating speeds, and core robot capabilities to avoid contact.
Sensors are one of the primary ways collaborative robots are able to achieve safety guidelines and capabilities. Common types of sensors include:
So are these machines truly safe? In many ways, the safety guidelines and technology described do make these robots far safer for close, regular contact with human coworkers. However, safety is also contingent on what the robot is doing. An often-cited example is a cobot with a sharp end effector like a knife. All of the latest safety features and sensors can’t change the fact that a sharp tool is a hazard.
Unfortunately, there are still many ways to be injured if application and operation are not planned and assessed carefully. This doesn’t mean cobots can’t use sharp or dangerous tools, but it does mean additional safety assessment and planning are necessary.
Robotic accessory company Robotiq suggests studying each of these when conducting a risk assessment of a particular task:
The Robotic Industries Association (RIA ) gives several detailed examples to help you understand exactly what the risks are for a task and how likely or unlikely they are. For example, as you review what the human and robot will both do in a given situation, consider risks of pinching, crushing, or pinning of a body part between the robot’s arm and wrist, between the gripper and part, between the part and fixture (the object against which the part rests or is held), or between the robot and other nearby structures (e.g. wall, movable cart, chair, table).
It’s important to look at all the components of a task, such as loading a tray. When broken down, steps might include gripping an object, lifting it, moving it a programmed number of inches by turning/rotating a set number of degrees, lowering the object, releasing it, and returning the arm or gripper to the starting point. In addition to the primary operation, consider any hazards involved in other tasks such as maintenance, cleaning, changeover, or transporting the machine.
The promise of collaborative robots and other automation is a combination of efficient production with safe, user-friendly equipment. Planned and implemented thoughtfully, they can transform your manufacturing processes. But the machines also have an impact on workers and jobs that can’t be ignored.
Currently manufacturing and other industries face a skills gap in which there are more open positions than workers qualified or willing to fill them. Main drivers include:
Robots and automation equipment can offset the skills gap to a degree by performing some of the tedious, dangerous, or unskilled tasks. It’s not hard to imagine a futuristic factory with robots at every workstation and no human beings in sight. While automation can eliminate some of the less desirable positions that go unfilled when older workers retire, it’s not a complete solution. The current reality, especially for small to medium-sized businesses, is humans and robots have a complementary working relationship.
This is partly due to production lines and work cells redesigned for robotic arms, and partly due to the type of work automation generates. Programming, engineering, and systems integration, and IT work are critical to keeping electronic automation equipment up and running. Even as artificial intelligence and machine learning work their way onto factory floors and industry 4.0 promises to take production to new levels of efficiency, humans are still very much a part of automated manufacturing. The trick is finding workers with the right skills for the jobs.
The traditionally “blue-collar” positions typical to manufacturing also start to look different as factories integrate collaborative robots. For example, skills like computer literacy or hand guiding a robotic arm through a new sequence may replace manual machine tending and simple pick-and-place tasks.
Experts disagree on exactly how many jobs might be lost completely to robotics and automation and how many will persist but with major changes. But there is agreement that manufacturing workers won’t be able to get by with just the skills they have now. Retraining current workers to program and manage computerized equipment is one of the keys to retaining employees. Likewise, students in training programs and technical schools need access to the latest technology so they have skills employers need.
If you’ve considered introducing cobots to your facility, you might see these changes in the nature of work:
It would probably be difficult to find two manufacturers using a collaborative robot in the exact same way, even for similar parts or processes. How they’re deployed for a low-volume/high-mix contract manufacturing environment differs greatly from use in a packaging facility or spray-painting department. The unique, often proprietary methods in this industry are a good match for the adaptability of cobots.
Because most cobots are small and can be equipped with a range of tools for different jobs, programmed with user-friendly interfaces, it might seem like the easiest solution is to purchase one and use as a “plug and play” piece of equipment to make some tasks more convenient. This is a viable option thanks to commercial off-the-shelf (COTS) products available from many manufacturers.
Depending on the application and if you anticipate moving it around your facility to support human workers in a number of work cells or departments, this can be an excellent option, especially when taking your first steps into automation. Just keep in mind even off-the-shelf models will still require some initial set up and selection of the proper size, end of arm tools, and other accessories.
If you’re ready to go all-in with robotics, working with a vendor to integrate cobots into your manual processes can be a great way to examine your setup as a whole system. It’s an opportunity to find areas for improvement or adjustment and make physical changes to the layout to get the most out of one or more cobots. An integrator’s expertise and experience with collaborative robots in variety of settings can be an introduction to applications you hadn’t considered, and accessories and features you didn’t realize exist.
Your workers have probably already thought “I wish I had a machine that could do this task for me.” If you haven’t already heard these musings from them, just ask. They’ll probably be able to come up with a few ideas for making their work less tedious, physically demanding, or more fulfilling.
Observe your process with an eye for what can be automated – online videos and robot vendor websites are a great way to see cobots in action and get a sense of all the things they can do. Can you picture it in your building alongside your employees? Brainstorm and have fun imagining what could be, such as:
As you perform a close review of your processes and workflows to identify areas where cobot might make a difference, trace any problems up and downstream to find root causes. These may be some of the best opportunities for automation. Things to pay attention to include:
It’s challenging to review long-standing processes, but try to observe operations with fresh eyes to identify risks that may have gone undetected. Just because you’ve always done something one way doesn’t make it the best option. Automating a process is not merely a one-to-one substitution where a machine is swapped for a human. It can include changes to the order of steps, operator tasks, materials used, and even other processes up- or downstream. Adding a cobot can alter entire processes, or even the parts being fabricated, which may be redesigned for greater efficiency, production or quality.
In general, the greatest opportunities for collaborative robots are where you need a reduction in time, labor, movements, steps, or even costs of consumables (e.g. weld wire, glue, paint, fasteners). Knowing which area is most important to reduce can help narrow the options. Or put another way, what’s the impact of not making a change in each scenario?
But what if you find a dozen potential uses for a cobot? What if you end up with more questions than answers?
Start by stating your goals for adding a robot, and be specific. Do you want to test whether a certain task can be done by a robot? Is this a test case for future additional automation in your facility? How will you quantify goals and measure success? Examples could be a 15% reduction in scrap materials, 100% fewer injury accidents, or a measurable increase in revenue tracked to production gains from automation.
Also consider available resources: time, money, training, existing workers and their abilities to learn new skills, space to rearrange and add equipment. If you’re overwhelmed with options, speaking with a reputable automation integrator can help you sort out the possible from the impracticable.
Automation is not all-or-nothing but can be combined with manual work (e.g. a robotic arm with a gripper that lifts and feeds a blank into a lathe or positions a small part to be welded by a person). You can also develop a scalable cobot plan: start by automating one simple task and build in ways to expand it’s use in other departments or work cells in the future. Most cobots can be used with a variety of grippers and tools for maximum flexibility, and they’re often quick and easy to program by hand-guiding or a straightforward HMI.
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