Adding a cobot to manufacturing operations is about more than just a robotic arm. Use these tips to make sure you get the most from your investment.
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Would you ever buy a piece of equipment, say a new CNC machine, and leave it to collect dust in a corner of your facility instead of using it? Of course not! Equipment is a big capital investment that must be running in order to contribute to ROI.
And yet, in both large and small factories, collaborative robots (i.e., cobots) are sitting in unopened boxes instead of doing what they do best: enhancing productivity. We see this time and time again when we visit manufacturers that ask us for advice on cobot automation.
Why would a company buy a cobot but not implement it? In many cases, it comes down to a lack of time or know-how. Today’s cobots are vastly different than the industrial robots of just a couple of decades ago, but they do still require some planning and skill to get up and running.
Don’t let that deter you from adding cobots to your operations! You can set yourself up for success if you know what capabilities and features to look for in a cobot (and cobot vendor), and by anticipating the set-up tasks that go along with integrating a cobot yourself. Here are our seven tips on how to do this successfully.
1. Determine How the Cobot will Interact with its Environment
We often focus on the cobot arm, but it is really only one component of an automated workspace or cell. Before you can put it to work, answer these questions:
Where will it be located in the work area? Can you roll the cobot into the space where the employee formerly stood or does the work area need to be redesigned first?
Once the cobot is in place, does it limit employee access to the area?
If the cobot will be tending/operating a CNC machine, how will it interface with that machine? Must it be electronically integrated, or can the cobot operate physical controls (e.g., opening and closing machine doors, loading and unloading parts, or pushing the start button)?
It’s important to remember work areas are designed for human beings, whose inherent flexibility and dexterity allows for a variety of movements. Typical cobots (and industrial robots) have six joints, which make them substantially less maneuverable than a human arm and hand. In contrast, cobots like Productive Robotics' OB7 have seven axes (or joints), which give them a level of maneuverability similar to a human arm.
In general, more axes equal more flexibility and versatility: Cobots with seven axes can fit into tighter spaces, reach around, between, and through obstacles, or be located on the side of the work area, so you have more options for placement. Look for a model that won’t require the workspace to be redesigned to fit both the cobot and an employee.
2. Determine if You Really Need an Integrator
An automation integrator can be an option for implementing cobots for manufacturing; however, many cobot applications don’t require them. OB7 cobots have many built-in capabilities and features that make them nearly “plug and play” solutions for a variety of tasks. Some examples include:
Seven-axis arms for reaching around obstacles and in tighter places
Simple steps for physically “teaching” it to do its work instead of traditional programming
Built-in safety features like lower operating speeds or variable speed settings, sensors to detect a person’s presence, and surfaces that are smooth and cool to the touch
Consider that not all integrators are familiar with cobots and may treat the project like an industrial robot that requires a full-scale integration program. As a result, many of the things an integrator does, such as programming or designing safety systems, are not required for most cobot applications, if designed correctly.
Ask your cobot supplier what help they can provide, and how much each service costs, before you decide to spend additional funds on an integrator. You will probably find that by planning out the work area and choosing the right accessories, you can do the setup yourself with a little help from your cobot vendor.
3. The Importance of Staging Work Which the Cobot Will Handle
Don’t underestimate the importance of proper staging and part presentation for optimal cobot performance. While cobots are highly precise in their movements and ensure consistent repetition, they can’t discern between a part that’s oriented correctly and one that’s out of alignment.
For this reason, careful preparation and planning of staging the work that the cobot will handle are critical. Examples can include:
Lining up parts in a tray
CNC-machined contraption with moving parts
Conveyors that are aligned with chutes and trays, and running at the correct speed
Building fixtures that will hold parts in registration for the cobot is a work-holding cost many potential customers don’t realize they’ll have to incur. This is often the main reason why cobot implementations fail at the start. Being aware of this important step is critical to ensure a successful implementation. Your cobot supplier can be a great source of experience and assistance.
4. Consider Machine Vision for Simpler Implementation
One way to relieve many of the challenges and requirements of fixturing is adding a machine vision system. While machine vision systems are traditionally complex to program and have a challenging learning curve, a new generation of vision systems, such as the OB-Vision, is coming to market.
OB-Vision guides the cobot to pick up parts without the need for fixturing. There’s also no programming required. The vision system camera is integrated into the end of the robot arm and “looks” at the work area to find the parts to pick up. Instead of writing code, simply “show” the camera one sample part, push a single button, and you’re on your way.
5. Find the Right End Effector for Your Application
End effectors are fundamental to a cobot’s success. Just like you wouldn’t use a drill to drive a nail, you need to determine the best end effector (a.k.a. end-of-arm-tooling) for the application. What you use will depend entirely on the parts the cobot is handling. For example, if the cobot is painting, polishing, sanding, deburring, or tending a CNC machine, that will require a different type of end effector.
End effectors can be driven by air (i.e., pneumatic), mechanical, controlled electronically, or via vacuum with suction cups or other vacuum surfaces. It’s even possible to custom-design end effectors for highly specialized functions.
If you’re unsure which type of end effector is best for your needs, ask your cobot supplier to examine the parts and operations for which you’ll use it.
6. Expect to Refine and Optimize as You Go
Once your cobot is setup and doing its work, it’s not uncommon to make adjustments to it. Incoming parts must be staged accurately, and changes to the staging location may require adjusting the robot position to compensate. Or, components may shift slightly out of position while remaining within tolerance. Or, a change in raw materials may be more difficult for the gripper to pick up, etc.
Traditional industrial robots would require time offline for reprogramming, but a teachable cobot like OB7 is much easier and faster to adjust. It “learns” by being shown what to do and is “taught”, rather than “programmed”. Simply move the arm through the desired motions.
The benefit of this is that an engineer or programmer is not required to make basic changes to the cobot’s work instructions. Most production personnel can modify the robot’s path or movements quickly and easily. This keeps productivity high and downtime to a minimum.
7. Plan for Safe Operations
Any time robotics and automation are introduced in a manufacturing setting, a risk assessment must be made. This is to ensure a cobot can be implemented safely into the application, and to identify things that must be changed in order to keep workers safe. This includes things like:
Looking for potential points of contact/collision between people and cobot (while stationary and in motion)
Assessing the path of the moving arm compared to nearby traffic and workspaces
Allowing enough space between operators and end effectors (especially sharp ones)
Determining the likelihood of collision, pinch points, or other injuries
Determining the severity of possible injuries
Look for a cobot with built-in safety features that keeps workers safe. These may include:
Operating speeds of no more than 10 inches/second
Multiple speed settings (e.g., a slower “collaborative” speed and a faster “standard” speed)
Power and force limiting capabilities that automatically slow the arm’s speed and momentum when a person or limb is detected
Locking or password-protected controls for speed adjustments
Set Yourself Up for Success with a Supplier You Can Count On
By following the tips above, you’ll know what capabilities and features to look for in a cobot – and you’ll be prepared for the ins and outs of setting it up! It’s critical to find a supplier you can count on for suggestions and help when you need it. At Productive Robotics, we have the experience and skills that can save you time and money – please contact us!