Integrating Cobots into Manufacturing
Cobots help manufacturers deal with challenges like labor shortages and cost increases. Deploying cobots in manufacturing leverages the skills of the people in the factory so they can do more. Cobots are still a relatively new technology though, so here’s an introduction to the machines and the benefits of using them.
“Cobot” is short for “collaborative robot.” These are five and even six axis arms like the industrial robots most people are familiar with, but they have a significant difference: a cobot can work safely alongside human workers.
Traditional robots are powerful, fast-moving machines. In addition, unlike the motions of a machine tool, it’s not always obvious where the arm is going to move. These characteristics make robots hazardous to be around, so they need elaborate safety devices and cages.
A cobot has technology that eliminates the risk to humans. In most cases this is done by limiting the power and force the robot can use as it moves. It may also have sensors to detect when it has touched an obstruction. Some even use cameras and other sensors to detect proximity to human workers.
The Role of Cobots in Manufacturing
Cobots are ideal for material handling, assembly, dispensing and inspection jobs. They can open and close guards and load and unload machines. They can lift and place small parts or items, they can apply sealants or adhesives and they can carry cameras or other sensors.
The safety of a cobot is related to the task it’s used for, particularly if it carries a tool. While the cobot won’t hurt someone who gets too close it’s still possible for something like a knife blade or abrasive wheel to cause an injury. For this reason every cobot application should be subjected to a risk assessment.
Eliminating the need for safety guarding means a cobot can be deployed faster and with less expense than a traditional robot. This means they can be used for relatively short production runs, then moved elsewhere in the factory and given a different task.
Types of Cobot
The ISO 10218 safety standard for industrial robots defines four types, distinguished by how they achieve safe operation. These are:
- Safety Monitored Stop – where sensors detect a human coming too close
- Speed and Separation – use cameras to measure human proximity and slow or stop the robot as appropriate
- Power and Force Limiting – lower powered machines with collision detectors and rapid responses
- Hand Guided – where the arm is directly steered by a human
The first two types on this list are generally large and powerful machines of the traditional robot type. This makes them expensive to buy and implement, even though they don’t need guards.
Power and force limited machines are those most often thought of as cobots. These are less rigid than the traditional machines and have a lower maximum payload. Their positional repeatability is usually a little lower too. Techman robots exemplify this approach to collaboration.
Hand guided cobots are useful for bearing the weight of a heavy tool and for removing operator shake. They will reduce fatigue and the risk of injury while improving quality. What they won’t do is free up the worker for additional tasks.
When selecting a robot, consider how the motion paths will be programmed. An important advantage of power and force limited cobots is their ease of programming. This entails physically moving the arm to where it needs to be and storing each position. Techman robots supplement this with a graphical, flow chart representation of the saved points, along with any programmed delays necessary.
With this approach no specialist skills are needed while the flow chart facilitates program editing if needed. In addition, the program is easily proven out at full speed. In contrast, traditional robots need a skilled programmer and prove-out must be conducted at low speeds and with great care.
Impacts and Benefits of Cobots
Any sequence of repetitive movements performed over short distances may be a good application. Machine tending and loading and unloading are good examples.
Assigning tasks like these to a cobot frees up a human worker for other, more complex tasks. This might include inspection, tending other machines or processes, or analyzing performance and identifying improvement opportunities. Cobot users report many benefits from their machines, including:
- Higher labor productivity
- Increased machine utilization
- Higher output rates
- Improved quality
- Short payback/good ROI
- No expert programmer needed
- Lower operator fatigue
- Increased operator job satisfaction
Identifying Potential Cobot Applications
If you’d like to explore the potential for cobots in your manufacturing operation, JHFoster can help. Contact us to arrange a consultation with one of our robotics applications specialists.
Collaborative robots are an ideal co-worker and they can work at peak efficiency. To learn just how cost-effective this solution could be, calculate your ROI.