Over the years, robotic welding has been utilized in various industries to increase productivity by automating production and ensuring consistent quality. Traditionally, robotic welders required large investments in equipment and in personnel training.
Why Robotic Welding?
Some of the reasons for using robotic welding are as follows:
- Production automation
- Cost reduction
- Quality improvement (consistency and repeatability)
- Improved health and safety (personnel are not exposed to hazardous fumes or radiation)
- Address shortage of skilled welders (an operator is required—not a welder)
- Increased flexibility (versus hard automation)
- Efficiency improvements
- Reduce repetitive strain injuries
However, there are some disadvantages with traditional robotic welding:
- High overall investment to implement (robot, controls, power source, jig/fixture, and safety fence/equipment)
- Specialized programming skills required
- Large space requirements
The above disadvantages restrict where robots can be used. Collaborative robots (cobots) have been introduced to address some of the limitations of traditional robots.
The Difference Between Cobots and Robots
Robots can seriously hurt people who get in the way of their movements. Since many robots move quickly, extensive safety measures are required to ensure that people and robots are separated when a robot is in operation. Contrary to this, cobots, if obstructed, will stop because of built-in safety features. Therefore, they do not require extensive protection infrastructure. This allows the operator to be close to the cobot when it is active and share the same space as required.
Safety of Cobots
The international standard ISO 10218 governs the safety requirements of cobots. Further guidance specific to the safety requirements of cobots is provided by technical specification ISO/TS 15066. According to this document, a cobot can achieve safe operation with personnel present in the cobot zone by using one or more of the following technologies:
- Safety-related monitored stop (cobot detects the worker and stops)
- Hand-guided control (operator can hold the cobot and guide it through the work)
- Speed and separation monitoring (sensor detects the distance between the cobot and the operator; cobot adjusts speeds accordingly)
- Power and force limiting by inherent design and control (when the co-worker touches the cobot, the cobot stops safely)
Cobots generally have a lower payload capacity than traditional robots, but this poses no issues because the welding gun is light. Moreover, the cable feed equipment does not need to be located on the robot and can be stationary. The speed of movements with cobots are generally slower than with robots. This ensures that personnel in the vicinity are kept safe. These characteristics make cobots more suitable than traditional robots for light applications.
Why Cobots?
Cobots offer several benefits:
- Higher flexibility than traditional robots
- Quick way to address welder shortages
- Lower overall investment to implement
- Easy programming and simulation (generally point-to-point teach programming)
- Economic setup for low-volume work
- Easy to relocate
- Compact cell layout (less space required)
- Considerations for implementing cobots for welding include the following:
- Type of power source, which depends on the welding type (e.g., MIG, spot welding, stud welding)
- Programming system
- Cobot physical dimensions (reach) and performance capabilities (e.g., speed/acceleration, payload)
- Cell layout
- End effector design
- Communications protocols
- Risk assessment and controls
How to Get Starte with Cobot Welders
When hiring cobot systems, all of the above considerations and selections have already been taken care of. The client can get straight to the work at hand, with no installation costs, and pay only for the time the system is being used.
Looking to get your feet wet? Red-D-Arc offers a turnkey collaborative welding system: BotX.
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