Collaborative robots enable direct collaboration between humans and machines. These tasks may include tasks that neither humans nor robots could accomplish independently. The instant success of these robots in a wide range of industrial applications spurred rapid product innovation that resulted in different types.
Programming and safety features or how they steer clear of potentially dangerous encounters with their human co-workers defines the different types of collaborative robots. Each collaborative robot uses unique technologies to maintain a safe operating distance. The differences also determine which applications the robot is best suited for.
In addition to the different safety features, collaborative robots are available in various lengths and sizes. These differences make them ideal for varying applications within a manufacturing or industrial setup. Collaborative robots were designed to be flexible in application, allowing them to imitate human movements and perform duties similar to a human being.
According to ISO 10218, there are four types of collaborative robots; power and force limiting, safety monitored stop, speed and automation, and hand guiding.
- Power and Force Limiting
The Power and Force Limiting is the most common type of collaborative robot in robotics and automation. These robots have rounded corners with no sharp edges because they are designed to work alongside human workers without additional safety devices such as barriers, vision systems, and external scanners. They also don’t have exposed motors and pinch points, enhancing human safety.
These collaborative robots have inbuilt intelligent collision sensors that immediately halt operations once they detect contact with a human co-worker. They are generally less powerful, smaller, and slower than traditional robots but more flexible.
Power and Force Limiting robots are best suited for dull, dirty, and dangerous tasks. They are ideal for tasks where danger is ergonomic, such as repetitive tasks that can cause strain on human workers.
Since they are the predominant type of collaborative robots in industrial applications, they are classified into four major categories based on their safety functionalities.
Joint Sensing
Collaborative robots with Joint Sensing are named for their unique feature. They use their joints to monitor forces applied to their body. These robots use force-torque sensors in their joints to sense motion.
Skin Sensing
Though it may be the safest collaborative robot, this Power and Force Limiting robot subgroup are the least produced. A skin sensing robot uses tactical sensing to detect any impact that may come its way. It uses sensor monitors to look out for its body and sends out commands to stop any motion even before impact. This technology makes it certainly safer but more complex.
Force Sensor Base
Force Sensor Base robots are similar to Joint Sensing, except their force-torque sensors are located at the robot’s base. This feature finds its application in manufacturing tasks that require a higher payload with good sensitivity to work alongside humans.
Adjusting this collaborative robot to meet your industrial needs makes it a better model in comparison to Joint Sensing robots. In addition, it is more precise and safer.
Inherently Safe
Manufacturers refer to this kind of collaborative robot as “inherently safe” because it cannot harm users in any possible way. This kind of Power and Force Limiting robot handles low payloads, which reduces the likelihood of any type of injury.
- Safety Monitored Stop
The Safety Monitored Stop robot is suitable for industrial applications that need assistance with minimal human interaction. This collaborative robot uses the traditional industrial robot injunction with various safety sensors.
As a result, the robot will stop what it is doing when a human gets in close proximity to the robot’s work area or zone. It does so to allow a human co-worker to perform their task. After the human worker completes their tasks, they can resume the robot’s operation with a push of a button.
- Speed and Separation
This collaborative robot has similar features to the Safety Monitored Stop robot. It also uses the traditional industrial robot injunction. However, it has more advanced features that allow human-to-robot interaction.
A vision system constantly monitors its zone of operations and has two zones, the warning zone, and the stop zone. The vision system slows down the robot to a safe speed when it detects motion in a “warning zone” proximity. When a human oversteps into the “stop zone,” the robot immediately stops operation and resumes after the employee exits.
Most of these collaborative robots have attached vision systems for concise and clear operations. They could also have in-built vision systems that cut costs on additional installments.
One of the most common applications of speed and separation robots is in picking, packing, and sorting.
- Hand Guiding
As the name suggests, this robot comes with a hand-guide feature that allows the operator to directly controls the robot’s motion.
The programmer can teach the robot by guiding it with their hand through the tasks it is supposed to perform. The feature makes it simple to reprogram the robot without re-coding its software. Users can teach this collaborative robot quickly, thus minimizing downtime.
While in automatic mode, the robot responds only to the direct control unit of the operator. This enables the robot, for example, to hold the weight of a heavy item while the operator adjusts it into position. The robot reduces the operator’s exposure to repetitive stress injury by supporting the weight.
Since Hand Guiding robots are easy and quick to reprogram, they find their applications in a high-mix, low-volume environment such as a job shop. You can easily set up these robots for tasks such as welding. Inspection is another good task for a hand-guided robot. The robot can easily pick an item in the inspection process while the operator uses hand guidance to inspect all the items’ sides visually.
Conclusion
Collaborative robots have been an important development in the robotics and automation industry. It is the first technological innovation that allows robots to work alongside their human co-workers safely. These four types of collaborative robots came up relatively quickly, and perhaps more are likely to come up as the industry matures.