As we move into a future with more and more robots being used in increasingly automated manufacturing environments, safety needs to be a primary consideration.
Currently the primary method for keeping personnel safe from industrial robots is barrier guarding. This method keeps personnel and robots physically separated while the robot is in operation with either a physical barrier or a barrier device that shuts down a robot whenever a person enters the robots working area.
Types of Barrier Guarding
OSHA currently defines 4 types of barrier guarding:
Interlocked Barrier Guard
Interlocked barrier guarding is the most typical type of guarding used in an industrial setting. The guarding fully encircles the robot restricting all human access to the work cell, but often has holes for product carried on conveyors to enter and leave the work cell. The guarding is designed with interlocks, or safety switches, connected to gates such that whenever a gate is opened the robot is shut down.
Fixed Barrier Guard
Similar to an interlocked barrier guard, the fixed barrier guard prevents a worker from entering a robotic work cell using a physical barrier. However, in order to enter a fixed barrier guarded work cell the barrier must be opened using tools.
Awareness Barrier Device
An awareness barrier is a device such as a chain or low railing that, while preventing inadvertent entry to a robotic work cell, can be climbed over or crawled under. These types of devices are only acceptable when the risk is minimal and a barrier guard is not feasible.
Presence Sensing Devices
Presence sending devices detect the presence of personnel using sensors such as floor mats or light curtains. When someone is detected breaking these barriers the robot is shut down similar to how a interlock operates when a barrier gate is opened.
The Barrier Free Future
A new area of development in robotics on the industrial floor is barrier or cage free robotics. New types of sensors are allowing robots such as Baxter to work in an uncaged area alongside human personnel. To create a safe working environment new types of technologies are being put to use.
These sensors detect when force is applied to a robotic arm or tool the same way a human can tell when they are touching an object with their hand. Using these sensors a robot can be made to quickly stop when an unknown object such as a human is contacted.
Using new breakthroughs in visual recognition software, robots can be made aware of the world around them using visual sensors such as cameras. The software can take the footage from the camera and interpret the information to tell robots where other equipment and personnel are present.
Combining the data from the visual and force sensors, new developments in artificial intelligence can bridge the gap allowing robots to determine unsafe operating conditions and have them respond accordingly.
Robots are moving into a future where they work more closely with humans on and off the factory floor. It's up to us to make sure its a safe future as well.