Industrial Robot Safety
The power and size of a traditional industrial robot means that they can be dangerous if programmed incorrectly or used in an unsafe manner without the necessary guarding in place. Due to the mass and high speeds of industrial robots, it is always unsafe for a human to remain in the work area of the robot during automatic operation. Safety for industrial robots is mainly about isolating personnel from the robots work envelope and ensuring the movement can be easily stopped in an emergency.
Today’s industrial robots range from lightweight benchtop units to large machines powerful enough to manipulate objects weighing 1000kg. Clearly the risk depends very much on the particular robot and its application, so the starting point for safeguarding a robot cell will always be a risk assessment. With this in mind safety should always be considered during the early planning of a robotic application.
Physical perimeter guards are the standard for ensuring robot safety, though light guards, laser area scanners and pressure-sensitive mats can be appropriate for use. Other types of guarding that are occasionally adopted include camera-based system and roller shutter doors.
Collaborative Robot Safety
The advantage of using a collaborative robot is that these robots need minimal or no external safety devices to be sure that the application is safe for the workers. In other words, the robot and all its tools can be fully safe for the workers and the need for traditional guarding is not required.
Collaborative robots, or cobots, are designed to work alongside humans to perform tasks simultaneously; this is a new era for robotics. Collaborative robots are power and force limited robots meaning that they are equipped with force sensing. This means that in any situation they can feel an abnormal force and stop their motion immediately. Although these robots can still not avoid a crash, they can reduce its impact and avoid certain types of incidents, like crushing accidents.
However, it is still important to carry out certain assessments to ensure the entire robotic cell is safe, for example if the robot has a sharp object as part of its end-of-arm-tooling it can still be considered dangerous for close proximity users.