In implementing a robot cell one of the major considerations must be the safety of operators and people working in the area. Modern robots are almost silent in operation and very fast. They can also be unpredictable to the inexperienced as they often have pauses built into their programs where they are waiting for something else to occur. This can appear to the uninitiated that the robot is deactivated where in fact it could continue at any time.
The only acceptable way to make robots safe is to exclude people from the robot working area. This is achieved by the use of safety fences, light curtains and doors with interlock switches. For the purpose of programming the robot the operator needs to be able to run the
robot while being within the cell. This is allowed but only with the robot running at a reduced speed and with the operator holding the dead mans handle on the teach pendant. The cost of making robot cells safe can be considerable and is generally between twenty and fifty percent of the overall cost of the cell. This can make a large difference to the cost justification for a project.
Apart form the safety of humans much can be done to ensure the safety of the equipment. Sensors can be used to ensure that components are present and loaded correctly or that tooling is operating properly. Collision sensors can be placed between the robot arm and the endeffector so that if excessive force is applied to the tool the robot arm will stop.