A robot system includes: a recognition means that recognizes an operator in distance image data as a security surveillance target; an area setting means that sets, in the distance image data, a common work area that a robot and the operator are allowed to enter; and a boundary setting means that sets, in the distance image data, a first boundary that the operator S is allowed to cross for entering the common work area but the robot is not allowed to cross, and a second boundary that the robot is allowed to cross for entering the common work area but the operator is not allowed to cross, wherein the crossing of the second boundary by the security surveillance target and the crossing of the first boundary by a non-target object not recognized as the security surveillance target are detected.

A robot system includes: a recognition means that recognizes an operator in distance image data as a security surveillance target; an area setting means that sets, in the distance image data, a common work area that a robot and the operator are allowed to enter; and a boundary setting means that sets, in the distance image data, a first boundary that the operator S is allowed to cross for entering the common work area but the robot is not allowed to cross, and a second boundary that the robot is allowed to cross for entering the common work area but the operator is not allowed to cross, wherein the crossing of the second boundary by the security surveillance target and the crossing of the first boundary by a non-target object not recognized as the security surveillance target are detected.

Safety and/or reliability may he improved in industrial control systems by optimally utilizing integrated circuit elements to reduce the amount of components required and to provide cross monitoring. In one aspect, circuitry that is part of an Integrated Circuit (IC) for controlling a first channel may also be used to monitor and provide safe operation for circuitry for controlling a second channel, and the circuitry for controlling the second channel may similarly be used to monitor and provide safe operation for the circuitry controlling the first channel. Circuitry may include a windowed watchdog circuit which may be used to monitor various events of the other circuitry, and safe operation may be provided by removing power from the other circuitry to provide a safe state.