A method for monitoring a payload-handling robot assembly having at least one robot includes identifying a robot-handled payload arrangement on the basis of a current position of the robot assembly relative to a specified change position of the robot assembly. In another aspect, a robot assembly includes at least one robot, a monitoring apparatus configured to determine a current position of the robot assembly and to identify a robot-handled payload arrangement on the basis of the current position of the robot assembly relative to a specified change position of the robot assembly, and a payload receptacle for receiving a plurality of different payloads. The robot is configured for handling the plurality of payloads in an alternating manner.

A tool replacement apparatus according to the present invention includes: a turning tool magazine capable of attaching or removing a tool to/from a spindle of a machine tool; a tool replacement control unit which controls operations of turning the tool magazine and attaching or removing a tool to/from a spindle; and a setting unit which sets a rotatable range of the tool magazine. The tool replacement control unit includes: a determining unit which determines whether or not a designated rotation angle in an instruction for turning the tool magazine is within the rotatable range set by the setting unit; and a unit which stops an operation of replacing a tool when the determining unit determines that a designated rotation angle is out of a rotatable range.

A tool replacement apparatus according to the present invention includes: a turning tool magazine capable of attaching or removing a tool to/from a spindle of a machine tool; a tool replacement control unit which controls operations of turning the tool magazine and attaching or removing a tool to/from a spindle; and a setting unit which sets a rotatable range of the tool magazine. The tool replacement control unit includes: a determining unit which determines whether or not a designated rotation angle in an instruction for turning the tool magazine is within the rotatable range set by the setting unit; and a unit which stops an operation of replacing a tool when the determining unit determines that a designated rotation angle is out of a rotatable range.