Inspection can be considered in a variety of ways.

Firstly, robotic technology has branched out in a specialised way to establish an industry which is dedicated to metrology. The CMM (Co-ordinate Measuring Machine) was designed to fulfill this task in a manual, semi-automatic or automated mode. This machine is accurate rather than repeatable and lends itself to the linear axis configuration. It exists solely to inspect and confirm dimensional accuracy of manufactured components.

In a mass production environment, a dedicated inspection station can be designed and built to carry out a very accurate check of dimensional conformity, 'in process'. This may be possible in-line or prehaps could constitute a robot transfer during a load/unload cycle of a machining centre or similar machine tool.

Although a robot has an inherent inaccuracy it is extremely repeatable. In the region of +/- 0.02mm can ensure that, when used with perhaps a probe station, dimensional checks of quite a high order can be carried out, simply by using the robot to manipulate the part.

Finally, another type of inspection is possible during the robot cycle. In an application like die casting, when a part has been removed from the dies, the robot can manipulate the part at a non contact sensor station to confirm that nothing has been left behind and that the part is incomplete. This prevents the machine cycling again if the robot does not confirm ok to proceed. A simple handshake with the sensor and the ability to react and branch in a program is all that is needed to carry out this 'in cycle' check. Cycle time must of course be sufficient to make this approach possible as otherwise, checking will generate lost time and production.

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