Method and apparatus for detecting and correcting a spatial position of a workpiece held in a positioning device

An apparatus for detecting and correcting a spatial position of a workpiece held in a positioning device by a machining head having at least one first positioning device for positioning a first workpiece, the positioning device adjusting orientation and placement of the workpiece, at least one machining head having at least one sensor for distance measurement and position sensing device sensing a current position of the at least one machining head and also a controller for changing the current position of the at least one machining head and/or of the workpiece in a controlled manner, the controller being configured such that the following steps take place as a result of action of the controller:

• partially infeeding the at least one machining head to at least two measuring positions;
• adjusting, via the positioning device, orientation and placement of the workpiece;
• contactlessly sensing an actual position, via a measured point on the workpiece, of the positioned workpiece at the at least two measuring positions by using the at least one sensor of the at least one machining head, the at least two measured points lying on a virtual measuring axis which runs along a surface of the workpiece, and determining from the sensed actual positions, an angular position of the virtual measuring axis with respect to a virtual reference axis;
• comparing the sensed actual position with an expected desired position and ascertaining deviation values between the actual position and the expected desired position;
• comparing the ascertained deviation values with an admissible tolerance value, the ascertained deviations being a first deviation in distance values between the actual position and the desired position and a second deviation in the angular position,
• infeeding the machining head to a contour along which the workpiece is to be machined by the machining head when the ascertained deviation lies within a range of admissible tolerance values;
• and
• when the ascertained deviation is not within the range of admissible tolerance values, aligning the machining head and the workpiece in relation to one another and in relation to the one contour in such a way that after the alignment the first deviation of the actual position lies within the range of admissible tolerance values.