Method of planning free-form tool paths for simultaneous two-sided machining with kinematic axis coupling

A dental machining system comprising:

• a dental tool machine comprising;
• and
• a control means adapted to perform a method comprising;
• planning of shapes of free-form tool paths for simultaneous two-sided machining of a dental restoration having an individual free-form target geometry from a workpiece by using the dental tool machine that comprises at least two tool spindles each having at least one tool arranged on a different side of the workpiece which is simultaneously movable along a workpiece axis relative to the at least two tool spindles and thereby imposing a kinematic axis coupling, further comprising:
• computing transformations of the free-form target geometry with respect to each machining side, into a common space in which coordinates along the workpiece axis for both at least one tool of the at least two tool spindles are transformed into a common coupling parameter;
• driving all participating of the at least two tool spindles simultaneously dependent on the transformations and based upon the shapes of free-form tool paths with the common coupling parameter being identical for all the participating tool spindles at each point in time;
• and
• avoiding collision between the at least two tool spindles and connected machine parts when the at least two tool spindles move in an opposite direction or in a same direction, wherein with avoiding collision, collision-afflicted areas and collision-free areas are determined along the free-form tool paths, and the free-form tool paths are synchronized in such a way that collision-relevant of the at least two tool spindles and the connected machine parts are never moved simultaneously in the collision-afflicted areas.

A non-transitory computer-readable storage medium storing a program which, when executed by a computer system, causes the computer system to perform a method comprising:

• planning of shapes of free-form tool paths for simultaneous two-sided machining of a dental restoration having an individual free-form target geometry from a workpiece by using a dental tool machine that comprises at least two tool spindles each having at least one tool arranged on a different side of the workpiece which is simultaneously movable along a workpiece axis relative to the at least two tool spindles and thereby imposing a kinematic axis coupling, further comprising:
• computing transformations of the free-form target geometry with respect to each machining side, into a common space in which coordinates along the workpiece axis for both at least one tool of the at least two tool spindles are transformed into a common coupling parameter;
• driving all participating of the at least two tool spindles simultaneously dependent on the transformations and based upon the shapes of free-form tool paths with the common coupling parameter being identical for all the participating tool spindles at each point in time;
• and
• avoiding collision between the at least two tool spindles and connected machine parts when the at least two tool spindles move in an opposite direction or in a same direction, wherein with avoiding collision, collision-afflicted areas and collision-free areas are determined along the free-form tool paths, and the free-form tool paths are synchronized in such a way that collision-relevant of the at least two tool spindles and the connected machine parts are never moved simultaneously in the collision-afflicted areas.