Method for operating a coordinate measuring machine

A method for operating a coordinate measuring machine (CMM) including a CMM control system, a surface scanning probe that measures a workpiece surface by outputting probe workpiece measurements, and a probe measurement timing subsystem, the method comprising:

• operating the CMM control system to output measurement synchronization trigger signals at predictable times;
• operating the probe measurement timing subsystem to determine the predictable times;
• operating the CMM to define a first probe workpiece measurement sample period that has a first sampling duration that is relatively shorter than a second sampling duration and that provides a faster type of probe workpiece measurement that has a first level of accuracy;
• operating the CMM to define a second probe workpiece measurement sample period that has a second sampling duration that is relatively longer than the first sampling duration and that provides a slower type of probe workpiece measurement that has a second level of accuracy that is better than the first level of accuracy;
• and
• operating the CMM to perform of set of measurement operations including the first and second probe workpiece measurement sample periods, the set of measurement operations comprising:
• initiating a current instance of the first probe workpiece measurement sample period at a first measurement lead time before a first measurement synchronization trigger signal and within a low-latency time window close to the first measurement synchronization trigger signal, wherein the first measurement synchronization trigger signal occurs at the next predictable time of the measurement synchronization trigger signals;
• operating the CMM control system to output the first measurement synchronization trigger signal at the next predictable time and latch a first set of CMM position coordinate values associated with the first measurement synchronization trigger signal;
• operating the surface scanning probe to output a current instance of the faster type of probe workpiece measurement associated with the current instance of a first probe workpiece measurement sample period, at a first output time that is associated with the first measurement synchronization trigger signal and that ends within the low-latency time window close to the first measurement synchronization trigger signal;
• initiating a current instance of the second probe workpiece measurement sample period at a second measurement time that is different than the first measurement lead time and that is defined relative to the first measurement synchronization trigger signal,
• operating the surface scanning probe to output a current instance of the slower type of probe workpiece measurement associated with the current instance of the second probe workpiece measurement sample period, at a second output time that is associated with the first measurement synchronization trigger signal, wherein the second output time occurs after the first output time;
• and
• operating the CMM control system to associate the current instance of the slower type of probe workpiece measurement with a properly combinable set of CMM position coordinate values that are determined based at least partially on the first set of CMM position coordinate values associated with the first measurement synchronization trigger signal.

A method for operating a coordinate measuring machine (CMM) including a CMM control system, a surface scanning probe that measures a workpiece surface by outputting probe workpiece measurements, and a probe measurement timing subsystem, the method comprising:

• operating the CMM control system to output measurement synchronization trigger signals at predictable times;
• operating the probe measurement timing subsystem to determine the predictable times;
• operating the CMM to define a first probe workpiece measurement sample period that has a first sampling duration that is relatively shorter than a second sampling duration, and that provides a faster type of probe workpiece measurement that has a first level of accuracy;
• operating the CMM to define a second probe workpiece measurement sample period that has a second sampling duration that is relatively longer than the first sampling duration, and that provides a slower type of probe workpiece measurement that has a second level of accuracy that is better than the first level of accuracy;
• and
• operating the CMM to perform of set of measurement operations including the first and second probe workpiece measurement sample periods, the set of measurement operations comprising:
• initiating a current instance of the first probe workpiece measurement sample period at a first measurement lead time before a first measurement synchronization trigger signal and within a low-latency time window close to the first measurement synchronization trigger signal, wherein the first measurement synchronization trigger signal occurs at the next predictable time of the measurement synchronization trigger signals;
• operating the CMM control system to output the first measurement synchronization trigger signal at the next predictable time and latch a first set of CMM position coordinate values associated with the first measurement synchronization trigger signal;
• operating the surface scanning probe to output a current instance of the faster type of probe workpiece measurement associated with the current instance of a first probe workpiece measurement sample period, at a first output time that is associated with the first measurement synchronization trigger signal and that ends within the low-latency time window close to the first measurement synchronization trigger signal;
• initiating a current instance of the second probe workpiece measurement sample period at a second measurement time that is defined relative its corresponding operative measurement synchronization trigger signal, wherein the corresponding operative measurement synchronization trigger signal is a second measurement synchronization trigger signal that occurs subsequent to the first measurement synchronization trigger signal,
• operating the CMM control system to output the second measurement synchronization trigger signal and latch a second set of CMM position coordinate values associated with the second measurement synchronization trigger signal;
• operating the surface scanning probe to output a current instance of the slower type of probe workpiece measurement associated with the current instance of the second probe workpiece measurement sample period, at a second output time that is associated with the second measurement synchronization trigger signal;
• and
• operating the CMM control system to associate the current instance of the slower type of probe workpiece measurement with a properly combinable set of CMM position coordinate values that are determined based at least partially on the second set of CMM position coordinate values associated with the second measurement synchronization trigger signal.