Method and apparatus for numerically controlled pattern determination

A method of determining whether a pattern having a plurality of features is within an acceptable tolerance, said method comprising the steps of:

• inputting an ideal position for each of the plurality of features;
• storing the ideal position for each of the plurality of features;
• measuring a position of each of the plurality of features;
• storing said measured position of each of the plurality of features forming the pattern;
• calculating an angle of variation between said measured position and the ideal position of each of the features by taking the angular difference between a line segment connecting the ideal position of two of the plurality of features and a line segment connecting the respective measured position of the plurality of features;
• offsetting said stored ideal position of each of the plurality of features by the angle of variation to create a new set of data representing an adjusted ideal position of each of the plurality of features;
• comparing said stored measured position of each of the plurality of features with said respective adjusted ideal position of each of the plurality of features;
• and
• determining whether said stored measured position of each of the plurality of features falls within the acceptable tolerance of each of the respective adjusted ideal position of each of the plurality of features and recording when said measured position falls outside of the acceptable tolerance.

A method of machining a desired pattern into a component and then probing the component to determine if the machined pattern on the component is within an acceptable tolerance of the desired pattern using an NC machining system having an input device, machining attachments, a probing device and a processor, said method comprising the steps of:

• inputting an ideal position and dimensions of each of a plurality of features of the desired pattern into the input device;
• machining each of the plurality of features into the component with the machining attachments in accordance with the position and dimensions of each of the plurality of features to form the desired pattern;
• probing each of the plurality of features machined into the component to acquire a measured position of each of the plurality of features forming the machined pattern on the component;
• storing the measured position of each of the plurality of features forming the machined pattern;
• aligning the ideal position of each of the plurality of features of the desired pattern with the stored measured position of each of the plurality of features of the machined pattern to form an aligned ideal pattern;
• and
• comparing the machined pattern and the aligned ideal pattern to determine if the machined pattern is within the acceptable tolerance.

A pattern measurement method for comparing a measured pattern with an ideal pattern that includes a position of a plurality of ideal features stored within a memory array to determine if the measured pattern is within an acceptable tolerance, said method including the steps of:

• detecting the existence of the measured pattern within a plurality of measured features;
• storing a position of each of the measured features forming the measured pattern in the memory array;
• calculating an angular difference between a measured vector defined by the position of two of the measured features and an ideal vector defined by the position of two features of the plurality of ideal features that correspond to the two measured features;
• shifting the position of each of the plurality of ideal features forming the ideal pattern such that a position of a selected one of the measured features overlaps the position of a corresponding one of the plurality of ideal features;
• rotating the position of each of the plurality of shifted ideal features forming the ideal pattern about the position of the selected one of the ideal features by the angular difference to a new position;
• comparing the position of each of the measured features with the new position of a corresponding one of the plurality of shifted and rotated ideal features;
• and
• flagging the measured features that have a position that deviates from the new position of the corresponding shifted and rotated ideal features by more than a specified tolerance.

A method for using an NC device equipped with a probe and a central processing unit having a memory to determine whether each hole in a pattern of holes in a workpiece is within a specified tolerance;

• said method comprising the steps of:
• measuring a plurality of holes in the workpiece with the probe to determine a centerpoint of each of the plurality of holes;
• detecting at least one of the pattern of holes in the workpiece;
• storing a set of data in the memory consisting of the measured centerpoint location of each of the holes within the pattern of holes that was identified in said step of detecting at least one of the pattern of the holes in the workpiece;
• storing a set of data in the memory consisting of a desired ideal centerpoint location of each of the holes within the pattern of holes in the workpiece that was identified in said step of detecting at least one of the pattern of holes in the workpiece;
• processing the set of data that includes the desired ideal centerpoint location of each hole in the pattern stored in the memory to form an adjusted set of data that includes adjusted ideal centerpoint locations for each hole in the desired pattern, and retains the same relative relationship of each hole as in the desired ideal pattern, yet is numerically offset to match the measured centerpoint location of each of the holes in the pattern of holes stored in the memory;
• and
• comparing the measured centerpoint of each of the holes in the pattern with the adjusted ideal centerpoint locations to determine if all the measured holes with the pattern are within the specified tolerance.

A method of determining whether a measured pattern of features is within a specified tolerance of a desired ideal pattern of the features, said method including the steps of:

• storing a position of measured features that form the measured pattern in a memory array;
• storing a position of ideal features that form the ideal pattern in the memory array;
• shifting the position of the ideal pattern of features in the memory array numerically, such that the position of a designated one of the ideal features overlaps the position of a corresponding one of the measured features;
• calculating an angular difference between an ideal vector between the designated one of the ideal features and another ideal feature and a measured vector between measured features corresponding to the designated one of the ideal features and the another ideal feature;
• rotating the position of the shifted ideal pattern of features numerically by the angular difference to yield an adjusted pattern of features;
• and
• comparing the position of each of the measured features that forms the measured pattern with the position of the corresponding features that form the adjusted pattern of features to determine whether the measured pattern of features is within the specified tolerance of the desired ideal pattern of the features.

An apparatus for determining whether a pattern of holes in a workpiece is within a predetermined tolerance, said apparatus comprising:

• a numerically controlled device including:
• a probe which takes samples of an edge of each hole that forms the pattern of holes;
• and
• encoders which indicate a position of said probe for each of the samples;
• a remote central processing unit including a memory array, said central processing unit electrically coupled to said numerically controlled device, said processing unit performing the operations of:
• calculating a measured centerpoint of each of the holes that form the pattern using the position of the samples indicated by said encoders;
• storing the measured centerpoint of each of the holes that form the pattern of holes numerically in the memory array along with an ideal centerpoint numerical value corresponding to each measured centerpoint;
• translating the numerical value of each ideal centerpoint in said memory array such that the numerical value of a designated ideal centerpoint is identical to a corresponding measured centerpoint;
• calculating an angular difference between an ideal vector between the designated ideal centerpoint and another ideal centerpoint and a measured vector corresponding to the ideal vector between the designated ideal centerpoint and the another ideal centerpoint;
• rotating the shifted ideal centerpoint of each of the holes in the pattern numerically by the angular difference to a numerically adjusted centerpoint;
• and
• comparing the measured centerpoint of each of the holes in the pattern with a corresponding numerically adjusted centerpoint to determine whether the measured pattern of holes is within the predetermined tolerance.