CMM Uncertainty Estimation for Variable Stylus Offset and Temperature
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating measurement uncertainty in coordinate measuring machines (CMMs) are inaccurate when the ram axis stylus tip offset or ambient temperature deviates from the values specified in product specifications, leading to discrepancies between calculated and actual measurement errors.
Innovation Solution
A method and program for CMMs to acquire and calculate variable values under different measurement conditions, such as stylus tip offset and temperature variations, to estimate measurement uncertainty accurately by interpolating or extrapolating from stored values, improving estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the maximum permissible length measurement error is calculated using the function described in Non-Patent Document 1 with predetermined measurement condition values, then the calculation is simple and follows product specifications, but the estimation accuracy of measurement uncertainty decreases when the actual measurement conditions (ram axis stylus tip offset, ambient temperature) differ from the specified values
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing maximum permissible length measurement error values for multiple measurement condition values (ram axis stylus tip offset, ambient temperature) in a lookup table during the product specification phase. This allows the system to quickly retrieve and interpolate appropriate values during actual measurements without performing complex real-time calculations, thereby improving estimation accuracy while maintaining operational simplicity
Solution Approach 2:
The patent implements parameter changes by introducing multiple measurement condition parameters (ram axis stylus tip offset, ambient temperature) and their corresponding variable values into the uncertainty estimation function. Instead of using a single fixed function with predetermined values, the system dynamically selects and interpolates values based on actual measurement conditions, allowing the estimation to adapt to varying parameters and improve accuracy across different operating scenarios
2Adaptability or versatility
If the measurement condition values (ram axis stylus tip offset, ambient temperature) are kept at predetermined specification values, then the uncertainty estimation is straightforward, but the method becomes inapplicable when actual measurement conditions deviate from specifications
Solution Approach 1:
The patent applies dynamics by making the uncertainty estimation method adaptive to changing measurement conditions. The system dynamically selects measurement condition values from a range of pre-stored values based on actual operating conditions (ram axis stylus tip offset, ambient temperature) and performs interpolation to determine the appropriate maximum permissible length measurement error. This dynamic adaptation allows the method to remain accurate across varying conditions rather than being fixed to predetermined values
Solution Approach 2:
The patent uses preliminary action by pre-computing and storing multiple sets of variable values corresponding to different measurement condition values in a lookup table during product specification. This preliminary preparation enables the system to handle diverse actual measurement conditions during operation by retrieving and interpolating from the pre-stored data, rather than requiring complex real-time calculations or re-specification
Data Source
AI summary
An uncertainty estimation method including: acquiring first variable values, which are a plurality of variable values included in a function indicating a relationship between a measurement dimension and a maximum permissible length measurement error when a predetermined measurement condition value of a coordinate measuring machine is a first value, and second variable values, which are the plurality of variable values occurring when the measurement condition value is a second value; calculating a maximum permissible length measurement error corresponding to a third value by calculating the variable values occurring when the measurement condition value is the third value on the basis of the plurality of first variable values and the plurality of second variable values; and estimating the measurement uncertainty of the coordinate measuring machine on the basis of the calculated maximum permissible length measurement error.