Surface Shape Measuring Device Misalignment Calculation
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Solution Overview
Problem
Existing surface shape measuring devices face challenges in achieving high precision and reproducibility, especially when measuring imperfectly circular objects or those with low roundness, due to complications in misalignment calculations and errors caused by reference workpiece abrasion.
Innovation Solution
A surface shape measuring method and device that acquire and collate shape data from opposite sides of the workpiece during rotation, calculating shape parameters like diameter by averaging data and performing phase inversion to determine misalignment, allowing for precise measurement without relying on high-precision reference workpieces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration with a reference workpiece is performed to determine the distance from rotational center to detection point, then measurement accuracy is improved, but measurement reproducibility deteriorates due to reference workpiece abrasion over time
Solution Approach 1:
The invention replaces the physical reference workpiece with a virtual reference circle stored in memory. The reference circle data is created once from a master workpiece and then reused indefinitely without physical contact, eliminating wear and ensuring consistent reference measurements across multiple calibration cycles
Solution Approach 2:
The mechanical reference workpiece is replaced with an electronic data storage system. Instead of physically measuring against a reference object that degrades, the system uses stored coordinate data of a reference circle and calculates distances through computational geometry, substituting mechanical interaction with mathematical computation
2Adaptability or versatility
If the diameter of the reference workpiece differs from the workpiece to be measured, then measurement versatility is improved, but measurement precision deteriorates due to detection point deviation
Solution Approach 1:
The system calculates a correction value based on the ratio between the reference circle radius and the actual workpiece radius. This correction value compensates for detection point deviations that occur when measuring workpieces of different diameters, allowing accurate measurements across varying sizes without requiring the reference to match the workpiece diameter
3Adaptability or versatility
If temperature changes occur after calibration, then environmental adaptability is improved, but measurement precision deteriorates due to displacement of detection point
Solution Approach 1:
The system performs preliminary measurement of the actual distance from rotational center to detection point using the stored reference circle data before each measurement session. This preliminary action detects temperature-induced displacements and calculates appropriate correction values, allowing the system to adapt to environmental changes without requiring frequent recalibration
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables high-precision and reproducible surface shape measurement with improved versatility, reducing measurement errors and variations caused by misalignment, even in low-roundness workpieces.
Implementation Method 1
The first detector has a probe (contactor) that comes into contact with the surface of a workpiece, and detects a displacement of the probe by a differential transformer
Data Source
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AI summary
There are provided a surface shape measuring method, a misalignment amount calculating method and a surface shape measuring device which can measure the diameter of a workpiece to be measured with high precision and high reproducibility and have excellent versatility. These method include: a first acquiring step of acquiring first shape data with a detector being disposed on one side with respect to a workpiece, the first shape data indicating a surface shape of the workpiece when detecting a displacement of a surface of the workpiece with the detector while rotating the workpiece relatively to the detector around a rotational center, and a second acquiring step of acquiring second shape data with the detector being disposed on the other side with respect to the workpiece, the second shape data indicating the surface shape of the workpiece when detecting a displacement of the surface of the workpiece by the detector while rotating the workpiece relatively to the detector around the rotational center.