Chromatic Point Sensor On-Site Calibration Object
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Chromatic point sensors face challenges in maintaining measurement accuracy due to component drift, requiring complex recalibration processes that are impractical for end-users, often necessitating the entire unit to be sent back to the factory for recalibration.
Innovation Solution
A calibration method and object that allows for on-site or field recalibration of chromatic point sensors using a calibration object with densely spaced measurement points, enabling self-verification of calibration data without precise motion of the object, and providing reliable calibration data through analysis of base plane and step measurement points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If known recalibration methods are used, then measurement accuracy can be restored, but the process requires complex equipment and expertise that is impractical for end-users
Solution Approach 1:
The patent creates a simplified copy of the calibration process by providing a calibration object with known measurement points that can be used directly in the field. Instead of requiring complex factory recalibration equipment, the invention uses a portable calibration object that replicates the essential calibration function, allowing end-users to perform recalibration without specialized equipment or expertise.
Solution Approach 2:
The calibration object is designed to enable self-verification and self-calibration by the end-user. The object contains measurement points with known positions that allow the sensor to automatically verify and adjust its measurements without external intervention or complex procedures, making the recalibration process accessible to ordinary users.
2Measurement precision
If factory recalibration is performed, then measurement accuracy is maintained, but the entire unit must be sent back to the factory causing loss of time
Solution Approach 1:
The calibration object is prepared in advance with known measurement points and characteristics that encode the necessary calibration information. This preliminary preparation allows field recalibration to proceed quickly without requiring time-consuming factory procedures, as the calibration data is already embedded in the portable object.
Solution Approach 2:
The calibration function is segmented from the main sensor unit and embodied in a separate portable calibration object. This segmentation allows the calibration process to be performed independently and quickly in the field without requiring the entire sensor unit to be disassembled or sent to the factory, significantly reducing recalibration time.
3Measurement precision
If precise motion of the calibration object is required, then calibration accuracy improves, but the complexity and difficulty of operation increases
Solution Approach 1:
The patent replaces mechanical precision positioning requirements with optical or field-based measurement methods. The calibration object contains measurement points whose positions are determined through non-mechanical means (such as optical fields or electromagnetic signals), eliminating the need for precise mechanical motion or positioning of the object during calibration, thereby simplifying operation while maintaining accuracy.
Solution Approach 2:
The invention changes the fundamental parameters of the calibration process by using measurement points with known positions that can be identified through their intrinsic characteristics rather than through precise mechanical positioning. This parameter change allows the calibration to proceed without requiring the operator to maintain precise motion control, making the process easier to operate while preserving calibration accuracy.
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 precise and reliable recalibration of chromatic point sensors without the need for extreme precision in moving the calibration object, reducing measurement errors and simplifying the recalibration process, making it feasible for end-users to maintain accuracy on-site.
Implementation Method 1
an optical element having axial chromatic aberration, also referred to as axial or longitudinal chromatic dispersion, may be used to focus a broadband light source such that the axial distance to the focus varies with the wavelength
Implementation Method 2
Upon reflection from the surface, the light is refocused onto a small detector aperture, such as a pinhole or the end of an optical fiber
Implementation Method 3
the light is refocused onto a small detector aperture
Implementation Method 4
A spectrometer type detector measures the signal level for each wavelength, in order to determine the surface height
Data Source
AI summary
A chromatic point sensor (CPS) calibration object and characterizing data are provided. The calibration object comprises a flat base plane with steps extending from it. Step measurement points provided by the steps and base plane measurement points provided by portions of the base plane are intermingled along a measurement track. The characterizing data characterizes known heights of the measurement points. A calibration method acquires measurement data such that some base plane measurement points should be at nearly the same measurement distance and therefore have the same common mode errors relative to known base plane measurement point heights. If such base plane measurement points exhibit minimal error variations, then measurements for those and proximate measurement points may provide reliable calibration data. In contrast, error variations outside an expected range indicate unreliable measurements that should be screened or replaced by new calibration measurements.