Inertial Dimensional Metrology for Hidden Points
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In large volume dimensional metrology, existing technologies face challenges in measuring hidden points lacking line-of-sight visibility and achieving high precision within small dimensional tolerances, often requiring complex and costly solutions.
Innovation Solution
A method incorporating an Inertial Measurement Unit (IMU) with an elongate probe in a portable metroprobe, allowing direct access to hidden survey points by correlating the probe's position and attitude with the IMU's coordinate system, reducing the need for line-of-sight and minimizing complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional portable CMM or laser tracker is used to measure hidden points, then line-of-sight visibility is required, but this limits access to obstructed survey points
Solution Approach 1:
The patent replaces optical line-of-sight-based measurement systems (laser trackers, theodolites) with an inertial measurement system using IMU and accelerometers. The inertial system measures gravity vector and acceleration to calculate 3D coordinates without requiring visual line-of-sight to targets, enabling access to hidden points while reducing system complexity.
Solution Approach 2:
The patent introduces an inertial measurement unit (IMU) as an intermediary between the measurement operator and the hidden survey points. The IMU serves as a mediator that provides orientation and position data through inertial sensing rather than direct optical observation, allowing measurement of points that would otherwise be inaccessible.
2Adaptability or versatility
If multiple portable CMMs are used to measure hidden points from different locations, then line-of-sight coverage is improved, but coordinate system alignment becomes complex
Solution Approach 1:
The patent changes the measurement parameters from optical coordinates requiring line-of-sight to inertial parameters (acceleration, gravity vector, orientation angles). This parameter change allows continuous tracking of probe position and orientation without requiring multiple stationary CMM locations or complex coordinate transformations between different viewing positions.
3Measurement precision
If high precision measurement is required within small dimensional tolerances, then measurement accuracy must be maximized, but this increases system complexity and cost
Solution Approach 1:
The patent replaces complex optical measurement systems with a simpler inertial measurement system. By using IMU sensors to directly measure the probe's position, orientation, and movement, the system achieves high precision coordinate determination without requiring the complex infrastructure of laser trackers, interferometers, or multiple CMMs, thereby reducing overall system complexity while maintaining measurement 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 measurement of hidden points with reduced complexity and cost, achieving high accuracy in 3D coordinate location determination, even in obstructed environments, by utilizing the IMU's inherent accuracy and minimizing drift errors.
Implementation Method 1
incorporating an Inertial Measurement Unit (IMU) with an elongate probe in a portable metroprobe
Data Source
AI summary
A method of performing dimensional metrology of an object (12) includes incorporating an Inertial Measurement Unit (IMU-18) with an elongate probe (20) in a portable metroprobe (10). A tip (22) of the probe (20) has an offset length (L) from an origin (26) of a coordinate system in the IMU (18) and position (X,Y,Z) thereof is correlated based on attitude (A,B,C) measurement of the IMU (18). The metroprobe (10) is transported in sequence to a complement of survey points (Pn) on the object (12) for measuring corresponding coordinates (X,Y,Z) thereof based on measured attitude (A,B,C) of the IMU (18).