Scanner Motion Error Compensation via Low Frequency Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Scanning apparatuses face issues with imperfect scanner motion due to mechanical imperfections in the drive train, leading to low frequency errors that affect scan quality and increase part costs, particularly in both open-loop and closed-loop systems.
Innovation Solution
A method and apparatus that generate an error array by measuring scanner position errors at multiple points, creating an error compensation array based on low frequency components, and using this array to adjust parameters during scanning operations, such as rotational velocity or scan timing, to correct for these errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional mechanical drive train components (gears, belts) are used in scanner systems, then the scanner can achieve basic motion control, but mechanical imperfections cause low frequency errors that degrade scan quality and increase part costs
Solution Approach 1:
The patent implements feedback by measuring the actual position of the scanner at multiple discrete points along its travel path, comparing these measurements to expected positions, and using the detected errors to generate compensation values that are applied to correct subsequent scanning operations. This closed-loop feedback mechanism directly addresses mechanical imperfections in the drive train.
Solution Approach 2:
The patent performs preliminary action by pre-measuring and storing error values at discrete positions along the scanner's travel path before actual scanning operations. These pre-characterized errors are used to create lookup tables and interpolation functions that enable real-time compensation without requiring complex real-time calculations during scanning.
2Measurement precision
If discrete error measurements are taken at spaced positions, then error compensation can be implemented, but continuous error correction along the entire scanning range is not achieved
Solution Approach 1:
The patent applies dynamics by transitioning from static discrete error measurements to dynamic continuous error compensation. Interpolation functions are used to calculate error values at any position between measured points, and the system dynamically adjusts compensation based on the scanner's current position, enabling continuous correction along the entire scanning range.
Solution Approach 2:
The patent introduces interpolation functions as intermediaries between discrete error measurements and continuous error correction needs. These mathematical functions act as mediators that estimate error values at unmeasured positions based on known measurements from adjacent points, bridging the gap between discrete data points and continuous correction requirements.
3Manufacturing precision
If error compensation arrays are generated and applied, then low frequency errors are reduced, but the system complexity and computational requirements increase
Solution Approach 1:
The patent uses simple, computationally inexpensive lookup tables stored in memory that can be quickly queried during scanning operations. Rather than implementing complex real-time error analysis algorithms, the system pre-calculates and stores compensation values in discrete lookup tables, trading minimal memory usage for significantly reduced computational complexity during operation.
Solution Approach 2:
The patent creates simplified copies of the error characteristics in the form of lookup tables that replicate the essential error patterns without storing or processing the full complexity of the original mechanical imperfections. These compact representations enable efficient error compensation while minimizing system complexity.
Data Source
AI summary
A method to compensate for imperfect scanner motion in a scanning apparatus having a moveable scanner includes generating an error array by measuring errors in a scanner position at each of a plurality of spaced positions along a direction of travel of the scanner; generating an error compensation array from the error array based on a low frequency component of the error array; and using the error compensation array to adjust at least one parameter associated with the scanning apparatus during a document scanning operation.