Surface Profile Measuring Instrument Drive Mechanism Error Correction
Solution Overview
Problem
Existing surface-profile measuring instruments face challenges in conducting high-speed and high-accuracy scanning measurements due to measurement errors caused by deformation of the drive mechanism during scanning, particularly when measuring large or complex workpieces like vehicle bodies, where centrifugal forces lead to radial deviations and inaccurate data correction.
Innovation Solution
A surface-profile measuring instrument that includes a scanning probe, a drive mechanism, a drive sensor, and a correction calculating unit. The correction unit calculates and applies a correction amount based on the scanning vector command to account for deformation errors, using stored correction parameters and estimating movement states to improve measurement accuracy without relying on actual measurement data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-speed scanning measurement is conducted, then productivity is improved, but measurement precision deteriorates due to deformation of the drive mechanism
Solution Approach 1:
The patent pre-stores correction parameters that represent the relationship between acceleration and drive mechanism deformation before measurement. During high-speed scanning, the correction calculating unit directly retrieves and applies these pre-computed parameters to correct measurement errors, eliminating the need for real-time complex calculations and enabling accurate correction even at high scanning speeds
Solution Approach 2:
The patent creates a correction parameter database that copies and stores the deformation characteristics of the drive mechanism under various acceleration conditions. This pre-established database allows the system to quickly reference and apply appropriate correction values during measurement without performing real-time physical simulations or complex computations
2Measurement precision
If correction parameters are stored in advance, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex real-time mechanical measurement correction systems with a computational approach using pre-stored correction parameters. Instead of using complex sensors and real-time calculation units to dynamically determine deformation compensation, the system uses a database of pre-computed correction parameters that can be quickly retrieved and applied through simple computational operations
Solution Approach 2:
The patent transforms the complex physical problem of real-time deformation correction into a parameter lookup and application problem. By pre-computing and storing correction parameters for various acceleration conditions, the system changes the nature of the correction process from complex real-time physics calculation to simple parameter retrieval and application
3Measurement precision
If acceleration sensors are added to detect movement state, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes the drive mechanism itself serve the dual purpose of both driving the scanning probe and providing acceleration information for correction. The drive mechanism's commanded motion and detected position data are used to calculate acceleration through differentiation, eliminating the need for separate acceleration sensors while still providing the necessary acceleration information for deformation correction
Solution Approach 2:
The patent makes the existing drive mechanism and position detection system perform multiple functions: driving the probe, detecting position, and providing data for acceleration calculation. This multi-functional approach eliminates the need for dedicated acceleration sensors while still achieving accurate deformation correction
4Measurement precision
If sampling cycle is shortened for high-resolution measurement, then measurement precision is improved, but productivity decreases due to increased data processing time
Solution Approach 1:
The patent pre-stores correction parameters for various acceleration conditions before measurement begins. During measurement, even at short sampling cycles, the system can directly retrieve and apply these pre-computed parameters without performing complex real-time calculations, enabling accurate correction to be applied quickly to each measurement point
Data Source
AI summary
A surface-profile measuring instrument includes a movement-estimating unit that estimates a movement state of a drive mechanism in accordance with a scanning vector command issued by a scanning vector commanding unit to calculate an estimated movement state quantity, and a correction calculating unit that corrects a detection value of a drive sensor in accordance with the estimated movement state quantity calculated by the movement-estimating unit. The movement-estimating unit has a nominal model setting unit in which a nominal model from the scanning vector commanding unit to the probe is set. The correction calculating unit includes a correction-amount calculating unit that calculates a correction amount for correcting a measurement error generated by a deformation of the drive mechanism in accordance with the movement thereof and a measurement data synthesizing unit that synthesizes the detection value of the drive sensor and the displacement sensor and the calculated correction-amount calculated by the correction-amount calculating unit.