Multi-Surface Position Measurement with Thermal Neutral Scanning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing position measuring devices face challenges in achieving precise measurements in the longitudinal direction and other degrees of freedom while being susceptible to temperature-related influences that can falsify the measurements.
Innovation Solution
A position measuring device with a carrier body having multiple surfaces with inclined measuring graduations and scanning units, where the scanning units are arranged to have a common thermally neutral point, allowing for precise measurement in all six degrees of freedom and minimizing temperature-related errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple measuring scales with inclined graduation marks are used on different surfaces, then measurement precision in all six degrees of freedom is improved, but device complexity increases
Solution Approach 1:
The measuring system is segmented into multiple independent measuring scales positioned on different surfaces of the carrier body. Each surface carries its own measuring scale with graduation marks inclined at specific angles, allowing independent measurement of different spatial dimensions. This segmentation enables comprehensive six-degree-of-freedom measurement while maintaining modular structure.
Solution Approach 2:
The invention transitions from single-plane measurement to multi-surface measurement by positioning measuring scales on different surfaces of the carrier body. The graduation marks on each surface are inclined at different angles relative to the feed direction, adding angular dimensionality to the measurement system. This dimensional expansion enables simultaneous measurement of position in multiple degrees of freedom.
2Measurement precision
If scanning units are positioned to measure multiple surfaces, then measurement coverage is improved, but temperature-related measurement errors increase
Solution Approach 1:
The scanning units are positioned asymmetrically relative to the carrier body's thermal neutral point rather than in symmetric arrangements. Each scanning unit's location is specifically calculated based on the inclination angle of its corresponding measuring scale and the requirement to intersect at the thermal neutral point. This asymmetric positioning compensates for thermal expansion effects that would otherwise cause measurement errors.
Solution Approach 2:
The invention changes the positional parameters of the scanning units dynamically based on temperature compensation requirements. The coordinates of each scanning unit are determined by mathematical relationships involving the inclination angles of the measuring scales and the thermal neutral point location. This parameter adjustment ensures that all scanning unit measurement planes intersect at the thermal neutral point, where thermal expansion effects are minimized.
3Adaptability or versatility
If measuring scales are arranged on multiple surfaces with different inclinations, then degrees of freedom measurement is improved, but manufacturing precision requirements increase
Solution Approach 1:
The carrier body is designed as a universal platform with multiple surfaces, each capable of carrying a measuring scale. The standardized carrier body structure can accommodate different configurations of measuring scales with various inclination angles, making the system versatile for measuring all six degrees of freedom. This multi-functionality is achieved through a unified carrier design that supports multiple measurement orientations.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a position measuring device for measuring the relative position of two objects in a feed direction and in further degrees of freedom. For this purpose, the carrier body (1) has at least three surfaces (O1, O2, O3) extending in the feed direction, each of which carries a first measuring scale (T11-T13) and a second measuring scale (T21-T23). The first measuring scale (T11-T13) and the second measuring scale (T21-T23) each have a sequence of graduations, wherein the graduations of the first measuring scale (T11-T13) are inclined relative to the graduations of the second measuring scale (T21-T23). For scanning the measurement divisions (T11-T13, T21-T23), several scanning units (A11-A13, A21-A23) are provided, which are arranged relative to the measurement divisions (T11-T13, T21-T26) in such a way that a common thermally neutral point (P) results.