Position Sensing Device Tilt Compensation Deflection Unit
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Solution Overview
Problem
Existing devices for precise vertical position determination are susceptible to errors due to tilting of the measuring reflector, as the signal phase changes linearly with tilt angles, affecting the accuracy of position determination.
Innovation Solution
A device with a deflection unit that compensates for beam direction deviations caused by tilting, using optical components such as refractive or diffractive elements and gratings to ensure that the reference signal depends only on vertical distance, not on tilting, by adjusting the beam path to maintain accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the measuring reflector tilts from its nominal position, then the signal phase changes, but this causes errors in position determination
Solution Approach 1:
The deflection unit is designed to preemptively counteract the beam direction deviation caused by reflector tilting. By compensating for the tilt effect before it reaches the detector, the system prevents phase errors from occurring in the first place, thereby maintaining measurement precision despite reflector orientation changes
Solution Approach 2:
The deflection unit acts as an intermediary component between the measuring reflector and the detector arrangement. It receives the tilted beam and redirects it to the correct detection position, isolating the measurement system from the harmful effects of reflector tilting and ensuring reliable position determination
2Measurement precision
If the beam path is extended to improve measurement accuracy, then the device complexity increases
Solution Approach 1:
The deflection unit is designed to perform multiple functions simultaneously: it compensates for beam direction deviations, maintains beam path alignment, and enables the system to tolerate reflector tilting. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while achieving improved measurement precision
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
The solution significantly reduces errors in position determination by ensuring insensitivity to tilting about at least one axis, maintaining high accuracy even when the measuring reflector is tilted, and can be further enhanced to be insensitive to tilting about additional axes.
Implementation Method 1
the deflection unit can comprise one or more optical components which exert a converging optical effect on a divergent bundle of rays incident on the measuring reflector or exert a diverging optical effect on a convergent bundle of rays incident on the measuring reflector
Implementation Method 2
the at least one optical component to be in the form of a refractive or diffractive optical element
Implementation Method 3
the deflection unit can comprise a first and a second deflection grating as diffractive optical elements
Implementation Method 4
at least one bundle of rays emitted by the light source impinges on the detector arrangement after it has acted on the measuring reflector
Data Source
Figure 1a~1b
Figure 1c
Figure 2a~2c
AI summary
The present invention relates to a device for position determination comprising a light source (11), a planar measuring reflector (1) which is movable along at least one measuring direction, wherein the measuring direction is oriented perpendicular to the measuring reflector (1), and a detector arrangement (18). At least one beam of light emitted by the light source (11) strikes the detector arrangement (18) after striking the measuring reflector (1), so that, in the event of movement of the measuring reflector along the measuring direction, at least one signal results which depends on the position of the measuring reflector and from which a reference signal can be generated at a defined reference position. The beam of light strikes the measuring reflector twice and passes through a deflection unit (15.1; 15.2) between striking the measuring reflector.2), which is designed in such a way that a beam direction deviation resulting from a tilting of the measuring reflector after the first reflection is compensated after the second reflection (Fig.1a).