Magnetostrictive Position Measuring Device Reflection Masking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetostrictive position measuring devices face interference from reflected waves, which can distort measurements due to overlapping torsional impulses and mechanical waves, especially at specific clock frequencies and positions within the measuring range.
Innovation Solution
Generating at least two mechanical waves with different clock frequencies to ensure that interfering reflections occur at different overlap positions, allowing for position-dependent switching between these frequencies to mask out overlapping reflections, thereby eliminating measurement interference without the need for calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single clock frequency is used for generating mechanical waves, then the device operation is simple, but interfering reflections overlap with measurement signals at specific positions causing measurement distortion
Solution Approach 1:
The patent applies dynamics by making the clock frequency adjustable and position-dependent. The control unit dynamically selects between a first clock frequency and a second clock frequency based on the measured position of the position encoder. This dynamic adaptation allows the system to avoid overlapping reflections at different positions while maintaining measurement accuracy, resolving the contradiction between measurement precision and operational simplicity.
2Length of moving object
If the measuring range is extended, then more position information is available, but interfering reflections affect larger portions of the measuring range
Solution Approach 1:
The patent applies parameter changes by utilizing multiple clock frequencies (first and second frequencies) to measure different portions of the extended measuring range. The control unit switches between frequencies based on position, ensuring that interfering reflections do not overlap with measurement signals even across the full extended range. This allows the system to maintain measurement accuracy throughout the entire extended measuring range.
3Productivity
If clock frequency is increased to improve measurement speed, then measurement resolution improves, but interfering reflections occur more frequently
Solution Approach 1:
The patent applies parameter changes by using multiple clock frequencies to manage the trade-off between measurement speed and interference. The higher second clock frequency provides improved measurement resolution and speed, while the control unit strategically switches to the lower first clock frequency when position-dependent analysis indicates that reflections would interfere. This dynamic parameter adjustment maintains high productivity while minimizing the harmful effects of reflections.
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
This approach effectively masks out interfering reflections across the measuring range, enabling accurate position measurement without calibration, by selecting clock frequencies that avoid overlap positions of interfering reflections, thus improving measurement accuracy and range coverage.
Implementation Method 1
An electronic control system generates a current pulse by means of an excitation signal having a temporally constant clock frequency, said current pulse being applied to the above-mentioned current-carrying line, whereby a magnetic field is generated which is directed circularly around the waveguide.
Implementation Method 2
By overlapping the two magnetic fields, a torsional impulse and thus a mechanical wave propagating on both sides of the waveguide arise by means of magnetostriction of the waveguide.
Implementation Method 3
The wave running towards the detection unit induces an electrical signal there by reversal of the magnetostrictive effect.
Data Source
AI summary
A method for operating a magnetostrictive displacement measuring device, having a wave guide for guiding at least one mechanical wave, at least one damping zone, a magnetic position encoder which is displaceably arranged along a measuring range of the position measuring device and a detection unit, generates the at least one mechanical wave by an excitation signal (IP) having a clock frequency (f1, f2), at least two mechanical waves having respectively different clock frequencies (f1, f2, f) being generated. The clock frequencies can be predetermined such that interfering reflections (R11, R12) occur at different positions (x11, x21, x2) of the measuring range of the displacement measurement device, and during the method of the position encoder, switching between the different clock frequencies (f1, f2, f) takes place, such that the interfering reflections (R11, R12) on the respective different positions (x11, x21, x22) of the measuring range are masked out.