Wiegand Sensor Position Determination Using Magnetization Direction
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Solution Overview
Problem
Existing Wiegand sensor systems face challenges in accurately determining absolute position due to non-optimal counting pulses, leading to ambiguity in movement direction and segment counting, especially when coupled with fine position encoders, as they require precise knowledge of movement sequences and magnetic field strengths, which is not adequately provided by existing additional sensor elements.
Innovation Solution
A method that utilizes the magnetization direction of the Wiegand wire to resolve ambiguity by storing conditions for adding or subtracting segments in a table, and employs induction coils or magnetic field-sensitive probes to determine the last direction of magnetization, allowing correct assignment of revolutions or segments without contradictions, enabling accurate absolute position determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a Wiegand sensor is used for position detection, then the sensor can operate autonomously with self-generated counting pulses, but the counting pulses may become non-optimal leading to ambiguity in movement direction and segment counting
Solution Approach 1:
An additional magnetic field-sensitive sensor element is introduced as an intermediary to detect the magnetization direction of the Wiegand wire. This mediator provides the missing information about the excitation magnet's polarity and position, enabling correct interpretation of counting pulses without compromising the autonomous operation capability of the Wiegand sensor system.
Solution Approach 2:
The magnetization direction of the Wiegand wire is determined in advance before it influences the counting result. By detecting the magnetization direction beforehand using the additional sensor element, the system can correctly interpret subsequent counting pulses and resolve directional ambiguity before it affects measurement accuracy.
2Measurement precision
If an additional sensor element is added to determine magnetization direction, then position determination accuracy improves, but device complexity increases
Solution Approach 1:
The additional sensor element serves multiple functions: it detects the magnetization direction of the Wiegand wire, determines the polarity and position of the excitation magnet, and provides information for correcting counting pulses. This multi-functionality reduces the need for separate components and minimizes overall device complexity while achieving accurate absolute position determination.
Solution Approach 2:
Instead of adding complex hardware, the solution changes the detected parameter by utilizing the magnetization direction of the existing Wiegand wire as an additional information source. This parameter change approach extracts more information from the existing system components, avoiding the need for significantly increased device complexity.
3Productivity
If the excitation magnet moves past the Wiegand sensor without triggering an optimal pulse, then the system can continue operating, but the counting result becomes incorrect or inaccurate
Solution Approach 1:
The additional magnetic field-sensitive sensor element provides continuous feedback about the magnetization direction of the Wiegand wire. This feedback mechanism allows the evaluation electronics to detect when a counting pulse should have been triggered but was non-optimal, and to correct the counting result accordingly, maintaining both continuous operation and counting accuracy.
Solution Approach 2:
The system determines the magnetization direction in advance using the additional sensor element, which allows it to predict and correct for potential non-optimal counting pulses before they affect the final counting result. This preliminary detection ensures that even if a pulse is non-optimal, the counting remains accurate.
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 method ensures accurate and consistent counting by using the stored magnetization direction information to correct counting results, providing a reliable absolute position value even in cases of non-optimal pulses, and is applicable to both rotational and translational movements.
Implementation Method 1
The initially irregularly oriented magnetic areas in the ferromagnetic material - referred to as magnetic domains or Weiss areas - align themselves to form a single domain under the influence of external forces. When an external magnetic field of a certain direction and size is applied, this domain 'suddenly flips over', which leads to a voltage pulse in the sensor coil
Implementation Method 2
The kinetic energy of the elementary magnets, which flip over in the form of a continuous wave in the direction of the external field, is large enough not only to draw electrical energy for a signal pulse from the coil associated with the Wiegand sensor, but also for counting electronics with a memory
Data Source
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AI summary
Method and arrangement for the error-free determination of a total position value from the count values of a segment counter with Wiegand sensors and the position values of a fine position sensor using the last magnetization direction of the Wiegand wire of a segment counter as one of the pieces of information for the combination of the count and fine position values.