Single-Sensor Position Detection Using Barkhausen Pulse Doubling
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Solution Overview
Problem
Existing position detection devices using power generation sensors face challenges in achieving high resolution and smaller size due to magnetic interference and the need for multiple sensors, which increase cost and size.
Innovation Solution
A position detection device with a single power generation sensor that uses a magnetic field generation source with equidistantly arranged magnetic poles, a magnetic wire exhibiting a large Barkhausen effect, and magnetic flux conducting pieces to generate positive and negative voltage pulses, allowing for higher resolution with a smaller number of sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple power generation sensors are used to identify movement direction, then movement direction can be identified, but device size and costs increase
Solution Approach 1:
The magnetic field generation source is segmented into multiple magnetic poles (N-pole and S-pole) arranged alternately. This segmentation allows a single power generation sensor to detect alternating magnetic field directions, enabling movement direction identification without requiring multiple sensors. The magnetic poles are divided into first and second groups positioned at different locations, creating distinct magnetic field patterns for direction detection.
Solution Approach 2:
Magnetic flux conducting pieces (first and second magnetic flux conducting pieces) are introduced as intermediary elements between the magnetic poles and the power generation sensor. These pieces guide and concentrate magnetic flux from specific magnetic poles to the sensor, enabling the single sensor to distinguish between different magnetic pole sources and thereby identify movement direction through the alternating pattern of detected pulses.
2Measurement precision
If multiple power generation sensors are used to detect position, then detection capability is improved, but costs and size increase
Solution Approach 1:
The magnetic field generation source is segmented into multiple magnetic poles that generate alternating magnetic fields. A single power generation sensor detects pulses from alternating N-poles and S-poles, effectively doubling the detection events per cycle compared to a single-pole configuration. This segmentation approach improves measurement precision while maintaining a single-sensor architecture.
Solution Approach 2:
The alternating arrangement of N-poles and S-poles creates a periodic magnetic field pattern as the magnetic field generation source moves relative to the power generation sensor. This periodic action generates alternating positive and negative voltage pulses, increasing the number of detectable events per unit distance and improving position detection precision without adding more sensors.
3Productivity
If magnetic flux conducting pieces are added to generate both positive and negative pulses, then pulse generation capability is improved, but device complexity increases
Solution Approach 1:
The first and second magnetic flux conducting pieces are merged with the magnetic field generation source structure, forming an integrated assembly. The magnetic flux conducting pieces are positioned to work in conjunction with the alternating magnetic poles, creating a unified system that generates both positive and negative pulses through coordinated magnetic flux guidance rather than requiring separate pulse generation mechanisms.
Solution Approach 2:
The magnetic flux conducting pieces serve multiple functions: they guide magnetic flux from alternating N-poles and S-poles to the power generation sensor, concentrate magnetic field strength, and enable the generation of both positive and negative voltage pulses through their strategic positioning. This multi-functionality improves pulse generation capability while minimizing additional complexity.
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 device achieves higher position detection resolution and smaller size by generating twice the number of pulses with a single sensor, reducing magnetic interference and sensor count.
Implementation Method 1
Magnetic wires having a large Barkhausen effect (large Barkhausen jump) are known in the name of Wiegand wire or pulse wire... When the hard layer and the soft layer are magnetized in the same direction axially of the wire and the strength of an external magnetic field applied in a direction opposite to that magnetization n direction is increased to a certain magnetic field strength, the magnetization direction of the soft layer is reversed. The reversal of the magnetization direction starts at a certain position of the magnetic wire to propagate to the entire wire, whereby the magnetization direction of the soft layer is totally reversed. At this time, the large Barkhausen effect is exhibited to induce a pulse signal in the coil wound around the magnetic wire.
Implementation Method 2
A power generation sensor is produced by winding a coil around the magnetic wire... the large Barkhausen effect is exhibited to induce a pulse signal in the coil wound around the magnetic wire... A voltage outputted from the coil is characteristically constant irrespective of the change rate of an input magnetic field (external magnetic field)
Data Source
AI summary
A position detection device includes: a first support; a second support that is movable relative to the first support; a power generation sensor disposed on the first support; and a magnetic field generation source fixed to the second support. The relative movement of the second support causes a plurality of magnetic poles having the same polarity to sequentially enter the detection region of the power generation sensor. The power generation sensor includes: a magnetic wire configured to exhibit a large Barkhausen effect; a coil wound around the magnetic wire; and a first magnetic flux conducting piece and a second magnetic flux conducting piece respectively magnetically coupled to the opposite end portions of the magnetic wire and each having a magnetic flux conducting end opposed to the detection region.