Magnetic Pointer Sensor Calibration Without Gauge Needle Rotation
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Solution Overview
Problem
Existing sensor systems require rotating the pointer of a measuring instrument for calibration, which is cumbersome and inefficient.
Innovation Solution
A sensor device system that contactlessly acquires measurement values by detecting the magnetic pole boundary direction of a magnet integrated with the pointer, using a sensor circuit to generate a correction value based on the magnetic pole boundary direction and a reference direction, allowing calibration without pointer rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pointer is rotated to perform calibration and obtain initial installation information, then the correction parameters can be calculated and stored, but the operation becomes troublesome and complex
Solution Approach 1:
The patent replaces the mechanical rotation operation with a magnetic field detection approach. The sensor device detects the magnetic pole boundary direction of the magnet to obtain the initial installation direction, eliminating the need for manual pointer rotation and mechanical calibration operations while maintaining measurement precision.
Solution Approach 2:
The patent introduces a magnet as an intermediary element that couples the pointer's mechanical position to the sensor's detection system. The magnet's magnetic pole boundary direction serves as a measurable proxy for the pointer's initial installation direction, enabling non-contact calibration.
2Measurement precision
If the pointer is rotated sequentially to acquire first and second meter reading values, then calibration parameters can be obtained, but the calibration process takes more time
Solution Approach 1:
The patent performs the calibration action in advance by detecting the magnetic pole boundary direction at the initial installation position. This preliminary detection captures the necessary calibration information in a single operation, eliminating the need for sequential rotations and multiple readings during the calibration process.
Solution Approach 2:
The patent substitutes the time-consuming sequential mechanical rotation process with a single magnetic field detection operation. The sensor device acquires the initial installation direction information instantaneously by detecting the magnetic pole boundary, dramatically reducing calibration time while maintaining accuracy.
3Ease of operation
If a magnet is integrated with the pointer and magnetic field detection is used, then pointer rotation is eliminated for calibration, but the device structure becomes more complex
Solution Approach 1:
The patent merges the magnet with the pointer assembly, creating an integrated component that combines the indicating function with the calibration reference function. This merging eliminates the need for separate calibration mechanisms while adding minimal structural complexity.
Solution Approach 2:
The magnet serves as an intermediary that provides a magnetic field signature corresponding to the pointer's position. This intermediary enables the sensor to detect calibration information without direct mechanical interaction, simplifying the overall calibration mechanism despite the added magnetic detection capability.
4Reliability
If traditional calibration methods are used requiring pointer rotation, then existing sensor systems can be maintained, but operational efficiency decreases
Solution Approach 1:
The patent replaces the traditional mechanical calibration system with a magnetic field-based detection system. This substitution eliminates the need for pointer rotation while maintaining the reliability of calibration through accurate magnetic pole boundary detection, thereby significantly improving calibration efficiency.
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
Enables calibration of meter reading values without rotating the pointer, reducing operational complexity and cost, while ensuring accurate and efficient measurement correction.
Implementation Method 1
the sensor circuit generating a magnetic pole boundary direction value by detecting a magnetic pole boundary direction parallel to an interface between the N pole and the S pole
Data Source
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AI summary
A sensor device system includes a sensor device (D1) that is attached for use to a measuring instrument (G1) including a scale plate (G16), a shaft member (G17), a pointer (G14) and a magnet (G18), and that contactlessly acquires a measurement value measured by the measuring instrument (G1). The pointer (G14) has an axial portion attached to the shaft member (G17) and an indicating portion that extends radially outward from the axial portion and points to the scale as viewed in an axial direction (Z). The magnet (G18) has one each of an N pole and an S pole disposed in a circumferential direction of the shaft member (G17). The sensor device (D1) includes a sensor circuit (2) and a case (1) accommodating the sensor circuit (2). The sensor circuit (2) generates a magnetic pole boundary direction value by detecting a magnetic pole boundary direction parallel to an interface between the N pole and the S pole, and generates a meter reading value by correcting the magnetic pole boundary direction value with a correction value. The correction value is calculated based on an extension direction of the pointer (G14) and an angle formed by the magnetic pole boundary direction and a reference direction of the magnetic pole boundary direction.