Magnetostrictive Sensor Calibration via Gap and Temperature Estimation
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Solution Overview
Problem
Conventional magnetostrictive sensors face accuracy issues due to variations in the magnetic gap, temperature, and runout, which affect the reliability of stress, torque, and rotation speed measurements.
Innovation Solution
A calibration apparatus comprising an estimation device and a calibrator that estimates the gap and temperature based on geometric information, excitation signals, and output signals from the magnetostrictive sensor, and adjusts the excitation signal to compensate for these variations, thereby reducing errors and enhancing measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional magnetostrictive sensors are used without calibration, then the device complexity is low, but the measurement precision deteriorates due to variations in magnetic gap, temperature, and runout
Solution Approach 1:
The calibration apparatus performs preliminary estimation of gap and temperature parameters before the actual measurement process. The estimation device calculates these parameters based on geometric information and sensor output signals, allowing the system to pre-compensate for environmental variations and establish accurate measurement conditions in advance
Solution Approach 2:
The system implements a feedback mechanism where the estimation device continuously monitors gap and temperature parameters, and the calibrator adjusts the excitation signal based on these estimated parameters. This closed-loop feedback ensures that measurement precision is maintained by dynamically compensating for variations in operating conditions
2Measurement precision
If calibration apparatus with estimation device and calibrator is added, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The calibration apparatus is designed to perform multiple functions using integrated components. The estimation device simultaneously estimates both gap and temperature parameters, while the calibrator adjusts excitation signals to compensate for both types of variations, reducing the need for separate calibration systems for each parameter
Solution Approach 2:
The system achieves self-calibration by using its own output signals and geometric information to estimate gap and temperature parameters. The magnetostrictive sensor's output signals are reused for both measurement and calibration purposes, eliminating the need for external reference standards or additional sensing components
3Reliability
If gap and temperature variations are not compensated, then the ease of operation is high, but the reliability deteriorates due to large errors in measured results
Solution Approach 1:
The system automatically performs calibration operations using its own output signals and geometric information. The estimation device and calibrator work autonomously to compensate for gap and temperature variations without requiring manual intervention, maintaining ease of operation while significantly improving measurement reliability
Solution Approach 2:
The calibration system implements automatic feedback control where the estimated gap and temperature parameters continuously adjust the excitation signal. This automated feedback mechanism ensures reliable measurements without requiring operator involvement in the complex calibration process
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 enables high-accuracy measurement of stress, torque, and rotation speed by minimizing the impact of gap and temperature variations, resulting in a self-calibration system with improved reliability.
Implementation Method 1
A magnetostrictive sensor is a device for measuring a stress or a torque of an object by coupling magnetic flux into subsurface of the object, because magnetic permeability of the object will change with applied stress or torque
Implementation Method 2
magnetic permeability of the object will change with applied stress or torque
Data Source
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AI summary
A calibration apparatus 120 is configured to calibrate a magnetostrictive sensor. The magnetostrictive sensor 110 is configured to measure an object 900 and comprises a sensing element positioned adjacent to the object. The calibration apparatus comprises an estimation device 130 and a calibrator 140. The estimation device 130 is configured to estimate at least one of a gap between the sensing element and the object and a temperature of the object to obtain at least one of an estimated gap and an estimated temperature, based on geometric information, an excitation signal and an output signal of the magnetostrictive sensor, and geometric information of the object. The calibrator 140 is configured to reduce an effect on the output signal of the magnetostrictive sensor imposed by variations in the at least one of the gap and the temperature, based on the at least one of the estimated gap and the estimated temperature, to obtain a calibrated output signal.