Position Sensor Calibration and Linearization for Inductive Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Position sensors, particularly inductive positioning systems, face inaccuracies due to non-uniform electromagnetic fields, wire trace connections, air-gap variations, and mismatches between receiver coils, leading to inaccurate position measurements.
Innovation Solution
A calibration and linearization system that involves reading spatial angle data from a position sensor, calculating calibration and linearization parameters, and writing these parameters into the sensor to correct for inaccuracies, allowing for precise position determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional position sensing systems are used without calibration, then the system is simpler and faster to implement, but the measurement precision deteriorates due to non-uniform electromagnetic fields, air-gap variations, and coil mismatches
Solution Approach 1:
The patent applies preliminary action by performing calibration measurements and calculating correction factors before actual position sensing operations. The system pre-determines calibration parameters (offsets, gains, linearization coefficients) that are stored and applied during normal operation, eliminating the need for real-time calibration computations and enabling accurate position sensing without ongoing calibration overhead.
Solution Approach 2:
The patent introduces intermediary calibration parameters as mediators between the physical sensor outputs and the desired accurate position measurements. These calibration parameters (including offset corrections, gain adjustments, and linearization coefficients) act as intermediate variables that transform raw sensor signals into corrected position data, resolving the discrepancy caused by non-uniform fields and hardware variations.
2Measurement precision
If multi-step calibration processes are used to correct systematic errors, then the measurement precision improves, but the productivity and time consumption worsen due to multiple measurement and computation steps
Solution Approach 1:
The patent merges multiple calibration operations into a unified calibration process. Instead of performing separate offset calibration, gain calibration, and linearization steps independently, the system combines all these calibration functions into a single integrated measurement sequence that collects all necessary data and computes all correction parameters in one calibration run, significantly improving calibration efficiency.
Solution Approach 2:
The patent implements multi-functionality by designing a calibration system that simultaneously performs multiple calibration tasks: offset correction, gain adjustment, and non-linearity compensation. The same set of calibration measurements and computational procedures accomplishes all three calibration objectives at once, eliminating the need for separate specialized calibration routines for each type of error correction.
3Reliability
If comprehensive calibration parameters are stored in the position sensor, then the measurement precision and reliability improve, but the device complexity and memory requirements increase
Solution Approach 1:
The patent extracts and separates the calibration parameter storage function from the main position sensing logic. Calibration parameters are stored in dedicated memory structures within the sensor, and the system selectively retrieves and applies only the necessary parameters during position calculations. This separation allows comprehensive calibration data to be maintained without complicating the core sensing algorithms, as the calibration functionality is modularized and isolated.
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 significantly improves the accuracy of position sensing by correcting for systematic errors, reducing production costs and time through a one-step calibration process, and enhancing the reliability of position sensor systems.
Implementation Method 1
a transmit coil is used to induce eddy currents in a metallic target that is sliding or rotating above a set of receiver coils. Receiver coils receive the magnetic field generated from eddy currents and the transmit coils
Implementation Method 2
a transmit coil is used to induce eddy currents in a metallic target that is sliding or rotating above a set of receiver coils
Data Source
AI summary
In some embodiments, a position sensor calibration and linearization system for position sensors is provided. A method of calibrating and linearization of a position sensor includes reading Spatial Angle data from a position sensor at a set of positions of a target swept over receive coils in the position sensor; calculating calibration parameters from the Spatial Angle data; determining an initial position values from the Spatial Angle data and the calibration parameters; determining linearization parameters from the initial position values; and writing the calibration parameters and the linearization parameters into the position sensor.