Sensor Secondary Coil Winding Pitch for Linearity Error Reduction
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Solution Overview
Problem
Conventional sensor devices, such as LVDTs, face challenges in maintaining sensitivity and accuracy due to high linearity errors caused by uniform winding profiles, which are inadequate for applications requiring precise mechanical motion to electrical signal conversion, especially under strain and vibrational loads.
Innovation Solution
The implementation of a secondary coil element with a non-linear, polynomial winding pitch along a bobbin tube, which reduces linearity errors by varying the number of turns according to a specific polynomial function, and includes coil transition portions to minimize pitch variability between sections, enhancing the sensor's ability to accurately detect relative movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a uniform winding pitch is used for the secondary coil element, then the manufacturing process is simple, but the linearity error increases and measurement precision deteriorates
Solution Approach 1:
The patent applies parameter changes by varying the winding pitch of the secondary coil element according to a non-linear polynomial function. Instead of using a constant pitch, the pitch is modified as a function of position along the bobbin tube, which compensates for non-linearities in the magnetic field and reduces linearity errors in the sensor output.
Solution Approach 2:
The patent implements local quality by creating different winding densities at different positions along the coil. The winding pitch is specifically tailored for different sections of the bobbin tube, with tighter winding in regions where greater sensitivity is needed and looser winding in regions where the magnetic field is naturally stronger, thereby optimizing measurement precision locally across the entire sensor length.
2Measurement precision
If the secondary coil element has varying pitch to reduce linearity error, then measurement precision improves, but the winding complexity and device complexity increase
Solution Approach 1:
The patent applies segmentation by dividing the secondary coil element into multiple winding sections, each with its own polynomial function defining the pitch variation. This allows the complex non-linear winding profile to be broken down into manageable segments that can be manufactured more easily while still achieving the overall linearity correction effect.
Solution Approach 2:
The patent uses preliminary action by pre-calculating and pre-defining the polynomial functions that describe the optimal winding pitch at each position along the bobbin tube. This allows the complex winding profile to be planned and prepared in advance, facilitating more accurate and consistent manufacturing despite the increased complexity.
3Measurement precision
If a non-linear polynomial winding function is applied to the secondary coil, then sensitivity and linearity improve, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies dynamics by using a continuous polynomial function to define the winding pitch, which allows for smooth transitions between different winding densities. This dynamic approach ensures that there are no abrupt changes or discontinuities in the winding profile, making it easier to manufacture with consistent precision while maintaining the linearity correction benefits.
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 reduces linearity errors and improves sensitivity, ensuring the sensor devices operate within acceptable thresholds, providing enhanced reliability and accuracy in mechanical motion to electrical signal conversion.
Implementation Method 1
a primary coil element wound around the bobbin tube configured to, in response to a current input, generate a primary magnetic flux
Implementation Method 2
magnetic interaction between the probe assembly and the primary coil element may induce a signal in the secondary coil element
Data Source
AI summary
Apparatuses, systems, and associated methods of assembly are described that provide for improved sensor devices. An example sensor device includes a bobbin tube that defines a hollow interior. The device includes a primary coil element wound around the bobbin tube configured to, in response to a current input, generate a primary magnetic flux and includes a secondary coil element wound around the primary coil element. In an instance in which the bobbin tube receives a probe assembly therein, magnetic interaction between the probe assembly and the primary coil element is configured to induce a signal in the secondary coil element. Furthermore, a pitch of the secondary coil element varies according to a non-linear, polynomial function along a second length of the bobbin tube so as to reduce linearity error of the sensor device.