Linear Inductive Sensor for Rotational Angle Measurement
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Solution Overview
Problem
Rotary inductive sensors face measurement errors and space constraints when trying to measure the angular position of a mechanical component, as they typically require the target to be positioned at one end of the component, which is not always feasible, especially in applications like motor vehicles where both ends are fixed.
Innovation Solution
A linear inductive sensor with a metal spiral target mounted on a ring that can be positioned anywhere on the mechanical component, transforming rotational movement into a linear movement, allowing for absolute measurement of rotational angles and enabling the sensor to be placed at various positions, including the periphery of the component.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a rotary inductive sensor is used to measure angular position, then the measurement function is achieved, but the sensor requires the target to be positioned at one end of the mechanical component, which creates space constraints and positioning limitations
Solution Approach 1:
The patent inverts the conventional rotary sensor configuration by using a linear sensor design where the target is positioned at the end of a linearly extending arm that rotates about a pivot point. This inversion allows the sensor to be positioned at the periphery of the mechanical component rather than requiring the target to be at the end of the component, thereby improving positioning flexibility while maintaining measurement capability.
Solution Approach 2:
The patent transitions from a conventional rotary sensor configuration to a linear sensor configuration by introducing a rotational dimension. The linear sensor arm rotates about a pivot point, converting the linear measurement capability into angular measurement capability. This dimensional transformation allows the sensor to be positioned anywhere along the periphery of the mechanical component, resolving the positioning flexibility issue.
2Ease of operation
If the target is positioned at one end of the mechanical component, then the sensor can function, but this creates space constraints especially when both ends are fixed as in motor vehicle applications
Solution Approach 1:
Instead of positioning the target at the end of the mechanical component, the patent positions the linear sensor at the periphery with its arm extending toward the component. This inverted configuration allows the sensor to be installed at various positions along the periphery rather than being constrained to the ends, significantly improving installation flexibility for applications like motor vehicles where both ends are fixed.
Solution Approach 2:
The patent creates a universal sensor configuration that can be installed at multiple positions (different peripheral locations) on the mechanical component. The linear sensor with rotating arm design provides multi-position installation capability, making the sensor adaptable to various installation scenarios including cases where both ends of the component are fixed.
3Adaptability or versatility
If a linear inductive sensor configuration is used instead of rotary sensor, then the sensor can be positioned anywhere on the mechanical component, but the measurement of rotational movement must be transformed from linear measurement principle
Solution Approach 1:
The patent applies dimensional transformation by using a linear sensor to measure the position of a rotating arm. The linear sensor measures the linear displacement of the arm's end point, while the rotation is achieved by pivoting the arm about a fixed point. This transforms the angular measurement problem into a linear measurement problem, allowing positioning anywhere along the arc while maintaining measurement simplicity.
Solution Approach 2:
The patent introduces a rotating arm with a pivot point as an intermediary mechanism. The linear sensor measures the position of the arm's end point, and the rotation is derived from this linear measurement through geometric relationships. This intermediary approach simplifies the measurement transformation by using a mechanical lever arm rather than requiring complex angular measurement transformations.
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 configuration provides a compact, versatile inductive sensor capable of accurately measuring rotational angles, overcoming space limitations and measurement errors, and allowing for the use of existing ring-shaped components, thus enhancing the range of possible positions for the sensor.
Implementation Method 1
the primary circuit being flowed through by a high-frequency alternating current capable of inducing an electrical voltage in each of said at least two secondary circuits
Implementation Method 2
The modification of the coupling of the primary with the secondaries takes place by means of the electromagnetic skin effect
Data Source
AI summary
Disclosed is a linear inductive sensor having, on the one hand, a fixed part of transformer type with a primary circuit and at least two secondary circuits, the primary circuit being flowed through by a high-frequency alternating current capable of inducing an electrical voltage in each of the at least two secondary circuits and, on the other hand, a moving part with a target intended to be fixed on a mechanical component executing a movement in rotation about an axis, which the inductive sensor measures angularly. The target is a metal spiral carried by a circular face of a ring having a central recess, the ring being intended to be fixed on the component while being concentric therewith, the spiral projecting axially from the ring while making at least one revolution around and moving away from the recess.