C-Shaped Inductive Angular Sensor Tilt Sensitivity Reduction
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Solution Overview
Problem
C-shaped inductive angular sensors suffer from lower accuracy and increased sensitivity to mechanical mounting tolerances, particularly mechanical tilt, compared to O-shaped sensors.
Innovation Solution
A C-shaped inductive angular sensor arrangement with a target having a rotational symmetric shape and a coil configuration where the detection coils define a first opening angle smaller than 330° and the excitation coil defines a second opening angle larger than the first, with a target duty cycle between 10% to 45% and a transmitter coil side opening between 25% to 75% of the target angular period, reducing intrinsic non-linearity and sensitivity to tilt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If C-shaped inductive angular sensor arrangement is used, then substrate size is reduced and compactness is improved, but measurement precision and accuracy deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the target duty cycle (ratio of lobe area to total target area) to a specific range of 10-45%, and by adjusting the transmitter coil side opening angle to 25-75% of the target angular period. These parameter optimizations enable the C-shaped sensor to achieve accuracy comparable to O-shaped sensors while maintaining its compact substrate size advantage.
2Device complexity
If C-shaped inductive angular sensor arrangement is used, then device complexity is reduced, but sensitivity to mechanical tilt increases
Solution Approach 1:
The patent reduces sensitivity to mechanical tilt through parameter optimization, specifically by setting the target duty cycle between 10-45% and the transmitter coil side opening between 25-75% of the target angular period. These parameter choices minimize the impact of mechanical misalignment and tilt errors while maintaining the simpler C-shaped structure.
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 provides improved accuracy and reduced sensitivity to mechanical tilt, achieving low intrinsic non-linearity and compactness without the need for excessive space, while maintaining low intrinsic non-linearity error.
Implementation Method 1
The transmitter coil and the receiving coils are inductively coupled to one another. The excitation coil may for example be excited with an AC signal, which induces eddy currents in the target.
Implementation Method 2
The excitation coil may for example be excited with an AC signal, which induces eddy currents in the target. The receiving coils will generate signals caused by the eddy currents in the target
Data Source
Figure 1(a)~1(f)
Figure 2(a)~2(c)
Figure 3(a)~3(b)
AI summary
C-shaped inductive angular sensor arrangement for determining an angular position of a target rotatable about an axis, comprising: said target having a rotational symmetric shape with a number (N) of lobes, and having an angular periodicity (Tap) of 360° divided by said number of lobes; a coil arrangement comprising at least one excitation coil (301) and a plurality of detection coils (302, 303, 304), wherein the plurality of detection coils define a first opening angle (Roa) smaller than 330°, and wherein the at least one excitation coil (301) defines a second opening angle (Eoa) larger than the first opening angle (Roa); wherein said lobes of the target define an opening angle (Loa) in the range from 10% to 45% of said angular periodicity (Tap) of the target. An angular sensor system, further comprising a substrate and/or a semiconductor device. A motor assembly, further comprising an electrical motor.