Resolver With 180-Degree Phase Shift Coils for Noise Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional resolvers face challenges in miniaturization while maintaining detection accuracy and reliability, particularly in micro-resolvers, due to reduced inductance and increased noise susceptibility from magnetic leakage flux and external disturbances.
Innovation Solution
The resolver design incorporates sheet coils with coil portions having the same multipolar pattern on both surfaces, with electrical phases differing by 180°, and uses modulation signals with inverted high-frequency polarity to enhance noise immunity and detection efficiency, along with a magnetic flux correction function to cancel harmonic components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the resolver size is reduced for miniaturization, then the device becomes smaller and lighter, but the inductance decreases and noise susceptibility increases
Solution Approach 1:
The excitation winding is divided into multiple independent coil portions (first coil portion and second coil portion) with different electrical phases. Each coil portion processes signals independently and then combines results, allowing the system to maintain sufficient inductance in each segment while reducing overall resolver size. This segmentation enables micro-miniaturization without sacrificing detection accuracy.
Solution Approach 2:
The patent transitions from single-surface coil winding to multi-surface coil portions, utilizing both front and back surfaces of the resolver structure. By distributing coil portions across multiple dimensions and surfaces, the effective inductance is maintained while the physical footprint is reduced, enabling miniaturization without compromising reliability.
2Reliability
If the drive frequency is increased to compensate for reduced inductance, then the inductance effect is enhanced, but magnetic leakage flux increases causing noise
Solution Approach 1:
By segmenting the excitation winding into multiple coil portions with different electrical phases, the patent achieves the necessary inductance effect at lower drive frequencies. Each coil portion contributes to the overall magnetic field in a controlled manner, preventing excessive magnetic leakage flux that would occur with high-frequency single-coil designs.
Solution Approach 2:
The patent changes the electrical phase parameter of different coil portions to create constructive interference patterns that enhance the effective inductance without requiring high drive frequencies. This parameter modification allows the system to achieve sufficient magnetic coupling while minimizing magnetic leakage flux and associated noise.
3Volume of moving object
If the resolver is miniaturized, then dead space is reduced, but the resolver becomes more susceptible to noise from disturbances
Solution Approach 1:
The patent divides the detection system into multiple coil portions with different electrical phases, creating redundant detection paths. This segmentation allows the system to process signals from multiple independent sources, enabling noise cancellation through differential processing and reducing susceptibility to external disturbances even in compact configurations.
Solution Approach 2:
By implementing multiple coil portions that provide feedback signals with different electrical phases, the system can detect and cancel noise components through signal processing. The feedback mechanism allows real-time compensation for disturbances, maintaining detection accuracy in miniaturized resolvers with reduced dead space.
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 enables miniaturization while ensuring sufficient detection accuracy and stability, reducing noise components and improving reliability by canceling excess magnetic flux and harmonic errors.
Implementation Method 1
The electrical phase of one coil portion Mf . . . is different from the electrical phase of the other coil portion Mr . . . by 180°, thereby coil portions Mf, Mr . . . having the same coil pattern Pc . . . , respectively constituted in a multipolar form are provided on the front and back surfaces of sheet coils Cx . . . constituting at least one winding 2x (2y and 2o) of excitation windings 2x and 2y and the detection winding 3
Implementation Method 2
a modulation signal obtained by modulating a high-frequency signal by the excitation signal is input to the excitation winding, and a detection signal is obtained by demodulating the modulation signal output from the detection winding
Implementation Method 3
when excitation signals V·sin cot and V·cos cot having phases different by 90° are respectively given to the excitation winding, the detection signal output from the detection winding becomes E=V·sin ωt·cos Φ+V·cos ωt·sin Φ=V·sin (ωt+Φ)
Data Source
AI summary
Sheet coils formed in a ring shape to constitute excitation windings and detection winding, and magnetic cores attached to the sheet coils are provided with coil portions of the same coil pattern constituted by a multipole type on the front and back surfaces of sheet coils constituting at least one winding of the excitation windings and detection winding, and the electrical phase of one coil portion in each coil portion is made 180° different from the electrical phase of the other coil portion.