Resolver Angle Verification Using Switch Matrix Signal Injection
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Solution Overview
Problem
Resolver circuits in certain applications cannot determine position accurately beyond a 90° range without knowing the quadrant, leading to measurement inaccuracies due to complex synchronization requirements and potential errors in DAC channels.
Innovation Solution
A novel configuration using an isolator and switch matrix simulates variable angle positions at the resolver secondary interface, eliminating synchronization issues by mimicking exact angles through signal polarity and short conditions, allowing for high-accuracy testing with a reduced number of angle measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a multiplexer is used to sample signals successively, then device complexity is reduced, but measurement precision deteriorates due to inability to determine position beyond 90° range
Solution Approach 1:
The patent introduces a signal injection circuit as an intermediary device that injects test signals into the resolver secondary coils. This mediator enables the resolver interface circuit to be tested without requiring actual mechanical rotation of the resolver, thereby simplifying the testing apparatus while maintaining measurement accuracy across all quadrants through electrical signal simulation rather than physical positioning.
Solution Approach 2:
The patent creates electrical copies of resolver output signals by injecting synthesized sine and cosine test signals into the secondary coils. These copied signals replicate what the resolver would produce at specific angular positions, allowing the interface circuit to be verified for full 360° operation without physically rotating the resolver through all positions, thus maintaining measurement precision while reducing testing complexity.
2Measurement precision
If simultaneous monitoring of excitation and output signals is implemented, then measurement precision is improved, but device complexity increases due to synchronization requirements
Solution Approach 1:
The signal injection circuit serves as an intermediary that eliminates the need for complex synchronization between excitation and output signal monitoring. By injecting test signals directly into the secondary coils with known phase relationships, the system can verify interface circuit functionality without requiring simultaneous sampling and synchronization of multiple signals, thus maintaining measurement precision while reducing system complexity.
Solution Approach 2:
The patent applies preliminary action by pre-configuring the signal injection circuit to generate test signals with predetermined phase relationships before actual testing begins. The sine and cosine test signals are prepared in advance with correct 90° phase separation, eliminating the need for real-time synchronization during the testing process, thereby maintaining accuracy while simplifying the overall system.
3Adaptability or versatility
If DAC channels are used to generate test signals, then adaptability is improved, but measurement precision deteriorates due to potential DAC errors
Solution Approach 1:
The patent extracts the critical signal generation function from the DAC channels and relocates it to a dedicated signal injection circuit. This separation removes the potential DAC errors from the test signal generation path while maintaining the adaptability to generate various test signals. The signal injection circuit uses analog signal synthesis methods that are less susceptible to quantization errors, thereby improving measurement precision while preserving testing versatility.
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 simplifies testing by reducing synchronization complexities and measurement errors, ensuring high accuracy and cost-effectiveness in resolver angle verification.
Implementation Method 1
a switching matrix comprising an excitation input connected to the excitation signal output, a first output connected to the sine signal input, and a second output connected to the cosine signal input, wherein the switching matrix further comprises a set of switches configured to route an excitation signal from the resolver circuit to simulate a sine and cosine signal output corresponding to a specified angle
Implementation Method 2
an isolator connected between the excitation signal output and the excitation input of the switching matrix
Data Source
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AI summary
A system and method for testing a resolver circuit is provided. Aspects include a resolver circuit (202) including an excitation signal output, a sine signal input, and a cosine signal input, a switching matrix (204) comprising an excitation input connected to the excitation signal output, a first output connected to the sine signal input, and a second output connected to the cosine signal input, wherein the switching matrix further includes a set of switches configured to route an excitation signal from the resolver circuit to mimic a sine and cosine signal output corresponding to a specified angle for a resolver sensor, a controller (208) configured to operate the resolver circuit to output an excitation signal, determine an angle value based on a sine signal received and a cosine signal received from the switching matrix, and compare the angle value to the specified angle to determine a fault condition in the resolver circuit.