Resolver Decoder Hardware Filtering for Accurate Motor Angle Estimation
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Solution Overview
Problem
Current resolver decoders for traction motor control in electrical vehicles require high hardware costs and computing power to accurately estimate the motor shaft angle, which is essential for efficient motor control.
Innovation Solution
A digital resolver decoder circuit with hardware filters and rectifiers is implemented, including tapped delay line filters to calculate weighted sums of analog signals from resolver windings and a rectifier to adjust signs based on the sine wave cycle, allowing for accurate angle estimation with reduced computational load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional resolver decoders are used to accurately estimate the motor shaft angle, then measurement precision is improved, but device complexity and computing power requirements increase
Solution Approach 1:
The patent replaces complex software-based angle estimation algorithms with dedicated hardware circuits (filter circuits and rectifier circuits) that perform the same function. The filter circuits calculate weighted sums of digital signals, and the rectifier adjusts signs of these weighted sums, effectively substituting computational tasks with hardware operations that achieve accurate angle estimation with lower computing power requirements
Solution Approach 2:
The patent introduces intermediate hardware components (filter circuits and rectifier circuits) between the resolver output and the angle estimation process. These intermediary circuits process the resolver signals through weighted summation and sign adjustment, providing accurate angle information without requiring high-power computing resources
2Measurement precision
If more computational resources are allocated to angle estimation, then measurement precision is improved, but productivity and real-time performance are reduced
Solution Approach 1:
The patent substitutes computationally intensive algorithms with dedicated hardware circuits that perform angle estimation operations in real-time. The filter circuits and rectifier circuits execute weighted summation and sign adjustment operations at hardware speed, eliminating the need for high-power computing resources and enabling real-time angle estimation without compromising productivity
Data Source
AI summary
A resolver decoder circuit includes: a first filter circuit configured to calculate a first weighted sum of a first digital signal over a pre-determined period of time, where the first digital signal includes first digital samples of a first analog signal from a sine winding of a resolver; a second filter circuit configured to calculate a second weighted sum of a second digital signal over the pre-determined period of time, where the second digital signal includes second digital samples of a second analog signal from a cosine winding of the resolver, where the first and the second analog signals are configured to be induced by a sine signal applied to an input winding of the resolver; and a rectifier configured to generate a first output and a second output by adjusting a first sign of the first weighted sum and adjusting a second sign of the second weighted sum, respectively.