Digital Phase Tracking Filter With Adaptive Bandwidth for Position Sensing
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Solution Overview
Problem
Existing position sensor technologies face limitations in accuracy and speed due to analog processing, noise interference, and the need for complex filtering techniques, especially at high angular velocities and accelerations.
Innovation Solution
A digital processing approach for position sensor signals using a phase-locked loop filter with a filter selector that adjusts bandwidth based on error signals, allowing for efficient estimation of position, velocity, and acceleration without substantial additional computational resources, and enabling automatic gear-shifting between different dynamic conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If analog filtering techniques are used to reduce noise and improve signal quality, then measurement precision is improved, but device complexity increases and processing speed decreases
Solution Approach 1:
The patent replaces complex analog filtering circuits with a digital phase-locked loop that performs filtering through computational algorithms. The digital processing unit implements a phase tracker that digitally filters position sensor signals, eliminating the need for complex analog filter hardware while achieving comparable or superior noise reduction and signal quality.
2Reliability
If complex filtering techniques are applied to handle high angular velocities and accelerations, then reliability is improved, but processing speed decreases and loss of time increases
Solution Approach 1:
The patent implements a dynamic phase-locked loop with adaptive bandwidth control that adjusts filtering parameters in real-time based on the detected motion conditions. The system automatically modifies its response characteristics to match the dynamic requirements of high-speed applications, maintaining reliability without excessive processing delay.
Solution Approach 2:
The phase-locked loop employs continuous feedback mechanisms where the estimated position is fed back to correct ongoing measurements. This feedback approach allows the system to maintain high reliability through continuous error correction while processing data in real-time, avoiding the need for heavy post-processing operations that would introduce time delays.
3Measurement precision
If multiple sensor elements are processed in parallel to improve signal-to-noise ratio, then measurement precision is improved, but device complexity and computational resources increase
Solution Approach 1:
The patent combines multiple sensor element outputs into a unified phase-locked loop processing pipeline. Instead of independently processing each sensor signal through separate complex filtering circuits, the system merges the signals and applies a single phase-tracking algorithm that inherently averages noise while maintaining precision, thereby reducing overall device complexity.
4Device complexity
If fixed bandwidth filtering is used, then device complexity is reduced, but adaptability to varying dynamic conditions deteriorates
Solution Approach 1:
The patent implements a dynamic bandwidth adjustment mechanism within the phase-locked loop that automatically adapts filtering parameters based on detected motion conditions. The system transitions between different bandwidth settings responsive to acceleration and velocity changes, providing optimal performance across varying dynamic conditions without requiring complex manual configuration.
Data Source
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AI summary
The present invention provides a position sensor device (1) for measuring a position, and a corresponding method (100). The device comprises position sensor elements (2) for generating analog sense signals (Sk), each signal being substantially a same sinusoid function shifted over a different offset phase, an input phase (θi) thereof being representative of the position. The device comprises a digitization circuit (3) for providing a digital signal representative of the input phase (θi) based on the analog sense signals, and a digital processing unit (4). The device outputs an output signal (P) indicative of the position based on a first output (P1) of the processing unit. The processing unit comprises an error signal generator (11) for computing an error signal indicative of a phase difference between the digital signal and a feedback signal, a digital filter (5) for filtering the error signal to generate the first output, a feedback path (6) for providing the feedback signal based on the first output, and a filter selector (7) to select a filter to be applied from different filters, wherein at least one input on which a common filter circuit operates is scaled differently for each of the different filters to select different filter bandwidths.