Coded Ultrasonic Transducer Echo Identification via Correlator Peak Ranking
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Solution Overview
Problem
Existing ultrasonic ranging systems in automotive applications face challenges in accurately detecting multiple obstacles simultaneously due to ambiguity in echo identification from multiple transducers, leading to delayed collision detection and reduced accuracy.
Innovation Solution
The implementation of frequency-modulation or phase-modulation coded burst signals allows concurrent operation of multiple ultrasonic transducers, enabling distinct identification of echoes through correlator processing, peak detection, and validation logic, thereby reducing ambiguity and enhancing detection speed and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple ultrasonic transducers operate concurrently to improve detection speed and coverage, then productivity and detection responsiveness are improved, but ambiguity in echo identification increases and measurement precision deteriorates
Solution Approach 1:
The patent applies segmentation by assigning unique coded burst patterns to each ultrasonic transducer. Each transducer emits a distinct code sequence, allowing the receiver to segment and identify echoes from specific transducers through correlation processing. This resolves the ambiguity that would otherwise arise from concurrent operation of multiple transducers, enabling both high productivity and precise measurement.
Solution Approach 2:
The patent changes the temporal and spectral parameters of ultrasonic bursts by using frequency-modulation or phase-modulation coded sequences. These parameter variations create unique signatures for each transducer's emissions, enabling the receiver to distinguish between simultaneous echoes from different transducers through matched filtering and correlation techniques.
2Device complexity
If simple ultrasonic burst signals are used to reduce system complexity, then device complexity is reduced, but the ability to distinguish true reflections from echoes deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-defining and storing transmission templates that characterize the expected coded burst signals from each transducer. These templates are prepared in advance and used during correlation processing to efficiently identify and validate echoes. This preliminary preparation enables reliable distinction between true reflections and spurious echoes without requiring complex real-time analysis.
Solution Approach 2:
The patent implements feedback through a validation mechanism that compares detected peak characteristics against expected patterns from the transmission templates. The system uses peak amplitude, timing, and correlation strength as feedback parameters to validate whether a detected echo corresponds to a true reflection or should be rejected as noise or interference from other transducers.
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 improves the speed and responsiveness of ultrasonic detection systems by distinguishing true reflections from echoes, allowing for simultaneous operation of multiple transducers and enhancing the accuracy of obstacle detection, particularly in time-critical applications like collision avoidance.
Implementation Method 1
an ultrasonic transducer that is configured to emit the burst signal as an ultrasonic acoustic signal and to transduce a reflected acoustic signal
Implementation Method 2
The correlator correlates a received signal, sampled from the transduced reflected acoustic signal, with a transmission template characterizing a frequency-modulation or phase-modulation code of the generated burst signal
Implementation Method 3
The round-trip time of the ultrasonic signals is measured so that distance to the object can be determined
Data Source
AI summary
In an ultrasonic detection system that uses frequency-modulation or phase-modulation coding to distinguish emitted bursts from multiple transducers, a receiver associated with a transducer uses peak search, peak buffer, and peak rank stages in one or more receiver signal processing paths to identify valid received ultrasonic signal envelope peaks in correlator outputs. The peak rank stage can support different modes respectively designed to handle one code, two or more codes, or two or more codes with support for Doppler frequency shift detection. Valid peak information (e.g., amplitude and time) can be reported to a central controller and/or stored locally in a fusion stage to generate more intelligent information for targets or obstacles using peaks from multiple bursts.