PAS Sensor Damping for Ultra-Short Range Obstacle Detection
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Solution Overview
Problem
Current parking assist sensors (PAS) are limited by a reverberation period, which prevents them from detecting obstacles at ultra-short ranges due to reverberations exceeding the echo detection threshold, restricting the minimum detection distance and sensitivity, especially in ranges within 5 to 7 centimeters.
Innovation Solution
The implementation of a process that involves obtaining transducer characteristics, determining a desired transmission frequency, selecting a reverberation time, and generating damping signals to reduce reverberation periods, allowing for earlier echo detection and improved sensitivity at ultra-short ranges by using counter-phase driving pulses to dampen transducer reverberations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the transducer emits ultra-sonic ranging signals, then obstacle detection is enabled, but reverberations exceed the echo detection threshold preventing ultra-short range detection
Solution Approach 1:
The patent applies counter-phase damping pulses that convert the harmful reverberation energy into beneficial dampening action. By applying pulses with opposite phase to the reverberation, the system transforms the interfering reverberation signals into a force that actively reduces and eliminates the reverberation, enabling ultra-short range obstacle detection within 5 to 7 centimeters.
2Length of stationary object
If the reverberation period is reduced by applying damping signals, then minimum detection distance is reduced, but the system complexity increases
Solution Approach 1:
The system applies damping pulses in advance and in synchronization with the expected reverberation period. By pre-calculating and applying the counter-phase pulses at the optimal timing, the system proactively reduces reverberation before it can interfere with echo detection, thereby reducing the minimum detection distance without requiring complex real-time signal processing.
3Measurement precision
If damping signals are applied to reduce reverberation, then ultra-short range detection is enabled, but energy consumption increases
Solution Approach 1:
The system applies damping pulses with controlled amplitude and duration that are sufficient to reduce reverberation below the detection threshold but not excessive. By applying just the right amount of damping action—neither too little nor too much—the system achieves ultra-short range detection capability while minimizing additional energy consumption beyond what is required for normal operation.
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 reduces the reverberation period and minimum detection distance, enabling PAS sensors to detect obstacles within 5 to 7 centimeters by shortening the time it takes for reverberations to fall below the echo detection threshold, thereby enhancing sensitivity and detection capability at ultra-short ranges.
Implementation Method 1
The ranging signals may be emitted as one or more pulses (or bursts of ultra-sonic sound waves). A non-limiting example of a transducer and one or more circuit elements for use therewith are described in paragraph [0030] of the '543 App.
Implementation Method 2
generating a damping signal command, and outputting each of the ranging signal command and the damping signal command. For at least one embodiment, the damping signal command may result in a dampening, at the damping ratio, of transducer reverberations arising from the ranging signal.
Data Source
AI summary
Embodiments include devices, system and processes for facilitating ultra-short range detection of obstacles using a PAS sensor. A process may include obtaining a correlation of at least two characteristics of a transducer; determining a given transmission frequency and selecting a reverberation time desired for the transducer; obtaining a damping ratio corresponding to the selected reverberation time; generating a ranging signal command; generating a damping signal command; and outputting each of the ranging signal command and the damping signal command. The ranging signal command may instruct a PAS sensor to drive the transducer to output a ranging signal at the given transmission frequency, at a transmission amplitude, and at a transmission phase and the damping signal command results in a dampening, at the damping ratio, of transducer reverberations arising from the ranging signal. The damping ratio may be between thirty percent (30%) and eighty percent (80%) of the transmission amplitude.