Ultrasonic Distance Sensor Post-Oscillation Echo Detection

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Solution Overview

Problem

Existing distance sensors face challenges in reliably detecting echo signals in the post-oscillation interval due to their low intensity, especially at close ranges, leading to limited near detection range and susceptibility to interference.

Innovation Solution

The method involves transmitting a pulse, detecting the post-pulse signal, determining an energy value by integrating the signal over a time period, and detecting echo signals based on this energy value, using a model signal to differentiate between ringing and echo signals, and reinitializing the model after echo detection to enhance sensitivity and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If the distance sensor operates in the post-oscillation interval to detect close-range objects, then the near detection range is improved, but the echo signal intensity becomes too weak to distinguish from ringing interference

Engineering Contradiction:
Improvenear detection rangeVSAvoidecho signal detection reliability
Core Design Contradiction:
Length of stationary objectVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by evaluating multiple signal parameters (amplitude, frequency, phase) before making an echo detection decision. The system pre-calculates expected ringing characteristics and compares incoming signals against these predictions, allowing reliable echo detection even when echo intensity is comparable to ringing levels in the post-oscillation interval

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes parameters by analyzing multiple signal characteristics simultaneously (amplitude, frequency, phase) rather than relying on a single parameter. This multi-parameter approach allows the system to distinguish echo signals from ringing interference even when their intensities are similar, thereby improving measurement precision in the post-oscillation interval

Inventive Principle:
Principle #35Parameter changes

2Length of stationary object

If traditional echo detection methods are used in the post-oscillation interval, then the system can operate at close ranges, but the detection becomes susceptible to interference from ringing signals

Engineering Contradiction:
Improvedetection rangeVSAvoidringing interference
Core Design Contradiction:
Length of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies feedback by continuously monitoring signal characteristics and using this information to adjust detection thresholds and parameters in real-time. The system evaluates the actual ringing behavior and uses this feedback to improve echo detection accuracy, reducing susceptibility to ringing interference while maintaining close-range detection capability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses signal processing algorithms as intermediaries to separate echo signals from ringing interference. By introducing computational mediation that analyzes multiple signal parameters and compares them against expected ringing patterns, the system can identify true echoes even in the presence of strong ringing signals

Inventive Principle:
Principle #24Intermediary (Mediator)

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 detection of echo signals in the post-oscillation interval, expanding the close detection range and reducing interference, resulting in more reliable and robust data processing for driver assistance systems, particularly in parking scenarios.

Implementation Method 1

distance sensors, which measure the distance to objects in the environment of the vehicle based on a transmitted pulse-echo method

Methodology Applied
Scientific EffectPulse-echo method: Echo

Implementation Method 2

with a sound propagation speed of about 300 m/s

Methodology Applied
Scientific EffectSound propagation: Sound

Implementation Method 3

there is a post-oscillation interval of about 1 ms

Methodology Applied
Scientific EffectPost-oscillation: Vibration

Implementation Method 4

During ringing, the frequency of the ringing approaches the resonance frequency

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3069164B1Method for detecting the surrounding of a vehicle
Publication Date: 2020.11.11 ROBERT BOSCH GMBH
  • EP3069164B1 patent drawingFigure 1~2
  • EP3069164B1 patent drawingFigure 3

AI summary

The invention relates to a method for detecting the surroundings of a vehicle using a distance sensor, comprising the following steps: a) an emitted pulse is emitted, b) a reverberation signal (34) is detected in a reverberation interval (26), c) an energy value is determined by integrating the reverberation signal (34) over a period of time in the reverberation interval (26), d) echo signals (30) in the reverberation interval (26) are determined based on the determined energy value. The invention also relates to a computer program and to a driver assistance system for carrying out said method.