Covered Ultrasonic Sensor Threshold Adaptation

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Solution Overview

Problem

Concealed ultrasonic sensors in vehicles face challenges in maintaining an optimal field of view due to temperature-dependent material properties of vehicle parts, leading to reduced sensitivity at low temperatures and increased sensitivity at high temperatures, which affects the detection of objects and noise signals.

Innovation Solution

Adapting the threshold value of the ultrasonic sensor based on the directional characteristic influenced by the vehicle part's properties, using temperature or resonant frequency relationships to adjust the threshold dynamically, ensuring reliable detection of objects regardless of ambient conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the ultrasonic sensor is concealed behind a vehicle part, then aesthetic appearance is improved, but the field of view and detection sensitivity are reduced due to material properties of the vehicle part

Engineering Contradiction:
Improveaesthetic appearanceVSAvoiddetection sensitivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent dynamically adjusts the threshold parameter based on temperature changes. As temperature varies, the material properties of the vehicle part change, affecting the directional characteristic. By adapting the threshold to temperature, the system compensates for the reduced sensitivity caused by the concealed installation, maintaining reliable detection while preserving aesthetic appearance.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a fixed threshold value is used for noise filtering, then device complexity is reduced, but detection reliability deteriorates under varying temperature conditions

Engineering Contradiction:
Improvethreshold adjustment mechanismVSAvoiddetection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a dynamic threshold adjustment mechanism where the threshold value changes based on temperature conditions. This dynamic approach allows the system to adapt to varying material properties of the vehicle part at different temperatures, ensuring consistent detection reliability without requiring complex mechanical adjustment mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses temperature as feedback to adjust the threshold value. By monitoring temperature changes and corresponding adjustments to the threshold, the system automatically compensates for environmental variations, maintaining optimal detection performance across different operating conditions.

Inventive Principle:
Principle #23Feedback

3Reliability

If the threshold is lowered to improve detection sensitivity, then object detection capability is improved, but false alarms from noise signals increase

Engineering Contradiction:
Improveobject detection capabilityVSAvoidfalse alarms
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent adjusts the threshold parameter dynamically based on temperature conditions. At different temperatures, the material properties of the vehicle part change, affecting the directional characteristic and noise profile. By adapting the threshold to match current temperature conditions, the system optimizes the balance between detecting weak echo signals and filtering out noise, preventing false alarms while maintaining high detection sensitivity.

Inventive Principle:
Principle #35Parameter changes

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 adaptive approach enhances the ultrasonic sensor's field of view by adjusting the threshold value according to temperature changes, ensuring reliable detection of objects at both high and low temperatures, reducing false alarms and expanding the detection area.

Implementation Method 1

Through the ultrasonic sensors, a signal is sent out, the echo whose echo is returned from the ultrasonic sensors to an obstacle from the ultrasonic sensors

Methodology Applied
Scientific EffectUltrasonic reflection: Echo

Implementation Method 2

the known propagation speed of the signal, the distance between the vehicle and the reflective obstacle can be calculated

Methodology Applied
Scientific EffectSound propagation: Sound

Implementation Method 3

a membrane of an ultrasound generator is connected to a vehicle part such that the vehicle part and the membrane together form a oscillable system which radiates the ultrasonic signals

Methodology Applied
Scientific EffectMechanical oscillation: Vibration

Implementation Method 4

determining a resonant frequency of a oscillable system formed from the membrane and the vehicle part

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3580583B1Method for operating an ultrasonic sensor, installed in a covered manner, of a vehicle
Publication Date: 2021.12.08 ROBERT BOSCH GMBH
  • EP3580583B1 patent drawingFigure 1
  • EP3580583B1 patent drawingFigure 2a~2b
  • EP3580583B1 patent drawingFigure 3

AI summary

The invention relates to a method for operating an ultrasonic sensor (14) of a vehicle (10), wherein the ultrasonic sensor is installed in a covered manner so that a membrane (16) of the ultrasonic sensor (14) is connected to a vehicle part (12), wherein the current properties of the vehicle part (12) influence a directional characteristic of the ultrasonic sensor (14) and wherein a threshold value for hiding interference signals is used in the case of pulse-echo measurements using the ultrasonic sensor (14). The threshold value is adapted to the directional characteristic of the ultrasonic sensor (14) specified by the current properties of the vehicle part (12). Additional aspects of the invention relate to a driver assistance system (60) comprising at least one ultrasonic sensor (14), installed in a covered manner, and a computer program product, which is designed to carry out the method.