Ultrasonic Sensor Calibration for Environmental Compensation

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Solution Overview

Problem

Existing ultrasonic detection systems face challenges in accurately calibrating for both temperature and humidity effects, leading to inefficiencies and increased costs due to the need for multiple frequencies and complex computing equations, while also requiring separate corrections for each environmental factor.

Innovation Solution

An ultrasonic detection system calibration processing unit that adjusts the reference threshold value based on acquired data from reception signals, using boundary values to distinguish between stable detection and noise, and automatically adjusts the threshold value according to environmental conditions, ensuring accurate distance information processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple receiving elements and multiple frequencies are used to handle humidity changes, then detection precision is maintained, but device complexity and cost increase

Engineering Contradiction:
Improvedetection precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines temperature compensation and humidity compensation into a single integrated system. The control unit performs both temperature correction and humidity correction using one receiving element, merging what would traditionally require separate systems into a unified correction mechanism that reduces overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control unit is designed to perform multiple functions: it calculates temperature correction values, calculates humidity correction values, and integrates both corrections into a single reference threshold value. This multi-functional approach eliminates the need for separate correction systems for temperature and humidity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If complex computing equations are used for humidity correction, then detection precision is maintained, but processing capacity requirements increase

Engineering Contradiction:
Improvedetection precisionVSAvoidprocessing capacity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a simple linear correction model for humidity compensation rather than complex physical equations. The humidity correction value is calculated using a straightforward formula that multiplies the uncorrected reference threshold by a humidity correction coefficient, significantly reducing computational requirements while maintaining adequate precision.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If separate corrections for temperature and humidity are implemented, then environmental factor accuracy is improved, but system complexity increases

Engineering Contradiction:
Improveenvironmental factor accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges temperature correction and humidity correction into a single integrated correction process. The control unit calculates both correction values and combines them to produce a single corrected reference threshold value, eliminating the need for separate correction systems and reducing overall complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system performs preliminary calculations of both temperature correction coefficients and humidity correction coefficients, then integrates them into a single reference threshold value before actual detection. This preliminary integration simplifies the detection process by providing a pre-corrected threshold that accounts for both environmental factors.

Inventive Principle:
Principle #10Preliminary action

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 solution improves the precision of distance information processing by automatically adjusting the reference threshold value, effectively addressing the challenges of temperature and humidity effects, reducing system complexity and cost, and maintaining accurate detection even under varying environmental conditions.

Implementation Method 1

a receiving element that receives reflected waves of the ultrasonic waves transmitted from the transmitting element and converts the reflected waves into reception signals

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

Ultrasonic waves have the property that their sound pressure attenuates due to changes in environmental conditions such as ambient temperature and humidity

Methodology Applied
Scientific EffectSound propagation and attenuation: Sound

Data Source

PatentEP2613172B1Correction processing device for ultrasound detector, correction processing method, and obstacle detector for vehicle
Publication Date: 2018.03.21 ROBERT BOSCH GMBH
  • EP2613172B1 patent drawingFigure 1
  • EP2613172B1 patent drawingFigure 2
  • EP2613172B1 patent drawingFigure 3

AI summary

To provide an ultrasonic detection system calibration processing unit and calibration processing method and an in-vehicle obstacle detection system that can automatically perform, without using an additional sensor or the like, calibration processing for ensuring that computational processing by an ultrasonic detection system can be performed precisely regardless of differences in the ambient environment such as temperature and humidity. The ultrasonic detection system calibration processing unit and calibration processing method acquire data of computational results of distance information found using, among reception signal groups that are output in a state in which ultrasonic waves are being reflected by a predetermined detection subject, reception signals equal to or greater than a predetermined decision threshold value, with the unit and method changing the decision threshold value and acquiring the data in regard to each of the decision threshold values; discriminate, from among the decision threshold values and on the basis of data groups of the computational results that have been acquired, a boundary value between a state in which the detection subject can be stably recognized and a state in which the detection subject cannot be stably recognized; and adjust, on the basis of the boundary value that has been discriminated, a reference threshold value used when performing the computational processing of the distance information.