Ultrasonic Sensor Blindness Detection via Multi-Cycle Impedance Analysis

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Solution Overview

Problem

Current methods for detecting sensor blindness in vehicle-mounted ultrasonic sensors are not reliable, particularly in conditions where sensors are affected by dirt, snow, or other environmental factors, leading to inaccurate assessments of sensor functionality.

Innovation Solution

A method and device that perform multiple independent measurements for each sensor in a group, evaluating physical variables and ultrasonic signals to determine blindness risks, using a combination of impedance measurements, crosstalk signal amplitudes, and signal levels to calculate blindness and confidence levels, with the aid of filters and algorithms to enhance detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If single measurement methods are used for sensor blindness detection, then the detection process is simple and fast, but the reliability and accuracy of blindness detection deteriorates

Engineering Contradiction:
Improvesensor blindness detection reliabilityVSAvoiddetection method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The detection process is segmented into multiple independent measurement cycles, each evaluating different physical quantities (impedance, crosstalk signal amplitude, signal level) separately. This segmentation allows comprehensive assessment while maintaining clarity in each individual measurement step.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic measurement cycles where multiple independent measurements are performed sequentially. Each cycle evaluates different parameters, and the results are combined to determine overall sensor functionality. This periodic approach enhances reliability through repeated assessment without requiring simultaneous complex multi-parameter measurement.

Inventive Principle:
Principle #19Periodic action

2Measurement precision

If multiple independent measurements are performed for each sensor, then the detection accuracy and reliability improves, but the measurement time and processing complexity increases

Engineering Contradiction:
Improveblindness detection precisionVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The measurement process is designed as a continuous sequence of independent measurement cycles that can be performed back-to-back without interruption. Each cycle completes a full evaluation of multiple parameters, and the system continuously monitors sensor status through these sequential measurements, maintaining useful action throughout the process.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent performs preliminary independent measurements of various physical quantities before making a final blindness determination. By pre-evaluating impedance, crosstalk signals, and signal levels in separate measurement cycles, the system prepares comprehensive data that speeds up the final assessment process.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If environmental factors like dirt and snow are present, then sensor functionality is degraded, but single measurement methods cannot reliably distinguish between environmental degradation and sensor blindness

Engineering Contradiction:
Improvefunctionality assessment reliabilityVSAvoidenvironmental interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent evaluates different local characteristics of sensor performance by measuring distinct physical quantities (electrical impedance, crosstalk signal amplitude, ultrasonic signal level) separately. Each measurement probes a different aspect of sensor functionality, allowing the system to identify whether degradation is due to environmental factors or actual sensor blindness based on the pattern of results across multiple measurement locations in the parameter space.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system performs more measurements than the minimum single measurement by conducting multiple independent measurement cycles evaluating different physical quantities. This excessive measurement approach ensures that environmental factors affecting one parameter do not lead to false blindness conclusions, as other parameters provide compensating information about actual sensor status.

Inventive Principle:
Principle #16Partial or excessive 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 approach provides reliable detection of sensor blindness by obtaining redundant and complementary information, allowing for more precise determination of existing blindness, thereby ensuring accurate assessment and maintenance of sensor functionality.

Implementation Method 1

each designed to transmit and receive ultrasonic signals

Methodology Applied
Scientific EffectUltrasonic signal transmission and reception: Ultrasound

Implementation Method 2

ground clutter signals, also known as ground echoes, received by the sensor and generated as a result of the transmission of ultrasonic signals

Methodology Applied
Scientific EffectGround reflection: Reflection

Implementation Method 3

a first measurement for each sensor comprises a step of repeatedly measuring an impedance value of the corresponding sensor

Methodology Applied
Scientific EffectImpedance measurement: Electrical Impedance Tomography

Data Source

PatentEP3073287B1Method and device for determining a blindness of any sensor of a sensor array
Publication Date: 2020.05.06 ROBERT BOSCH GMBH
  • EP3073287B1 patent drawingFigure 1
  • EP3073287B1 patent drawingFigure 2~3
  • EP3073287B1 patent drawing

AI summary

The present invention relates to a method for determining the blindness (BLi) of each sensor in a sensor group comprising at least one sensor from several sensors mounted on a vehicle, each configured to transmit and receive ultrasonic signals. The method includes a step of performing several independent measurements (Mi1, Mi2, Mi3, Mi4) for each sensor in the sensor group. In each of the measurements (Mi1, Mi2, Mi3, Mi4) performed for each sensor in the sensor group, at least one blindness risk (BRi1, BRi2, BRi3, BRi4, BRi5) is determined for the corresponding sensor by evaluating a physical parameter of the corresponding sensor or by evaluating ultrasonic signals received by the corresponding sensor.The procedure further includes a step of determining a blindness (BLi) and an associated confidence (Ki) of each sensor in the sensor group, based on the blindness risks (BRi1, BRi2, BRi3, BRi4, BRi5) determined for the respective sensor.