Ultrasonic Sensor Calibration Using Side-Lobe Ground Echoes

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing ultrasonic sensors in vehicle ultrasound-based driver assistance systems face challenges in achieving accurate calibration due to the disruptive nature of side lobes, which are typically suppressed rather than utilized for calibration.

Innovation Solution

A method that utilizes side lobes for calibration by emitting ultrasonic pulses with the main lobe directed away from the ground, detecting side-lobe ground echoes, and using these echoes to ascertain correction values for elevation and azimuth angles, thereby enhancing precision and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If side lobes are suppressed to avoid disruptive effects, then measurement reliability improves, but calibration precision deteriorates

Engineering Contradiction:

Improvemeasurement reliabilityVSAvoidcalibration precision

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent converts the previously harmful side lobes into a beneficial calibration resource. By directing side lobes toward the ground and using the resulting side-lobe ground echoes, the system transforms what was considered disruptive interference into a useful signal for determining correction values for elevation and azimuth angles, thereby improving calibration precision without compromising measurement reliability

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Instead of suppressing side lobes as conventionally done, the patent inverts the approach by intentionally utilizing side lobes for calibration purposes. The emission is directed such that side lobes strike the ground and reflect back, allowing the system to extract calibration information from these previously discarded signals

Inventive Principle:

Principle #13The other way round (Inversion)

2Use of energy by moving object

If main lobe is directed toward ground for calibration, then calibration signal strength improves, but measurement accuracy deteriorates due to wide coverage including erroneous reflections

Engineering Contradiction:

Improvecalibration signal strengthVSAvoidmeasurement accuracy

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent applies local quality by using the side lobe's narrower spatial coverage compared to the main lobe. The side lobe strikes the ground in a narrow region, providing localized calibration signals that are less susceptible to erroneous reflections from distant or irrelevant surfaces, thereby maintaining signal strength while improving measurement accuracy

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the ultrasonic pulse energy into distinct main lobe and side lobe components with different directional characteristics. By utilizing the side lobe specifically for ground calibration while keeping the main lobe directed away from the ground, the system separates calibration functions from normal operation functions, improving overall measurement accuracy

Inventive Principle:

Principle #1Segmentation

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 allows for precise calibration of ultrasonic sensors, effectively excluding erroneous measurements and achieving high accuracy while being cost-effective and applicable during vehicle use, such as during parking maneuvers.

Implementation Method 1

emitting a number, for example 1 to 50, of ultrasonic pulses, wherein each ultrasonic pulse is emitted to form a main lobe and a side lobe

Methodology Applied

Scientific EffectUltrasonic pulse emission: Ultrasound

Implementation Method 2

detecting a plurality, for example 5 to 100, of side-lobe ground echoes with the ultrasonic sensor

Methodology Applied

Scientific EffectAcoustic reflection: Reflection

Data Source

PatentUS20260063777A1Method for calibrating an ultrasonic sensor of an ultrasound-based driver assistance system of a vehicle and vehicle

Publication Date: 2026.03.05 ROBERT BOSCH GMBH

AI summary

A method for calibrating an ultrasonic sensor of an ultrasound-based driver assistance system of a vehicle. The vehicle is placed on a ground. The method includes: a) prespecifying a height of the ultrasonic sensor from the ground or ascertaining the height of the ultrasonic sensor from the ground; b) emitting a number of ultrasonic pulses, wherein each ultrasonic pulse is emitted to form a main lobe and a side lobe, and the emission takes place such that the side lobe is directed toward the ground; c) detecting a plurality of side-lobe ground echoes; d) ascertaining and storing a correction value for detecting an elevation angle with the ultrasonic sensor and/or ascertaining and storing a correction value for detecting an azimuth angle with the ultrasonic sensor based on a number of the plurality of side-lobe ground echoes detected in step c).