Obstacle Determination Device Using Radar Null Point Distance

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Solution Overview

Problem

Existing collision prediction devices face increased control load and accuracy issues when determining obstacles on slopes, as they struggle to differentiate between subjacent objects on descending slopes and collision targets on flat roads using radar output, leading to potential mistaken determinations.

Innovation Solution

An obstacle determination device that analyzes the distance between null points in radar output waveforms to differentiate between collision targets and subjacent objects on slopes, using a reference zone and threshold values to accurately assess collision likelihood, thereby reducing control load and improving accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If slope determination means is added to differentiate subjacent objects from collision targets, then obstacle determination accuracy is improved, but device complexity and control load increase

Engineering Contradiction:
Improveobstacle determination accuracyVSAvoidcontrol load
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts and utilizes only the radar output information that is already available in the collision prediction device, specifically the reception intensity waveform. By analyzing the distance between null points in this existing radar output, the system differentiates subjacent objects from collision targets without adding external sensors or complex determination means, thus improving accuracy while avoiding increased device complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The radar output waveform itself provides the information needed for differentiation. The null points and their distances in the reception intensity waveform contain the characteristics needed to identify whether an obstacle is a subjacent object or collision target. The system uses the radar's own output data for self-diagnosis and differentiation, eliminating the need for separate slope determination means

Inventive Principle:
Principle #25Self-service

2Productivity

If radar output analysis is used to differentiate obstacles, then control load is reduced, but obstacle determination accuracy may deteriorate due to multipath interference

Engineering Contradiction:
Improvecontrol load reductionVSAvoidobstacle determination accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The invention converts the harmful multipath interference into a useful characteristic for differentiation. The multipath causes null points in the reception intensity waveform, and the distance between these null points becomes the key parameter for identifying subjacent objects versus collision targets. By utilizing the pattern created by multipath interference rather than treating it as noise, the system achieves accurate differentiation while maintaining simple radar-only analysis

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

Solution Approach 2:

The invention changes the analysis parameter from general reception intensity to the specific parameter of null point distance. By focusing on the distance between null points in the radar waveform rather than overall signal strength, the system creates a new discriminative parameter that effectively differentiates obstacle types while using only the existing radar output data

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

Enhances collision determination accuracy by preventing mistaken identification of subjacent objects on slopes as collision targets, allowing for precise collision prediction using only radar output, thus reducing the control load associated with collision determination.

Implementation Method 1

detection of an obstacle in front of a vehicle is performed by detecting a reflected wave from the obstacle by a radar

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

since the reflected wave from the obstacle is affected by multipath, a null point where a reception intensity of the reflected wave decreases

Methodology Applied
Scientific EffectMultipath interference: Interference

Data Source

PatentEP2818892B1Obstacle determination device
Publication Date: 2019.12.25 TOYOTA JIDOSHA KK
  • EP2818892B1 patent drawingFigure 1(a)~1(b)
  • EP2818892B1 patent drawingFigure 2(a)~2(b)
  • EP2818892B1 patent drawingFigure 3(a)~3(b)

AI summary

Disclosed is an obstacle determination device (1) including a driving assistance ECU (3) that determines collision with an obstacle detected by output of a radar (2) mounted on a vehicle and performs driving assistance for the vehicle. When a distance of a null-point zone divided by null points where the output of the radar (2) is low is represented as a distance between the null points, the driving assistance ECU (3) determines, in a distant zone that is away from a reference zone that is the null-point zone nearest to a host vehicle in a predetermined range, if the null-point zone of the distance between the null points shorter than the distance between the null points in the reference zone is detected by a predetermined number or more, that the host vehicle does not collide with the detected obstacle.