Dynamic Kalman Filter Response for Road Edge Estimation

Solution Overview

Problem

Conventional lane recognition technologies face delays in responding to environmental changes, particularly when vehicles enter curves, and are unstable due to factors like faded road markings, cracks, and coal-tar repairs, leading to reduced accuracy in estimating road state values.

Innovation Solution

A travelling road estimating apparatus and method that extracts edge points from images, calculates their coordinates, and adjusts the response level of a Kalman filter based on the stability of edge point accuracy, ensuring a balanced response for straight and curved road sections, and reducing the impact of unstable conditions like coal-tar lines and cracks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the response level of the filter is increased to improve response speed when entering curves, then the response speed improves, but the stability of edge point extraction deteriorates due to reduced accuracy from road conditions like faded markings and cracks

Engineering Contradiction:

Improveresponse speed of filterVSAvoidstability of edge point extraction

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The filter response level is dynamically adjusted based on road condition assessment. The system transitions from a static filter configuration to a dynamic one where the response level changes according to the detected stability of edge points, allowing high response during stable conditions and low response during unstable conditions like faded markings or cracks

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system implements feedback by monitoring the stability of extracted edge points and using this information to adjust the filter response level. The stability assessment feeds back to the filter configuration, creating a closed-loop control system that adapts to changing road conditions

Inventive Principle:

Principle #23Feedback

2Reliability

If the response level of the filter is decreased to improve stability during straight road travel, then the stability improves, but the response speed deteriorates causing delay in detecting curve entries

Engineering Contradiction:

Improvestability of road estimationVSAvoiddelay in detecting curve entry

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The filter response level is dynamically adjusted based on road condition assessment. The system transitions from a static filter configuration to a dynamic one where the response level changes according to the detected stability of edge points, allowing high response during stable conditions and low response during unstable conditions like faded markings or cracks

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system performs preliminary assessment of road conditions by analyzing edge point stability before adjusting the filter response. This preliminary detection of stable versus unstable road conditions allows the system to proactively set appropriate response levels, preventing both excessive responsiveness to noise and excessive lag in legitimate changes

Inventive Principle:

Principle #10Preliminary action

3Speed

If the filter response is adjusted based on yaw rate to improve curve detection, then the response to curves improves, but the timing is delayed because yaw rate is measured after the vehicle has already entered the curve

Engineering Contradiction:

Improveresponse timing to curvesVSAvoiddelay in response timing

Core Design Contradiction:

SpeedVSLoss of time

Solution Approach 1:

The system performs preliminary assessment of road conditions by analyzing edge point stability before adjusting the filter response. This preliminary detection of stable versus unstable road conditions allows the system to proactively set appropriate response levels, preventing both excessive responsiveness to noise and excessive lag in legitimate changes

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The filter response level is dynamically adjusted based on road condition assessment. The system transitions from a static filter configuration to a dynamic one where the response level changes according to the detected stability of edge points, allowing high response during stable conditions and low response during unstable conditions like faded markings or cracks

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10691959B2Estimating apparatus

Publication Date: 2020.06.23 SOKEN CO LTD

AI summary

In a travelling road estimating apparatus, an estimator estimates, based on the coordinates of at least one of edge points included in a selected candidate, a road parameter using a previously prepared filter having an adjustable response level. The road parameter is associated with a condition of the travelling road relative to the vehicle and a shape of the travelling road. A determiner determines whether there is an unstable situation that causes an accuracy of estimating the edge points by an edge extractor to be reduced. A response level adjuster adjusts the response level of the filter in accordance with determination of whether there is an unstable situation that causes an accuracy of estimating the edge points by the edge extractor to be reduced.