Road Gradient Segmentation for Consistent Vehicle Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vehicle control systems face challenges in setting segments with constant gradients on roads without blanks or overlaps, leading to inconsistent control parameter settings and frequent gear changes, which affect ride comfort.

Innovation Solution

A segment determination device that acquires and processes gradient information from a map unit to set constant gradient segments by calculating altitude equivalent values and determining feature amounts, ensuring consistent control parameters and minimizing gear changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If segments are determined based on relative altitude information from vehicle location, then control parameters can be set for constant gradient segments, but segments may have blanks or overlaps leading to inconsistent control parameters

Engineering Contradiction:
Improveconsistency of control parametersVSAvoidsegment boundary accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The road is divided into multiple segments based on gradient characteristics. Each segment is defined by start and end points with associated gradient values. The system segments the road such that each segment has relatively constant gradient, allowing consistent control parameters to be applied within each segment while avoiding blanks or overlaps between segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system pre-calculates and stores segment information including start points, end points, and gradient values for multiple segments ahead of the vehicle. This preliminary segmentation allows the vehicle to receive consistent control parameter settings before reaching each segment, eliminating the need for real-time boundary determination and preventing parameter inconsistency.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If segments are set with strict constant gradient criteria, then control parameters remain consistent within segments, but segments become shorter requiring more frequent parameter changes

Engineering Contradiction:
Improvecontrol parameter consistencyVSAvoidfrequency of gear changes
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system applies gradient threshold values to determine segment boundaries. By adjusting the threshold parameter, the system can balance between segment length and gradient constancy. A larger threshold allows longer segments with more gradient variation, reducing gear change frequency, while maintaining sufficient parameter consistency for effective control.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If segments are extended to reduce gear changes, then ride comfort improves, but gradient consistency within segments deteriorates requiring more frequent parameter adjustments

Engineering Contradiction:
Improvegear change frequencyVSAvoidgradient constancy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system determines segments based on gradient changes exceeding a predetermined threshold rather than requiring perfectly constant gradients. This partial action approach allows segments to extend beyond ideal constant gradient boundaries, reducing gear change frequency while maintaining sufficient gradient consistency for effective control parameter application.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3522132B1Segment determination device and segment determination method
Publication Date: 2024.02.21 ISUZU MOTORS LTD
  • EP3522132B1 patent drawingFigure 1
  • EP3522132B1 patent drawingFigure 2
  • EP3522132B1 patent drawingFigure 3

AI summary

A section determination device 1 is provided with: an altitude information acquisition unit 41 for acquiring altitude information for a plurality of points on a road provided with sections in which vehicles travel; a remaining-distance calculation unit 45 for calculating the distance between the point, among the plurality of points, at which a vehicle is positioned and the end point of the section; a reference point determination unit 46 for determining a reference point that is the nearest point, among the plurality of points, to the end point of the section, on the basis of the distance calculated by the remaining-distance calculation unit; a characteristic value determination unit 42 for determining a characteristic value that indicates inclination information, on the basis of the altitude information for the plurality of points, including the reference point and a point, among the plurality of points, further ahead of the vehicle than the reference point; and a section determination unit 44 for, when the characteristic value is outside a prescribed range, determining a separate section in which the end point of the section is defined as the starting point, and the point nearer to the vehicle, among two points adjacent to the point ahead of the vehicle, is defined as the end point.