Altitude-Based Road Segmenting for Stable Vehicle Gear Control
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Solution Overview
Problem
In vehicles traveling on roads with constant gradients, it is challenging to determine suitable control parameters when segments are long, leading to frequent changes that impair ride comfort, especially when segments are short.
Innovation Solution
A segment determination device calculates the sum of areas of regions on either side of the road to determine feature amounts, allowing for the setting of longer constant gradient segments by determining the end point when the distance between the start and end points is within a predetermined limit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the segment length is increased to reduce the frequency of control parameter changes, then ride comfort is improved, but the accuracy of representing the actual road gradient deteriorates
Solution Approach 1:
The road is divided into multiple segments based on gradient characteristics. Each segment is determined by calculating the standard deviation of gradient values within candidate segments, allowing the system to identify regions where the gradient can be regarded as constant. This segmentation approach enables the vehicle to operate with constant control parameters in appropriate segments while maintaining accuracy in representing actual road conditions.
Solution Approach 2:
The system dynamically adjusts the segment length based on the calculated standard deviation of gradient values. When the standard deviation is below a threshold, longer segments are formed; when it exceeds the threshold, segments are shortened. This adaptive parameter change allows the system to optimize between ride comfort and gradient representation accuracy according to actual road conditions.
2Measurement precision
If the segment length is decreased to improve the accuracy of gradient representation, then the control parameter accuracy is improved, but the frequency of control parameter changes increases impairing ride comfort
Solution Approach 1:
The segment determination system dynamically adjusts segment boundaries based on real-time calculation of gradient standard deviations. Rather than using fixed segment lengths, the system adapts segment boundaries to match actual gradient changes in the road, ensuring control parameters are as accurate as needed while minimizing unnecessary changes that would affect ride comfort.
3Ease of operation
If a long segment is set to reduce control parameter changes, then the number of gear shifts is reduced improving ride comfort, but the suitability of control parameters for actual road gradient deteriorates
Solution Approach 1:
The system performs preliminary calculations of gradient standard deviations for multiple candidate segments before finalizing segment boundaries. By pre-calculating and comparing standard deviations across different segment lengths, the system identifies the optimal segment configuration that ensures control parameters are suitable for actual road gradients before vehicle operation begins, preventing both excessive gear shifts and inappropriate control parameters.
Data Source
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AI summary
A segment determination device 1 is provided with: an altitude information acquisition unit 41 that acquires altitude information for a plurality of points on a road on which a vehicle travels; a feature amount determination unit 42 that determines a feature amount indicating gradient information for the road on the basis of altitude information for the plurality of points including a first point in front of the vehicle in the direction of travel thereof and a second point further frontward than the first point among the plurality of points; and a segment determination unit 44 that, when the feature amount is outside of a predetermined range, determines a segment in which the first point serves as a starting point and whichever of two points adjacent to the second point is closer to the vehicle serves as an end point.