Step Detection Device Using Multi-Position Gradient Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing step detection technologies face challenges in accurately detecting the position of steps on a road surface, particularly when the angle between the step and the horizontal scanning line is small, leading to low detection accuracy due to errors in the road surface structure estimation from stereo camera images.
Innovation Solution
A step detection device that uses a distance sensor to detect the distance and direction to the road surface, setting multiple step determination positions and calculating height changes to accurately detect steps based on the gradient of the road surface, thereby reducing the influence of errors and improving detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the angle between the horizontal scanning line and the step tangent direction is small, then the detection coverage is improved, but the detection accuracy deteriorates due to smaller height change gradients
Solution Approach 1:
The patent transitions from two-dimensional image-based height estimation to three-dimensional spatial measurement by introducing multiple step determination positions (first and second positions) at different locations. This dimensional expansion allows the system to capture height changes from multiple perspectives, resolving the accuracy loss that occurs when the scanning angle is small.
Solution Approach 2:
The patent changes the measurement parameters by detecting both distance and direction to the road surface in addition to height changes. By monitoring the gradient of height changes at multiple positions and comparing these parameters, the system can accurately detect step positions even when the angle between the scanning line and step tangent is small.
2Measurement precision
If multiple step determination positions are used to improve detection accuracy, then the measurement precision is improved, but the calculation load and device complexity increase
Solution Approach 1:
The patent divides the detection task into segmented measurements at specific step determination positions (first and second positions). By focusing measurements at these predetermined locations rather than continuously across the entire road surface, the system reduces the overall calculation load while maintaining detection accuracy through strategic positioning.
Solution Approach 2:
The patent implements a conditional calculation approach where the second height change is only calculated when the first height change gradient is below a threshold. This partial action principle reduces unnecessary calculations: when the first position already provides sufficient detection accuracy, the system skips the second measurement, thereby reducing computational overhead while preserving accuracy when needed.
3Adaptability or versatility
If the gradient of height change is small due to small angle, then the detection coverage is maintained, but the reliability of step detection deteriorates
Solution Approach 1:
The patent introduces multiple step determination positions as intermediary measurement points between the vehicle and the step. By measuring height changes at these intermediate positions and comparing the gradients, the system can reliably detect steps even when the direct measurement angle is small, as the intermediary positions provide additional geometric information to overcome the small gradient issue.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A step detection device detects the distance and the direction to a road surface around a vehicle Vc, using a distance sensor 12 mounted on the vehicle, and sets a first step determination position Pa1 and a second step determination position Pa2 on the road surface. Then, the step detection device calculates the height changes of the road surfaces at the first step determination position Pa1 and the second step determination position Pa2 based on the distance and the direction to the road surface, and detects a step LD on the road surface based on one of the step determination positions, the gradient of the height change of the road surface at the one being larger.