Vehicle Position Control Using Reliable Voxel Map Matching
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Solution Overview
Problem
The accuracy of position estimation is compromised when matching with map information containing position data of low accuracy, leading to decreased estimation precision.
Innovation Solution
An output device that acquires and utilizes accuracy information attached to map data to control a moving body, enhancing position estimation by weighting regions with high reliability and considering occlusion possibilities, using Normal Distributions Transform (NDT) scan matching to adjust vehicle position for accurate measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If matching is performed with reference to stationary objects with low accuracy position information in map data, then the matching process can be completed, but the accuracy of the estimated own vehicle position decreases
Solution Approach 1:
The patent applies local quality by differentiating the reliability of map data across different spatial locations. It divides the map into multiple regions and assigns different reliability degrees to each region based on the accuracy of position information for stationary objects. This allows the system to weight matching results differently depending on the local reliability of map data in each region, thereby improving overall position estimation accuracy by relying more on high-reliability regions and less on low-reliability regions.
2Area of stationary object
If all regions in map data are used for matching, then the coverage is complete, but the accuracy decreases due to inclusion of low reliability regions
Solution Approach 1:
The patent applies parameter changes by introducing a reliability degree parameter that varies across different regions of the map. Instead of treating all map regions uniformly, the system modifies the matching process by incorporating region-specific reliability parameters. This allows the system to maintain complete spatial coverage while adjusting the influence of each region on the final position estimate based on its reliability, thus preventing low-reliability regions from degrading overall accuracy.
Data Source
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AI summary
An onboard device 1 acquires, from map DB 10 including voxel data, reliability information included in the voxel data corresponding to voxels around the route when determining that the accuracy of an estimated position has decreased. Then, on the basis of the acquired reliability information, the onboard device 1 sets a voxel suitable for estimating the own vehicle position as a reference voxel Btag. Then, the onboard device 1 output, to an electronic control device of the vehicle, control information for correcting the target track of the vehicle so as for the vehicle to pass the position suitable for measuring the reference voxel Btag.