Onboard Positioning Device Calibration via Roadside Locus Comparison
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Solution Overview
Problem
Traditional GPS systems, even with differential GPS (DGPS), face significant positioning errors due to multipath interferences in complex urban environments, which cannot be adequately corrected, limiting accuracy to beyond the lane level, and are costly to implement and maintain.
Innovation Solution
A positioning system comprising an onboard device and a roadside device that calculates a calibration value by comparing satellite positioning signals with real vehicle loci obtained from roadside sensors, allowing for accurate calibration and output of calibrated positioning coordinates with errors reduced to less than 1 meter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If DGPS technology is used to reduce positioning errors, then atmospheric effects error and ephemeris error are reduced, but multipath errors cannot be reduced and implementation costs are expensive
Solution Approach 1:
The patent introduces an intermediary calibration process that mediates between satellite positioning signals and the actual vehicle position. The calibration value acts as a mediator that translates satellite coordinates into accurate road coordinates by comparing positioning loci with real moving loci detected by roadside devices, thereby resolving the limitation of DGPS in handling multipath errors without requiring complex physical infrastructure
Solution Approach 2:
The patent creates a virtual copy of the vehicle's real moving locus by detecting positioning loci through satellite signals and comparing them with the actual locus obtained from roadside devices. This copying approach allows the system to generate calibration data that corrects positioning errors without needing physical correction infrastructure at every location
2Measurement precision
If DGPS broadcasts correction information to improve positioning accuracy, then atmospheric effects error and ephemeris error are reduced, but positioning accuracy cannot reach lane level in complex urban environments
Solution Approach 1:
The patent implements a feedback mechanism where the calibration value is continuously updated by comparing positioning loci with real moving loci. This feedback loop allows the system to adapt to changing multipath interference conditions in complex urban environments, continuously improving positioning accuracy to reach lane level by adjusting calibration parameters based on observed errors
Solution Approach 2:
The patent changes the parameter of positioning accuracy by introducing calibration values that adjust the relationship between satellite coordinates and road coordinates. By modifying these calibration parameters based on comparative analysis of positioning loci and real moving loci, the system overcomes the limitation of fixed DGPS correction data and adapts to dynamic urban environments
3Measurement precision
If physical entities such as base station and main control station are set up for DGPS, then positioning correction is achieved, but implementation costs are expensive and communication requirements increase
Solution Approach 1:
The patent makes the roadside device multi-functional by enabling it to both detect real moving loci of vehicles and provide calibration data to multiple onboard positioning devices. This universal approach eliminates the need for dedicated base stations and main control stations, as the roadside devices serve multiple purposes: vehicle detection, locus tracking, and calibration data provision, thereby reducing implementation costs
Solution Approach 2:
The system enables self-service by allowing onboard positioning devices to autonomously calculate calibration values using data from roadside devices without requiring centralized control. The roadside devices automatically detect and broadcast calibration information, and onboard devices independently process this data to correct their positioning, eliminating the need for expensive centralized control infrastructure
Data Source
AI summary
A positioning system having an onboard positioning device and a roadside device is provided. The onboard positioning device receives a plurality of first positioning signals and records a positioning moving locus of a vehicle according to the first positioning signals. The roadside device detects a real moving locus of the vehicle. The onboard positioning device obtains the real moving locus from the roadside device, and calculates a positioning calibration value according to coordinates of the positioning moving locus and coordinates of the real moving locus. Furthermore, the onboard positioning device receives a plurality of second positioning signals and calculates and outputs a plurality of calibrated positioning coordinates according to the second positioning signals and the positioning calibration value.