Vehicle Control System Position Accuracy GPS Interference
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Solution Overview
Problem
Conventional vehicle control systems face challenges in maintaining accurate vehicle positioning and continuous control due to GPS signal interference and errors, particularly in urban environments, leading to reduced usability and accuracy in navigation and control operations.
Innovation Solution
A vehicle control system that sets routes with predefined base points and control points, using a combination of autonomous and hybrid navigation to determine vehicle position, allowing for advanced control execution based on calculated distance and error levels, thereby broadening the control range and improving driver convenience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS radio wave based navigation is used to determine vehicle current position, then the vehicle control system can obtain position information, but the position accuracy deteriorates in urban environments with high-rise buildings due to radio wave interference and multi-path effects
Solution Approach 1:
The patent divides the navigation system into multiple independent positioning methods: GPS-based positioning and autonomous navigation-based positioning. Each method operates independently and can be selected based on environmental conditions, allowing the system to segment the harmful effect of GPS interference by switching to an alternative method when GPS accuracy deteriorates in urban environments.
Solution Approach 2:
The patent changes the positioning parameter from GPS radio wave based coordinates to autonomous navigation based coordinates (odometry and dead reckoning) when GPS signal quality deteriorates. This parameter change allows the system to maintain position accuracy by switching to a different measurement basis that is not affected by radio wave interference from high-rise buildings.
2Object-affected harmful factors
If autonomous navigation is used to determine vehicle current position without GPS, then the system is not influenced by GPS reception environment, but position accuracy deteriorates due to accumulated errors in calculated movement distance
Solution Approach 1:
The patent introduces map matching as an intermediary mechanism that corrects accumulated positioning errors in autonomous navigation. By comparing the autonomously calculated position with known road geometry and map data, the system can correct drift and maintain accuracy over longer distances, effectively using map data as a mediator to reduce cumulative errors.
Solution Approach 2:
The patent implements feedback by continuously comparing autonomous navigation results with map data and correcting position calculations accordingly. When autonomous navigation drift occurs, the system uses map matching feedback to realign the calculated position with actual road geometry, preventing error accumulation from worsening position accuracy.
3Ease of operation
If map matching is executed with erroneous map data, then the map display can still be generated, but the vehicle current position determination becomes inaccurate due to forced matching with nearest road
Solution Approach 1:
The patent makes the map matching process dynamic by allowing bidirectional correction: both the vehicle position and the map data can be corrected based on their respective reliability. When map data is identified as erroneous, the system dynamically switches to using autonomous navigation position as the reference, and vice versa, ensuring that the most reliable data source is always used for position determination.
Solution Approach 2:
The patent implements feedback mechanisms that detect inconsistencies between map data and autonomous navigation results, allowing the system to identify erroneous map data and correct both the map database and current position calculations. This feedback loop prevents forced matching with incorrect road geometry from compromising position accuracy.
4Measurement precision
If the vehicle control range is limited due to position accuracy requirements, then sophisticated control can be executed, but driver convenience deteriorates due to restricted control availability
Solution Approach 1:
The patent dynamically adjusts the vehicle control range based on real-time position accuracy assessment. When position accuracy is high (GPS available and reliable), the system allows sophisticated control with narrow control range. When position accuracy deteriorates (GPS interference or autonomous navigation drift), the system automatically broadens the control range to maintain driver convenience, allowing control execution over wider positional tolerances.
Solution Approach 2:
The patent changes the control parameter thresholds dynamically based on positioning method and accuracy level. Different control algorithms and tolerance levels are applied depending on whether GPS or autonomous navigation is used, and based on the current position uncertainty. This parameter adaptation allows sophisticated control to be maintained when possible while ensuring driver convenience when position accuracy is limited.
Data Source
AI summary
A vehicle control system includes a route setting unit for setting a route from a start point to a destination; an information obtaining unit for obtaining from a memory position information of at least one base point and at least one control point existing in the route set by the setting unit; a base point recognition unit for recognizing that a current position of a vehicle reaches a position of the base point obtained by the obtaining unit; a running situation monitoring unit for determining as a predetermined distance a running distance from the base point most lately recognized by the recognition unit; and a control unit for executing an advanced control to the vehicle if the predetermined distance obtained by the monitoring unit is shorter than any of first and second threshold distances, when the current position reaches a position of the control point obtained by the obtaining unit.