Vehicle Road Specification Using External Data

The patent introduces an intermediary system consisting of roadside stations and communication units that mediate between the vehicle and the map data storage. Instead of requiring detailed map data to be stored in the vehicle, the system uses external roadside stations to provide road information and enables the vehicle to obtain necessary navigation data through communication with these external facilities, thus solving the contradiction between reliability and adaptability.

The patent creates a universal navigation system where the same basic device can operate both in areas with detailed map data and areas without detailed map data. The system achieves this by implementing multiple functions: it can use stored map data when available and switch to external communication-based road information when detailed map data is not available, making the device universally applicable across different geographic regions.

The patent implements a feedback mechanism where the system continuously monitors the reliability of obtained road information and adjusts its behavior accordingly. When road information is obtained from external devices, the system evaluates the reliability based on multiple factors such as signal strength, data consistency, and geographic context. This feedback loop enables the system to maintain high reliability by selecting the most trustworthy data sources dynamically.

The patent changes the parameters used for road information acquisition based on the operational context. Instead of using a fixed method, the system adjusts parameters such as the type of road information source (roadside station, communication unit), data transmission mode, and reliability thresholds according to the current geographic environment and availability of external facilities, thereby maintaining high reliability while operating without detailed map data.

The patent segments the reliability determination process into distinct modules, each responsible for evaluating specific reference information sources. The system divides the reliability assessment into separate functions: one for evaluating GPS signal reliability, another for evaluating road information reliability from roadside stations, and another for evaluating communication quality. This segmentation allows the complex reliability determination to be managed through modular, independent components.

The patent applies partial action by selectively using different numbers and types of reference information sources based on the specific operational conditions. Instead of always using all possible reference sources, the system uses only the necessary subset for each situation - for example, using GPS and roadside station data when available, but relying on fewer sources when operating in areas with limited infrastructure. This approach maintains high reliability while minimizing the complexity burden in each specific context.