Map-based location and navigation system for motor vehicle - corrects distance covered for tyre wear and pressure errors using known positions of detected bridges and tunnels

摘要

The system contains an Earth's magnetic field sensor and sensors for determining the distance travelled from the road distance and steering angle. At least one further sensor is used to monitor or correct the road distance. The additional sensor detects bridges which the vehicle passes under or tunnels which it travels through. The system determines the instantaneous vehicle position from the known locations of the bridges and tunnels. USE/ADVANTAGE - Corrects for measurement errors caused by tyre pressure or tyre wear without requiring time-consuming monitoring and correction.