Dead Reckoning Positioning Using Displacement Data

The patent combines GPS positioning with dead reckoning positioning to create a hybrid positioning system. When GPS signals are unavailable (in urban canyons or indoor environments), the system switches to dead reckoning mode, which uses motion sensors (accelerometers, gyroscopes, magnetometers) to calculate position based on previous known position and measured movements. This merging allows the system to maintain positioning functionality across diverse environments including open areas, urban canyons, and indoor spaces.

The system implements feedback mechanisms where GPS positioning results are used to correct and update dead reckoning position estimates. When GPS signals become available, the system compares the GPS-derived position with the dead reckoning position and uses the difference to reset or correct the dead reckoning baseline. This feedback loop maintains positioning reliability by periodically anchoring the dead reckoning calculations to accurate GPS positions, preventing error accumulation while maintaining independence from continuous GPS reception.

The patent enables the use of low-cost wireless devices without expensive GPS receivers by implementing dead reckoning positioning using motion sensors that are already present in modern smartphones and wireless devices. The system uses accelerometers, gyroscopes, and magnetometers (which are standard components in contemporary devices for other purposes like screen orientation and step counting) to perform positioning calculations. This approach replaces the need for dedicated GPS hardware in scenarios where GPS signals are unavailable, significantly reducing device cost while maintaining positioning availability through the dead reckoning mechanism.