Un-Tethered Positioning And Navigation Solution For Iot Applications And Land Vehicles

Several absolute and relative positioning systems have been developed during the last decades with the Global Navigation Satellite System (GNSS) at the core of any navigation system utilized for the Internet of Things (IoT) and car navigation applications. However, in harsh environments such as urban canyons, tunnels, and covered or underground parkades, the overall GNSS positioning accuracy deteriorates due to frequent cycle slips, signal blockage, and attenuations. Dead Reckoning (DR) systems, such as Inertial Navigation Systems (INS) that utilize a full Inertial Measurement Unit (IMU) have been widely used as a complementary system to GNSS to provide a reliable, high-rate navigation solution and bridge GNSS gaps. Low-cost MEMS-based IMUs accumulate errors very rapidly due to bias errors in both the accelerometers and gyroscopes. In addition, these bias errors are random in nature and need to be modeled efficiently using stochastic processes. Thus, proper integration of the measurements from both GNSS and INS systems have provided great value by mitigating each other problems.