Complex Kalman Filter Algorithm For Smartphone-based Indoor UWB/INS Navigation Systems

Precision indoor positioning is an urgent engineering task, since in the modern world it is increasingly difficult for a person to do without navigation tools that are applicable in indoor or in underground facilities where the signals of global navigation satellite systems are not available. Among the many existing systems, it is possible to distinguish systems where the consumer's smartphone is used as a tag. Such systems allow using smartphone sensor measurements - from narrow-band radio sensors and inertial sensors. And in the near future, some smartphones will include ultra-wideband sensors with signals of a navigation-communication standard, which means that they can be used as part of navigation systems. This paper presents a complex Kalman filter algorithm for indoor navigation system based on smartphones using UWB and INS measurements. The efficiency of the algorithm has been tested both by simulation and by experiments. In the simulation, the gain of the complex UWB / INS filter relative to the UWB filter under the same conditions is more than 5, and in real measurements-more than 3.