Pedestrain Navigation Using an INS/EKF Framework Aided by UWB Ranging

Inertial Measuring Units (IMU) can be used to estimate the movement of a person with a methodology that is called Pedestrian Dead-Reckoning (PDR). PDR positioning error will accumulate over time, and other measurement information is needed to eliminate the error gradually increasing. The distance information between pedestrian and fixed points can be obtained by UWB ranging, which is a good means of correcting IMU positioning errors. In order to utilize ranging information, the position of the UWB fixed point (be called beacon) in the navigation frame is required. In some cases, the position of the beacon needs to be estimated online. Meanwhile, IMU output and UWB ranging information all contain time-varying biases. Estimating the biases in real time can improve positioning accuracy. In this paper, we present a navigation framework which positioning pedestrian no accumulating error over time, using MEMS IMU and UWB chips. At the same time, unknown UWB beacon position will be estimated at pedestrian initial stage, and biases of IMU and UWB ranging will be estimated in real time.