Cubature Kalman Filter (CKF) based IMU/Wi-Fi (Inertial Measurement Unit/Wireless Fidelity) signal tightly-coupled indoor navigation method

The invention discloses a Cubature Kalman Filter (CKF) based IMU/Wi-Fi (Inertial Measurement Unit/Wireless Fidelity) signal tightly-coupled indoor navigation method. The method comprises the steps of building RSS (Really Simple Syndication) fingerprinting database of Wi-Fi signals; locating by use of an IMU to obtain the PoIMU of the pedestrian position, the speed, the acceleration, the posture and other information; correcting the drifting of an IMU accelerometer through zero-speed correction to obtain a corrected speed; locating by use of the Wi-Fi signals to obtain the PoWi-Fi of the pedestrian position; finding n reference points nearby the PoIMU and n reference points nearby the PoWi-Fi, obtaining the distances diIMU and diWi-Fi from the measurement point to the reference points according to the positions of the given reference points, and then obtaining a distance difference delta d; and performing information fusion by CKF to obtain the position, the acceleration, the speed and the posture of a pedestrian. The method adopts the indoor Wi-Fi signals and the IMU information in an integrated manner, realizes information fusion by the CKF, and has the advantages of high filtering precision, high rate of convergence, strong robustness and high navigation precision.