The Research Of Indoor Navigation Positioning Method Based On Ultrasonic

In the indoor environment, the indoor navigation positioning method of the mobile carrier has become the hot research topic in various countries. This paper has studied on the research of the indoor navigation and positioning method based on ultrasonic. A series of work is carried out with the ultrasonic positioning as the core in this paper. According to the existing problems of existing ultrasonic positioning method, the new method of CDMA-TDMA ultrasonic positioning method and the indoor ultrasonic differental positioning method are proposed. Making the indoor ultrasonic positioning method and the Inertial Navigation System for information fusion, which is combined with ultrasonic positioning, Inertial Navigation System and non integrity aonstraints, in order to achieve high precision indoor combination navigation. The main work of this paper is as follows:1. The basic theory of ultrasonic and the principle of ultrasonic positioning are introduced. The CDMA ultrasonic positioning method is analyzed and studied according to the existing ultrasonic positioning method. This paper introduces the forms of ultrasonic signals and principle of the system, making the simulation of this method through the MATLAB, laying the foundation for the follow-up work;2. The multi ultrasonic signals received in positioning terminal in CDMA ultrasonic positioning method will be made autocorrelation, and in large amount we need to deploy multi beacon nodes caused the large autocorrelation compution; aiming to solve this problem this paper comes up with an CDMA-TDMA ultrasonic positioning method. The principle of TDMA, the principle of CDMA-TDMA, the structure of system and the realization method are introduced. Making the simulation of multi-channel ultrasonic signal identification in CDMA-TDMA ultrasonic positioning method by MATLAB, the results shows that this method can distinguish the multi-channel ultrasonic effectively, and it is suitable for the indoor positioning;3. Due to the influence of sound velocity error, time synchronization error, and other errors, indoor ultrasonic positioning cannot reach a high degree of accuracy. This paper proposes an ultrasonic differential positioning method. The differential positioning principle and the specific implementation steps are discussed from two aspects of distance measurement differential and position differential. Making the experimental analysis of ultrasonic differential positioning method in the indoor environment, the experimental results show that this method can improve the positioning accuracy effectively;4. In the indoor environment, this paper has researched on the ultrasonic/INS combined navigation because of the divergence of the navigation error of Inertial Navigation System with the increase of time. The inertial navigation method is introduced in detail; the inertial sensor and the solution methods of attitude, position and velocity in Strapdown Inertial Navigation System(SINS) are introduced; the information fusion method(Kalman Filter, KF) in integrated navigation is analyzed and the specific implementation process is given; and the model of integrated navigation system is built. Making the simulation by MATLAB according to the actual indoor environment, the silulation results show that the navigation error can be controlled in a certain range, it can achieve the high-precision indoor navigation.