Research And Implementation Of Micro-inertial Pedestrian Positioning System Based On Cooperative Navigation Mechanism

As navigation function becomes a more and more common application in intelligent mobile terminal and LBS (Location-Based Service) is growing rapidly,people's demand for positioning is increasing urgently, including the positioning accuracy and continuity. With the development of the Satellite Positioning Technology, pedestrian navigation method using satellite navigation technology tends to be mature. However, in urban area, citizens usually use location services indoor, where satellite positioning system is blocked due to signal interference and has poor positioning accuracy. In order to solve the problem, pedestrian navigation system must be augmented by other positioning technologies for obtaining continuous navigation data. The pedestrian navigation based on INS (Inertial Navigation System) is a fully autonomous and doesn't need extra infrastructure, so that it has received extensive attention and concentrated research in engineering field and academia circles.This dissertation focuses on the autonomous navigation and localization of pedestrians under the condition of weak or missing satellite signals. For meeting the actual needs of pedestrian navigation and positioning, this dissertation is started from two aspects of single and multi personal positioning. Pedestrian navigation systems based on MEMS inertial devices can provide precise positioning for single person. Then through the combination of cooperative navigation technologies, function of navigation and positioning for multiple users is realized.The working principle of strapdown inertial navigation system (SINS) is studied, and single inertial positioning system is constructed with micro inertial devices. In order to overcome the positioning errors caused by the long time drift of inertial measurement units, the zero velocity correction technique is applied to the strapdown inertial navigation system. On the basis of pedestrian gait analysis, a multi-condition zero velocity detection algorithm with zero speed is studied, and the Kalman filter with velocity errors as observation is constructed. In order to validate the method, a set of navigation and positioning experiments are designed. The experimental results show that the zero velocity update technology based on the Kalman filter can effectively improve the positioning accuracy of strapdown inertial navigation system.For meeting the needs of multi-person positioning in the specific environment, multi-person localization system based on cooperative navigation mechanism is studied. For assisting the inertial navigation system to achieve multi-person cooperative navigation and positioning, RSSI ranging technique is introduced into the navigation system. In order to improve the positioning accuracy, the algorithm of multi-person cooperative navigation based on ranging and localization is studied. After the study of multi-person cooperative navigation method, the prototype of multi-person localization system is designed and implemented. On the basis of this, the performance indexes of the multi-person localization system are evaluated by navigation experiments. The navigation experiment results show that the pedestrian positioning system constructed can realize the positioning function of multiple users in complex environment, and has certain engineering application value.