Research On High Precision Indoor Robot Position Based On Multi Sensor Fusion In Large Space

Mobile robot is a complex technology,of which the most basic part is autonomous navigation.For navigation,how to realize the robot's high-precision localization is of great significance.For indoor mobile robot localization application,how to balance a wide range,centimeter-level,scalable,low cost is a major problem.This article is targeted at indoor mobile robot localization.The research is focus on calibration and localization framework,which is based on the fusion of infrared and ultrasound.Multiply technologies are studied in this paper,including ZigBee communication technology,ultrasonic ranging principle,infrared clock synchronization technology,multi-line laser SLAM,backend nonlinear optimization,and so on.A software and hardware localization framework based on infrared and ultrasonic fusion was designed and implemented.The localization system was deployed in a indoor environment,and the technical verification of the system was carried out.The main research contents and contributions of this paper lies in the following:1.A innovative design of the indoor location framework for multi-sensor fusion,including the design and production of related hardware unit,which gives a low-cost solution to achieve centimeter-level localization.The framework is divided into two stages,namely,calibration and localization.Precise pose estimation is achieved with expensive sensors in the calibration phrase to calibrate inexpensive sensors which are used in deployment.In the localization phrase,the localization accuracy is equivalent to that of the laser SLAM,which is achieved only by a self-designed inexpensive sensor.In terms of hardware design,three different hardware modules are designed and manufactured based on infrared signal model,ultrasonic propagation model and ZigBee network model.Based on the STM32 single-chip microcomputer,the generation,acquisition and calculation of localization data can be realized efficiently.At the same time,the distance,frequency and angle of the ultrasonic hardware unit with the self-designed routing were tested to verify the stability of the sensor,which is the foundation of subsequent high-precision calibration and localization.2.An algorithm to calibrate the base station unit for indoor localization is proposed.The high cost is concentrated in this calibration solution,which solves the problem of global pose calibration of base station units in a wide range of environments.After deploying a plurality of base station units in the environment,the expensive laser radar is used to compute the global pose of the calibrating unit using the laser SLAM(Simultaneous Localization and Mapping)algorithm,while the ultrasonic distance data collected by the base unit is recorded to the calibration unit.Finally,the existing non-linear optimization method is used to solve the global location of each base station unit deployed in the environment,and the feasibility of the proposed framework is verified in practice to prepare for subsequent localization with low cost and high accuracy.3.A localization algorithm for indoor robots based on multi-sensor fusion to achieve centimeter-level localization with minimum cost,which solves centimeter-level locating of locating unit in a wide range of environments is proposed.When the localization unit moves in the range covered by the calibration unit,the calibration unit measures and calculates the distance information of the localization unit.Based on the known position of the base unit,the localization result is obtained by the non-linear optimization method.The above scheme aims to shift the high cost required for localization to the calibration stage,and provides the localization information in 20 Hz with error of less than 10 cm,only requiring the inexpensive sensor in the localization stage.In deployment,the high cost calibrating unit is operated by professional workers and the calibration result can be reused in many other projects.The cost of the localization stage is paid by the user,and the cost for replacement of a single damage part can be controlled within 50 RMB,which has great engineering value.