Research On AGV Guidance Based On Micro Inertial Attitude And Heading Reference System

Autonomous Guided Vehicles(AGV)also known as Mobile robots,which have been applied widely in industry,logistics and other areas.To date,most industrial AGVs still usemagnetic stripe guidanceor other fixed path guidance methodsto ensurethat it is operating ina specified path.However,all the method mentioned above can not achieve flexible manufacturing and personalized system configuration.Thus,the development of guidance method which can be applied to constraint free,non-fixed pathhas received significant attentionfrom AGV guidance area.Moreover,with the development of Micro Electro-Mechanical Systems(MEMS),MEMS sensors are becoming more and more popular.The state-of-art of MEMS sensors makesit possible expensive,large size Attitude and Heading Reference System(AHRS)to be scaled down with a relatively low cost.Although AHRSis commonly utilized in ship and airplane navigation,it is still reasonable and valuable to introduce AHRS to to AGVguidance in order to lower the expense while obtain high accuracy.In this thesis,the kinematics analysis of AGV was carried out,and the kinematics model of AGV was established,which laid the foundation for AGV guidance control.Based on micro-inertial sensors,a AHRS was successfully designed and praparedbymeans ofanalyzingattitude algorithmand sensors data fusion algorithm,followed by introducing this AHRS inthe guidance of an indoor omnidirectional AGV.To be more specific,the mathematical principles of AHRS and quaternion attitude algorithm were analyzed.Data fusion algorithm using gradient descent method and using complementary filter were mainly interpreted,based on which,anadaptive sensor data fusion algorithm based on gradient descent method and complementary filter was proposedand combined withthe quaternion attitude calculating procedure to calculate attitude.This algorithm was also simulated by Matlab Simulink.In this thesis,therefore,a MEMS AHRSachieved by using the proposed algorithm on a 9-axis IMU(Inertial Measurement Unit)integrated with MEMS accelerometer,gyroscope and magnetometer.In order to prepare for AGV guidance experiment,the communication protocol between AHRS,omnidirectional AGV and host computer was designed,so was the software ran on the host computer writtenin Qt.UsingAHRS,AGV and host computer,an AGV guidance experiment platform with MEMS AHRS was constructed.With the proposed experiment platform,the performance of the AHRS and the guidance of AGV using AHRS was testedand analyzed.Theresults of these experiments verified the feasibility of applying the MEMS AHRSto AGV or mobile robot guidance and demonstrated the property of the proposed algorithm.