Research On A Logistics Storage AGV Control Technology With Integrated Inertial Navigation And RFID

The manual operation mode is unable to complete the multi variety and less batch logistics work efficiently in traditional distribution center because of the high work intensity,low handling efficiency and high error rate of picking process.It is urgent to develop the key technology of automation and intellectualization of logistics system to enhance the business capability of logistics links.In order to solve the problem of cost and picking efficiency in the fast developing logistics distribution center and improve the flexibility of the warehouse,this thesis studies a new navigation and control mode of storage and handling AGV in distribution center based on the operation mode of AGV in the distribution center environment.The main research contents are as follows.Firstly,based on the analysis of the AGV working environment and movement mode in the logistics distribution center,this thesis proposes a design scheme of navigation with inertial navigation and RFID technology and a differential driving mode based on PID control.The scheme applies RFID positioning and image recognition to correct the positioning error and angle error in the traditional AGV inertial navigation,which can improve the accuracy and reliability of the traditional inertial navigation system and ensure the AGV to be on-line at any time.Secondly,this thesis designs a real-time attitude updating algorithm for AGV positioning system based on the quaternion method and constructs AGV inertial navigation software and hardware control system using STM32 controller.In addition,a complementary filtering method is proposed to reduce the noise of gyroscopes and accelerometers during motion.According to experimental comparison of different calculation methods,the results show that the proposed method of filtering and magnetic correction can effectively improve the stability and accuracy of attitude angle.Thirdly,aiming at the displacement error and angle deviation accumulated by time in inertial navigation,a precise location method combining RFID and image processing is proposed.The method realizes the displacement correction by reading the coordinates information stored in the RFID and the attitude angle correction byusing image processing method to identify the tilt angle of marking line on RFID in the inertial navigation system.Fourthly,this thesis establishes the kinematic model of two wheeled differential AGV trolley,and derives the system state equation of the angle deviation and distance deviation of AGV.On this basis,a PID controller for AGV trolley walking deviation correction is designed.Using MATLAB/Simulink module,the simulation model of the AGV trolley correction control system is set up and the example simulation is carried out.The accuracy of the designed PID control and the reasonableness of the parameters are verified.Lastly,the AGV experiment platform which combines inertial navigation and RFID is built and the experiment of straight walking and rectangular walking of AGV trolley is carried out.The result verifies the feasibility of the navigation mode and the accuracy of the extraction of navigation parameters.