Research On Structure Design And Guiding Of Latent Traction AGV

When the product of traditional automobile parts assembly line changes,it is necessary to re-layout the assembly line.In order to improve the flexibility of the assembly line,a latent traction AGV is designed to realize the mobile assembly of automobile parts.Firstly,the wheel train layout principle of AGV is studied,the minimum turning radius is calculated,and the six-wheel structure and differential steering AGV car are put forward.Then the principle of AGV inertial navigation is introduced.Aiming at the deficiency of angle accumulation error caused by gyroscope working for a long time,the integrated navigation and positioning method of compensating magnetic nail+inertial navigation+RFID positioning is proposed.Secondly,the functional requirements of automotive parts assembly line are analyzed.Aiming at the occasion of automotive parts assembly,the mechanical structure of AGV is designed,including chassis design,drive unit design and traction module design,including driving force calculation,traction force calculation,motor parameter calculation,electric push rod parameter calculation,linear bearing parameter calculation and three-dimensional module design,finite element analysis of key parts,SolidWorks overall modeling,etc.Then,the hardware and software of the system are designed with STM32 MCU,and the driving circuit of BLDCM is designed,The armature voltage of the motor is controlled by PWM wave,which lays a foundation for correcting the deviation of the car;The interface circuit between the MCU and the magnetic sensor,gyroscope and radio frequency module is designed,and the acquisition of the deviation,heading angle and landmark information by the MCU is completed.;The interface circuit of obstacle avoidance module is designed,the obstacle detection of AGV is completed;the Zigbee communication circuit is designed,and the communication between AGV and PC is completed.Then,the kinematics model of AGV car is built,and the transfer function of the system is deduced.According to the transfer function,the PID controller is designed.In order to prevent differential saturation,the differential term is improved and the incomplete differential PID control is obtained.In view of the deficiency of the PID control,the parameters of the PID control are corrected by the fuzzy control in real time,and the fuzzy PID control is obtained.The simulation is completed in Simulink.The results show that the effect of fuzzy PID control is better than that of incomplete differential PID control.Finally,a small AGV prototype is made by a 3D printer,and the reliability of the system software and hardware,the quality of two kinds of deviation correction control algorithms and the error of straight-line driving are experimentally explored.