Research On Wireless Data Transmission And Positioning Sysyem For Workshop Environment

The proposal of “Made in China 2025” and Industry 4.0 has promoted the rapid development of intelligent manufacturing in the country.The acquisition and transmission of the status of production components in the manufacturing process is the basis for achieving intelligent manufacturing.The use of wireless communication technology in the Industrial Internet of Things can realize the acquisition and positioning of the working status of production equipment and personnel,but the mechanical equipment in the manufacturing environment will interfere with the wireless signal and affect the positioning accuracy.In order to implement the transmission and positioning of the working status of equipment and personnel,this paper conducts research on key technologies such as wireless data transmission,positioning system architecture and positioning algorithms in the manufacturing environment,and also builds an indoor wireless data transmission and positioning system suitable for the manufacturing environment.The main research contents and results are as follows:(1)In order to meet the needs of data transmission and positioning,a wireless data transmission and positioning system is designed based on Zigbee technology and UWB(Ultra-wide Bandwidth)technology.The system is composed of gateways,nodes,and master-slave base stations,respectively using STM32F407ZGT6 and STM32F103C8T6 chips as the main controllers to complete the hardware circuit design of the gateway,masterslave base station and node,and to complete the design and manufacture of the PCB.(2)Using the Time Of Arrive(TOA)method for ranging,the TOA-based bilateral twoway ranging algorithm reduces the ranging errors introduced by the clock crystal oscillator,and increases the return information to achieve multi-node positioning.In the manufacturing environment,mechanical equipment interferes with and occludes signals.This non-line-ofsight(NLOS)propagation will lead to a decrease in positioning accuracy.The design of multiple base stations and Kalman filtering algorithms reduces the errors introduced by nonline-of-sight and improves positioning accuracy.(3)The communication data frames between the gateway and the main base station,upper management system and nodes are designed.The master base station initiatively calls the slave base stations and nodes to complete the ranging and positioning,and uploads the node location information through the Modbus protocol.The node transmits the working status,the gateway receives the working status and location information of the node and stores it and uploads it to the upper management system.Build the system according to10*10*3.5m in the manufacturing laboratory and complete the experiment,After many tests,the wireless data transmission and positioning system can obtain and locate the working status of the node well,and the static positioning error is within 25 cm.The system algorithm improves the stability of dynamic positioning,and the test trajectory is closer to the actual motion trajectory.