Design And Implementation Of Control System For Heat Sealing Automatic Packaging Machine

Heat seal type automatic packaging machine is an automatic equipment that can automatically complete the packaging process of feeding,adsorption,conveying,clamping,weighing and sealing.Its high control accuracy,good production efficiency and low failure rate are especially suitable for modern industrial packaging production.This paper focuses on the design and implementation of the control system of heat-sealing automatic packaging machine,mainly completing a series of work such as control system hardware and software design,communication between field devices,system reliability analysis,etc.The main work is as follows.(1)The overall scheme of heat-sealing automatic packaging machine control system is designed.The overall framework of the control system is designed according to the connection relationship between STM32 control devices and field devices and instruments.According to the functional requirements of the control system,the overall hardware architecture is designed.For the problem of complicated relationship and low reliability in the control process,the software implementation scheme of "hierarchical structure +modularity" combined with "multiple redundancy judgment mechanism + state migration" is designed.For the motor driving problem in the interference environment,the command driving scheme combining RS485 and Modbus RTU protocols is designed;for the communication problem between devices in the interference environment,the communication scheme combining TCP/IP communication and Modbus TCP protocols is designed.(2)The hardware of heat-sealing automatic packaging machine control system is designed and implemented.In this paper,under the constraints of cost and application environment,the design is implemented based on the overall architecture of the control system and the overall architecture of the STM32 control device in three parts: device selection and interface circuit,input-output circuit and control circuit circuit.Decoupling,filtering,isolation and resistive absorption are used to reduce the impact of transient disturbances on the STM32 control device.(3)The software of the heat-sealing automatic packaging machine control system is designed and implemented.According to the software implementation scheme of "layered structure +modularity" combined with "multiple redundancy judgment mechanism + state migration",for the problems of difficult implementation of Modbus RTU protocol and Modbus TCP protocol in communication protocol layer and limited resources of microcontroller,the design and implementation of communication protocol layer are completed by means of bit segmentation and category division.For the problem of complex control relationship and easy interference in the control management layer,the design and implementation of the control management layer is completed by setting self-test procedures,multiple redundancy judgment and state migration.(4)Completed the analysis and testing of the control system of heat seal type automatic packaging machine..The reliability of the control system is qualitatively analyzed using the FMECA analysis method,and it is determined that poor contact is the key factor affecting the reliability of the control system.Subsequently,the reliability of the automatic packaging machine control system is quantitatively analyzed using the fault tree analysis method,and software factors is incorporated into the system reliability analysis to determine that program logic errors are also a key factor affecting the control system reliability.Finally,this thesis completes the testing of parameters,functions and performance according to the testing process of the control system,and the test results show that the system initially meets the standard of operational testing.