Design Of Flexographic Printing Pressure Regulating Controller Based On FPGA

Motion control is a multidisciplinary technology,which is the key technology to promote industrial intelligence.With the development of "Made in China 2025",the demand for motion control market is increasing,the motion control technology develops rapidly and the product category of motion controller is increasing day by day.In recent years,with the progress of microelectronic technology,the motion controller is developing rapidly in the direction of multi-axial,networking,openness and intelligentization.Based on domestic and international controller research status,a stepping motor motion controller is designed,of which FPGA as the core processor,flexographic printing pressure regulating control system designing,which is the actual engineering project as the background.Commencing from the project requirements,the overall scheme of the controller is designed with Altera company's EP4CE15F17C8 N FPGA chip as the core,which is a cost-effective chip,the controller of the FPGA core circuit,communication circuit,storage circuit,motor drive circuit and the grating signal processing circuit of hardware circuit is designed,the PCB manufacture and debugging of hardware circuit is completed.The application of the grating ruler and memory chip in controller hardware,makes the pressure regulating control system has a power-down position memory function and alternatives to traditional encoder structure,the grating ruler can measure the position of the pressure regulating system platform and realize the absolute position memory of the moving platform.In the software design of the controller,according to the torque-frequency characteristics of stepping motor,a S type acceleration and deceleration algorithm is designed in order to ensure the stepping motor running smoothly to avoid the acceleration mutations in the process of motor running.For the complexity of the S type acceleration and deceleration algorithm,the speed curve is discretized and the finite state machine is used in the FPGA to complate the implementation of the algorithm.In order to ensure the control accuracy of roller position in printing process,closed loop position control of the roller motion platform is used in design according to the grating ruler structure to solve the problem of losing platform position accuracy caused by the mechanical structure of error,a loop error compensation algorithm is used,make ensure the consistency between actual location and HMI given position.For the synchronous error of the coaxial two motor of the printing roller,an incremental PID control algorithm is adopted based on the cross coupling controlling to ensure the synchronization performance of the coaxial motor in the running process.According to the design style of structural hierarchical coding,Verilog HDL hardware description language was used to complete the coding of each function module in the Quartus II environment and complete the simulation of each module in the Modelsim.After functional testing of the controller prototype using designed test board in the laboratory,the experimental platform in the actual industrial field is set up to complete the performance analysis and verification of the overall controller.According to the overall flexographic printing pressure regulating control system joint debugging,the actual working conditions of the system shows that the FPGA based stepping motor controller is in practical application value.