Development Of High Speed Needle Selector Control System For The Stocking Machine

The needle selection system is the core of the stocking machine and determines the knitting efficiency and stability of the stocking machine.The paper designs a complete high-speed needle selection control system by analyzing the selection mechanism of the stocking machine.The paper is mainly divided into two parts: the analysis of needle selection mechanism and the design of needle selection control system.In the analysis section of the needle selection mechanism,firstly,thesis determine The parameters of knitting maximum dynamic range,knitting process point,tuck point height of process,and refund process point height,through the analysis of the knitting process of the stocking machine's stockings,the knitting establishment principle,the loop forming mechanism,and the trajectory of the stitching loop.Then,the static and dynamic force analysis of the high-speed knitting braided triangle and latch needle was carried out to determine the stability of the movement of the loop forming part of the stocking machine.Finally,the three-dimensional model of the loop forming mechanism was established using SolidWorks software.The three-dimensional model was imported into ANSYS/Workbench software,The modal analysis and transient dynamics analysis were performed on the loop forming mechanism to determine the vibration characteristics and collision stability of the looped parts.In the design part of the needle selection control system,firstly,the selection of the needle selector was completed,the working principle of the piezoelectric needle selector was analyzed,and the control requirements of the control system were clarified.Then the control system is designed.The control system is composed of a main control board and a needle selection driving board.The main control board adopts an ARM+CPLD control structure.The main control circuit schematic includes the main controller peripheral circuit and the auxiliary controller internal logic circuit.The control system outputs four-way needle selection data interface circuit,CAN communication circuit,system power supply circuit,program download and debugging circuit,and power supply monitoring circuit.The needle selection master control system has a simple structure and high real-time performance.The needle drive board uses the optocoupler row scanning principle to perform voltage conversion on the needle selection data.The schematic diagram of thedriving circuit includes the input interface circuit of the driver board,the needle drive circuit,and the output interface circuit of the driver board.The driver circuit has strong anti-interference and the stability of the needle selection signal.Finally,the software design of the control system and the assembly of the main control board and the needle selection drive board were completed.The high-speed needle selection control system is tested on the machine and the stability of the loop forming mechanism is analyzed.TDS 2012 oscilloscope was used to monitor the scanning frequency of the control system.The test results show that the control system has the ability to process large amounts of data for a short period of time,and the real-time performance is strong.Stocking machine knitting speed of up to 800r/min,the control system realizes the predetermined control requirements of the stocking machine.