Research On Weft And Selvage Embedded Control System Of High Speed Rapier Loom

With the continuous development of the textile industry,the market's requests for production quality and efficiency of textiles are more and more.The weft selecting device of the high speed rapier loom achieves the selection of weft yarn in different color and the leno-selvage device achieves the reinforcement to rough selvedge of the textiles.These two devices work closely with other devices to directly affect the production efficiency and quality of the loom.At current,the loom weft-selecting and leno-selvage control system can not achieve the precise control of the weft selecting device and leno-selvage device to increase the shut-down frequency of the loom,seriously affecting the production efficiency of the loom and the production quality of the product.In this thesis,the high-speed rapier loom weft-selecting and leno-selvage control system is deeply studied.The design of the control system and the application of the control algorithm can achieve the purpose of improving the system performance.The study mainly includes the following aspects:1.System overall program research.The key problems of the weft-selecting device and leno-selvage device are analyzed.It is pointed out that the low frequency oscillation and counter electromotive force of the actuator(stepping motor)are the main factors influencing the stability of the control system and reducing the response speed of the system.It studies the improvement methods of the control system and combines the key influencing factors to determine the solutions,that is,current closed loop subdivision driving and current-decay control.The principle of two H-bridge current attenuation modes is analyzed,and an optimized hybrid current attenuation algorithm is proposed to improve the performance of the system.2.The system hardware platform is built.The control system uses STM32F103 as the core for the modular design,including minimum system,power conversion module,input interface circuit,H-bridge drive circuit,current sampling circuit,RS485 communication circuit and completes the establishment of the hardware platform of the high speed rapier loom weft-selecting and leno-selvage embedded control system.3.The software system is designed on the basis of the completion of the hardware platform establishment.The technological requirements of the weft-selecting device are combined for the software design of the weft-selecting control system,including the main program and the interrupted service program,for the study on the key submodules,including commutation control module,current control module and the hybrid current decay module,and for the theoretical analysis and software design of the speed control of the stepping motor of the weft-selecting device.The technological requirements of the leno-selvage device are combined for the software design of the leno-selvage control system,including design of the main program and each submodule and for the completion of the software design of the communication module.4.Experimental verification.The basic hardware is tested to verify the functionality of the hardware platform;The motor winding current waveform is tested to verify the effectiveness of the hybrid current decay algorithm and the current subdivision driving;The effects of the acceleration and deceleration control under the current decay mode is compared to verify that the mixed current decay algorithm can effectively improve the dynamic performance of the motor.Finally,the debugging is made on the testing platform of the high speed rapier loom and the experiment indicates that the weft-selecting and leno-selvage control system can achieve the precise control of the weft-selecting and leno-selvage device,meet the weft-selecting and leno-selvage technological requirements and effectively increase the production rate of the loom,laying the foundation for the future research in the weft-selecting and leno-selvage control field of high speed rapier loom.