Development Of Electronic Weft Feeder Based On Vector Control

Air-jet loom weft feeder is a key component to complete weft insertion with loom.It has the functions of self-fixed length,high efficiency of weft insertion and balanced weft tension.Current domestic weft feeder is commonly uses three-phase induction motor which exists problems like high energy consumption,slow feeding weft speed and so on;some domestic forward-looking enterprises begin to use the brushless direct-current motor(BLDCM)as weft feeder motor.But it still remains problems of low speed smoothness or long start-up time.This paper proposes the permanent magnet synchronous motor(PMSM)based on vector control for the weft feeders to solve the above problems.Firstly,the function and application value of the weft feeders are introduced,and the development status in recent years is summarized by reading the domestic and foreign literatures.The technical emphasis and difficulty of the weft feeders control system are pointed out.Secondly,by studying the characteristics of weft feeder motor during weaving process,the speed trajectory of weft storage motor and weft margin curve are simulated by software.The start-up time and speed requirement of the weft feeder motor are analyzed,and the vector control strategy of the weft feeder motor is proposed.Thirdly,the rotor position estimation algorithm of the weft feeders based on low resolution position sensor is discussed,and the algorithm is verified by software simulation.In order to improve the low speed performance of the weft feeder motor,a dead zone compensation algorithm based on vector control with id = 0 is proposed.Aiming at the drawback of sampling resistor in detection current,a method to avoid the noise interference is proposed to improve the detection precision.Fourthly,according to the characteristics of the weaving scene,a weft yarn detection circuit based on a second order active high-pass filter circuit is designed.With the weft detection self-adaptive program it can automatically adjust the system according to the state of the environment,so that the system can be detected weft with high accuracy for a long time.Finally,this paper tests the modules of the control system,and used in the air-jet loom and water-jet loom workshop for a long time.The results show that this control system based on vector control with 32-bit MCU as the core has the advantages of high speed of inserting latitude,high precision of weft detection and stable performance,which can be used in factory.