Research On The Dynamic Characteristics And Control Strategy Of Balloon In Direct Cabling Corder

In order to reduce the energy consumption in twisting process,direct cabling corder usually uses active yarn feeding device to control the balloon shape of outer yarn.In this way,the automatic adjustment of the balloon tension of the storage cylinder will fail,causing the instability of the balloon and ultimately affecting the quality of the cord.Therefore,in order to reduce energy consumption in production,closed-loop control of the balloon shape of outer yarn should be carried out through the control system.Actively control the balloon,while maintaining the stability of the balloon.Based on the balloon theory,the kinematic analysis of the outer yarn in the direct cabling corder was carried out,and the kinematic model of the balloon of the outer yarn was established.The motion path of outer yarn and the structure of limiting balloon size on twisting mechanism were analyzed,and the boundary conditions of the model were set up according to them.Based on the analysis of the kinematic model of the balloon,it was found that the influencing factors of the balloon shape were the rotating speed of the spindle,twist and thread density of yarn when the structure size of the straight twist machine was unchanged.The kinematic model of outer yarn coil was established in MATLAB,and the influence of balloon shape change on the radius,tension,length and energy consumption of balloon was compared by numerical simulation when the spindle speed,yarn density and yarn twist were different.Based on the above theoretical analysis,a steady-state control system for balloon yarn of direct cabling corder was designed.The system can control the size of the shape of the balloon by controlling the yarn feeding speed of the stepping motor.At the same time,the infrared sensor was used to detect the balloon radius,and the Hall sensor was used to detect the real-time ingot velocity.The two values were combined into control parameters.After the control parameters were compared with the preset values,PID controller was used to control the speed of the yarn feeding motor in a closed loop,and the balloon shape was adjusted in real time,so as to reduce the balloon fluctuation during active yarn feeding.At the same time,the balloon radius data collected by the control system,combined with the relationship curve between the balloon shape and energy consumption obtained by the theory,can predict the current energy consumption situation in real time.Taking TC21 direct cabling corder as the object,an experiment platform was built,and several sets of parameters of different yarn twist,yarn density and spindle speed were set up for experiments.Meanwhile,a power meter was used to verify the predicted energy consumption.The results show that the control system can achieve short adjustment time in different experiments,the balloon shape is stable,the energy saving ratio of single spindle unit of direct cabling corder is above 38%,and the balloon shape error range is-3 ～ 6%,which indicates that the method has good applicability and feasibility.At the same time,the energy consumption curve of each group is close to the simulation prediction curve,and the error range is 3%-7%,which is in the acceptable range and has high accuracy.