Research And Development Of A Stranded Wire Helical Spring Pitch Control System

Stranded wire helical spring(referred to as SWHS)is to twist multiple strands of steel wire(usually 3 to 17 strands,0.4 to 14 mm carbon steel wire)into 1 to 3 layers of steel wire,and then winded through the core winding or coreless winding process.Due to the close contact between the steel wires during the tightening of the steel cable,SWHS has excellent properties such as high strength,long life,good vibration damping,and resistance to oil pollution,and can be used in areas with special requirements such as strength and life.At present,there are mainly two applications of resetting and damping.In military equipment,it is used as a re-entry spring for launching weapons,and in civilian equipment,it is used as a reset spring to keep components in the set position.The three main parameters of SWHS are the spring pitch,the cable pitch and the middle diameter.Among them,the pitch is the most critical control index.After ensuring the uniformity of the pitch of the springs,the uniformity of the cable pitch and the middle diameter can be ensured by adjusting the motor speed and the diameter of the mandrel accordingly.In the current production process,there are little research on the pitch control mechanism.The motors of each axis only use uniform speed movement,lack of real-time feedback,and various coupling factors affect the forming process,making the pitch uneven.Taking the improvement of the uniformity of the pitch as the control goal,first of all,the design of the pitch control system of the SWHS CNC machine tool is carried out,the characteristics of the system are analyzed,the control algorithm is proposed,and the pitch control system is implemented.This article conducts research on the following four aspects:(1)Aiming at the requirement of pitch uniformity,the scheme of SWHS pitch control system is designed.In order to ensure the reliability of the system,the detection scheme and the execution mechanism were selected respectively,and the system mechanical structure and communication network design were completed.At the same time,the speed matching method was analyzed.(2)Perform mechanical analysis on the forming process of SWHS,and establish the theoretical model of the SWHS pitch control,including the cable equivalent cross-section model,the pitch calculation model,the feeding position model and the influence of tension fluctuation model.The error change caused by the system is analyzed under no-load response.Based on the Simulink simulation platform,a simulation model of pitch control is established.The simulation results verify the effectiveness of the model and the role of feedback control.(3)The algorithm of multi-strand spring pitch control is studied.In view of the characteristics of many disturbance factors in the production process of multi-strand spring,the system model is unknown,and the control is difficult,the PID-SDAE control method is proposed in conjunction with the stacked denoising autoencoder.The experimental results show that the proposed method effectively improves the robustness and anti-interference ability of the system,and guarantees the accuracy of manufacturing the spring.(4)The host computer program was designed using the c# software,the MODBUS protocol between the host computer and the servo driver was designed,the host computer interactive interface was developed,including the feed displacement monitoring interface and the control parameter setting interface,and the architecture and pitch control monitoring system were developed.The control system determines the speed matching relationship of each motor.