Shanghai Daoqin Plastics Co., Ltd.

in injection molding parts machine in, application most is control is ratio/proportion, separation, micro separation control, 简称PID control. injection molding parts machine pressure, speed degree and temperature degree parameters can full can 靠掌握, or to 精确 数学模 type, control its it technology difficult using/adopting 时, parameters must experience and debugging 确定, this application PID control technology most is 方便. 即当我们不完 full understanding injection molding parts 时实际 pressure, speed degree, temperature degree ﹐ or can through has 效 测 amount obtain upper parameters 时, most combined use PID control technology. PID control, in has PI and PD control. PID control is according to system 误差, utilizing ratio/proportion, separation, micro separation 计算出 control amount control. 　　 ratio/proportion （P） control ratio/proportion control is types most simple control methods. its control and 输入误差信号 formed ratio/proportion 关系. has ratio/proportion control system 输出存 in 稳态误差（Steady-state error）. 　　积 separation （I） control in separation control in, control system and 输入误差信号 积 separation formed positive ratio 关系. for injection molding parts machine control system, if in 进入稳态 rear in 稳态误差, this control system is has 稳态误差 or has system （System with Steady-state Error）. is remove 稳态误差, in injection molding parts machine pressure, speed degree, temperature degree control in must 引入“积 separation 项”. separation for 误差取决于 time separation, time increase, separation increase large. this 样, 即便误差 very small, separation 项也会随 time increase add large, it injection molding parts machine electrical 脑 输出 increase large make 稳态误差进一步 decrease small, to and other 于零. therefore, ratio/proportion +积 separation (PI) control, can make injection molding parts machine system in 进入稳态 rear 无稳态误差. 　　 micro separation （D） control 　　 in micro separation control in, injection molding parts machine electrical in pressure, speed degree, temperature degree 信号输出 and 输入误差信号 micro separation （即误差 变化 rate ） formed positive ratio 关系. injection molding parts machine electrical in 克服误差 adjustment process in can can 会出现振荡甚至失稳. its causes is due to in has relatively large property parts （ step/link ） or has rear (delay)组 parts, tool has made function, its 变化总 is rear 于误差 变化. solution method is make made function 变化“ ultra- front ”, in 误差接近零时, made function 就应该 is 零. this is 说, in control device in 仅引入“ ratio/proportion ”项往往 is 不够, ratio/proportion function is large 误差 幅 value, currently need increase is “ micro separation 项”, it can forecast 误差变化 trend, this 样, tool has ratio/proportion + micro separation injection molding parts machine electrical 脑, can front make made control function and other 于零, is negative value, from 而避免 by amount heavy ultra- 调. therefore for has relatively large property or rear by for 象, ratio/proportion + micro separation (PD) control device can improvement system in adjustment process in features. 　　PID parameters is injection molding parts machine control system design core inner 容. it is according to injection molding parts process features pressure, speed degree, temperature degree PID control ratio/proportion 系数, separation time and micro separation time large small. PID control parameters methods very more, 概括起 has large type: is 理论计算整定 method. it main/primary is based on injection molding parts machine as system 数学模 type, 经 理论计算确定 control parameters. this type of methods to data can use, also must through injection molding parts machine 实际动 as adjustment and 修改. is injection molding parts machine as process methods, it main/primary injection molding parts machine as control experience, in injection molding parts machine 运转时进行 pressure, speed degree and temperature degree adjustment, methods simple, easy 于掌握, in injection molding parts machine debugging in by using/adopting. PID control parameters engineering methods, main/primary has ratio/proportion method, reaction method and decrease method. types methods has its features, its 共同点都 is through experiment/testing, rear according to injection molding parts machine debugging experience for PID parameters 进行整定. 但无论 using/adopting types methods to PID parameters, need in 实际运行 in most rear adjustment and 完善. in injection molding parts 现场整定 process in, need maintain PID parameters ratio/proportion, rear separation, most rear micro separation 顺序进行, in 观察现场 process value PV trend meanwhile, slow slow 改变PID parameters, 进行反复凑试, to control quality combined requirements is 止. in for injection molding parts machine pressure, speed degree and temperature degree specific in, usually 先关闭积 separation and micro separation 项, will TI设置 is large, TD设置 is 零, make its formed is pure ratio/proportion adjustment. ratio/proportion degree experience data setting, according to PV曲线, again slow slow ratio/proportion control ratio/proportion degree, make system to 4: 1衰 decrease PV曲线, rear, again add separation function. in add separation function front, will ratio/proportion degree add large is 原 1.2倍 left right. will separation time TI由 large to small adjustment, true to system again to 4: 1 衰 decrease PV曲线 is 止. 若需引入 micro separation function, micro separation time 按TD=(1/3～1/4) TI计算, this can will ratio/proportion degree to 原 数 value or more small 一, again will micro separation time small to large adjustment, to PV曲线达 to is 止. has need attention/notes is: in process in, need 改变TI, TD时, maintain ratio value 不变. in to most 佳整定 parameters front, need for PV value 曲线进行走势 analysis, 判断扰动存 in large small, again slow slow 进行凑试. if more 次乃找不 to most 佳整定 parameters or parameters method to 理想状态, injection molding parts production process also must requirements relatively is 准确, that 就 考虑 mono 回路PID control has property, is 否应该 selection more complex PID control. value attention/notes is: PID most 佳整定 parameters rear, can it 永远都 is most 佳, outer 界扰动 发生根本 property 改变时, ratio pressure ratio/proportion adjustment 清洗, add hot more 换, its temperature degree need precision adjustment, different is product, different back pressure, hot property different, need adjustment! 我们就必 must heavy new according to need again most parameters 整定, it is ensure PID control has important step/link. 当然实际 injection molding parts production in need time one-time 检定即 can! 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