外文翻译--制袋机控制系统研究

附录一

Bag-making machine control system research The bag-making machine control system is controls based on the labor machine the integration computer control system, controls machine the control software by the labor to complete the system bag process each kind of function coordination control, and substitutes the original mechanical major axis by the electronic axis, had guaranteed strictly each printing unit's synchronization, provides one kind for the bag-making machine based on the computer control integration solution. The bag-making machine is on the processed foods production line manufactures bag's processing equipment using the plastic film.

Bag-making machine's control system mainly includes: The main actuation electrical machinery servocontrol, the fixed-length positioning control system, the tensity control system, the temperature control system, to feed control system and the electro-optic correct an error the control system. At present, the most bag-making machine control system's host actuation electrical machinery servocontrol and the fixed-length positioning control system is a body, namely controls take the labor machine forms a three servocontrol as the control core, but the tensity, the electro-optic correct an error, the temperature and to feed control system independence in this three servocontrol. Each system independent types of control increased the bag-making machine coordination control difficulty mutually, also reduced the entire control system's reliability, to further enhance system's automated performance, must develop the new control plan.

In the system bag process, the thin film volume material launches continuously, and corrects an error through the electro-optic with the advanced gear to enter in continuously the folding formation installment. Thin film after folding formation, carries on the hauling and the localization by the fixed-length localization draw gear enters the heat-seal working procedure. Makes in the bag flow the heat-seal working procedure, is causes the laminated film heat-seal spot using the heating wire heating the heat-seal level to turn the plastic flow condition, draws support again cutting tool's

pressure, causes high and low two heat-seal material each other to fuse together in together, after the cooling, can maintain certain intensity, has leak-proof and so on good. The heat-seal good bag may according to need to carry on processings and so on punch and margin, finally completes the dinking die by the dinking die installment, makes the end product bag.

Bag-making machine's control system must complete the main servo electrical machinery and the feed bag hauling servo electrical machinery's motion control, this contained feed bag's fixed-length positioning control, the system must also complete the feed bag to correct an error, to feed, the tensity and the heat-seal temperature control. The control system controls take the labor machine as a core, carries on each control function the hardware expansion, controls machine the control software through the labor to improve each function conformity the system coordination control performance, forms a computer control system. In addition, the remote diagnosis technology applies in the bag-making machine can strengthen bag-making machine's maintainability.

The main servo electrical machinery's types of control are the speed control, the main electrical machinery leads the hot knife vertical motion through four pole organizations, through controls the main electrical machinery driver's speed to control hot knife's state of motion. The feed bag hauling servo electrical machinery's control is the position control, must realize the fixed-length localization hauling. These three servo electrical machinery's coordination control can guarantee the hauling and the heat-seal and the dinking die coordinated work. Puts the material and the feed bag to feed servo electrical machinery may unify with this three servo motor control forms a multiple spindle servo to actuate the control system together. The use may complete many servo electrical machinery's motion control based on the PC machine main line's multiple spindle movement controller, like this simplified the servo to actuate control system's hardware, favored each servo electrical machinery's coordination control. The movement controller controls machine the main line through the labor to carry on the communication with it, like this causes employing labor to control machine the control software then to monitor the movement controller, realizes to

each servo electrical machinery's control.

Fixed-length, the positioning control must have custom-made in firmly the bag process bag's length, the heat-seal and the dinking die position. The longitudinal localization is refers to the thin film carries on the fixed-length hauling the control, enables the product to have the good uniformity. The longitudinal localization completes by two feed bag hauling servo electrical machinery, the servo electrical machinery must move according to the S shape curve addition and subtraction ship promptly carries on the intermittent type fixed-length localization hauling, guaranteed that the hauling dynamic process is steady. Two servo electrical machinery must maintain the synchronized movements, this may complete the synchronization control through the movement controller. Regarding the synchronization accuracy requirement high situation, may use the torque synthesis feedback form the control policy, realizes two axis couplings. When the accuracy requirement is ordinary, may use the synchronized main reference form the control policy. Two kind of control policy hardware request basic consistent, is only the software complex degree is different.

The crosswise localization, namely the electro-optic corrects an error to control, refers to the route which the control plastic membrane walks, enables it not to deviate the fixed track, must overcome so-called “the fishtail” the question. At present is independent the electro-optic to correct an error the equipment to use the photoelectric sensor to examine the plastic membrane boundary, when occurs runs, corrects an error the controller to correct an error the servo to send out the control signal, causes it to lead a material volume movement through the guide screw to correct the plastic membrane. Corrects an error the controller to be possible to control machine the substitution by the labor, gathers the error signal and the control through AD and the DA board card corrects an error the servo. Advantage employing labor controls machine the software resource may design the very friendly man-machine contact surface, this is the traditional electro-optic corrects an error the controller to be unable to complete.

The plastic membrane is one flexible material, will have the stretch elongation

under certain temperature and the tensity, both will cause thickness to be uneven, and will have the bulging, will affect the product the quality. The tensity control's quality has the material effect to the product quality, when complete machine movement in high speed is especially obvious. The tensity control mainly exists in putting between the material and to feed and two carry-over pinch rolls. Is similar corrects an error with the electro-optic to control, at present the tensity control completes most by the independent tensity control system, mainly includes the tensity controller, the tensity detector, the tensiometer, the coupling and the brake. The completely automatic tensity control has the tensity detector to come the immediate determinant volume material the tensity, then turns tensity data the tensity signal to feed in the tensity controller, the tensity controller adjusts the coupling or brake's exciting current controls the volume material the tensity. The tensity controller and the tensiometer control machine the substitution completely by the labor, the signal transformation and the output may complete by AD and the DA board card, the parameter hypothesis, the demonstration and the tensity adjustment value's computation completes by the systems control software. Like this controls through the labor machine the software and hardware resources substitute for the independent tensity control system equipment components, may simplify the system, saves the cost.

Heat-seal temperature control quality immediate influence system bag's rate of finished products. Some plastic membrane under 5 degrees temperature differences, the stretch situation will have the very big change, its heat-seal will become very bad, therefore the temperature also will be an important link. The temperature control mainly uses the intelligent program/temperature controller, this kind of controller has the thermo-element input channel and the temperature control output channel. Uses the thermo-element to take bag-making machine's temperature measurement sensor, and adopts the fuzzy PID control the strategy and the PWM technology, causes the thermal rating continuously adjustable, definitely may meet 1℃within deviation requirements. Figure 2 is the system structure diagram. This system has used the function formidable multiple spindle movement controller and the AD/DA board card, I/O expands hardware equipment and so on exhibition board card to substitute for

some general controllers, controls machine the control software by the labor to complete the systems control and coordinated. This kind simplified the system hardware based on the industry computer's integration control policy, has increased the integration rate, not only this enhanced system's reliability, but also facilitates the system function coordinated, reduced control system's costThe system in a control platform - - - labor controls within the aircraft realizes each control function, enhances the reliability, facilitates the system function to be coordinated, the elimination general control device sinks the after effect energy, reduces the cost. The integrated fundamental mode is uses each kind based on the PC machine main line's board card, this includes the multiple spindle movement controller, the AD/DA board card and so on, substitutes for each independent control system's controller. Each kind of sensor and the actuating equipment may are connected through the field bus or the serial interface and the control platform, thus forms a computer control system. The hardware equipment provided each function to realize the platform, the control function realizes must controlled by the labor machine the control software complete. The control software must complete each hardware equipment's communication, the coordinated, the process value establishment and the examination, as well as work and so on system value of exports computation, may realize each kind conveniently using computer's software resource complex and the advanced control algorithm. In addition the control software must have the friendly man-machine contact surface, may demonstrate that bag-making machine's state variable and so on, may facilitate the operation and the monitoring like this This control system was controlled based on the labor machine the integration computer control system, the labor controls machine has provided the hardware platform for the system, controlled machine the control software by the labor to complete the system bag process each kind of function coordination control. Various units' electronic axis has substituted the original mechanical major axis, carries on the data transmission using the optical fiber, its high accuracy had guaranteed each printing unit's strict synchronization, provides one kind for the bag-making machine based on the computer control integration solution.

附录二

制袋机控制系统研究

制袋机控制系统是基于工控机的一体化计算机控制系统,由工控机中的控制软件来完成制袋过程的各种功能的协调控制,并由电子轴来替代原先的机械长轴,严格保证了各印刷单元的同步,为制袋机提供一种基于计算机控制的一体化解决方案。制袋机是软包装生产线上利用塑料薄膜制作袋子的加工设备。

制袋机的控制系统主要包括:主驱动电机伺服控制系统、定长定位控制系统、张力控制系统、温度控制系统、进给控制系统和光电纠偏控制系统。目前,多数制袋机控制系统的主驱动电机伺服控制系统和定长定位控制系统是一体的,即以工控机为控制核心形成一个三伺服控制系统,而张力、光电纠偏、温度和进给控制系统独立于这个三伺服控制系统。各个系统相互独立的控制形式增加了制袋机协调控制的难度,也降低了整个控制系统的可靠性,为进一步提高系统的自动化性能,须研制新的控制方案。

在制袋过程中,薄膜卷材连续展开,并通过光电纠偏和进给机构源源不断地进入折叠成型装置中的。薄膜经过折叠成型后,由定长定位牵引装置进行牵引和定位进入热封工序。制袋流程中的热封工序,是利用电热丝加热使复合薄膜热封部位的热封层变成粘流状态,再借助于刀具的压力,使上下两层热封材料彼此熔合在一起,冷却后能保持一定的强度,具有良好的密封性等。热封好的袋子可以根据需要进行打孔和切口等加工,最后由裁切装置完成裁切,制成

成品袋。

制袋机的控制系统要完成主伺服电机和料袋牵引伺服电机的运动控制,这包含了料袋的定长定位控制,系统还要完成料袋纠偏、进给、张力和热封温度控制。控制系统以工控机为核心,进行各个控制功能的硬件扩展,通过工控机中的控制软件将各个功能整合以改善系统协调控制性能,形成一个计算机控制系统。此外,远程诊断技术应用于制袋机能够增强制袋机的可维护性。

主伺服电机的控制形式是速度控制,主电机通过四杆机构带动热封刀上下运动,通过控制主电机驱动器的速度来控制热封刀的运动状态。料袋牵引伺服电机的控制是位置控制,要实现定长定位牵引。这三个伺服电机的协调控制能够保证牵引与热封和裁切间的协调工作。放料和料袋进给伺服电机可以与这个三伺服电

机控制结合到一起形成一个多轴伺服驱动控制系统。利用基于PC机总线的多轴运动控制器可以完成多个伺服电机的运动控制,这样简化了伺服驱动控制系统的硬件,利于各个伺服电机的协调控制。运动控制器通过工控机总线与其进行通讯,这样使用工控机控制软件即可监控运动控制器,实现对各个伺服电机的控制。

定长、定位控制要确定制袋过程中袋子的长度、热封和裁切的位置。纵向定位是指对薄膜进行定长牵引的控制,使产品有良好的一致性。纵向定位由两个料袋牵引伺服电机来完成,伺服电机要按S形曲线加减速运动进行间歇式定长定位牵引,以保证牵引动态过程平稳。两个伺服电机要保持同步运动,这可以通过运动控制器来完成同步控制。对于同步精度要求高的场合,可以使用转矩综合反馈形式的控制策略,实现两轴的耦合。精度要求一般时,可以使用同步主参考形式的控制策略。两种控制策略硬件要求基本一致,只是软件复杂程度不同。

横向定位,即光电纠偏控制,是指控制塑料膜行走的路线,使它不偏离固定的轨道,要克服所谓的“蛇行运动”问题。目前独立光电纠偏设备采用光电传感器来检测塑料膜边界,当发生跑偏时,纠偏控制器给纠偏伺服机构发出控制信号,使其通过丝杠带动料卷架运动以纠正塑料膜。纠偏控制器可由工控机取代,通过AD 和DA板卡来采集偏差信号和控制纠偏伺服机构。利用工控机的软件资源可以设计出非常友好的人机界面,这是传统光电纠偏控制器所无法完成的。

塑料膜是一种柔性材料,在一定的温度下及张力下会发生拉伸变形,既会造成厚薄不均,又会产生折皱,影响产品的质量。张力控制的好坏对产品质量有重要影响,在整机运行于高速时尤为明显。张力控制主要存在于放料与进给之间和两个牵引辊之间。类似与光电纠偏控制,目前张力控制多数由独立的张力控制系统来完成,主要包括张力控制器、张力检测器、张力表、离合器及制动器。全自动张力控制是有张力检测器来直接测定卷料的张力,然后把张力数据

变成张力信号传回张力控制器,张力控制器来调整离合器或制动器的励磁电流以控制卷料的张力。张力控制器和张力表完全由工控机取代,信号的转换和输出可以由AD和DA板卡完成,参数的设定、显示和张力调整值的计算则由系统控制软件来完成。这样通过工控机的软硬件资源来取代独立张力控制系统部分设备,可以简化系统,节约成本。

热封温度控制的好坏直接影响着制袋的成品率。有的塑料膜在5度温差下,拉伸

情况会发生很大的变化,它的热封性会变得很差,因此温度也是一个重要的环节。温度控制主要采用智能程序/温度控制器,该类控制器具有热电偶输入通道和温度调节输出通道。采用热电偶作为制袋机的测温传感器,并采取模糊PID控制的策略和PWM技术,使得加热功率连续可调,完全可以达到1℃以内的偏差要求。图2为系统结构框图。该系统使用了功能强大的多轴运动控制器和AD/DA板卡、I/O 扩展板卡等硬件设备来取代一些通用的控制器,由工控机的控制软件完成系统控制和协调。这种基于工业计算机的一体化控制策略简化了系统硬件,增大了集成度,这不仅提高了系统的可靠性,还方便系统功能的协调,降低了控制系统的成本。系统在一个控制平台———工控机内实现各个控制功能,提高可靠性,方便系统功能协调,去除通用控制设备的沉余功能,以降低成本。集成的主要方式是使用各种基于PC机总线的板卡,这包括多轴运动控制器,AD/DA板卡等,以取代各个独立控制系统的控制器。各种传感器和执行设备则可通过现场总线或者串行接口与控制平台相连,从而形成一个计算机控制系统。硬件设备提供了各个功能的实现平台,控制功能的实现还要由工控机的控制软件来完成。控制软件要完成各个硬件设备的通讯、协调、过程值设置和检测,以及系统输出值计算等工作,利用计算机的软件资源可以方便地实现各种复杂和先进的控制算法。此外控制软件还要有友好的人机界面,可以显示制袋机的状态参数等,这样可以方便操作和监控。此控制系统是基于工控机的一体化计算机控制系统,工控机为系统提供了硬件平台,由工控机中的控制软件来完成制袋过程的各种功能的协调控制。各单元的电子轴替代了原先的机械长轴,利用光纤进行数据传输,其高精度保证了各印刷单元的严格同步,为制袋机提供一种基于计算机控制的一体化解决方案。