重庆大学-过程控制-process-control-中文-翻译-第八章

1ProcessControlsystems陈刚自动化学院2PracticalIssuesofProcessControlOutline:DigitalControl数字控制Progressin在……有进展ProcessControlSamplingthemeasurement测量采样DigitalPIDcalculationandexecutionperformance数字PID计算和执行的性能MakePIDwork（inpractice在实践中）Selectproperfieldinstrumentation选择适当量程的仪表Validate验证andcorrect调整measurements测量值Use&tunevariousindustrialPIDalgorithms使用&调整各种工业PID算法Improveperformanceof“simple”PID提高简单PID的性能3PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlThe（steamengine蒸汽机）worksallthetimecontrolthe（boilerpressure锅炉压力）thespeedofthedevice设备的速度Peopleexperienced人们靠经验控制Explosions易爆炸unstablebehavior不稳定Controlengineering控制工程wasborn4PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControl控制领域的进步Manual手工的Mechanical机械的devicesPneumatic气动的devicesElectronic电子的devicesDigitalcalculation数字计算Digitalcalc.&communication通信5PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlManualMechanicaldevicesPneumaticdevicesElectronicdevicesDigitalcalculationDigitalcalc.&communication6PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlManualMechanicaldevicesPneumaticdevicesElectronicdevicesDigitalcalculationDigitalcalc.&communication7PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlManualMechanicaldevicesPneumaticdevicesElectronicdevicesDigitalcalculationDigitalcalc.&communicationP(t)8PneumaticPracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlManualMechanicaldevicesPneumaticdevicesElectronicdevicesDigitalcalculationDigitalcalc.&communication9ElectronicSimplifiedDiagramofTaylortranscopeelectroniccontrollerPracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlManualMechanicaldevicesPneumaticdevicesElectronicdevicesDigitalcalculationDigitalcalc.&communication10PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlManualMechanicaldevicesPneumaticdevicesElectronicdevicesDigitalcalculationDigitalcalc.&communicationElectronicDevice电子设备11PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlManualMechanicaldevicesPneumaticdevicesElectronicdevicesDigitalcalculationDigitalcalc.&communicationDigitalCalculationforElectronicDevice电子设备的数字计算12PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlManualMechanicaldevicesPneumaticdevicesElectronicdevicesDigitalcalculationDigitalcalc.&communicationDigitalCalculationandCommunication•transmissionbylocalnetwork通过本地网络传递•sensorandvalvehavemicroprocessor微处理器13PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlDistributedcomputingnetwork分布式计算网络14PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlDistributedcomputingnetwork15PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlAroughindicationoftheprogressin大致方面的进步在processcontrol16PracticalIssuesofProcessControlDigitalControl:ProgressinProcessControlManualMechanicaldevicesPneumaticdevicesElectronicdevicesDigitalcalculationDigitalcalc.&communicationApplicablefor适用于digitalsampling采样andcalculation计算•Transmissioncanbeelectronicordigital.传输可以电子的或数字的•Measurementisperiodicallysampledforcalcution测量是定期的采样和计算17PracticalIssuesofProcessControlDigitalControl:SamplingTimes采样时间Thecontrolloop控制回路sampletimehowoftencontrollersamplestheprocessvariable(PV)采样频率compute&transmit传输anewcontrolleroutput(p)signalThep-PVrate,atwhichp-PVdataaresampledandrecordedduringabumptest颠簸试验18PracticalIssuesofProcessControlDigitalControl:SamplingTimesSamplingtooslow:negativeimpactonperformance负面响应Aliasing欠采样:Samplingmuchslowerthanthemeasurementchangescausessignificantlossofinformation.采样比测量慢得多会造成重大损失的信息Samplingslow19PracticalIssuesofProcessControlDigitalControl:SamplingTimesSamplingtooslow:negativeimpactonperformanceAliasing:SamplingmuchslowerthanthemeasurementchangescausessignificantlossofinformationZero-orderhold零阶保持器20PracticalIssuesofProcessControlDigitalControl:SamplingTimesSamplingtooslow:negativeimpactonperformanceIntroducing介绍dead-timeTd=T/221PracticalIssuesofProcessControlDigitalControl:SamplingTimesSamplingtoofast（notnecessarily不一定）providebetterperformance性能,spendmorethannecessaryonhigh-end高端instrumentation仪表spendmorecomputingresources计算资源22PracticalIssuesofProcessControlDigitalControl:SamplingTimes“Fastandslow”Beingdefinedbytheprocesstimeconstant定义过程时间常数,Howtochoosesamplingtime,tBestPractice1:Sampletimeshouldbe10timesperprocesstimeconstantorfaster采样时间应是每个过程时间常数的10倍或更快,i.e.,t≤0.1Thisruleappliesfor应用于bothcontrolloopsampletimeandbumptestdatacollection颠簸试验数据采集arethesame23PracticalIssuesofProcessControlDigitalControl:SamplingTimes“Fastandslow”Beingdefinedbytheprocessdeadtimeconstant,TdHowtochoosesamplingtime,tBestPractice2:Sampletimeshouldbe0.8timesperdeadtimeconstantorfaster,i.e.,t≤0.8TdThisruleappliesforbothcontrolloopsampletimeandbumptestdatacollectionarethesame24PracticalIssuesofProcessControlDigitalControl:ThedigitalP-I-DControllersSupposesampledata,PV1,PV2,……,PVi,controlleroutputp(i),p(i)isthedeviation偏差variable)()(:Control-PiE