KU1101 Pengantar Rekayasa dan Desain I

Control

Luaran pertemuan pekan keempatbelasMahasiswa memahami prinsip pengendalian sistem

Mahasiswa dapat mengenali elemen-elemen dari sebuah sistem denganpengendalian

uncontrolled

controlled

What is Control ?Microsoft® Encarta® Reference Library 2003

operate, work, run, use, utilize, manipulate, maneuverrestrain, limit, restrict, hold back, rein in, containmanage, command, supervise, organize, run, directrule, manipulate, influence, dominate, oppress, have a hold over, hold sway over, dictateoversee, monitor, regulate, inspect, limit, restrict

Merriam-Webster :to direct the actions or function of (something) : to cause (something) to act or function in a certain way

Open loop vs Closed loopOpen loop

No feedback

INPUTTap handle

OUTPUTWater flowSYSTEM

Open loop vs Closed loopClosed loop

Feed backsensor

INPUTDesired water level

OUTPUTWater level

SYSTEM

Open or closed loop ?

Mesin pengering gabah

Open or closed loop ?

Governor -> control steam engine pressure

Boulton-Watt steam engine

Balls fly out as speed

increases,

Valve closes,slowing engine

Flyballgovernor

Steamengine

Human body

Control System Element

Control Unit strategyOn-offProportionalOthers : PID (proportional-integral-dirivative), model based, etc

Air Conditioning

Elements:Controlled variable : ambient temperatureReferences value : temperature settingComparison Element : thermostat (RTD)Error Signal : temperature differenceControl Unit : thermostat (on-off)Correction Unit : air conditioning unitProcess : room temperatureMeasuring device : thermostat

Toilet water tank

Elements :Controlled variable: water levelReference value: initial setting of float & leverComparison element: leverError signal: difference setting vs lever positionControl unit: pivoted lever (proportional)Correction unit: valveProcess: water level in tankMeasuring device: floating ball & lever

Iron

Elements:Controlled variable : plate temperatureReferences value : temperature settingComparison Element : thermostat (RTD)Error Signal : temperature differenceControl Unit : thermostat (on-off)Correction Unit : electric plate heaterProcess : plate temperatureMeasuring device : thermostat

ExerciseMicrowave ovenWater pumpSegway

Elements:Controlled variable :References value :Comparison Element :Error Signal :Control Unit :Correction Unit :Process :Measuring device :

Purpose of controlTo regulate : maintain certain steady state condition with respect to disturbanceTo manipulate (tracking) :perform a specific predefined task

Copy-milling machine

Elements:Controlled variable :References value :Comparison Element :Error Signal :Control Unit :Correction Unit :Process :Measuring device :

System QualitiesStability

the quality or state of something that is not easily changed or likely to change (Merriam-Webster)The ability of a system to return to its initial/new steady state condition in respond to a disturbance after a certain time

PerformanceHow fast a system response to a disturbance/voluntary change

Robustness How big disturbance can be manage by the system

Challenge in controller development to determine a proper corrective action from the controller that result in system stabilityto determine a proper action from the controller that result in a new desired condition