SimpleControl

Directly influencing a stock to keep it at setpoint value

Diagram

Information

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SimpleControl uses a →CloseGap component to arrive (naively) at a flow that is needed to move a connected stock "under management" to a given setpoint, i.e., goal. The strength of the flow, i.e., the speed of the adjustment, is controlled by the parameter adjTime.

The control's setpoint can be provided either by a →RampInput or by an exogenous input u. In case of a ramp input the setpoint will move from initialSetpoint to finalSetpoint in linear fashion for a period given by duration starting at startTime.

The controller by default is active over the whole simulation run, but can be restricted to an on-off period using tc = TimingChoices.period and the parameters onTime and offTime.

Implementation

DiagramView

Parameters (10)

hasRateOutput	Value: false Type: Boolean Description: = true, if the rate is reported via real output connectors
tc	Value: TimingChoices.permanent Type: TimingChoices Description: Select whether contoll is permanent or timed
onTime	Value: modelSettings.modelStartTime Type: Time (s) Description: Time for component to become effective
offTime	Value: modelSettings.modelTimeHorizon Type: Time (s) Description: Time for component to become ineffective
hasExogenousSetpoint	Value: false Type: Boolean Description: = true, if the setpoint is to be given by an input connector
initialSetpoint	Value: Type: SetpointType Description: Setpoint valid from modelStartTime to startTime
finalSetpoint	Value: Type: SetpointType Description: Final setpoint valid from startTime + duration until the end of the simulation
startTime	Value: modelSettings.modelStartTime Type: Time (s) Description: Start time for change of setpoint
duration	Value: modelSettings.modelTimeHorizon Type: Time (s) Description: Time until final setpoint is reached
adjTime	Value: 1 Type: Time (s) Description: Time constant for stock control

Connectors (4)

	flowPort	Type: FlowPort Description: Used to represent stock and flow connections
	y	Type: RealOutput Description: Output of current rate of flow
	y1	Type: RealOutput Description: Output of current rate of flow
	u	Type: RealInput Description: Setpoint input for controller

Components (8)

	onOff	Type: PulseInput Description: Generate pulse or pulse-train signal of real input
	permanent	Type: ConstantConverter Description: A constant value is turned into a constant signal
	setpoint	Type: RampInput Description: Ramp input determining the setpoint
	currentValue	Type: FlowPortSensor Description: Current value of connected stock
	modelSettings	Type: ModelSettings Description: Setting important global variables within a model
	rate	Type: CloseGap Description: Rate of Change
	changing	Type: ExogenousChange Description: Flow to adjust the stock
	actualRate	Type: Product_2 Description: Actual rate, which becomes zero when control is turned off