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systemcomposer.analysis.Instance

Element in analysis instance

Description

An Instance object represents an instance of a System Composer™ model element.

Related objects include:

Creation

Create an instance of an architecture.

instance = instantiate(model.Architecture,'LatencyProfile','NewInstance', ...
'Function',@calculateLatency,'Arguments','3','Strict',true, ...
'NormalizeUnits',false,'Direction','PreOrder')

Properties

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Name of instance, specified as a character vector.

Example: 'NewInstance'

Data Types: char

Object Functions

getValueGet value of property from element instance
setValueSet value of property for element instance
hasValueFind if element instance has property value
isArchitectureFind if instance is architecture instance
isComponentFind if instance is component instance
isConnectorFind if instance is connector instance
isPortFind if instance is port instance

Examples

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Create an instantiation for analysis for a system with latency in its wiring. The materials used are copper, fiber, and WiFi.

Create Latency Profile with Stereotypes and Properties

Create a System Composer profile with a base, connector, component, and port stereotype. Add properties with default values to each stereotype as needed for analysis.

profile = systemcomposer.profile.Profile.createProfile('LatencyProfileC');

% Add base stereotype with properties
latencybase = profile.addStereotype('LatencyBase');
latencybase.addProperty('latency','Type','double');
latencybase.addProperty('dataRate','Type','double','DefaultValue','10');

% Add connector stereotype with properties
connLatency = profile.addStereotype('ConnectorLatency','Parent',...
'LatencyProfileC.LatencyBase');
connLatency.addProperty('secure','Type','boolean','DefaultValue','true');
connLatency.addProperty('linkDistance','Type','double');

% Add component stereotype with properties
nodeLatency = profile.addStereotype('NodeLatency','Parent',...
'LatencyProfileC.LatencyBase');
nodeLatency.addProperty('resources','Type','double','DefaultValue','1');

% Add port stereotype with properties
portLatency = profile.addStereotype('PortLatency','Parent',...
'LatencyProfileC.LatencyBase');
portLatency.addProperty('queueDepth','Type','double','DefaultValue','4.29');
portLatency.addProperty('dummy','Type','int32');

Instantiate Using Analysis Function

Create a new model and apply the profile. Create components, ports, and connections in the model. Apply stereotypes to the model elements. Finally, instantiate using the analysis function.

model = systemcomposer.createModel('archModel',true); % Create new model
arch = model.Architecture;

model.applyProfile('LatencyProfileC'); % Apply profile to model

% Create components, ports, and connections
components = addComponent(arch,{'Sensor','Planning','Motion'});
sensorPorts = addPort(components(1).Architecture,{'MotionData','SensorData'},{'in','out'});
planningPorts = addPort(components(2).Architecture,{'SensorData','MotionCommand'},{'in','out'});
motionPorts = addPort(components(3).Architecture,{'MotionCommand','MotionData'},{'in','out'});
c_sensorData = connect(arch,components(1),components(2));
c_motionData = connect(arch,components(3),components(1));
c_motionCommand = connect(arch,components(2),components(3));

% Clean up canvas
Simulink.BlockDiagram.arrangeSystem('archModel'); 

% Batch apply stereotypes to model elements
batchApplyStereotype(arch,'Component','LatencyProfileC.NodeLatency');
batchApplyStereotype(arch,'Port','LatencyProfileC.PortLatency');
batchApplyStereotype(arch,'Connector','LatencyProfileC.ConnectorLatency');

% Instantiate using the analysis function
instance = instantiate(model.Architecture,'LatencyProfileC','NewInstance', ...
'Function',@calculateLatency,'Arguments','3','Strict',true, ...
'NormalizeUnits',false,'Direction','PreOrder')
instance = 
  ArchitectureInstance with properties:

        Specification: [1x1 systemcomposer.arch.Architecture]
             IsStrict: 1
       NormalizeUnits: 0
     AnalysisFunction: @calculateLatency
    AnalysisDirection: PreOrder
    AnalysisArguments: '3'
      ImmediateUpdate: 0
           Components: [1x3 systemcomposer.analysis.ComponentInstance]
                Ports: [0x0 systemcomposer.analysis.PortInstance]
           Connectors: [1x3 systemcomposer.analysis.ConnectorInstance]
                 Name: 'NewInstance'

Inspect Component, Port, and Connector Instances

Get properties from component, port, and connector instances.

defaultResources = instance.Components(1).getValue('LatencyProfileC.NodeLatency.resources')
defaultResources = 1
defaultSecure = instance.Connectors(1).getValue('LatencyProfileC.ConnectorLatency.secure')
defaultSecure = logical
   1

defaultQueueDepth = instance.Components(1).Ports(1).getValue('LatencyProfileC.PortLatency.queueDepth')
defaultQueueDepth = 4.2900

Clean Up

Uncomment the following code and run to clean up the artifacts created by this example.

% bdclose('archModel')
% systemcomposer.profile.Profile.closeAll

Overview

Model a typical automotive electrical system as an architectural model and run a primitive analysis. The elements in the model can be broadly grouped as either a source or a load. Various properties of the sources and loads are set as part of the stereotype. This example uses the iterate method of the specification API to iterate through each element of the model and run analysis using the stereotype properties.

Structure of Model

The generator charges the battery while the engine is running. The battery and the generator support the electrical loads in the vehicle, like ECU, radio, and body control. The inductive loads like motors and other coils have the InRushCurrent stereotype property defined. Based on the properties set on each component, the following analyses are performed:

  • Total KeyOffLoad.

  • Number of days required for KeyOffLoad to discharge 30% of the battery.

  • Total CrankingInRush current.

  • Total Cranking current.

  • Ability of the battery to start the vehicle at 0°F based on the battery cold cranking amps (CCA). The discharge time is computed based on Puekert coefficient (k), which describes the relationship between the rate of discharge and the available capacity of the battery.

Load Model and Run Analysis

archModel = systemcomposer.openModel('scExampleAutomotiveElectricalSystemAnalysis');
% Instantiate battery sizing class used by the analysis function to store
% analysis results.
objcomputeBatterySizing = computeBatterySizing;
% Run the analysis using the iterator.
archModel.iterate('Topdown',@computeLoad,objcomputeBatterySizing);
% Display analysis results.
objcomputeBatterySizing.displayResults;
Total KeyOffLoad: 158.708 mA
Number of days required for KeyOffLoad to discharge 30% of battery: 55.789.
Total CrankingInRush current: 70 A
Total Cranking current: 104 A
CCA of the specifed battery is sufficient to start the car at 0 F.

Close Model

bdclose('scExampleAutomotiveElectricalSystemAnalysis');

More About

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Introduced in R2019a