Getting Started with the MapleSim Simulink Connector … You are now ready to use the MapleSim...

Getting Started with theMapleSim Simulink Connector

Toolbox

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Getting Started with the MapleSim Simulink ConnectorToolboxCopyright

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ContentsIntroduction ................................................................................................... v1 Getting Started ............................................................................................. 1

1.1 Setting Up the MapleSim Simulink Connector Toolbox .................................. 1Establishing a Connection with MATLAB .................................................... 1

1.2 Getting Help .......................................................................................... 11.3 Using the Simulink Block Generation Template ............................................ 2

Viewing MapleSim Simulink Connector Toolbox Examples ............................ 21.4 Example: RLC Circuit Model ................................................................... 31.5 Preparing a Model for Export .................................................................... 5

Converting the Model to a Subsystem .......................................................... 6Defining Subsystem Inputs and Outputs ...................................................... 7Define and Assign Subsystem Parameters ................................................... 11Exporting Your Model Using the Simulink Block Generation Template ............ 13Implement the S-Function Block in Simulink .............................................. 15

2 Creating and Exporting Mathematical Models in Maple ..................................... 172.1 Using a Template to Generate an S-Function Block ..................................... 172.2 Creating and Exporting a DynamicSystems Object Programmatically ............. 192.3 Example: DC Motor .............................................................................. 20

Index ........................................................................................................... 23

iii

iv • Contents

IntroductionThe MapleSim™ Simulink Connector Toolbox provides all of the tools you need to prepareand export your dynamic systems models to Simulink® as S-function blocks. You cancreate a model in MapleSim, simplify it in Maple™ by using an extensive range of analyt-ical tools, and then generate an S-function block that you can incorporate into your Simulinktoolchain.

You can also use these tools for exporting mathematical models that you have created fromfirst principles in Maple as S-functions.

Furthermore, various options allow you to use the C code generation feature in Maple tocreate code libraries of your MapleSim models for implementation in other applications.

Features of this toolbox include:

• Maple templates, which provide an intuitive user interface for optimizing yourMapleSim model, and then generate an S-function in Simulink.

• A range of examples illustrating how to prepare and export your models.

• A direct interface between Maple and Simulink allows you to generate and test an S-function block as you develop the model.

• Commands for developing S-functions of mathematical models from first principles inthe Maple environment and examples to illustrate how to do it.

• Access to commands in the Connectivity and DynamicSystems packages for developingautomated applications to generate S-functions.

Scope of Model SupportMapleSim is a very comprehensive modeling tool where it is possible to create models thatcould go beyond the scope of this MapleSim Simulink Connector Toolbox release. In gen-eral, the MapleSim Simulink Connector Toolbox supports systems of any complexity, in-cluding systems of DAEs of any index, in any mix of domains, as long as they exhibitcontinuous behavior. Systems that contain any type of discontinuity, including discretetransforms, switches, logic gates, relational and Boolean operations are not supported bythe current release of this product.

Apart from all of the engineering and signal components that are continuous, this productalso supports lookup tables, and custom components that do not use discontinuous operationssuch as piecewise functions.

v

System RequirementsThe MapleSim Simulink Connector Toolbox requires the following:

• MATLAB® 2008b, 2009a or 2009b

• Simulink 7.0 or later

• The latest versions of Maple and MapleSim

For installation instructions and a complete list of system requirements, see the Install.htmlfile on the product CD.

vi • Introduction

1 Getting Started1.1 Setting Up the MapleSim Simulink ConnectorToolboxEstablishing a Connection with MATLAB

To generate an S-function block, you must set up Maple to communicate with MATLAB.

Start Maple and enter the following command to establish a connection with MATLAB.

>

A MATLAB command window is opened and the connection is established. If the windowdoes not open, follow the instructions in the ?Matlab[setup] help page to configure theconnection.

Next, set up the MATLAB mex compiler. Go to the MATLAB command window and enterthe setup command.

Follow the instructions to choose a local C compiler that supports ANSI (American NationalStandards Institute) C code.

See the ?SimulinkConnector,setup help page for more information.

You are now ready to use the MapleSim Simulink Connector Toolbox.

1.2 Getting HelpIn Maple, enter ?SimulinkConnector at a prompt in a worksheet.

1

1.3 Using the Simulink Block Generation TemplateThe MapleSim Simulink Connector Toolbox provides a Simulink Block Generation tem-plate in the form of a Maple worksheet for manipulating and exporting MapleSim subsystems.This template contains pre-built embedded components that allow you to generate S-functionor C code from a MapleSim subsystem, export the subsystem as a Simulink block, and savethe source code.

Using this template, you can define inputs and outputs for the system, choose the format ofthe resulting S-function, and generate the source code, library code, block script, or Simulinkblock. You can also assign the model equations to a variable and use any Maple commandsto perform analysis tasks.

Viewing MapleSim Simulink Connector Toolbox Examples

Toolbox examples are available in the Simulink Connector Examples palette in MapleSim.

Each example includes a code generation template in its document folder.

To view an example:

1. In the Simulink Connector Examples palette at the left side of the MapleSim window,expand one of the submenus, and then click the entry for the model that you want to view.

2. Click the Display Document Folder icon on the top menu bar.

3. From the document list, select Simulink Block Generation.

2 • 1 Getting Started

4. Click Open Selected. The code generation template is opened in Maple.

Some models include additional documents, such as templates that display model equationsor define custom components. You can open any of these documents by selecting its entryin the list and clicking Open Selected.

1.4 Example: RLC Circuit ModelIn this example, you will generate a Simulink block from an RLC circuit model that wascreated in MapleSim.

Before starting this tutorial, you must set up MATLAB and the mex compiler. For moreinformation, see Establishing a Connection with MATLAB (page 1).

To generate an S-function block:

1. In the Simulink Connector Examples palette, select the RLC Parallel Circuit example.

2. Click Display Document Folder icon on the top menu bar.

3. From the drop-down menu, select Simulink Block Generation.

4. Click New.

5. Enter RLC Circuit as the worksheet name and click OK.

1.4 Example: RLC Circuit Model • 3

6. In the document list at the left side of the dialog box, select RLC Circuit and click OpenSelected. Your MapleSim model is opened in the Simulink Block Generation forMapleSim Template in Maple.

7. In the Model Summary section of the template, from the Subsystem drop-down menu,select the RLC_Parallel subsystem. This list box displays all of the subsystems in yourMapleSim model.

8. Click System Update. All of the template fields are populated with information specificto the subsystem.

9. In the S-Function block name field, enter RLC_Circuit. This is the name that will bedisplayed for the block in Simulink.

You can now specify which subsystem parameters will be kept as configurable parametersin the generated Simulink block. In this example, the resistance parameter will be kept asa configurable parameter.

10. In the Setting Parameters section, select the R1.R parameter entry in the SubstitutedParameters list.

11. Click the > button. The entry is added to the Simulink Parameters list. The resistanceparameter will be kept as a configurable parameter in the generated Simulink block and theparameters remaining in the Substituted Parameters list will be assigned to values duringthe code generation process.

12. To change the default value of the resistance parameter, select R1.R from the SimulinkParameters list and enter 5 in the Parameter Value field and click anywhere outside ofthe field.

13. In the Advanced Code Generation Settings section, set the Code Optimization optionto Full. This option specifies the degree of simplification applied to the model equationsduring the code generation process. This option eliminates redundant variables and equationsin the system.

14. In the Generate Simulink Block section, click the Model radio button.

15. Click Generate to Simulink to generate the S-function code and create the block.


Note: Generating a block may require a few minutes.

A MATLAB command window is opened and the block with the specified parameters isgenerated in Simulink.

Double-clicking the block opens the mask that contains the symbolic parameters from theoriginal model. This block can now be connected with any compatible Simulink blocks.

1.5 Preparing a Model for ExportIn this example, you will perform the steps required to prepare a slider-crank mechanismmodel and export it as an S-function block:

1. Convert the slider-crank mechanism model to a subsystem.

2. Define subsystem inputs and outputs.

3. Define and assign subsystem parameters.

4. Export the model using the Simulink Block Generation template.

5. Implement the S-function block in Simulink.

The following tutorial will take you through these steps in detail. Before starting this tutorial,you must set up MATLAB and the mex compiler. For more information, see Establishinga Connection with MATLAB (page 1).

To open the slider-crank mechanism example:

1. In MapleSim, expand the Examples palette and then expand the Multibody submenu.

2. Open the Slider Crank Mechanism example.

1.5 Preparing a Model for Export • 5

Converting the Model to a Subsystem

By converting your entire model or part of your model into a subsystem, you identify whichparts of the model that you want to export. In this example, you will prepare the system forexport by grouping all of the components into a subsystem.

1. Using the selection tool ( ) located above the model workspace, draw a box around allof the components in the model.

2. From the Edit menu, select Create Subsystem.

3. In the Create Subsystem dialog box, enter SliderCrank as the subsystem name.


4. Click OK. A SliderCrank subsystem block is displayed in the model workspace.

Defining Subsystem Inputs and Outputs

Simulink only supports data signals. Properties on acausal ports, such as mechanical flangesand electrical pins, must be converted to signals using the appropriate components. Theresulting signals can then be directed as inputs and outputs for the subsystem in MapleSimand for the S-function block.

In this example, you will convert the displacements of the slider and the joint between thecrank and connecting rod to output signals. The input signal needs to be converted to atorque that is applied to the revolute joint that represents the crank shaft.

1. Double-click the subsystem block to view its contents. The broken line surrounding thecomponents indicates the subsystem boundary, which can be resized by clicking and draggingits sizing handles.

2. Delete the probes that are attached to the model.

3. On the left side of the MapleSim window, expand the Multibody palette and then expandthe Sensors submenu.

4. Drag the Absolute Translation component to the model workspace and place it belowthe Prismatic Joint component.

5. Right-click (Control-click for Macintosh®) the Absolute Translation component andselect Rotate Counterclockwise.

6. From the Signal Blocks → Routing → Demultiplexers menu, drag a 3-port Demulti-plexer component to the model workspace and place it to the right of the Absolute Trans-lation component.


7. To connect the Absolute Translation component to the model, click the frame (the whitesquare connector). The frame is highlighted in green when you hover your pointer over it.

8. Draw a vertical line and click the connection line directly above the component. Thesensor is connected to the rest of the diagram.

9. In the same way, connect the r output port of the Absolute Translation component tothe navy blue input port of the demultiplexer. This is the displacement signal from the sensorin x, y, and z coordinates. Since the slider only moves along the x axis, you need to outputthe first coordinate as a signal.

10. Hover your pointer over the first demultiplexer port and click your mouse button once.


11. Drag your pointer to the subsystem boundary.

12. Click the boundary once. A real output port is added to your subsystem.

13. Add another Absolute Translation component above the Connecting Rod subsystem.

14. Right-click (Control-click for Macintosh) this Absolute Translation component andselect Flip Vertically.

15. Add a 3-port Demultiplexer component to the right of the sensor and connect thecomponents as shown below.


Since the crank is moving in the x, y plane, you only need to output the first two signals.

You will now add a real input port to your subsystem to control the torque on the crankshaft.

16. From the 1-D Mechanical → Rotational → Torque Drivers menu, add a Torquecomponent to the model workspace and place it above the Fixed Frame component.

17. Connect the white flange of the Torque component to the white flange of the leftmostRevolute Joint.

18. Click the input port of the Torque component and drag your pointer to the subsystemboundary.


19. Click the boundary once. A real input port is added to your subsystem.

The complete subsystem is displayed below.

Define and Assign Subsystem Parameters

You can define custom parameters that can be used in expressions in your model to editvalues more easily. To do so, you define a parameter with a numeric value in the parametereditor. You can then assign that parameter as a variable to the parameters of other compon-ents; those individual components will then inherit the numeric value of the parameterdefined in the parameter editor. By using this approach, you only need to change the valuein the parameter editor to change the parameter values for multiple components.

1. While in the detailed view of the SliderCrank subsystem, click the Parameters buttonabove the model workspace. The parameter editor is displayed.


2. In the New Parameter field, define a parameter called CrankL and press Enter.

3. Specify a default value of 1 and enter Length of the crank as the description.

4. In the second row of the table, define a parameter called ConRodL and press Enter.

5. Specify a default value of 2 and enter Length of the connecting rod as the description.

6. Click Diagram to switch back to the diagram view. The parameters are defined in theParameters pane.

7. In the model workspace, select the Crank subsystem.

8. In the Parameters pane, change the length value (L) to CrankL.


The Crank subsystem now inherts the numeric value of CrankL that you defined.

9. Select the ConnectingRod subsystem and change its length value to ConRodL.

10. In the model tree, click [Top] to navigate to the top level of the model.

You will include these parameter values in the model that you export. You are now readyto convert your model to an S-function block.

Exporting Your Model Using the Simulink Block Generation Template

After preparing the model, you can use the Simulink Block Generation template to set exportoptions and convert the model to an S-function block.

1. Click View Document Folder... at the top of the window.

2. From the drop-down menu, select Simulink Block Generation.

3. Click New.

4. Enter Slider Crank S-Function as the worksheet name and click OK.


5. In the document list at the left side of the dialog box, select Slider Crank S-Functionand click Open Selected. The slider-crank subsystem is opened in the Simulink BlockGeneration for MapleSim Template in Maple.

6. From the Subsystem drop-down menu, select SliderCrank and click System Update.All of the template fields are populated with information specific to the subsystem.

7. In the Setting Parameters section, click the >> button. The ConRodL and CrankLparameters, which you defined in the previous section, are added to the Simulink Parameterslist. These parameters will be kept as configurable parameters in the generated Simulinkblock.

8. In the Generate Simulink Block section, select the Model radio button to place thegenerated block into a new Simulink model instead of the Simulink block library.

9. Click Generate to Simulink to generate the S-function code and create the block.


A MATLAB command window is opened and the block with the specified parameters isgenerated in Simulink.


Implement the S-Function Block in Simulink

In Simulink, you can connect your block to other compatible blocks, specify initial conditions,and edit the component parameter values.

1. In Simulink, double-click the block. The Parameter Mask dialog box is displayed.

This dialog box displays the ConRodL and CrankL parameters that you defined inMapleSim as a vector. The text in the dialog describes each parameter in the order theyappear in the vector. Initial conditions can also be changed in this dialog box.

2. Click the Help button. This window provides a model description and information aboutthe inputs, outputs, parameters, and initial conditions.

3. All inputs and outputs are implemented as vector signals. To access individual signalsin Simulink, use a Mux block for inputs and a Demux block for outputs.


2 Creating and ExportingMathematical Models in MapleIn Maple, you can use commands from the DynamicSystems package to create a systemfrom first principles. Maple contains a data structure called a system object that encapsulatesthe properties of a dynamic system. This data structure contains information, for example,the description of the system, and the description of the inputs. Five different types of systemscan be created.

• Differential equation or difference equation

• Transfer function as an expression

• Transfer function as a list of numerator and denominator coefficients

• State-space

• Zero, pole, gain

You can use the Simulink Block Generation for DynamicSystems template, which providesembedded components for generating source code and exporting a DynamicSystems objectto Simulink. To open this template, enter ?MapleSimSimulinkConnector,DynamicSys-temsBlockGeneration at a prompt in a Maple worksheet.

Alternatively, you can create a DynamicSystems object in a new worksheet and use com-mands from the SimulinkConnector package to generate source code and save it as aMATLAB .m file.

2.1 Using a Template to Generate an S-Function BlockIn this tutorial, you will use the Simulink Block Generation for DynamicSystems templateto generate a Simulink block from a dynamic system defined in Maple.

Before starting this tutorial, you must set up MATLAB and the mex compiler. For moreinformation, see Establishing a Connection with MATLAB.

To generate an S-function block from a dynamic system:

1. In a Maple worksheet, enter ?MapleSimSimulinkConnector,DynamicSystemsBlock-Generation. The template is opened.

2. If prompted to execute the entire worksheet, click Yes.

In the Component Equations section, you would normally define variables to store com-ponent equations and parameters.

17

These variables are referenced in the equations that define the system object. For demon-stration purposes, the equations and parameters of a DC Motor have been defined for you.

3. In the Generate Simulink Block section, select the Model radio button. This optionplaces the S-function into a new Simulink model instead of a Simulink block library.

4. Click Code Generation. The generated C code is displayed in the View Code section.

5. Click Generate to Simulink.

6. In the Select File dialog box, specify the path and name of the .m and .c files to whichto save the generated code.

7. Click Save. Maple generates the Simulink block.


A MATLAB command window is opened and the block with the specified parameters isgenerated in Simulink. Double-clicking the block opens the mask that contains the symbolicparameters from the original model. This block can now be connected with any compatibleSimulink blocks.

18 • 2 Creating and Exporting Mathematical Models in Maple

2.2 Creating and Exporting a DynamicSystems ObjectProgrammaticallyFirst, load the DynamicSystems and SimulinkConnector packages in the Maple worksheet.

>

>

To create a system object from the transfer function , use the following

command:

>

(2.1)

To view the details of the system, use the PrintSystem command.

>

(2.2)

The default values for the input names ( and output names have been used.Alternatively, during creation of the system, different input and output names can be spe-cified.

2.2 Creating and Exporting a DynamicSystems Object Programmatically • 19

To define parameters values, use the following command:

>

(2.3)

Finally, use the Simulink command to generate the source code and the SaveCode commandto save the code as a .c file and MATLAB .m file.

>

>

>

2.3 Example: DC MotorConsider the classic example of the simplified DC motor. Using the built-in functionalityof the DynamicSystems package in Maple, you can define the system model, and thenvisualize and simulate it before saving the code.

This example demonstrates how to define, analyze, and export a system programmatically.

1. In a new Maple worksheet, define the system model.

Differential Equation Model:

>


>

Transfer Function Model:

>

(2.4)

In place of the above commands, you could use the PrintSystem command to display eachpart of the model.

2. Specify the parameters in the model.Units(Initial) ValueDescription

Input Variables

Applied voltage

Output Variables

Motor shaft angular position

Motor current

Parameters

Moment of inertia of the motor

Damping of the mechanical system

Electromotive force constant

Motor coil resistance

Motor coil inductance

2.3 Example: DC Motor • 21

Units(Initial) ValueDescription

External Spring Load Constant

>

>

3. Generate and save the source code as a .c file and MATLAB .m file.

>

>

>

With the basic tools shown in this guide, you are now ready to use the MapleSim SimulinkConnector Toolbox to solve many system design problems. Enter ?DynamicSystems and?SimulinkConnector at a prompt in a Maple worksheet for more information about thecommands used in this guide.


IndexCConnector Examples Palette, 2

DDynamicSystems object, 17

Creating and Exporting Programmatic-ally, 19Transfer function, 19

IInputs and outputs, 7

MMathematical model, 17MATLAB

Setup, 1

SSimulink, 15Subsystem

Creating, 6Subsystem parameters, 11System object, 17

TTemplates

DynamicSystems, 17Simulink Block Generation, 2, 13

23

24 • Index

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