.VehicleInterfaces.Brakes.Tutorial

Information

Tutorial - Defining a new brakes model

The following process will demonstrate how to create a new brakes model using these interface definitions. This tutorial will guide you through building a braking system for a passenger car, i.e. a vehicle with 4 wheels.

1. Create a new model that extends VehicleInterfaces.Brakes.Interfaces.TwoAxleBase, it should look like this:
   
    
2. In the component browser, right click on TwoAxleBase and select Parameters from the context menu to produce the following parameter dialog
   
    
3. This dialog allows you to enable/disable the optional connections by setting includeWheelBearings and includeBrakePedal as required for your new brakes model. The wheelHub connectors are of the type Modelica.Mechanics.MultiBody.Interfaces.FlangeWithBearing, the parameter includeWheelBearings controls whether the bearing connectors within the wheelHubs is enabled or not.
4. You can now define your brakes model as required.

Creating a simple braking system example

The following steps demonstrate how to create anbsp;simple braking system model. The brakes will be modelled using the standard brakes component from the Modelica standard library. A position sensor will measure the brake pedal position and a 1D table block will be used to convert this to a force that will be applied to each wheel brake. The reactions in to the wheel carriers will not be modelled.

Starting from step 3 above.

1. First, decide which of the optional connectors are required in the model. For this example we need the brake pedal connection but not the wheel bearing connector
   
    
2. Add the following blocks and connections to the diagram. When you draw the connections from the brake components to the wheelHub connectors the dialog box shown below will appear asking which connector within the wheelHub connector you would like to make the connection to. As we are modelling the brakes as a 1D system you should select flange from the list of options which is the 1D connector within the wheelHub connector.
   
   
    
3. Next, we need to check to see if any connections to the control signal bus are required for the brakes, see a complete list of the minimum connections required. In this case we need to add the four individual wheel speeds to the control signal bus and this can be done by connecting speed sensors to each wheel and then connecting these to the signal bus. As the wheel speed signals are added to the brakesBus we first need to add this connector. The brakesBus connector is VehicleInterfaces.Interfaces.BrakesBus. This should be connected to the controlBus; when this connection is made the following dialog is produced and should be completed as shown.
   
    
4. When the connections between the sensors and the brakesBus connector are added the dialog below appears and should be completed with the correct index for all four wheel speeds being measured.
   
    
5. The model is now complete and should check successfully and can be used in any model compatible with the VehicleInterfaces library assuming the selected Driver model also uses the brake pedal connection.