Controlling a 3D Vehicle with Simulink Jeff Bender ME-114 12-22-06

Controlling a 3D Vehicle with Simulink

Jeff Bender

ME-114

12-22-06

visualNastran 4D Process

The completed SolidWorks assembly is transferred to Nastran using the visualNastran link in the SolidWorks program:

Additional Nastran Constraints

Each wheel must be set to collide with the road

A motor must be added to each wheel

Torque Control

Addition of Control Bar in Nastran

The Torque Control bar in Nastran will be used by Matlab as an input parameter

Addition of Meter in Nastran

The Angular Velocity Meter will be used by Matlab as an output parameter

Matlab Process

The first step in Matlab is to open a new document in Simulink and then open the Simulink Library Browser

New Document

Simulink Library Browser

Matlab Process

Add a “constant”, “sum”, “gain” and “vNPlant” from the Library Browser by clicking and dragging

The constant is found under Sources

The sum and gain are found underMath Operations

The vNPlant is found under MSC.visualNastran 4D

Matlab Process

Open the vNPlant by double clicking it and use the Browse function to open the appropriate Nastran file

Add each of the Torque controls as inputs

Add each of the Angular Velocities of the wheels in the y-direction

Matlab Operations

A feedback loop will be created using data measured from the model as the input and values from the drive motor as the output. The output will adjust according to the target input value.

There will be a large output when far away from the desired input value but the output will gradually reduce until the input matches the desired value.

Matlab Process

Enter Target Value of 720 deg/sec and set damping to -400

Click on “Start Simulation” inthe Simulink window

Results

You can see the difference between the two models

Car running with constant torque value

Click on picture to see simulation

Car running with Simulink Control

Click on picture to see simulation

Velocity Control

Addition of Control Bar in Nastran

Similar to the Torque Control bar, the Velocity Control Bar in Nastran will be used by Matlab as an input parameter

The Rotational Velocity Controlmust be added to each motor

Addition of Meter in Nastran

•The Velocity Meter will be used by Matlab as an output parameter

The Velocity Meter must be added to each wheel

Matlab Process

As before, open a new Simulink file and add a “constant”, “sum”, “gain” and “vNPlant” from the Library Browser

Open the vNPlant and use the Browse function to open the appropriate Nastran file

Add each of the Rotational Velocity controls as inputs

Add each of the Velocities of the wheels in the y-direction

Matlab Process

Enter Target Value of 720 deg/sec and set damping to 0.5and press the “Start Simulation” button

Results

Click on picture to see Matlab simulation

Results

Simulink increases and decreases the velocity of the wheels to compensate for the changing forward velocity with each rotation

Conclusion

Simulink was successfully used to control the torque and velocity of a three dimensional vehicle.

These techniques can be used to analyze many different three dimensional models