Controlling a 3D Vehicle with Simulink Jeff Bender ME

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 under Math 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” in the 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 Control must 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 0.5 and 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