Specify the Velocity of the Propellers

  1. Before you can specify the velocity, you must first create the solver variables.
    1. Right-click SolverVariable from the toolbar to display the Add SolverVariable dialog.
    2. For Label, enter Throttle_Command.
    3. For Variable, enter sv_Throttle_Command and click OK.
      Figure 1.


      Figure 2.


    4. Repeat the steps a-c to create the Pitch and Roll solver variables.
      Label
      Variable
      Roll_Command
      sv_Roll_Command
      Pitch_Command
      sv_Pitch_Command
  2. Now you can update the propeller motion velocity.
    1. From the Project Browser, browse to the Motions folder and select Prop_Left_Rotation motion.
    2. From the Motion panel, go to the Properties tab.
    3. From the Properties tab, change Define by to Expression and enter: 
      `VARVAL({sv_Throttle_Command.idstring})+VARVAL({sv_Roll_Command.idstring})`
    4. Repeat the steps above for Propeller Right, Front and Rear, following the table entries below:
      Motion
      Expression
      Prop_Right_Rotation
      `VARVAL({sv_Throttle_Command.idstring})-VARVAL({sv_Roll_Command.idstring})`
      Prop_Front_Rotation
      `-VARVAL({sv_Throttle_Command.idstring}) -VARVAL({sv_Pitch_Command.idstring})`
      Prop_Rear_Rotation
      `-VARVAL({sv_Throttle_Command.idstring})+ VARVAL({sv_Pitch_Command.idstring})`
      Note: The lateral propellers (left and right) control the Roll of the vehicle and the vertical propellers control the Pitch. The signal difference in the expressions determine the rotation direction of the quadrotor.
      Figure 3.