Under normal atmospheric conditions, helium has a lifting ability of 1 gram per liter*. The maximum volume of your robot is 28x38x60. Let's pretend you fill that entire volume with helium (impossible, since you would need to lose some volume for the electronics, battery, bumpers, etc.)
28" x 38" x 60" x 1 gram/liter = 2.3 pounds of lifting capability. Not even enough for the cRIO itself.
*
http://science.howstuffworks.com/helium2.htm