Quote:
Originally Posted by asid61
Of course, driver training is extremely important. That's why I suggested a software limit for speed at first and later.
Personally, I think the game doesn't matter as much as driver training. The drivetrain should be what the driver can handle; pretty much every game in FRC in the past several years has required speed.
If you used PWM control to the motor, wouldn't it technically accelerate faster with a software limited top speed? If you don't stall the CIMs, that is. I feel like that doesn't work out, but can anybody explain why?
From what I've seen, acceleration can probably be mitigated as a problem with a 3 + 2/3 cim per side gearbox. (heheheh)
Does anybody know what the maximum speed it is physically possible to go on an FRC robot? Assuming you want to drive for 10 seconds before the main breaker blows with a 100lb robot.
|
Empirically higher top speed = less torque which in turn = less acceleration because T = I*M*A/R (Moment of Inertia, Mass, Acceleration, Radius)
If torque decreases with the others staying the same, then acceleration must decrease. That's why adding motors increases acceleration, because it adds torque to the drive.
A small piece I found on HP, I havn't checked the math but it seems logical
Quote:
Originally Posted by BBray_T1296
Fun fact: 6 CIMs at stall consume a total of roughly 9576 watts of electrical power, which is over 9000!
Seriously though, a robot with 6 CIMs under "normal load" output (excluding friction) a total of 2.6 Horsepower, while a 4 Cim drive does just 1.75. At exactly 40 Amps per motor the numbers are (theoretically) 3.86hp and 2.57hp, respectively.
And as everybody knows, power/weight ratio is the most important figure. 
 |