Design model versus actual motor
Will a controller tuned for the nominal motor behave the same if inertia doubles?
Try it in the current lab
Compare inertia scale 1× and 2× at the same gains, then vary friction separately. The frequency panel intentionally stays on the nominal design model.
Pin the nominal run. Change actual inertia while leaving the controller and nominal frequency model fixed; compare time response and control effort.
The lab recalculates after a setting changes. Pin a run before changing one variable; the response and control-effort plots share the same replay time. PID experiments also show the P/I/D terms; estimator experiments show measured and estimated states.
What the system is doing
A model is a prediction, not the hardware. Parameter error changes the time response while nominal Bode and root-locus plots stay the same. Test a plausible parameter range rather than claiming a single run proves robustness.
Connect the design method
The nominal motor is the design model. Inertia and friction multipliers change only the simulated actual plant. Bode, Nyquist and the P-only root locus intentionally stay nominal; compare their expectation against the time run and a held-out target or load. No real hardware data is identified here.
Jactual = scaleJ · Jnominal; bactual = scaleb · bnominal