Making a tank in Stormworks. I've programmed the regenerative braking, which is quite simple. It is very effective on a tank, since it uses brakes for steering and 50 tons has a lot of energy to store.

How the motor should work in response to driver inputs, saving the engine (due to low RPMs), and smoothing out the power delivery... More complex.

The engine has enough power to accelerate pretty well, but diesel engines disadvantage in tanks compared to turbines is that the jet can deliver very high torque, allowing (say) an Abrams or T80 to accelerate from stationary much faster than their diesel equivalents. Thus, hybrid tank.

Main cases:

• starter. Probably the simplest case, the motor gives power until the diesel gets to ignition
• Saving the engine from stalling: keeps the RPMs above ignition until the engine's controller catches up to the situation. Needs a safety cut-off in case something is jammed to prevent damage.
• driver wants to accelerate. WS controls, should turn off when clutch is disengaged for gear changing (no torque converters, sorry)
• sudden dips in RPMs when there is no driver input. Sudden hills, rougher terrain. Not to prevent the RPM from going down entirely, but to provide smooth running while going over rough terrain.

One thing I am finding is that the diesel engine is very hard to tune if I do any of these, so I should probably do that first before doing anything but the starter case.

The motor on its own can rolling start the tank pretty well