I’ve been reading a lot lately about autonomous vehicles (self-driving cars), and see lots of different algorithms people use to try to regulate what speed the car should be going. What I don’t find many articles on lately (mostly articles from the 90s) are how to actually regulate the car’s current parameters (speed, acceleration, steering) compared to the desired outcome (i.e. what your algorithm told you to adjust your parameters to).

My initial thought (and this is what cruise control uses, at least in the past, for example) is that velocity and steering are controlled by PID controllers. Is that true now, even on vehicles whose desired velocity/steering inputs are determined from machine learning algorithms? If not, can anyone elaborate or point me in a direction where I can learn more about this? For example, if you train a vehicle to drive based off of driving data, suppose your algorithm tells you to speed up. When you increase the throttle, if for some unseen reason your acceleration isn’t at what the algorithm wants you to be at, what happens, and what is in charge of how to handle these differences?