Is PID still used?

I haven’t done vex since V5 came out. I remember there being something about automatic PID so now that I’m restarting robotics I have to ask. Are PID controllers still used or is the V5 auto PID good enough to where you don’t need your own anymore?

It is a most definite yes!
In fact, coding your own PID is the preferred method of making sure you have a well-polished control algorithm. VEXcode’s speed commands are all PID, but you can code your own by sending commands via voltage:

LB_motor.spin( fwd, 12.0, voltageUnits::volt );
LR_motor.spin( fwd, -12.0, voltageUnits::volt )
Arm_motor.spin( fwd, 10.0, voltageUnits::volt );;

Voltage is from -12.0 to 12.0 in VEXcode, so you adjust your PID accordingly.


I remember DROW had to release some download thing to let you do that. Is that still the case or is it in the Vanilla Coding environment

I think that was 2-3 ago. But it was an update, not a separate download, so just install the latest vexcode or vexcode pro and you’re good to go :slight_smile:

The VEXcode V5 has made significant improvements over the Cortex programming platforms (as you would expect). With a little bit of training, teams programming a Drivetrain with an Inertial sensor can build a decent, reasonably accurate program with autonomous code in under an hour. It doesn’t account for wheel slip or robot weight, and you can’t adjust the constants (k) so it has limitations. The benefit being that it’s quick and easy. You will have to determine if it is good enough.


I tell my students that the base drivetrain object available in vexcode is something like 80-85% as good as the best programming students are doing in VRC (which includes PID and more.) Getting to that last 15-20% of performance and reliability is very admirable, but you can achieve a great deal without it. In-game, 15 second autonomous in particular can be quite solid with only the base code. It is a good starting point to build from. If you look to create a one minute skills autonomous, you will most likely find you need to add additional sensors and start chipping away at that 20% to be successful.


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