Since the new V5 motors have integrated motor encoders, is there still any use for quadrature encoders anymore? (Especially for the drive train). What are the benefits and drawbacks of each?
There are definitely still uses, but they’re more limited.
A lot of teams use tracking wheels or encoder wheels on their drive train for better position tracking. (Notably 5225A.) Basically the idea is you have a free spinning wheel attached to a standoff and rubber banded down. Thus, the wheels cannot skid or leave the ground if the robot tilts slightly, and you get extremely accurate position tracking. This is the magic behind the 5225A programming skills, and it absolutely cannot be done with the v5 encoders.
The only other application I can think of is if you have a flywheel and you want more precise velocity tracking. Putting an encoder after a 5:1 or 7:1 ratio will obviously give you more precision (each tic is a smaller unit of rotation of the motor), meaning you can regulate the speed more tightly.
However, not everyone needs ultra precise PID control on the chassis, and the speed function of the v5 motors might be plenty for flywheels. I honestly have no idea. But I’d be surprised if the quad encoders were totally dead after this season.
Thanks! I am debating whether to keep the quad encoder also because of the difficulty involved in putting it on my robot too. Anyways, I was wondering if there is a video for 5225A’s programming skills you mentioned.
That’s clever. I believe the most consistent form of error I’ve seen with encoders directly tied into the drive has been when the wheels slip during acceleration. We always focused on writing good acceleration programming to eliminate burn outs, but this is simple way to mechanically eliminate that.
