Dual encoders

[Joe Ross]

We use 2 encoders and check if one or the other is where we want, that way we can handle a single encoder failure.

[tr6scott]

^ Same, we typically just check if either is greater than target, and call it good. Close enough for FRC... We use $60 encoders, not wanting to buy another, to know which is broke, as I am broke. . .

[mehnadnerd]

Having two encoders also helps to ensure driving straight. The way we implement it can be found at https://github.com/FRC1458/turtleshe...tDrivePID.java, we combine the gyro data and the difference (left - right) to figure out how much the motors need to drive differently.

[Caleb Sykes]

Originally Posted by Joe Ross

We use 2 encoders and check if one or the other is where we want, that way we can handle a single encoder failure.

Can you tell which one is behaving correctly and which one is failing? Or do you just abort if they are different enough?

[Alan Anderson]

Originally Posted by Caleb Sykes

Can you tell which one is behaving correctly and which one is failing? Or do you just abort if they are different enough?

His description suggests that it accounts only for an encoder reporting too few counts. If either of the two reaches the target, the code considers the travel distance satisfied and continues to the next step. Since the typical encoder failure results in it not counting at all, this is highly likely to have the desired result.