Encoder vs gyro

[technik3k]

@9227, just like I said in the other thread a lot depends on your chassis geometry and what type of wheels you use.

If you have fully symmetric chassis with all omnis - it will be easy to control it based on encoder values. However, if you have a pair of traction wheels either on the front or the back of the robot and they are not chained together, then encoders on the front and back wheels could return different counts as you turn and you have to watch out and go slow to avoid slippage of the wheels.

Encoders are digital sensors and their error source is wheel slippage. Gyro is an analog sensor and its errors are result of the electrical and thermal noise as well as mechanical vibrations.

If you have V5 and are a beginner, I would stick with encoders, but if you want to learn and willing to try custom Gyro library that does some filtering, here are some links:

QCC2 Gyro and PID Control Code

Hi all, I have been asked by a few people about how we managed to accurately use the VEX gyroscope for our autonomous routines that we used at the world championship this year so I decided to share the ROBOTC code I used for reading and filtering the gyro’s rate of change and controlling our motors with PID. I have also included some example code that shows how to use it to turn a desired number of degrees. https://github.com/JMMcKinneyWPI/GyroPIDLibrary I also would like to thank VEX for a g…

Using 2 gyros

You could do that and it will work well for small drift errors, but if error from one of the gyros suddenly jumps then it is not going to help. The root of the problem is that actual Gyro reports angular velocity measurement (how fast the robot is rotating) and not the true heading angle. The heading is estimated in (vex) software by integrating measured rotation rate over time. If every once in a while you get erroneous measurement, the errors will accumulate and averaging two separate gyro e…

Gyros in Turning Point

What are your thoughts on ways to apply the gyro in this year’s competition, and if it is viable to use one. My team is using the gyro to rotate the bot so it has a perfect aim at the flags.