# Glossary

Let's be real, the nomen clature around control theory is incredibly intimidating at first; it should't be like this. Also this is not in alphabetical order lol.

- 1.Reference - The target position we would like to be at. This is often used interchangably with other terms such as set point or target.
- 2.Gain - A value we multiply by another value. In a PID controller Kp, Ki, and Kd are "gains"
- 3.Feedback - a process where given a measurement and a desired state we calculate the best input to reach the state. A synonym for closed-loop control
- 4.Feedforward - a process where given just a desired state we calculate the best input to reach the state. A synonym for open-loop control
- 5.PID control - A type of feedback control with three main components. A proportional, an integral, and a derivative.
- 6.Integral - the sum of a signal over time
- 7.Derivative - the rate of change of a singal
- 8.Full State Feedback - a feedback control method that is basically just a bunch of proportional controllers strapped together.
- 9.State - where our system currently is, usually a combination of position / velocity.
- 10.Roadrunner - A library for First Tech Challenge that incorperates a ton of really powerful control techniques. It has built in localization (using drive encoders or dead wheels), trajectory generation, and trajectory following algorithms
- 11.Path - a set of points that makes up where our robot should be in space. Usually traversed through by the robots current position.
- 12.Trajectory - a set of position and velocity points, usually indexed by the given time.
- 13.State machine - a way to code your robots that emulates asynchronous behavior but without the side effects.