PID Definitions by Neil Hazra
Some definitions:
1. Control System:
a. Drives an actuator (i.e. motor) towards a desired value based on sensor readings.
2. PID
a. A type of control system where the error is computed and the broken down into three subcomponents: Proportional, Integral, and Derivative.
Variable Definitions
1. Input
a. The value measured by sensors on a robot
2. Output
a. The value sent to an actuator (i.e. motor, servo etc.)
3. Setpoint
a. The desired value. For example, on a tricopter the setpoint could be 0 degrees, meaning a stable and hovering drone.
4. Error
a. The numerical difference between the desired value and the input.
5. Correction
a. The final value computed by the PID algorithm
Function Definitions:
1. u(t)
a. u(t) is the correction at a particular point in time
2. e(t)
a. e(t) is the error at a particular point in time
3. i(t)
a. The input at a particular point in time