pid Struct Reference

PID Controller. More...

Data Fields
float	kP
float	kI
float	kD
float	lastError
float	integral

Detailed Description

PID Controller.

The PID controller is a linear control algorithm that has three terms:

• Proportional: A simple scaling of the error value by a gain kP
• Integral: Integration of the error value over time, then multipled by gain kI
• Derivative: Rate of change of the error value over time, multiplied by gain kD

Terms of the controller can be removed by setting their gain to 0, creating a PI (kD = 0) or PD (kI = 0) controller. Depending on the control problem at hand, some terms may not increase the performance of the system, or may have a negative effect.

For a more mathematical expanation of the PID Controller, see https://en.wikipedia.org/wiki/PID_controller

Limitations of this implementation:

• Since this implementation is just for demonstration, the pid_step function takes the dt as a parameter, and it can be provided by the user in main(). This allows deterministic experimentation with the algorithm, rather than using time(NULL) which would make the function non-deterministic.

Inputs: e(t) - Current error at time t. For example, how far a servo is off the desired angle Output: u(t) - Controller output at time t.

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The documentation for this struct was generated from the following file:

• misc/pid.c