Difference between revisions of "PID control"

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(PID controller)
(PID controller)
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Examples:
 
Examples:
  
1) Tracking: input sensor is inside/outside, output plant is the left and right motor. Goal is to keep error (inside/outside state time) small.
+
# Tracking: input sensor is inside/outside, output plant is the left and right motor. Goal is to keep error (inside/outside state time) small.
2) Motor speed: input sensor is odometry, output plant is the motor. Goal is to keep the error (setpoint rpm - actual rpm) small.
+
# Motor speed: input sensor is odometry, output plant is the motor. Goal is to keep the error (setpoint rpm - actual rpm) small.
  
 
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Revision as of 12:10, 29 May 2016

Abstract

Ardumower uses a digital PID controller for

  • heading/course tracking
  • perimeter tracking
  • motor speed control
  • ...

PID controller

Proportional, Integral and Derivative (PID) controller concept:

P : Determines how aggressively the PID reacts to the current amount of error (Proportional) 
D : Determines how aggressively the PID reacts to the change in error (Derivative) 
I : Determines how aggressively the PID reacts to error over time (Integral) 

Examples:

  1. Tracking: input sensor is inside/outside, output plant is the left and right motor. Goal is to keep error (inside/outside state time) small.
  2. Motor speed: input sensor is odometry, output plant is the motor. Goal is to keep the error (setpoint rpm - actual rpm) small.

Velocity PID

The standard form is most used for position control. If you derivate the standard form, you obtain the velocity form:

Simulator

For interactive learning, you can find a PID simulator here: PID simulator