Revision as of 12:47, 20 September 2017

References

• ROS PID
• ROS PID API

PID Calibration

• ROS PID Tuning
  • A quick and dirty tuning experiment
    • Target linear speed 0.2 m/sec, angular 0.2 radians/sec
    • Definite oscillation with P = 60.
    • Set P to 1/2 of that or 30
    • Tried a I of 60
  • See Phidgets PID Tuning

• Manual PID Tuning

"If the system must remain online, one tuning method is to first set K_i and K_d values to zero. Increase the K_p until the output of the loop oscillates, then the K_p should be set to approximately half of that value for a "quarter amplitude decay" type response. Then increase K_i until any offset is corrected in sufficient time for the process. However, too much K_i will cause instability. Finally, increase K_d, if required, until the loop is acceptably quick to reach its reference after a load disturbance. However, too much K_d will cause excessive response and overshoot. A fast PID loop tuning usually overshoots slightly to reach the setpoint more quickly; however, some systems cannot accept overshoot, in which case an over-damped closed-loop system is required, which will require a K_p setting significantly less than half that of the K_p setting that was causing oscillation."

Other PID References

• PID Controller Theory and Tuning
• Using PID based Techniques For Competitive Odometry and Dead-Reckoning G.W. Lucas