PID control

pid

 * http://blog.solutions-cubed.com/pid-motor-control-with-an-arduino/ position control pid with dc motor.
 * http://www.solutions-cubed.com/motor-control/

github

 * https://github.com/X-Sim/X-PID-Arduino-PID-motor-control, http://www.x-sim.de/forum/portal.php GUI interface for tuning
 * https://github.com/sebnil/Selfbalancing-robot PID, FIR links to https://github.com/br3ttb/Arduino-PID-Library , http://brettbeauregard.com/blog/2011/04/improving-the-beginners-pid-introduction/

Segway
https://github.com/ovaltineo/SegwayClone

A MPU-6050 3-axis accelerometer and gyroscope. The accelerometer and gyroscope readings are combined using a Kalman filter library. See my blog post: http://blog.tkjelectronics.dk/2012/09/a-practical-approach-to-kalman-filter-and-how-to-implement-it/ and source https://github.com/TKJElectronics/KalmanFilter for more information. USB Host support is implemented using the MAX3421E and the USB Host library: https://github.com/felis/USB_Host_Shield_2.0. Two VNH5180 motor controller ICs is used to drive the two motors. More information can be found at the Wiki article: http://wiki.balanduino.net/Overview.
 * http://balanduino.com/
 * https://github.com/TKJElectronics/BalancingRobotArduino, https://developer.mbed.org/users/Lauszus/code/BalancingRobotPS3/
 * https://github.com/TKJElectronics/Balanduino the Balanduino hardware consist of an ATmega1284P running at 10MHz.

Journals
https://www.researchgate.net/publication/285759625_Optimal_PID_controller_design_through_swarm_intelligence_algorithms_for_sun_tracking_system

http://folk.ntnu.no/skoge/prost/proceedings/afcon03/Papers/050.pdf In this paper the Preitl and Precup equations for Symmetrical Optimum tuning are  further  refined  to  allow  explicit  specification  of  the  closed  loop  damping  factor. The resulting  tuned controller values are applied to position control of a dc servomotor. by Martin Braae  University cape town. http://folk.ntnu.no/skoge/prost/proceedings/afcon03/Papers/069.pdf

PID algorithm
Applied Control Theory for Embedded Systems" came out in April. See details at http://www.wescottdesign.com/actfes/actfes.html
 * http://groups.google.com/group/comp.arch.embedded/browse_thread/thread/68223435f15d9f1e/#
 * http://www.wescottdesign.com/articles/pidwophd.html.
 * http://www.wescottdesign.com/articles/articles.html, or buy my book:*
 * http://www.wescottdesign.com/actfes/actfes.html.
 * http://www.wescottdesign.com
 * http://www.chiefdelphi.com/media/papers/download/1829
 * http://www.wescottdesign.com/articles/MSK/mskTop.html Masters Thesis http://www.wescottdesign.com/articles/MSK/msk.pdf File  msk.pdf

Applied digital micro control

 * Microcontroller Based Applied Digital Control (Hardcover) by Ibrahim Chapters 10 and 11 round out the discussion with controller realization and a practical case study; A liquid level digital control system.
 * Microcontroller Based Temperature Monitoring & Control by Dogan Ibrahim
 * Digital PID controller.Closing the loop with a PIC, by Kohtz D. http://mgnet.me/bOUDbGa

Links
Arduino code https://github.com/grbl/grbl Grbl is a no-compromise, high performance, low cost alternative to parallel-port-based motion control for CNC milling. It will run on a vanilla Arduino (Duemillanove/Uno) as long as it sports an Atmega 328. The controller is written in highly optimized C utilizing every clever feature of the AVR-chips to achieve precise timing and asynchronous operation. It is able to maintain up to 30kHz of stable, jitter free control pulses Optical encoders