Merge pull request #1716 from PX4/literature_reference

added references

src/modules/mc_att_control/mc_att_control_main.cpp

@@ -35,6 +35,10 @@
  * @file mc_att_control_main.cpp
  * Multicopter attitude controller.
  *
+ * Publication for the desired attitude tracking:
+ * Daniel Mellinger and Vijay Kumar. Minimum Snap Trajectory Generation and Control for Quadrotors.
+ * Int. Conf. on Robotics and Automation, Shanghai, China, May 2011.
+ *
  * @author Tobias Naegeli <naegelit@student.ethz.ch>
  * @author Lorenz Meier <lm@inf.ethz.ch>
  * @author Anton Babushkin <anton.babushkin@me.com>

src/modules/mc_pos_control/mc_pos_control_main.cpp

@@ -35,6 +35,12 @@
  * @file mc_pos_control_main.cpp
  * Multicopter position controller.
  *
+ * Original publication for the desired attitude generation:
+ * Daniel Mellinger and Vijay Kumar. Minimum Snap Trajectory Generation and Control for Quadrotors.
+ * Int. Conf. on Robotics and Automation, Shanghai, China, May 2011
+ *
+ * Also inspired by https://pixhawk.org/firmware/apps/fw_pos_control_l1
+ *
  * The controller has two loops: P loop for position error and PID loop for velocity error.
  * Output of velocity controller is thrust vector that splitted to thrust direction
  * (i.e. rotation matrix for multicopter orientation) and thrust module (i.e. multicopter thrust itself).