Package fr3_impedance_controller_real in nix env

Including all deps. Tested with nix develop then roslaunch franka_example_controllers ....

Issue with libfranka version, in the end needed to use fetchGithub in Nix to get proper files.

Closes #7 (closed)

fr3_impedance_controller_real/include/franka_example_controllers/cartesian_impedance_example_controller.h

@@ -25,6 +25,10 @@
 #include <franka_hw/franka_model_interface.h>
 #include <franka_hw/franka_state_interface.h>
 
+#include "DisturbanceObserver.hpp"
+#include "SlidingModeObserver.hpp"
+#include "MomentumObserver.hpp"
+
 namespace franka_example_controllers
 {
 class CartesianImpedanceExampleController :