add support for unmanned underwater vehicles (#14079)

* add support for unmanned underwater vehicles:
* airframe uuv_generic + uuv_hippocammpus including mav_type = 12 for submarines
* mixer for UUVs with X-shaped thruster setup similar to quadcopter
* add module  uuv_att_control for underwater robot attitude control
* add rc.uuv_defaults/apps for autostarting e.g. ekf2 and uuv_att_control app

ROMFS/px4fmu_common/init.d/airframes/60000_uuv_generic

@@ -0,0 +1,29 @@
+#!/bin/sh
+#
+# @name Generic Underwater Robot
+#
+# @type Underwater Robot
+# @class Underwater Robot
+#
+# @board px4_fmu-v2 exclude
+#
+# @maintainer
+#
+
+sh /etc/init.d/rc.uuv_defaults
+
+if [ $AUTOCNF = yes ]
+then
+	#Set data link loss failsafe mode (0: disabled, 4: Data Link Auto Recovery (CASA Outback Challenge rules))
+	param set NAV_DLL_ACT 0
+
+	# disable circuit breaker for airspeed sensor
+	param set CBRK_AIRSPD_CHK 162128
+
+	#param set CBRK_GPSFAIL 240024
+fi
+
+set MAV_TYPE 12
+param set MAV_TYPE ${MAV_TYPE}
+
+set MIXER uuv_x

ROMFS/px4fmu_common/init.d/airframes/60001_uuv_hippocampus

@@ -0,0 +1,29 @@
+#!/bin/sh
+#
+# @name HippoCampus UUV (Unmanned Underwater Vehicle)
+#
+# @type Underwater Robot
+# @class Underwater Robot
+#
+# @board px4_fmu-v2 exclude
+#
+# @maintainer Daniel Duecker <daniel.duecker@tuhh.de>
+#
+
+sh /etc/init.d/rc.uuv_defaults
+
+if [ $AUTOCNF = yes ]
+then
+	#Set data link loss failsafe mode (0: disabled, 4: Data Link Auto Recovery (CASA Outback Challenge rules))
+	param set NAV_DLL_ACT 0
+
+	# disable circuit breaker for airspeed sensor
+	param set CBRK_AIRSPD_CHK 162128
+
+	#param set CBRK_GPSFAIL 240024
+fi
+
+set MAV_TYPE 12
+param set MAV_TYPE ${MAV_TYPE}
+
+set MIXER uuv_x

ROMFS/px4fmu_common/init.d/airframes/CMakeLists.txt

@@ -146,4 +146,8 @@ px4_add_romfs_files(
 	50001_axialracing_ax10
 	50002_traxxas_stampede_2wd
 	50003_aion_robotics_r1_rover
+
+	# [60000, 61000] (Unmanned) Underwater Robots
+	60000_uuv_generic
+	60001_uuv_hippocampus
 )