Clarify which setpoints supported (#545)

PX4 · Aug 6, 2019 · 6a42e8c · 6a42e8c
1 parent 536c350
commit 6a42e8c
Showing 1 changed file with 8 additions and 3 deletions.
diff --git a/en/flight_modes/offboard.md b/en/flight_modes/offboard.md
@@ -30,16 +30,21 @@ The action is defined in the parameters [COM_OBL_ACT](#COM_OBL_ACT) and [COM_OBL
 
 ### Copter/VTOL
 
-* [SET_POSITION_TARGET_LOCAL_NED](https://mavlink.io/en/messages/common.html#SET_POSITION_TARGET_LOCAL_NED) - Control vehicle position, velocity, or thrust. 
-  - Acceleration setpoints are combined to create a 'thrust' setpoint.
+* [SET_POSITION_TARGET_LOCAL_NED](https://mavlink.io/en/messages/common.html#SET_POSITION_TARGET_LOCAL_NED)
+  * The following input combinations are supported: <!-- https://github.com/PX4/Firmware/blob/master/src/lib/FlightTasks/tasks/Offboard/FlightTaskOffboard.cpp#L166-L170 -->
+    * Position setpoint (only)
+    * Velocity setpoint (only)
+    * *Thrust* setpoint (only)
+      > **Note** Acceleration setpoint values are mapped to create a normalized thrust setpoint (i.e. acceleration setpoints are no "properly" supported).
+    * Position setpoint **and** velocity setpoint (the velocity setpoint is used as feedforward; it is added to the output of the position controller and the result is used as the input to the velocity controller).
   - PX4 supports the coordinate frames (`coordinate_frame` field): [MAV_FRAME_LOCAL_NED](https://mavlink.io/en/messages/common.html#MAV_FRAME_LOCAL_NED) and [MAV_FRAME_BODY_NED](https://mavlink.io/en/messages/common.html#MAV_FRAME_BODY_NED).
 * [SET_ATTITUDE_TARGET](https://mavlink.io/en/messages/common.html#SET_ATTITUDE_TARGET) - Control vehicle attitude/orientation.
 
 ### Fixed Wing
 
 * [SET_ATTITUDE_TARGET](https://mavlink.io/en/messages/common.html#SET_ATTITUDE_TARGET) - Control vehicle attitude/body rates.
 
-> **Warning** Position setpoints are **not supported** on Fixed Wing offboard mode (`SET_POSITION_TARGET_LOCAL_NED`).
+> **Warning** Position setpoints are **not supported** on Fixed Wing offboard mode (`SET_POSITION_TARGET_LOCAL_NED`). 
 
 <!-- Limited for offboard mode in Fixed Wing was added to master after PX4 v1.9.0.
 See https://github.com/PX4/Firmware/pull/12149 and https://github.com/PX4/Firmware/pull/12311 -->