commander: fix abs bug / trigger POSCTL both ways

The check if stick were touched was only working in one direction (per
axis) because fabsf was used incorrectly.

However, this check is still only a differential check triggered by
fast movement and does not trigger if someone slowly moves a stick to
the side. Also, the sensitivity depends on the rate of the commander
loop and/or the RC update loop. The correct solution would be a proper
filtering and trigger for movement.

src/modules/commander/commander.cpp

@@ -2534,10 +2534,10 @@ int commander_thread_main(int argc, char *argv[])
 
 			// transition to previous state if sticks are touched
 			if ((_last_sp_man.timestamp != sp_man.timestamp) &&
-				((fabsf(sp_man.x) - fabsf(_last_sp_man.x) > min_stick_change) ||
-				 (fabsf(sp_man.y) - fabsf(_last_sp_man.y) > min_stick_change) ||
-				 (fabsf(sp_man.z) - fabsf(_last_sp_man.z) > min_stick_change) ||
-				 (fabsf(sp_man.r) - fabsf(_last_sp_man.r) > min_stick_change))) {
+				((fabsf(sp_man.x - _last_sp_man.x) > min_stick_change) ||
+				 (fabsf(sp_man.y - _last_sp_man.y) > min_stick_change) ||
+				 (fabsf(sp_man.z - _last_sp_man.z) > min_stick_change) ||
+				 (fabsf(sp_man.r - _last_sp_man.r) > min_stick_change))) {
 
 				// revert to position control in any case
 				main_state_transition(&status, commander_state_s::MAIN_STATE_POSCTL, main_state_prev, &status_flags, &internal_state);
@@ -2550,11 +2550,12 @@ int commander_thread_main(int argc, char *argv[])
 			internal_state.main_state == commander_state_s::MAIN_STATE_AUTO_MISSION ||
 			internal_state.main_state == commander_state_s::MAIN_STATE_AUTO_LOITER) {
 			// transition to previous state if sticks are touched
+
 			if ((_last_sp_man.timestamp != sp_man.timestamp) &&
-				((fabsf(sp_man.x) - fabsf(_last_sp_man.x) > min_stick_change) ||
-				 (fabsf(sp_man.y) - fabsf(_last_sp_man.y) > min_stick_change) ||
-				 (fabsf(sp_man.z) - fabsf(_last_sp_man.z) > min_stick_change) ||
-				 (fabsf(sp_man.r) - fabsf(_last_sp_man.r) > min_stick_change))) {
+				((fabsf(sp_man.x - _last_sp_man.x) > min_stick_change) ||
+				 (fabsf(sp_man.y - _last_sp_man.y) > min_stick_change) ||
+				 (fabsf(sp_man.z - _last_sp_man.z) > min_stick_change) ||
+				 (fabsf(sp_man.r - _last_sp_man.r) > min_stick_change))) {
 
 				// revert to position control in any case
 				main_state_transition(&status, commander_state_s::MAIN_STATE_POSCTL, main_state_prev, &status_flags, &internal_state);