Copter: change RTL_ALT_MIN from 200cm to 30cm

ArduPilot · Mar 7, 2024 · 809c168 · 809c168
1 parent d911475
commit 809c168
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Showing 3 changed files with 10 additions and 5 deletions.
diff --git a/ArduCopter/Parameters.cpp b/ArduCopter/Parameters.cpp
@@ -102,7 +102,7 @@ const AP_Param::Info Copter::var_info[] = {
     // @DisplayName: RTL Altitude
     // @Description: The minimum alt above home the vehicle will climb to before returning.  If the vehicle is flying higher than this value it will return at its current altitude.
     // @Units: cm
-    // @Range: 200 300000
+    // @Range: 30 300000
     // @Increment: 1
     // @User: Standard
     GSCALAR(rtl_altitude,   "RTL_ALT",     RTL_ALT),

diff --git a/ArduCopter/config.h b/ArduCopter/config.h
@@ -429,8 +429,12 @@
  # define RTL_ALT                   1500    // default alt to return to home in cm, 0 = Maintain current altitude
 #endif
 
+#ifndef RTL_ALT_LOW
+ # define RTL_ALT_LOW               200    // Height used when RTL_ALT is set to a value lower than RTL_ALT_MIN
+#endif
+
 #ifndef RTL_ALT_MIN
- # define RTL_ALT_MIN               200     // min height above ground for RTL (i.e 2m)
+ # define RTL_ALT_MIN               30     // min height above ground for RTL (i.e 30cm)
 #endif
 
 #ifndef RTL_CLIMB_MIN_DEFAULT

diff --git a/ArduCopter/mode_rtl.cpp b/ArduCopter/mode_rtl.cpp
@@ -443,8 +443,9 @@ void ModeRTL::compute_return_target()
     // set curr_alt and return_target.alt from range finder
     if (alt_type == ReturnTargetAltType::RANGEFINDER) {
         if (copter.get_rangefinder_height_interpolated_cm(curr_alt)) {
+            int32_t min_rtl_alt = g.rtl_altitude >= RTL_ALT_MIN ? g.rtl_altitude : RTL_ALT_LOW;
             // set return_target.alt
-            rtl_path.return_target.set_alt_cm(MAX(curr_alt + MAX(0, g.rtl_climb_min), MAX(g.rtl_altitude, RTL_ALT_MIN)), Location::AltFrame::ABOVE_TERRAIN);
+            rtl_path.return_target.set_alt_cm(MAX(curr_alt + MAX(0, g.rtl_climb_min), min_rtl_alt), Location::AltFrame::ABOVE_TERRAIN);
         } else {
             // fallback to relative alt and warn user
             alt_type = ReturnTargetAltType::RELATIVE;
@@ -484,9 +485,9 @@ void ModeRTL::compute_return_target()
     // Note: ignore negative altitudes which could happen if user enters negative altitude for rally point or terrain is higher at rally point compared to home
     int32_t target_alt = MAX(rtl_path.return_target.alt, 0);
 
+    const int32_t min_rtl_alt = g.rtl_altitude < RTL_ALT_MIN ? RTL_ALT_LOW : g.rtl_altitude;
     // increase target to maximum of current altitude + climb_min and rtl altitude
-    const float min_rtl_alt = MAX(RTL_ALT_MIN, curr_alt + MAX(0, g.rtl_climb_min));
-    target_alt = MAX(target_alt, MAX(g.rtl_altitude, min_rtl_alt));
+    target_alt = MAX(target_alt, MAX(min_rtl_alt, curr_alt + MAX(0, g.rtl_climb_min)));
 
     // reduce climb if close to return target
     float rtl_return_dist_cm = rtl_path.return_target.get_distance(rtl_path.origin_point) * 100.0f;