From 4da32dcb06a4482afe3e6bc60b0244759d8bd7e3 Mon Sep 17 00:00:00 2001
From: timtuxworth <tim@objectivedata.com>
Date: Mon, 16 Dec 2024 14:59:58 -0700
Subject: [PATCH] ArduPlane: parameterize lookahead climb ratio

---
 ArduPlane/Parameters.cpp | 10 +++++++++-
 ArduPlane/Parameters.h   |  2 ++
 ArduPlane/altitude.cpp   |  2 +-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/ArduPlane/Parameters.cpp b/ArduPlane/Parameters.cpp
index 8dcd235220..d9bca9b364 100644
--- a/ArduPlane/Parameters.cpp
+++ b/ArduPlane/Parameters.cpp
@@ -1303,7 +1303,15 @@ const AP_Param::GroupInfo ParametersG2::var_info[] = {
     // @User: Standard
     AP_GROUPINFO("RNGFND_LND_ORNT", 36, ParametersG2, rangefinder_land_orient, ROTATION_PITCH_270),
 #endif
-    
+
+    // @Param: PTCH_LKAHD_CLMB
+    // @DisplayName: lookahead climb pitch ratio
+    // @Description: The ratio of pitch to use when doing a terrain lookahead so the plane is not constantly at 100% throttle.
+    // @Range: 0 100
+    // @Units: %
+    // @User: Standard
+    AP_GROUPINFO("PTCH_LKAHD_CLMB", 37, ParametersG2, pitch_lookahead_climb_ratio, 50),
+
     AP_GROUPEND
 };
 
diff --git a/ArduPlane/Parameters.h b/ArduPlane/Parameters.h
index e7cc5326f4..b0086c0070 100644
--- a/ArduPlane/Parameters.h
+++ b/ArduPlane/Parameters.h
@@ -588,6 +588,8 @@ public:
     // orientation of rangefinder to use for landing
     AP_Int8 rangefinder_land_orient;
 #endif
+
+    AP_Float        pitch_lookahead_climb_ratio;
 };
 
 extern const AP_Param::Info var_info[];
diff --git a/ArduPlane/altitude.cpp b/ArduPlane/altitude.cpp
index 230a16d067..3495a49496 100644
--- a/ArduPlane/altitude.cpp
+++ b/ArduPlane/altitude.cpp
@@ -605,7 +605,7 @@ float Plane::lookahead_adjustment(void)
     // we need to know the climb ratio. We use 50% of the maximum
     // climb rate so we are not constantly at 100% throttle and to
     // give a bit more margin on terrain
-    float climb_ratio = 0.5f * TECS_controller.get_max_climbrate() / groundspeed;
+    float climb_ratio = g2.pitch_lookahead_climb_ratio * TECS_controller.get_max_climbrate() / groundspeed;
 
     if (climb_ratio <= 0) {
         // lookahead makes no sense for negative climb rates