From eebef857f1a24a720a9fbdc712b6c050cd7eb191 Mon Sep 17 00:00:00 2001
From: JU Han <570818564@qq.com>
Date: Sat, 12 Aug 2017 10:27:30 +0800
Subject: [PATCH] AP_TECS: gain scaler K_STE2Thr multiplies by (THRmax -
 THRmin)

Makes both feed forward and feed-back consistent
---
 libraries/AP_TECS/AP_TECS.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libraries/AP_TECS/AP_TECS.cpp b/libraries/AP_TECS/AP_TECS.cpp
index 19d7581e80..cef7da74a0 100644
--- a/libraries/AP_TECS/AP_TECS.cpp
+++ b/libraries/AP_TECS/AP_TECS.cpp
@@ -608,7 +608,8 @@ void AP_TECS::_update_throttle_with_airspeed(void)
     else
     {
         // Calculate gain scaler from specific energy error to throttle
-        float K_STE2Thr = 1 / (timeConstant() * (_STEdot_max - _STEdot_min));
+        // (_STEdot_max - _STEdot_min) / (_THRmaxf - _THRminf) is the derivative of STEdot wrt throttle measured across the max allowed throttle range.
+        float K_STE2Thr = 1 / (timeConstant() * (_STEdot_max - _STEdot_min) / (_THRmaxf - _THRminf));
 
         // Calculate feed-forward throttle
         float ff_throttle = 0;