From e66a360e273188f100418aee8e18c6c2df8e299b Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Sat, 22 Dec 2018 14:37:21 +1100
Subject: [PATCH] AC_AutoTune: added lower limit on scaler reduction

---
 libraries/AC_AutoTune/AC_AutoTune.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/AC_AutoTune/AC_AutoTune.cpp b/libraries/AC_AutoTune/AC_AutoTune.cpp
index 546d941d1e..afd381c7ed 100644
--- a/libraries/AC_AutoTune/AC_AutoTune.cpp
+++ b/libraries/AC_AutoTune/AC_AutoTune.cpp
@@ -1309,7 +1309,7 @@ void AC_AutoTune::twitching_test_rate(float rate, float rate_target_max, float &
 void AC_AutoTune::twitching_abort_rate(float angle, float rate, float angle_max, float meas_rate_min)
 {
     if (angle >= angle_max) {
-        if (is_equal(rate, meas_rate_min)) {
+        if (is_equal(rate, meas_rate_min) && step_scaler > 0.5) {
             // we have reached the angle limit before completing the measurement of maximum and minimum
             // reduce the maximum target rate
             step_scaler *= 0.9f;