AC_AttitudeControl: use relax_integrator

libraries/AC_AttitudeControl/AC_AttitudeControl.cpp

@@ -182,9 +182,9 @@ void AC_AttitudeControl::reset_rate_controller_I_terms()
 // reset rate controller I terms smoothly to zero in 0.5 seconds
 void AC_AttitudeControl::reset_rate_controller_I_terms_smoothly()
 {
-    get_rate_roll_pid().reset_I_smoothly();
-    get_rate_pitch_pid().reset_I_smoothly();
-    get_rate_yaw_pid().reset_I_smoothly();
+    get_rate_roll_pid().relax_integrator(0.0, AC_ATTITUDE_RATE_RELAX_TC);;
+    get_rate_pitch_pid().relax_integrator(0.0, AC_ATTITUDE_RATE_RELAX_TC);;
+    get_rate_yaw_pid().relax_integrator(0.0, AC_ATTITUDE_RATE_RELAX_TC);;
 }
 
 // The attitude controller works around the concept of the desired attitude, target attitude

libraries/AC_AttitudeControl/AC_AttitudeControl.h

@@ -25,6 +25,7 @@
 #define AC_ATTITUDE_RATE_CONTROLLER_TIMEOUT             1.0f    // body-frame rate controller timeout in seconds
 #define AC_ATTITUDE_RATE_RP_CONTROLLER_OUT_MAX          1.0f    // body-frame rate controller maximum output (for roll-pitch axis)
 #define AC_ATTITUDE_RATE_YAW_CONTROLLER_OUT_MAX         1.0f    // body-frame rate controller maximum output (for yaw axis)
+#define AC_ATTITUDE_RATE_RELAX_TC                       0.16f   // This is used to decay the rate I term to 5% in half a second.
 
 #define AC_ATTITUDE_THRUST_ERROR_ANGLE                  radians(30.0f) // Thrust angle error above which yaw corrections are limited