From e8706db382aa5df111e6471f253b8d521a13492d Mon Sep 17 00:00:00 2001
From: Paul Riseborough <p-riseborough@live.com.au>
Date: Sun, 15 Nov 2015 12:40:29 +1100
Subject: [PATCH] AP_NavEKF2: Update IMU tuning parameter limits

---
 libraries/AP_NavEKF2/AP_NavEKF2.cpp      | 6 +++---
 libraries/AP_NavEKF2/AP_NavEKF2_core.cpp | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/libraries/AP_NavEKF2/AP_NavEKF2.cpp b/libraries/AP_NavEKF2/AP_NavEKF2.cpp
index b19a55064e..5170c17a8b 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2.cpp
+++ b/libraries/AP_NavEKF2/AP_NavEKF2.cpp
@@ -333,8 +333,8 @@ const AP_Param::GroupInfo NavEKF2::var_info[] = {
     // @Param: GYRO_PNOISE
     // @DisplayName: Rate gyro noise (rad/s)
     // @Description: This control disturbance noise controls the growth of estimated error due to gyro measurement errors excluding bias. Increasing it makes the flter trust the gyro measurements less and other measurements more.
-    // @Range: 0.001 0.05
-    // @Increment: 0.001
+    // @Range: 0.0001 0.01
+    // @Increment: 0.0001
     // @User: Advanced
     // @Units: rad/s
     AP_GROUPINFO("GYRO_PNOISE", 24, NavEKF2, _gyrNoise, GYRO_PNOISE_DEFAULT),
@@ -342,7 +342,7 @@ const AP_Param::GroupInfo NavEKF2::var_info[] = {
     // @Param: ACC_PNOISE
     // @DisplayName: Accelerometer noise (m/s^2)
     // @Description: This control disturbance noise controls the growth of estimated error due to accelerometer measurement errors excluding bias. Increasing it makes the flter trust the accelerometer measurements less and other measurements more.
-    // @Range: 0.05 1.0
+    // @Range: 0.01 1.0
     // @Increment: 0.01
     // @User: Advanced
     // @Units: m/s/s
diff --git a/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp b/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp
index 000c1f2c8a..cd481dfacc 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp
+++ b/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp
@@ -668,9 +668,9 @@ void NavEKF2_core::CovariancePrediction()
     day_s = stateStruct.gyro_scale.y;
     daz_s = stateStruct.gyro_scale.z;
     dvz_b = stateStruct.accel_zbias;
-    float _gyrNoise = constrain_float(frontend->_gyrNoise, 1e-3f, 5e-2f);
+    float _gyrNoise = constrain_float(frontend->_gyrNoise, 1e-4f, 1e-2f);
     daxNoise = dayNoise = dazNoise = dt*_gyrNoise;
-    float _accNoise = constrain_float(frontend->_accNoise, 5e-2f, 1.0f);
+    float _accNoise = constrain_float(frontend->_accNoise, 1e-2f, 1.0f);
     dvxNoise = dvyNoise = dvzNoise = dt*_accNoise;
 
     // calculate the predicted covariance due to inertial sensor error propagation