From ddfe077f7cae2928d339809d48df3c74a80f6e87 Mon Sep 17 00:00:00 2001
From: Paul Riseborough <p_riseborough@live.com.au>
Date: Fri, 24 Nov 2017 12:19:41 +1100
Subject: [PATCH] commander: strengthen pre-flight fail checking

The commander checks use instantaneous values which are vulnerable to false negatives  or positives with noisy data or transient faults.

This patch checks the estimators published pre flight check status which is based on persistent checks using filtered data.
---
 src/modules/commander/PreflightCheck.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/modules/commander/PreflightCheck.cpp b/src/modules/commander/PreflightCheck.cpp
index 72b769c9f4..9a0485215b 100644
--- a/src/modules/commander/PreflightCheck.cpp
+++ b/src/modules/commander/PreflightCheck.cpp
@@ -502,6 +502,12 @@ static bool ekf2Check(orb_advert_t *mavlink_log_pub, bool optional, bool report_
 		goto out;
 	}
 
+	// Check if preflight check perfomred by estimator has failed
+	if (status.pre_flt_fail) {
+		success = false;
+		goto out;
+	}
+
 	// check vertical position innovation test ratio
 	param_get(param_find("COM_ARM_EKF_HGT"), &test_limit);
 	if (status.hgt_test_ratio > test_limit) {