From f5f31006a0a54fa4a68526121e780e07ce45569d Mon Sep 17 00:00:00 2001
From: bresch <brescianimathieu@gmail.com>
Date: Tue, 26 Jul 2022 22:12:03 +0200
Subject: [PATCH] Ekf2: create HeightBiasEstimator class

Contains some logic common to all height bias estimators
---
 src/modules/ekf2/EKF/bias_estimator.hpp       |  6 +-
 .../ekf2/EKF/height_bias_estimator.hpp        | 74 +++++++++++++++++++
 2 files changed, 77 insertions(+), 3 deletions(-)
 create mode 100644 src/modules/ekf2/EKF/height_bias_estimator.hpp

diff --git a/src/modules/ekf2/EKF/bias_estimator.hpp b/src/modules/ekf2/EKF/bias_estimator.hpp
index faf8ae720d..5f70ec5204 100644
--- a/src/modules/ekf2/EKF/bias_estimator.hpp
+++ b/src/modules/ekf2/EKF/bias_estimator.hpp
@@ -65,10 +65,10 @@ public:
 	};
 
 	BiasEstimator() = default;
-	~BiasEstimator() = default;
+	virtual ~BiasEstimator() = default;
 
-	void predict(float dt);
-	void fuseBias(float measurement, float measurement_var);
+	virtual void predict(float dt);
+	virtual void fuseBias(float measurement, float measurement_var);
 
 	void setBias(float bias) { _state = bias; }
 	void setProcessNoiseStdDev(float process_noise)
diff --git a/src/modules/ekf2/EKF/height_bias_estimator.hpp b/src/modules/ekf2/EKF/height_bias_estimator.hpp
new file mode 100644
index 0000000000..9082842b9e
--- /dev/null
+++ b/src/modules/ekf2/EKF/height_bias_estimator.hpp
@@ -0,0 +1,74 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2022 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file height_bias_estimator.hpp
+ */
+
+#pragma once
+
+#include "bias_estimator.hpp"
+
+class HeightBiasEstimator: public BiasEstimator
+{
+public:
+	HeightBiasEstimator(uint8_t sensor, const uint8_t &sensor_ref):
+		BiasEstimator(0.f, 0.f),
+		_sensor(sensor),
+		_sensor_ref(sensor_ref)
+	{}
+	virtual ~HeightBiasEstimator() = default;
+
+	void setFusionActive() { _is_sensor_fusion_active = true; }
+	void setFusionInactive() { _is_sensor_fusion_active = false; }
+
+	virtual void predict(float dt) override
+	{
+		if ((_sensor_ref != _sensor) && _is_sensor_fusion_active) {
+			BiasEstimator::predict(dt);
+		}
+	}
+
+	virtual void fuseBias(float bias, float bias_var) override
+	{
+		if ((_sensor_ref != _sensor) && _is_sensor_fusion_active) {
+			BiasEstimator::fuseBias(bias, bias_var);
+		}
+	}
+
+private:
+	const uint8_t _sensor;
+	const uint8_t &_sensor_ref;
+
+	bool _is_sensor_fusion_active{false}; // TODO: replace by const ref and remove setter when migrating _control_status.flags from union to bool
+};