sensors: move gyro filtering to sensors/vehicle_angular_velocity

- gyro filtering (low-pass and notch) only performed on primary gyro in `sensors/vehicle_angular_velocity` instead of every gyro in `PX4Gyroscope`
 - sample rate is calculated from actual updates (the fixed value was slightly wrong in many cases, and very wrong in a few)
 - In the FIFO case the array is now averaged and published in `sensor_gyro` for filtering downstream. I'll update this in the future to use the full FIFO array (if available), but right now it should be fine.

src/modules/sensors/vehicle_angular_velocity/VehicleAngularVelocity.cpp

@@ -43,11 +43,15 @@ VehicleAngularVelocity::VehicleAngularVelocity() :
 	ModuleParams(nullptr),
 	WorkItem(MODULE_NAME, px4::wq_configurations::rate_ctrl)
 {
+	_lowpass_filter.set_cutoff_frequency(kInitialRateHz, _param_imu_gyro_cutoff.get());
+	_notch_filter.setParameters(kInitialRateHz, _param_imu_gyro_nf_freq.get(), _param_imu_gyro_nf_bw.get());
 }
 
 VehicleAngularVelocity::~VehicleAngularVelocity()
 {
 	Stop();
+
+	perf_free(_interval_perf);
 }
 
 bool VehicleAngularVelocity::Start()
@@ -77,6 +81,50 @@ void VehicleAngularVelocity::Stop()
 	_sensor_selection_sub.unregisterCallback();
 }
 
+void VehicleAngularVelocity::CheckFilters(const Vector3f &rates)
+{
+	if ((hrt_elapsed_time(&_filter_check_last) > 100_ms)) {
+		_filter_check_last = hrt_absolute_time();
+
+		// calculate sensor update rate
+		const float sample_interval_avg = perf_mean(_interval_perf);
+
+		if (PX4_ISFINITE(sample_interval_avg) && (sample_interval_avg > 0.0f)) {
+
+			const float update_rate_hz = 1.0f / sample_interval_avg;
+
+			if ((fabsf(update_rate_hz) > 0.0f) && PX4_ISFINITE(update_rate_hz)) {
+				_update_rate_hz = update_rate_hz;
+
+				// check if sample rate error is greater than 1%
+				if ((fabsf(_update_rate_hz - _filter_sample_rate) / _filter_sample_rate) > 0.01f) {
+					++_sample_rate_incorrect_count;
+				}
+			}
+		}
+
+		const bool sample_rate_updated = (_sample_rate_incorrect_count > 50);
+		const bool lowpass_updated = (fabsf(_lowpass_filter.get_cutoff_freq() - _param_imu_gyro_cutoff.get()) > 0.01f);
+		const bool notch_updated = ((fabsf(_notch_filter.getNotchFreq() - _param_imu_gyro_nf_freq.get()) > 0.01f)
+					    || (fabsf(_notch_filter.getBandwidth() - _param_imu_gyro_nf_bw.get()) > 0.01f));
+
+		if (sample_rate_updated || lowpass_updated || notch_updated) {
+			PX4_INFO("updating filter, sample rate: %.3f Hz -> %.3f Hz", (double)_filter_sample_rate, (double)_update_rate_hz);
+			_filter_sample_rate = _update_rate_hz;
+
+			// update software low pass filters
+			_lowpass_filter.set_cutoff_frequency(_filter_sample_rate, _param_imu_gyro_cutoff.get());
+			_lowpass_filter.reset(rates);
+
+			_notch_filter.setParameters(_filter_sample_rate, _param_imu_gyro_nf_freq.get(), _param_imu_gyro_nf_bw.get());
+			_notch_filter.reset(rates);
+
+			// reset state
+			_sample_rate_incorrect_count = 0;
+		}
+	}
+}
+
 void VehicleAngularVelocity::SensorBiasUpdate(bool force)
 {
 	if (_estimator_sensor_bias_sub.updated() || force) {
@@ -165,6 +213,9 @@ bool VehicleAngularVelocity::SensorSelectionUpdate(bool force)
 						// force corrections reselection
 						_corrections_selected_instance = -1;
 
+						// reset sample rate monitor
+						_sample_rate_incorrect_count = 0;
+
 						return true;
 					}
 				}
@@ -205,15 +256,23 @@ void VehicleAngularVelocity::ParametersUpdate(bool force)
 void VehicleAngularVelocity::Run()
 {
 	// update corrections first to set _selected_sensor
-	bool sensor_select_update = SensorSelectionUpdate();
-	SensorCorrectionsUpdate(sensor_select_update);
-	SensorBiasUpdate(sensor_select_update);
+	bool selection_updated = SensorSelectionUpdate();
+
+	SensorCorrectionsUpdate(selection_updated);
+	SensorBiasUpdate(selection_updated);
 	ParametersUpdate();
 
-	if (_sensor_sub[_selected_sensor_sub_index].updated() || sensor_select_update) {
+	bool sensor_updated = _sensor_sub[_selected_sensor_sub_index].updated();
+
+	if (sensor_updated || selection_updated) {
 		sensor_gyro_s sensor_data;
 
 		if (_sensor_sub[_selected_sensor_sub_index].copy(&sensor_data)) {
+
+			if (sensor_updated) {
+				perf_count_interval(_interval_perf, sensor_data.timestamp_sample);
+			}
+
 			// get the sensor data and correct for thermal errors (apply offsets and scale)
 			const Vector3f val{sensor_data.x, sensor_data.y, sensor_data.z};
 
@@ -226,14 +285,32 @@ void VehicleAngularVelocity::Run()
 			// correct for in-run bias errors
 			rates -= _bias;
 
-			// publish
-			vehicle_angular_velocity_s out;
+			// Filter: apply notch and then low-pass
+			CheckFilters(rates);
+			const Vector3f rates_filtered = _lowpass_filter.apply(_notch_filter.apply(rates));
 
-			out.timestamp_sample = sensor_data.timestamp_sample;
-			rates.copyTo(out.xyz);
-			out.timestamp = hrt_absolute_time();
 
-			_vehicle_angular_velocity_pub.publish(out);
+			bool publish = true;
+
+			if (_param_imu_gyro_rate_max.get() > 0) {
+				const uint64_t interval = 1e6f / _param_imu_gyro_rate_max.get();
+
+				if (hrt_elapsed_time(&_last_publish) < interval) {
+					publish = false;
+				}
+			}
+
+			if (publish) {
+				vehicle_angular_velocity_s out;
+
+				out.timestamp_sample = sensor_data.timestamp_sample;
+				rates_filtered.copyTo(out.xyz);
+				out.timestamp = hrt_absolute_time();
+
+				_vehicle_angular_velocity_pub.publish(out);
+
+				_last_publish = out.timestamp_sample;
+			}
 		}
 	}
 }
@@ -244,4 +321,12 @@ void VehicleAngularVelocity::PrintStatus()
 	PX4_INFO("bias: [%.3f %.3f %.3f]", (double)_bias(0), (double)_bias(1), (double)_bias(2));
 	PX4_INFO("offset: [%.3f %.3f %.3f]", (double)_offset(0), (double)_offset(1), (double)_offset(2));
 	PX4_INFO("scale: [%.3f %.3f %.3f]", (double)_scale(0), (double)_scale(1), (double)_scale(2));
+
+	PX4_INFO("sample rate: %.3f Hz", (double)_update_rate_hz);
+	PX4_INFO("low-pass filter cutoff: %.3f Hz", (double)_lowpass_filter.get_cutoff_freq());
+
+	if (_notch_filter.getNotchFreq() > 0.0f) {
+		PX4_INFO("notch filter freq: %.3f Hz\tbandwidth: %.3f Hz", (double)_notch_filter.getNotchFreq(),
+			 (double)_notch_filter.getBandwidth());
+	}
 }