battery.cpp 5.17 KB
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#include "battery.hpp"

#include <lib/ecl/geo/geo.h>
#include <px4_defines.h>

const char *const UavcanBatteryBridge::NAME = "battery";

UavcanBatteryBridge::UavcanBatteryBridge(uavcan::INode &node) :
	UavcanSensorBridgeBase("uavcan_battery", ORB_ID(battery_status)),
	ModuleParams(nullptr),
	_sub_battery(node),
	_warning(battery_status_s::BATTERY_WARNING_NONE),
	_last_timestamp(0)
{
}

int UavcanBatteryBridge::init()
{
	int res = _sub_battery.start(BatteryInfoCbBinder(this, &UavcanBatteryBridge::battery_sub_cb));

	if (res < 0) {
		PX4_ERR("failed to start uavcan sub: %d", res);
		return res;
	}

	return 0;
}

void
UavcanBatteryBridge::battery_sub_cb(const uavcan::ReceivedDataStructure<uavcan::equipment::power::BatteryInfo> &msg)
{
	battery_status_s battery{};

	battery.timestamp = hrt_absolute_time();
	battery.voltage_v = msg.voltage;
	battery.voltage_filtered_v = msg.voltage;
	battery.current_a = msg.current;
	battery.current_filtered_a = msg.current;
	// battery.average_current_a = msg.;

	sumDischarged(battery.timestamp, battery.current_a);
	battery.discharged_mah = _discharged_mah;

	battery.remaining = msg.state_of_charge_pct / 100.0f; // between 0 and 1
	// battery.scale = msg.; // Power scaling factor, >= 1, or -1 if unknown
	battery.temperature = msg.temperature + CONSTANTS_ABSOLUTE_NULL_CELSIUS; // Kelvin to Celcius
	// battery.cell_count = msg.;
	battery.connected = true;
	battery.source = msg.status_flags & uavcan::equipment::power::BatteryInfo::STATUS_FLAG_IN_USE;
	// battery.priority = msg.;
	battery.capacity = msg.full_charge_capacity_wh;
	// battery.cycle_count = msg.;
	// battery.run_time_to_empty = msg.;
	// battery.average_time_to_empty = msg.;
	battery.serial_number = msg.model_instance_id;
	battery.id = msg.getSrcNodeID().get();

	// Mavlink 2 needs individual cell voltages or cell[0] if cell voltages are not available.
	battery.voltage_cell_v[0] = msg.voltage;

	// Set cell count to 1 so the the battery code in mavlink_messages.cpp copies the values correctly (hack?)
	battery.cell_count = 1;

	// battery.max_cell_voltage_delta = msg.;

	// battery.is_powering_off = msg.;

	determineWarning(battery.remaining);
	battery.warning = _warning;

	publish(msg.getSrcNodeID().get(), &battery);
}

void
UavcanBatteryBridge::sumDischarged(hrt_abstime timestamp, float current_a)
{
	// Not a valid measurement
	if (current_a < 0.f) {
		// Because the measurement was invalid we need to stop integration
		// and re-initialize with the next valid measurement
		_last_timestamp = 0;
		return;
	}

	// Ignore first update because we don't know dt.
	if (_last_timestamp != 0) {
		const float dt = (timestamp - _last_timestamp) / 1e6;
		// mAh since last loop: (current[A] * 1000 = [mA]) * (dt[s] / 3600 = [h])
		_discharged_mah_loop = (current_a * 1e3f) * (dt / 3600.f);
		_discharged_mah += _discharged_mah_loop;
	}

	_last_timestamp = timestamp;
}

void
UavcanBatteryBridge::determineWarning(float remaining)
{
	// propagate warning state only if the state is higher, otherwise remain in current warning state
	if (remaining < _param_bat_emergen_thr.get() || (_warning == battery_status_s::BATTERY_WARNING_EMERGENCY)) {
		_warning = battery_status_s::BATTERY_WARNING_EMERGENCY;

	} else if (remaining < _param_bat_crit_thr.get() || (_warning == battery_status_s::BATTERY_WARNING_CRITICAL)) {
		_warning = battery_status_s::BATTERY_WARNING_CRITICAL;

	} else if (remaining < _param_bat_low_thr.get() || (_warning == battery_status_s::BATTERY_WARNING_LOW)) {
		_warning = battery_status_s::BATTERY_WARNING_LOW;
	}
}