Anyway to tell the drone that it has landed?

kolohe · March 2, 2021, 9:49pm

I am writing a program that can teleport the drone from mid-air to the ground. I notice when it is on the ground, the land-detector does not detect that it has landed. Is there a way that I can manually tell the drone that it has landed?

rroche · March 3, 2021, 1:25am

Here’s an example on how we are testing for land status on our own test suite using the MAVSDK, originally written by @JulianOes

github.com

PX4/PX4-Autopilot/blob/master/test/mavsdk_tests/autopilot_tester.cpp#L577-L590


void AutopilotTester::wait_for_landed_state(Telemetry::LandedState landed_state, std::chrono::seconds timeout)
{
	auto prom = std::promise<void> {};
	auto fut = prom.get_future();

	_telemetry->subscribe_landed_state([&prom, landed_state, this](Telemetry::LandedState new_landed_state) {
		if (new_landed_state == landed_state) {
			_telemetry->subscribe_landed_state(nullptr);
			prom.set_value();
		}
	});

	REQUIRE(fut.wait_for(timeout) == std::future_status::ready);
}

kolohe · March 3, 2021, 5:02pm

Thank you for your reply. The problem is, after teleported to the ground, the drone will immediately fly up(probably due to ekf). The briefe time frame between touching the ground and flying up could be why the land-detector was never able to detect the landing. I am wondering if there is something that can force the drone to land, or force to acknowledge that it has landed after touching the ground.