"The first photo looks like a point cloud that successfully captures overhead transmission line wires, is that right? Do you made those with commercial soft, or the open-source one?"

"As I pointed out before, APM is coded assuming soft-realtime. The PixHawk misses deadlines so do we.

Whether that is even completely true is quite irrelevant to the fact that missing a hard deadline from an autopilot is not a "degraded…"

"Testing results in screenshot are interesting. Haven't looked at them very closely, but that's what I noticed- uptime 17.0 is not 17%. Still not clear on CPU utilization vs load, are we.- On the terminal in upper right corner load steadily grows as…"

"Erle-brain can handle more than just the autopilot itself. I've seen myself scenarios that involved networking traffic, the autopilot, ROS and a web server simultaneously.

Neat feature. So this drone can be made to crash remotely, by overloading…"

"That's what I expected, actually. "stress -c 1" means that the system was not highly loaded, load barely above 1.0. And you just loaded CPU, without stressing memory subsystem. Cursory and inadequate testing, it seems to me.

"stress command…"

"Roberto: Yes, PRU is important for using BB as a flight controller. I read somewhere that the next release of BeagleBone will not use Texas Instruments CPU, however, so I don't know what will they do about interfacing to external sensors then.

To…"

"Victor, you did not specify the options of "stress" command that you used in your testing, even though in previous discussion I asked about it, I think, more than once. You also did not provide any information about system load during the testing,…"

"I am talking about the operating system that is used to run the flight control software. Aircraft may fly without using a real-time software, but it runs the risk of freezing up and crashing, if the system used to run flight control software gets…"

"It seems lik a good time to remind, that this extensively promoted autopilot does not use real-time operating system and for that reason its usage is intrinsically unsafe"

"There's no such thing as "PREEMPT" patch. There can be a mainline kernel compiled with CONFIG_PREEMPT option. Have _you_ read the paper?

By the way, just about any introductory text on real-time systems mentions that latency and performance are two…"

"@Dinuka: "This means that you have about 5-10ms from the time the sensors are read till you need to produce actuator signals. I'm quite confident that a beagle bone can handle that with right thread priorities."

That is true only as long as…"

"(And of course, PRU-ICSS on ARM Sitara does not run Linux)"

"PRU-ICSS subsystem in TI ARM processor used by BeagleBone is really a separate dedicated microcontroller on the same chip. Other platforms such as Odroid or RPi do not have similar feature, and port PRU-ICSS part to them is plain impossible.

Other…"

""The hard deadlines are handled by the PRU, and support for the RT patches could be added if needed."

What are non-hard deadlines in the autopilot code? I struggle to think of one. Failing to compute attitude estimation or PID controller output on…"

"If by "Linux" you mean mainline kernel without RT hypervisor or PREEMPT_RT patch, than there is no way to tune it to guarantee maximum latency. Your statement to the contrary is just plain wrong, and you testing does not establish it.

So maybe your…"

"Dinuka - it is not possible to have control code real-time on Linux computer, because Linux is not real-time operating system. There're real time patches, but they are in effect another real-time operating system, that runs Linux as a process.

The…"