Servers by jDrones

Ardupilot Log Analyser


(Artem Skorsky) #41

Thanks for nice and valuable replies, new updates on DRONEEPLOTTER will be available soon.

(.) #42

Thank you for this interesting project!
Is there a possibility to calculate average? E.g. I want to see average current of 10sec time period.

(.) #43

No way to calculate average? Any alternatives?

(Nathan E) #44

Use the total current chart. Find the current drawn at time=0 and at time=10. Divide the difference by 10, and you’ll have the average miliamps drawn during that time.

(.) #45

Thanks for your answer but that is not exactly what I am looking for. When I want to know the average current or voltage of a specific time period, I need to consider all values of that time period. I mean summarizing all values and dividing by their number. So not only the difference. When it is a long time period, it is hard to do it manually.

But I found somebody that helped me creating a matlab code that creates an excel file where I only have to chage the beginning time and ending time of what I am looking for.

(Nathan E) #46

It’s mathematically the same though, so you can pick the current consumed at any time without having to export the data. I think it’s easier and more accurate during longer periods… your denominator is the number of seconds.

(.) #47

You are right! When I want to see the everage power consumption, I just have to divide “current drawn” by the time. I will do it like this in other calculations.

(.) #48

Okay with Pixhawk logs it works very well because of the parameter “EnrgTot”. I just have to divide EnrgTot by the time and then I have average power consumption.

But what can I do when I have older APM logs? They only have “CurrTot”. With that parameter I can calculate average milliamps drawn during that time. If I want to have average power I have to multiply by the voltage. But how can I get average voltage during that time? MP log browser only shows whole numbers of voltage. That is too imprecise.

(George Zogopoulos Papaliakos) #49

Let’s say that i_t are the values of the CurrTot messages and v are the values of the instantaneous battery voltage readings.
Also, you are interested in the interval [t_s, t_e].

The average power value for that interval is
Sum((i_t(k)-i_t(k-1)) * v(k) for all k in [t_s, t_e].

The energy is power x time, so you’ll have to decide the size of the window yourself.

Out of curiosity: What is your education level?

@moderators, can you move this discussion in its own thread, away from the DroneePlotter thread?

(.) #50

Okay thank you, yes your solution works.
I also found another way for analyzing APM logs. I just calculated the everage voltage by using Ecxel and multiplied it by the current drawn. My APM records only 1 data packet per second so there are not so many numbers. Thanks to the physics there are many ways to calculate. So I should be finished now and ask no more questions in this thread.

My education level? You mean because I am too stupid to use simple formulas like P=IU and E=tP? :grinning: Yes sometimes I am but I think now I got it! I am just a mechanical engineering student that tries to analyze his VTOL wing.

(wkf94025) #51

@Mr.1, I agree with your interpretation of this question. I would never ask that.


(George Zogopoulos Papaliakos) #52

Nothing like that. I just wanted to adjust my future posts to your level of understanding; it’s a habit you pick up after teaching for a few years.

Talking to you as if you were in primary school would be mostly useless, whereas trying to communicate as if I had a PhD student in front of me would be equally unproductive.

(Artem Skorsky) #53

Hey everyone,

We have implemented Multi-Chart and Multi-Scale features to DRONEE PLOTTER

Now you can visualize multiple log attributes on multiple charts, zoom to the time frame synchronously. Also, you can visualize multiple scale data on the same chart.