Search found 377 matches

by whoenig
Tue Apr 06, 2021 9:53 am
Forum: Autonomous flight
Topic: Random Behavior while hovering/flying autonoumously
Replies: 10
Views: 659

Re: Random Behavior while hovering/flying autonoumously

From your plots, what is the problem with the unsuccessful flight? It looks like the hover height is not as high as it should be, but otherwise "normal"? It would also be interesting to plot the commands you send (roll, pitch, yaw, thrust), as sudden spikes there could hint to an issue with the moca...
by whoenig
Mon Apr 05, 2021 10:37 am
Forum: Autonomous flight
Topic: Random Behavior while hovering/flying autonoumously
Replies: 10
Views: 659

Re: Random Behavior while hovering/flying autonoumously

Do you see the same problem when flying a single CF only? I had a brief look at your code and I noticed that this is not threadsafe. In order to exchange data, you should either use queues (https://docs.python.org/3/library/queue.html) or semaphores (https://docs.python.org/3/library/threading.html#...
by whoenig
Sat Apr 03, 2021 2:28 pm
Forum: Lighthouse positioning system
Topic: Lighthouse Deck Red and Blue LED Remaining On
Replies: 7
Views: 704

Re: Lighthouse Deck Red and Blue LED Remaining On

Was the LH deck installed during flashing? In the progress bar at the bottom of the flash dialog, does it actually show you that it attempts to flash the LH deck when you upgrade to 2021.03?
by whoenig
Thu Apr 01, 2021 4:16 pm
Forum: Developer Discussions
Topic: How to obtain thrust from PWM
Replies: 6
Views: 305

Re: How to obtain thrust from PWM

I can think of multiple reasons: 1. Unbalanced rotors, i.e., during hover your PWM is actually not the same for all motors. You can look at m1-m4 and apply the transformation to each of them. 2. Numerical issues. The paper only shows 2 digits. Here are the full parameters: C_00 = 11.093358483549203 ...
by whoenig
Thu Apr 01, 2021 9:06 am
Forum: Developer Discussions
Topic: How to obtain thrust from PWM
Replies: 6
Views: 305

Re: How to obtain thrust from PWM

The accelerometer is in the body frame using a right-handed coordinate system with z-axis pointing up. You can also test this pretty easily if you use the CFClient and log the "acc.{x,y,z}" variables and visualize them in the Plotter tab. This signal tends to be pretty noisy and you will have much b...
by whoenig
Thu Apr 01, 2021 8:52 am
Forum: External positioning systems
Topic: StdDev of External Measurements
Replies: 5
Views: 536

Re: StdDev of External Measurements

Glad you got it working so far! The order does not matter - logging variables will remain independent on what estimator you choose and you can switch estimators at any time. How do you push external measurements from Vicon to the Crazyflie? Do you send positions or full pose information? To me, it s...
by whoenig
Thu Apr 01, 2021 7:39 am
Forum: Lighthouse positioning system
Topic: Lighthouse Deck Red and Blue LED Remaining On
Replies: 7
Views: 704

Re: Lighthouse Deck Red and Blue LED Remaining On

You need to update the firmware with the LH deck installed using the latest cfclient and release 2021.03. You can find instructions for the update procedure at https://www.bitcraze.io/documentation/tutorials/getting-started-with-crazyflie-2-x/#update-fw. If you updated your firmware using an older c...
by whoenig
Thu Apr 01, 2021 6:56 am
Forum: Developer Discussions
Topic: How to obtain thrust from PWM
Replies: 6
Views: 305

Re: How to obtain thrust from PWM

All your guesses are correct! For the last one (battery voltage compensation), this is just an approximation and not necessarily up-to-date with the current hardware. You can find a better mapping in Table 1, https://arxiv.org/pdf/2012.05457.pdf, which was obtained from a force stand. We are plannin...
by whoenig
Mon Mar 29, 2021 11:52 am
Forum: External positioning systems
Topic: StdDev of External Measurements
Replies: 5
Views: 536

Re: StdDev of External Measurements

1. Yes, https://github.com/bitcraze/crazyflie-firmware/blob/master/src/modules/src/crtp_localization_service.c#L115-L116. You can also query the current values of locSrv.extPosStdDev and locSrv.extQuatStdDev using the parameter subsystem. 2. There is an adaptive mode, where the stddev is based on th...
by whoenig
Mon Mar 29, 2021 9:25 am
Forum: Developer Discussions
Topic: external orientation as quaternion
Replies: 1
Views: 203

Re: external orientation as quaternion

This strange signage is only true for the euler angle logging variables (stateEstimate.{roll,pitch,yaw}) and it is there for historical reasons and was not changed to keep backwards compatibility. The on-board quaternion follows the regular right-handed rule, which is also used by VICON. Thus, you c...