Search found 17 matches

by carlos.luis306
Thu Oct 18, 2018 10:14 pm
Forum: Loco Positioning System
Topic: TWR-TDMA problem
Replies: 1
Views: 412

TWR-TDMA problem

Hi all, I want to test the TWR-TDMA protocol to estimate 3D positions of 2 Crazyflies simultaneously. I'm encountering the following problem: once I turn both Crazyflies on, I'll see the LPS deck LEDs flashing appropriately, but after a few seconds in one of the Crazyflies the LEDs will stop flashin...
by carlos.luis306
Thu Oct 11, 2018 4:38 pm
Forum: Loco Positioning System
Topic: [SOLVED] Unable to change anchor TX power
Replies: 1
Views: 289

[SOLVED] Unable to change anchor TX power

Hi all, I'm trying to run the script set_tx_power.py to play around with the transmission power of the anchors to see if I can get better localization with different settings. The problem is that when I run the script it gets stuck at : "Connecting to radio://0/120/2M/E7E7E7EC05" (that's the address...
by carlos.luis306
Tue Oct 09, 2018 7:43 pm
Forum: Loco Positioning System
Topic: LPS with Flow Deck and uneven terrain
Replies: 7
Views: 735

Re: LPS with Flow Deck and uneven terrain

Hi Carlos, Would you mind to share with me how you manage to ignore Z data from UWB (I assume you did this, anyway I will be happy to learn what you did and how)? We are dealing with the same system now (UWB + Flow Deck) and I am searching for some ways to improve Z performance. Thanks in advance, ...
by carlos.luis306
Thu Oct 04, 2018 6:40 pm
Forum: Loco Positioning System
Topic: LPS with Flow Deck and uneven terrain
Replies: 7
Views: 735

Re: LPS with Flow Deck and uneven terrain

For the point #2, I believe you can simply comment this line: https://github.com/bitcraze/crazyflie-firmware/blob/857c1e64ec91eaa5b0e2799447dffcb75343ea27/src/deck/drivers/src/zranger.c#L116 That will basically prevent you from queueing any Z-ranger measurements and feed them into the Kalman Filter....
by carlos.luis306
Thu Feb 08, 2018 1:33 am
Forum: Loco Positioning System
Topic: Variance of TDOA2 measurements
Replies: 5
Views: 780

Re: Variance of TDOA2 measurements

Thanks for the very insightful response!

I'll keep you posted if we achieve higher performance using the TDoA algorithm, and will look forward no any updates on your side.

Keep up the astounding work at Bitcraze!
by carlos.luis306
Wed Jan 31, 2018 10:03 pm
Forum: Loco Positioning System
Topic: Variance of TDOA2 measurements
Replies: 5
Views: 780

Re: Variance of TDOA2 measurements

Progress so far: I made some iterations on different node position configuration, and finally found one that eliminated the peaks on the raw measurements, as seen in the figure attached. http://i63.tinypic.com/11scahv.png However, this doesn't seem to improve the large variance I get in the position...
by carlos.luis306
Wed Jan 31, 2018 5:06 pm
Forum: Loco Positioning System
Topic: Variance of TDOA2 measurements
Replies: 5
Views: 780

Re: Variance of TDOA2 measurements

Hi Kristoffer, thanks for your response I'm including a graph with raw data from the TDOA and the statistics, as you suggested. Our arena is roughly 8x8x3.4 (WxLxH). However, shouldn't UWB measurements, theoretically, improve with distance? (given that they are within the 200m range of the radio). A...
by carlos.luis306
Mon Jan 29, 2018 6:36 pm
Forum: Loco Positioning System
Topic: Variance of TDOA2 measurements
Replies: 5
Views: 780

Variance of TDOA2 measurements

Hello everyone, I have setup 8 UWB nodes in our lab (following the cuboid recommendation) and I'm getting a large variance using the new TDOA2 algorithm. I'm using the latest anchor and crazyflie firmware (both STM32 and NRF51). I'm attaching a cfclient capture of a static Crazyflie in the middle of...
by carlos.luis306
Fri Aug 19, 2016 3:16 pm
Forum: Developer Discussions
Topic: Trajectory Tracking Open Source project
Replies: 5
Views: 1998

Re: Trajectory Tracking Open Source project

Hey Arnaud, The LQT controller is run offboard through MATLAB, but in general it shouldn't need more processing power than your classical PID. The thing about the LQT algorithm is that it computes time-varying feedforward and feedback gains based on the trajectory you want to follow, hence optimizin...
by carlos.luis306
Sun Aug 14, 2016 2:21 pm
Forum: Developer Discussions
Topic: Trajectory Tracking Open Source project
Replies: 5
Views: 1998

Re: Trajectory Tracking Open Source project

Well I'd say the UWB technology needs still some improvement, more on the side of bias compensation. As of now I've only used the UWB measurement to estimate the quad position in the X-Y plane while the altitude came from the VICON. I've been playing lately with the geometry of the base estimations ...