Search found 96 matches

by kristoffer
Wed Jun 12, 2019 12:03 pm
Forum: Support
Topic: Issue with LPS Deck
Replies: 1
Views: 88

Re: Issue with LPS Deck

Hi! That is interesting! I have not seen this type of behaviour before. In theory you could for instance imagine a scenario where the antenna in one of the decks is not as good as it should be, or some other defect. I suggest that you take a look at the buckets in the outlier filter that is used in ...
by kristoffer
Fri May 10, 2019 7:03 am
Forum: Loco Positioning System
Topic: Loco positioning system performance in TDoA 2 mode
Replies: 3
Views: 211

Re: Loco positioning system performance in TDoA 2 mode

Hi! 1. First, we have used Optitrack It is good to have the correct positions of the anchors, but it does not have to be millimeter precision :-) A few centimeters off should work fine. unfortunately we made a mistake and always started the drone in a wrong orientation Yes, that's important :-) 3. W...
by kristoffer
Tue Apr 30, 2019 7:33 am
Forum: Autonomous flight
Topic: Preload a trajectory in CF2 in firmware
Replies: 8
Views: 510

Re: Preload a trajectory in CF2 in firmware

Hi! Is there another strategy to increase the usable memory? Right now it looks like the trajectory is stored in RAM, in this array https://github.com/bitcraze/crazyflie-firmware/blob/master/src/modules/src/crtp_commander_high_level.c#L84. The High Level commander was added as a part of Crazy swarm ...
by kristoffer
Thu Apr 18, 2019 9:02 am
Forum: Loco Positioning System
Topic: Loco positioning system performance in TDoA 2 mode
Replies: 3
Views: 211

Re: Loco positioning system performance in TDoA 2 mode

Hi! I think it looks a bit wobbly in TDoA, it can probably be better. What is the performance like if you fly one drone in TDoA at the same position as you did with TWR? When you fly two drones you are getting closer to the edges of the space and I would expect the positioning to degrade a bit compa...
by kristoffer
Thu Apr 18, 2019 8:39 am
Forum: Autonomous flight
Topic: Preload a trajectory in CF2 in firmware
Replies: 8
Views: 510

Re: Preload a trajectory in CF2 in firmware

Hi! The lth-2019 branch is hardcoded for the lighthouse deck. You can turn it off by uncommenting https://github.com/bitcraze/crazyflie-firmware-experimental/blob/lth-2019/src/deck/drivers/src/lighthouse.c#L55-L57 Since you are flying with the LPS system you might want to use the PID controller inst...
by kristoffer
Mon Apr 01, 2019 1:53 pm
Forum: Loco Positioning System
Topic: Measure the reliability of the LPS
Replies: 1
Views: 146

Re: Measure the reliability of the LPS

Hi! I suppose another way of putting this is that you are looking for a measurement of how good the current estimated position is? There are two possibilities that comes to mind: 1. Figure out if it is possible to get some sort measurement out of the kalman filter. I'm not an expert on EKFs and I do...
by kristoffer
Mon Mar 18, 2019 3:05 pm
Forum: Loco Positioning System
Topic: Get distance tag to anchor in TDoA mode
Replies: 2
Views: 212

Re: Get distance tag to anchor in TDoA mode

Hi! In TDoA (Time Difference of Arrival) the data you get is the difference in distance to two anchors. An example: See this image https://wiki.bitcraze.io/doc:lps:tdoa:principles#geometry on the wiki. This is 2D to simplify the graphics, but it can easily be extended to 3D. The Tag is at (0.0, -0.5...
by kristoffer
Mon Mar 11, 2019 1:18 pm
Forum: General discussions
Topic: Use PC Client for 10 Crazyflies
Replies: 3
Views: 233

Re: Use PC Client for 10 Crazyflies

There is unfortunately no simple way to detect if the Crazyflie has found its position or not. There is a "hack" that we often use though (not fool proof) that might be interesting. You will find a python implementation in https://github.com/bitcraze/crazyflie-lib-python/blob/0.1.7/examples/autonomo...
by kristoffer
Mon Mar 04, 2019 1:52 pm
Forum: Loco Positioning System
Topic: Get LPS Node Position via CF2.0
Replies: 1
Views: 146

Re: Get LPS Node Position via CF2.0

Hi! The node positions are available through a memory mapping in the memory sub system, https://github.com/bitcraze/crazyflie-lib-python/blob/0.1.7/cflib/crazyflie/mem.py#L526. Use the memory type MemoryElement.TYPE_LOCO2 and the LocoMemory2 class. The anchor_data member is a dictionary containing m...
by kristoffer
Fri Nov 09, 2018 10:10 am
Forum: Quadcopters
Topic: tdoa data of Crazyflie
Replies: 1
Views: 1012

Re: tdoa data of Crazyflie

The TDoA log data is a bit messy, sorry about that. It is unfortunately not possible to get a measurement of the distance from the CF to an anchor in TDoA, what you can get is the difference in distance to two anchors (see https://wiki.bitcraze.io/doc:lps:tdoa:principles). You can calculate the esti...