VOXL2 NOT DETECTING APRIL TAG

[taiwohazeez]

Hello support,
I have an issue detecting apriltags with my voxl2 (starling 2), I looked at the documentation online to see how it works.
I ran voxl-tag-detector, and i got this

voxl2:/$ voxl-tag-detector
loading tag-detector config file
loading apriltag config file
=================================================================
detector #0
enable: 1
input_pipe: tracking_front
en_fast_mode: 1
n_threads: 1
en_undistortion: 1
undistort_scale: 0.60
overlay_name: tracking_tag_overlay
lens_cal_file: /data/modalai/opencv_tracking_intrinsics.yml
skip_n_frames: 5
detector #1
enable: 0
input_pipe: stereo
en_fast_mode: 1
n_threads: 1
en_undistortion: 1
undistort_scale: 0.90
overlay_name: stereo_tag_overlay
lens_cal_file: /data/modalai/opencv_stereo_intrinsics.yml
skip_n_frames: 5
detector #2
enable: 0
input_pipe: extra
en_fast_mode: 1
n_threads: 1
en_undistortion: 0
undistort_scale: 1.00
overlay_name: extra_tag_overlay
lens_cal_file: /data/modalai/opencv_extra_intrinsics.yml
skip_n_frames: 5
=================================================================
default_size_m: 0.160
#0:
id: 0
name: default_name
loc_type: unknown
size_m: 0.400
T_tag_wrt_fixed: 0.0 0.0 0.0
R_tag_to_fixed: 0.0 -1.0 0.0
1.0 0.0 0.0
0.0 0.0 1.0
found cam matrix with name 'M' for detector #0
detector #0 is fisheye
waiting for cam pipe tracking_front
detector #0 connected to camera pipe tracking_front
lens #0: fx:460.04 fy:460.58 cx:666.72 cy:382.58
lens #0: fxrect:276.02 fyrect:276.35.

Then on another terminal, i ran voxl-inspect-detections -a tag_detections, but i keep getting unknown, can you help with what i might be doing wrong.

Meanwhile, I have ros2 run voxl_mpa_to_ros2 voxl_mpa_to_ros2_node running.

KIndly assist @tom @teddy-zaremba
Thanks,
Taiwo

[Zachary Lowell 0]

Hi @taiwohazeez - can you paste the output? Usually you get NANS or unknown when the locations.txt file isnt filled out meaning the tag detector service is referencing an empty file. Once you paste the output of voxl-inspect-detections I will be able to give you better guidance.

Thanks!
Zach

[taiwohazeez]

@Zachary-Lowell-0 thank you for your response, this is the output,
Class Name	Camera	Class Confidence	Detection Confidence	Frame ID	Timestamp(
unknown		nan	nan	62	447765889248

Thanks,
Taiwo

[Zachary Lowell 0]

Class confidence and detection confidence are pertinent towards voxl tflite server not voxl-tag-detector - are you sure this is the right output?

[taiwohazeez]

@Zachary-Lowell-0 yes, i copied that directly from the terminal after running this command voxl-inspect-detections -a tag_detections.

[taiwohazeez]

@taiwohazeez @Zachary-Lowell-0 , please i am still waiting for a response, an advice on how to go about Apriltag detection on starling 2 would be greatly appreciated.

Thanks

[Zachary Lowell 0]

@taiwohazeez I am not fully convinced you are running the right command still

Running voxl-inspect-tag shoudl show the following headers:

ID | XYZ | RPY | SIZE_M | CAM

As shown in the code below:
printf("\n"); printf("id:%3d name: %s\n", d.id, d.name); printf("XYZ: %6.2f %6.2f %6.2f \n", (double)d.T_tag_wrt_cam[0], (double)d.T_tag_wrt_cam[1], (double)d.T_tag_wrt_cam[2]); printf("RPY: %6.1f %6.1f %6.1f \n", (double)roll, (double)pitch, (double)yaw); printf("size_m: %4.2f latency_ms: %6.2f\n", (double)d.size_m, latency_ms); printf("cam: %s type: %s\n", d.cam, pipe_tag_location_type_to_string(d.loc_type)); printf("\n");

https://gitlab.com/voxl-public/voxl-sdk/services/voxl-tag-detector/-/blob/dev/clients/voxl-inspect-tags.c?ref_type=heads

Just run voxl-inspect-tags and that will output the right data.
Zach

[Zachary Lowell 0]

Detections is pertinent to voxl-tflite-server and onboard computer vision on yolo, NOT on april tags.