single_aruco.launch error [viewpoint_estimation-2]

[HU-Yi-ming]

Hi there, i just follow your wiki,and when i use

roslaunch drone_application single_aruco.launch

i got an error

core service [/rosout] found
process[link1_broadcaster-1]:
started with pid [4349]
process[viewpoint_estimation-2]: started with pid [4350]
Reading calibration file from: /home/ros/ardrone_ws/src/eYSIP-2017_Navigation-in-Indoor-Environments-using-drone/camera_calibration_files/ardrone_bottom.ini
Intrinsics:
[686.17417, 0, 272.11582;
0, 685.88416, 149.06945;
0, 0, 1]
Distortion: [-0.01796; 0.10867; -0.00334; -0.00192; 0]
[ INFO] [1536240880.782920418]: Calibration file loaded successfully
[viewpoint_estimation-2] process has died [pid 4350, exit code -11, cmd /home/ros/ardrone_ws/devel/lib/viewpoint_estimation/viewpoint_estimation /image_raw:=/ardrone/bottom/image_raw __name:=viewpoint_estimation __log:=/home/ros/.ros/log/7e577e5e-b1d9-11e8-a07f-b8763fc5403f/viewpoint_estimation-2.log].
log file: /home/ros/.ros/log/7e577e5e-b1d9-11e8-a07f-b8763fc5403f/viewpoint_estimation-2*.log

how can i fixed this and to detection the marker?
Thank you.