运行vehicle_state.py示例后，会显示如下错误。
追踪（最近一次呼叫最后一次）：
File "C:\Users\CVLAB\Downloads\dronekit-python-master\dronekit-python-master\examples\vehicle_state\test.py", line 5, in <module>
print vehicle.wait_ready('autopilot_version')
File "C:\Python27\lib\site-packages\dronekit\__init__.py", line 2199, in wait_ready
timeout)
APIException: wait_ready experienced a timeout after 30 seconds.