Respeaker 4mic array doa angle estimation

Hi, im planning to use the DOA (detection of arrival) in the mic, referring to this github : GitHub - respeaker/mic_array: DOA, VAD and KWS for ReSpeaker Microphone Array
I faced a problem when running the file : the angle of the mic is not consistent, how should I calibrate it to obtain consistent results?

I am facing the same problem also.