During debugging, it is found that the voice prompts of system start and stop sometimes make mistakes, and the soft start time cannot be set for more than 10s, otherwise the start fails. According to the error phenomenon of voice prompt, after analyzing the causes, it is found that the logic of the start stop judgment program is not rigorous. When there are faults and start failures again, the relevant registers are not cleared, resulting in this phenomenon. After the program is modified, the problem can be solved. In view of the problem that the soft start time cannot exceed 10s, it is found that the setting time of the soft start judgment time parameter is too short after debugging.