# wiki
http://wiki
.ros.org/message_filters
# blog
https://blog
.csdn.net/start_from_scratch/article/details/
52337689
A set of message filters which take in messages and may output those messages at a later time, based on the conditions that filter needs met.
相当于修改订阅话题的时间戳，在之后一同发布，软消息同步。
