Simulate communication delay mapping

[xh1613221034]

Hello!Sorry to bother you, I am a beginner, I am using ROS to simulate the impact of poor communication in reality on fusion mapping, I tried to add a timer to the beginning of the callback function fullMapUpdate, so that the subscriber subscribes to the topic information once in a certain time, and the publishing end is 20hz, But the first car will report an error if the delay exceeds 0.1s, but strangely the third car I can set to 0.3s will not report an error, but it has no effect on the final mapping effect, can you give me some advice on how to simulate poor communication, thank you！