Hello,I am doing some work on ROS navigation,just at the start，and I encountered some problems.When I roslaunch the *.launch,there are a lot of erros like this:[ERROR] [1493084059.568174116]: Extrapolation Error: Lookup would require extrapolation into the future. Requested time 1493084059.049999952 but the latest data is at time 1493084059.012892115, when looking up transform from frame [odom] to frame [map].It seems that time differences exist during the program running.How can I fix this error or how can I set the time to be the same during the program?
Originally posted by little_bob on ROS Answers with karma: 88 on 2017-04-24
Post score: 0
Original comments
Comment by Geoff on 2017-04-24:
What launch files are you running? Are you using a simulator or a real robot? What simulator or robot? Is your computer's clock set accurately?
Comment by little_bob on 2017-04-25:
not a real robot,but a small car based on arduino and raspberry Pi.the name of the launch file ishongrobot_configuration.launch,this may be a launch to set the nodes.Can I upload this file?
Comment by Geoff on 2017-04-25:
If you are using hardware, then you are using a real robot. Not all robots are made by Kuka! :)
Yes, upload the launch file and the rest of your source so we can check it for problems.
Comment by Geoff on 2017-04-25:
Are you using running nodes on any computers other than the Raspberry Pi? If you are, then you need to make sure their clocks are synchronised.
Comment by little_bob on 2017-04-25:
Let's put the file aside.Sorry to forget the details:I run nodes on the raspberrypi to manipulate the arduino to controll the little car and send data of laser_scanner to a Vmware machine(Ubuntu 14.04,bridged to the physical machine) and generating maps with RVIZ.But these errors only happen on the
Comment by little_bob on 2017-04-25:
RaspberryPi's terminal and maps did exist on RVIZ,but not so correc、explicit.And the car can't be self-navigated.How can I sychronize the time of raspberrypi with the virtualmachine？I baidu and googled these things and doubt about the time.Should I change the codes or just run some commands in the
Comment by little_bob on 2017-04-25:
terminal?谢谢你的热心帮助。望回复。
Comment by little_bob on 2017-04-27:
remote refid st t when poll reach delay offset jitter
*ntp1.flashdance 193.11.166.20 2 u 32 64 377 396.120 -29.788 8.509
+ec2-34-198-99-1 192.53.103.108 2 u 42 64 277 278.546 -36.187 8.326
Comment by little_bob on 2017-04-27:
+61-216-153-104. 62.161.56.158 3 u 30 64 367 208.137 22.236
9.779
-61-216-153-106. 62.161.56.158 3 u 37 64 377 207.653 21.762 7.686
Comment by little_bob on 2017-04-27:
upon is raspberrypi
Comment by little_bob on 2017-04-27:
remote refid st t when poll reach delay offset jitter
61.161.155.29 202.118.1.46 2 u 6 64 1 43.822 7.451 0.000
Comment by little_bob on 2017-04-27:
darwin.kenyonra 127.67.113.92 2 u 5 64 1 195.455 1.015 0.000
dns1.synet.edu. 202.118.1.48 2 u 4 64 1 43.509 3.007 0.000
61-216-153-106. 211.22.103.157 3 u 4 64 1 205.772 57.655 0.000
Comment by little_bob on 2017-04-27:
golem.canonical 193.79.237.14 2 u 2 64 1 346.202 -9.797 0.000
