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How to set rosbag recording to stop when robot reaches a goal?

asked 2021-11-06 04:10:46 -0500

ganesh112 gravatar image

Hello all, I am working on a project in 3D space, I am giving command to robot through topic to reach a goal, I want to record a specific robot moving topic ( /UAV/goal), for only when robot start moving to reach goal. is it possible through rosbag record arguments?? (PS. I do not know how much time it takes to reach goal, so i can not set timing through rosbag record arguments) (I am planning to verify 1. how much time taken to reach the goal, 2. Actual travelled distance by robot.)

currently I am recording using rosbag and using matlab to find the specific time and distance.

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answered 2021-11-06 14:46:25 -0500

osilva gravatar image

This answer is in Python but you could use something for Matlab. The source of the code:

#!/usr/bin/env python

import rospy
import subprocess
import os
import signal

class RosbagRecord:
    def __init__(self):

        if rospy.has_param('~record_script') and rospy.has_param('~record_folder'):
            self.record_script = rospy.get_param('~record_script')
            self.record_folder = rospy.get_param('~record_folder')

            # Start recording.
            command = "source " + self.record_script
            self.p = subprocess.Popen(command, stdin=subprocess.PIPE, shell=True, cwd=self.record_folder,

            # Wait for shutdown signal to close rosbag record
            rospy.signal_shutdown(rospy.get_name() + ' no record script or folder specified.')

    def terminate_ros_node(self, s):
        # Adapted from
        list_cmd = subprocess.Popen("rosnode list", shell=True, stdout=subprocess.PIPE)
        list_output =
        retcode = list_cmd.wait()
        assert retcode == 0, "List command returned %d" % retcode
        for str in list_output.split("\n"):
            if (str.startswith(s)):
                os.system("rosnode kill " + str)

    def stop_recording_handler(self):
        rospy.loginfo(rospy.get_name() + ' stop recording.')

if __name__ == '__main__':
    rospy.loginfo(rospy.get_name() + ' start')

    # Go to class functions that do all the heavy lifting. Do error checking.
        rosbag_record = RosbagRecord()
    except rospy.ROSInterruptException:

It can be used as ROS node, so once you reach the goal, then you can publish to stop recording. I searched in prior answers and couldn't find something more concise to do this. Hope this helps.

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Measuring the time between when you start and stop recording can be done separately or by slightly modifying this script.

osilva gravatar image osilva  ( 2021-11-06 14:48:05 -0500 )edit

It seems I can start recording by this script but stopping the recording should also should be done automatically, when robot reaches a goal. Say If i stop the rosbag record manually it is difficult to find exact time spent to reach the goal.

ganesh112 gravatar image ganesh112  ( 2021-11-06 15:50:56 -0500 )edit

When you know that is time to stop then you publish to stop rosbag and get a time stamp

osilva gravatar image osilva  ( 2021-11-06 16:02:48 -0500 )edit

list_cmd = subprocess.Popen("rosnode list", shell=True, stdout=subprocess.PIPE)

Kills rosbag

osilva gravatar image osilva  ( 2021-11-06 16:07:50 -0500 )edit

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Asked: 2021-11-06 04:10:46 -0500

Seen: 120 times

Last updated: Nov 06 '21