min_max_finder.py

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#!/usr/bin/env python3
# Copyright (c) 2018-2022, Martin Günther (DFKI GmbH) and contributors
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
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#    * Redistributions of source code must retain the above copyright
#      notice, this list of conditions and the following disclaimer.
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#    * Redistributions in binary form must reproduce the above copyright
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#      documentation and/or other materials provided with the distribution.
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#      contributors may be used to endorse or promote products derived from
#      this software without specific prior written permission.
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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# Author: Martin Günther
 
import rospy
 
from nav_msgs.msg import Odometry
 
lin_min = 0.0
lin_max = 0.0
ang_min = 0.0
ang_max = 0.0
 
 
def odom_cb(msg):
    global lin_min, lin_max, ang_min, ang_max
    if lin_min > msg.twist.twist.linear.x:
        lin_min = msg.twist.twist.linear.x
    if lin_max < msg.twist.twist.linear.x:
        lin_max = msg.twist.twist.linear.x
    if ang_min > msg.twist.twist.angular.z:
        ang_min = msg.twist.twist.angular.z
    if ang_max < msg.twist.twist.angular.z:
        ang_max = msg.twist.twist.angular.z
 
    rospy.loginfo('linear: [%f, %f]   angular: [%f, %f]', lin_min, lin_max, ang_min, ang_max)
 
 
def main():
    rospy.init_node('min_max_finder', anonymous=True)
    rospy.Subscriber('odom', Odometry, odom_cb)
    rospy.loginfo('min_max_finde node ready and listening. now use teleop to move your robot to the limits!')
    rospy.spin()
 
 
if __name__ == '__main__':
    main()