marawy_alsakaf's profile - activity

Hello

I have a robot that is supposed to navigate autonomously, i decided to use the navigation stack in ROS. but i feel lost ! i do not know how to start with it. i already read its tutorials but i can not understand how to apply it to my robot.

specifically the tutorial is not clear for me in the following points

from the beginning how to write the tf for my robot is it only about base_link to base_laser ? and if my URDF is written, how to use it for tf ? ,, next thing i wrote the laser node, the IMU node, the GPS .. separately i did not get how to use them with navigation stack

so i need clear steps to start with navigation stack please.

Hello everybody, my project is an outdoor autonomous navigation mobile robot using ROS, the sensors used are Lidar, GPS, encoders and IMU

i prepared the drivers for the sensors and actuators and each part is worked well separately with ROS, but now i want to connect and gather all the project so i am trying to find a suitable ROS package (providing autonomous navigation & SLAM),

what are the main differences between the existed packages and what is the preferred package for outdoor navigation , "Any help and ideas are welcomed "

Hello, what is the next step after installing the Gmapping package from (GitHub) i install it in a workspace,

my lidar is working with Rviz ,, what is next ?

Hello all i have a real robot. using ROS. i have a problem with (Joint State Publisher)

i understand that i should write my own (joint state publisher node). i read the related tutorials but i do not get how to convert encoders' messages to joint state message. i need steps or tutorial for doing that.

thanks in advance.

edit

i test the code in

my code becomes as follows

#!/usr/bin/env python
# Lucas Walter
# make a joint exactly what the command wants it to be- this only works
# for position control.

import rospy

from sensor_msgs.msg import JointState
from std_msgs.msg import Int64


class CommandToJointState:
    def __init__(self):
        self.joint_name = rospy.get_param("lwheel",True)
        self.joint_state = JointState()
        self.joint_state.name.append(self.joint_name)
        self.joint_state.position.append(0.0)
        self.joint_state.velocity.append(0.0)
        self.joint_pub = rospy.Publisher("joint_states", JointState, queue_size=1)
        self.command_sub = rospy.Subscriber("lwheel", Int64,
                                            self.command_callback, queue_size=1)


    def command_callback(self, msg):
        self.joint_state.position[0] = msg.data
        self.joint_state.header.stamp = rospy.Time.now()
        self.joint_pub.publish(self.joint_state)

if __name__ == '__main__':
    rospy.init_node('diffdrive_controller')
    diffdrive_controller = CommandToJointState()
rospy.spin()

but i get error as in the image attached

i am not familiar with python. all my codes are in C++

What is the difference between joint_state_publisher and robot_state_publisher? I understand that I get robot state publisher from the URDF but the joint state? What if i want real data not fake?

@billy sorry for being late. would you mind to give me an idea how to do that? i did not do it !

@billy i answered by the lines of code. after each rotation the step count is reseted . isn't it enough as index?

@billy hmmm actually i assumed the number of steps, because the datasheet standard number does not work. and for that it

@billy i have these lines in arduino code is it what you mean by zero index? void stepmotor( void ) { digitalWrite(

@billy i have these lines in arduino codem is it ehat you mean by zero index? void stepmotor( void ) { digitalWrite

@billy i do not get how to replace data by fake one?

@billy if i connect the lidar alone without rotation i get circles