Baumboon's profile - activity

Hello Guys,

I am thinking about switching from Gazebo to Unreal engine. Are Here any users who tried this ? And are there any Plugins that will Ros and Unreal Work together ?

Actual i just need a Turtlebot in Unreal and all camera data from depth and RGB Image.

Hello Guys,

i use ros kinetic with gazebo 7.0. I have a world with a turtlebot inside and i want to get pcd files from the /camera/depth/point topic. Now i found a method to get pcd files from the published pointcloud with:

rosrun pcl_ros pointcloud_to_pcd input:=/camera/depth/points

But i got only 1 file every second is there a way to speed it up ?

Hello Guys,

I run ros Kinetic with gazebo 7.0. My project is a turtlebot who should drive to several objects and try to push them away after a try he should drive to the middle of the room again and drive to the next object. I tried Odometry for get information about the position of the robot but i need accurated position so i need model state.

So i think it should have a higher accuracy when i use modelstates.

I got my odometry information with following piece of code:

def newOdom(msg):
    global x
    global y
    global theta

    x = msg.pose.pose.position.x
    y = msg.pose.pose.position.y

    rot_q = msg.pose.pose.orientation
    (roll,pitch,theta) = euler_from_quaternion ([rot_q.x,rot_q.y,rot_q.z,rot_q.w])
rospy.init_node("speed_controller")
sub = rospy.Subscriber("/odom",Odometry,newOdom)

My question is: It is correct to make the same with the gazebo_msgs/ModelState I updated my code to :

def newModel(msg):
    global x
    global y
    global theta

    x = msg.pose[1].pose.position.x
    y = msg.pose.pose[1].position.y

    rot_q = msg.pose[1].pose.orientation
    (roll,pitch,theta) = euler_from_quaternion ([rot_q.x,rot_q.y,rot_q.z,rot_q.w])
rospy.init_node("speed_controller")
sub = rospy.Subscriber("/gazebo/ModelStates",ModelState,newModel)

I looked in publishing message and mobile base is at position 2 so it should be index 1. But all i got as x and y value is 0 even if i move the robot. Any further help?

With the subscriber note above i got no error but not the correct values.

I even tried out :

sub = rospy.Subscriber("/gazebo/model_states",ModelState,newModel)

If u use this i got following error:

[ERROR] [1430752035.526287969, 184.707000000]: Client [/listener] wants topic /gazebo/model_states to have datatype/md5sum [gazebo_msgs/ModelState/9330fd35f2fcd82d457e54bd54e10593], but our version has [gazebo_msgs/ModelStates/48c080191eb15c41858319b4d8a609c2]. Dropping connection.

This is also solved at Modelstate error

Hi guys,

can i dual install those ? If i can't is there a clean way to purge Lunar?

Can i kept my catkin workspace?

i am happy for all help and answers.

I found no way to bring it up for Ros Lunar so i switched to Kinect.

Is there any way how i can use Turtlebot ?

It would be fine enough for me when i could get a model for the turtlebot and when i can move him.

I hope someone can help me !

I got struggel here :

sudo apt-get install ros-kinetic-turtlebot ros-kinetic-turtlebot-apps ros-kinetic-turtlebot-interactions ros-kinetic-turtlebot-simulator ros-kinetic-kobuki-ftdi ros-kinetic-rocon-remocon ros-kinetic-rocon-qt-library ros-kinetic-ar-track-alvar-msgs Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package ros-kinetic-rocon-remocon E: Unable to locate package ros-kinetic-rocon-qt-library

My Solution until now is that i dont install those packages. Until now Simulation works fine,

Hello Guys,

is there a way how i can get information if my robot can push an object or he can't. I am using Gazebo 7.0 with Ros Kinetic turtlebot package.

I looked in odom but i didn´t find anything whats helps me with my problem.

Is there a topic that will help me with the problem?

Maybe with wheel movement ?

To clear the meaning of pushing : My robot drive into an object some objects he can move and some he can't. I need a parameter to decide which objects he can push away and which he can't.

Maybe I can solve this with my Slam Map. I can get the position if my robot and I can compare it with the object position. If the robot push away the object he should stand in the object position or am I wrong ?

Hello Guys,

I have encountered the problem that my Turtlebot didn't drive really straight and he also have some problems with the rotation. After a short period the robot loose the straight path and he drifts away more and more. I use the turtlebot from the turtlebot package in gazebo.

I create a Twist msgs: self.cmd_vel = rospy.Publisher('cmd_vel_mux/input/navi', Twist, queue_size=10) and then i set a linear speed: move_cmd = Twist() move_cmd.linear.x = 0.1 move_cmd.angular.z = 0

Is there a way to drive straight with no deviation?

How can i publish the wheel velocity of my turtlebot maybe the wheels have a different velocity?

Hello Guys,

i have created my own arm model in gazebo with models from blender. I combine all meshes with joints to have a arm. Now i have no idea how i could move the joints.

I have a SDF model with 4 joints. Now i tried Ros Control but in the tut it was written it is for URDF models. Can i use it for SDF models too? Is there another option when i can´t use ros control?

Or would it be easier to use Ros with Move it for such an task ?

Hello guys,

first of all i must excuse i messed up by posting this question wrong and it got to confusing so i delete it and post it correct again. A special excuse to jayess i messed up with copying my code correct he is fully right that at this point:

 if abs(angle_to_goal - theta) > 0.1:

        speed.linear.x = 0.0
        speed.angular.z = 0.1

Here needs to be bigger then 0.1 before here stands less...

So my question is how i can drive with my Turtlebot to a specific point or an array of points i give the robot. I am using Turtlebot package for ros kinetic and i run this in gazebo 7.0.

i tried this code:

#! /usr/bin/env python

import rospy
from nav_msgs.msg import Odometry
from tf.transformations import euler_from_quaternion
from geometry_msgs.msg import Point, Twist
from math import atan2
x = 0.0
y= 0.0
theta = 0.0
def newOdom(msg):
    global x
    global y
    global theta

    x = msg.pose.pose.position.x
    y = msg.pose.pose.position.y

    rot_q = msg.pose.pose.orientation
    (roll,pitch,theta) = euler_from_quaternion ([rot_q.x,rot_q.y,rot_q.z,rot_q.w])
rospy.init_node("speed_controller")
sub = rospy.Subscriber("/odom",Odometry,newOdom)
pub = rospy.Publisher('cmd_vel_mux/input/navi', Twist, queue_size=1)
speed = Twist()
r = rospy.Rate(4)
goal = Point()
goal.x = 2
goal.y = 2
while not rospy.is_shutdown():
    inc_x = goal.x - x
    inc_y = goal.y - y

    angle_to_goal = atan2(inc_y,inc_x)

    if abs(angle_to_goal - theta) > 0.1:

        speed.linear.x = 0.0
        speed.angular.z = 0.1
    else:
        speed.linear.x = 0.5
        speed.angular.z = 0.0

    pub.publish(speed)
    r.sleep()

So the program works for a few rotations but the turtlebot don´t reach the correct angle he drives most time before he reachs the correct angle and lands left of the target point.

I used this tutorial :

tutorial to drive to specific point with twist

He used same controller and the robot drives perfectly as he should... Only difference i use a turtlebot for it