Problems encountered in the use of ROS installation and solutions (including Ubuntu)

0, written in front of the words and directories

Here, I mainly explain in what circumstances I encountered the following problems. (Continuous update ...) ）
I want to install Ros Hidigo on the Ubuntu14.04 and use him to use Microsoft's Kinect 2. But there are some column problems in the process.
1. Ubuntu14.04 installation and configuration of Ros Indigo
2. Apt-get Cat ' t connect to ' security.ubuntu.com '
3. GPG error:http://download.opensuse.org release:the following signatures couldn ' t be verified the public key I s not available:no_pubkey e3757b8e0d988d6e
4. An error occurred in the execution of Roslaunch freenect_launch freenect-registered-xyzrgb.launch: No divices connected ... waiting for devices to be con nected
5. Ubuntu Open SSH Service
6. Image_view Symbol Lookup Error
7. Roslaunch Turtlebot_exploration_3d/turtlebot_gfind:cannot Search ': No such file or directory
8. Dukto R6-Super Utility free cross-platform LAN file/folder Transfer tool 1, Ubuntu14.04 Installation and configuration of Ros Indigo

Reference: http://www.jianshu.com/p/04be841e2293
One of the most critical areas is: Ros official website with the key is

$ sudo apt-key adv--keyserver hkp://ha.pool.sks-keyservers.net--recv-key 0xb01fa116

But I have a problem, the following key can be used normally:

$ wget Http://packages.ros.org/ros.key-O-| sudo apt-key add-

The possible reasons for this are: priority access to ipV6, so can be changed to ipV4 first, and then try 2, Apt-get cat ' t connect to ' security.ubuntu.com

The main reason for this problem is that the IPv6 is used preferentially, causing the address to be found, so the shell has been waiting. The solution is:
$ sudo gedit/etc/gai.conf
Then make the following modifications, that is, delete the annotation:

# for
sites which prefer IPv4 connections change the last line to
#
precedence:: FFFF:0:0/96 100

The meaning of this modification is to set the IPv4 as priority access.
Reference: https://zach-adams.com/2015/01/apt-get-cant-connect-to-security-ubuntu-fix/ 3, GPG error:http:// The download.opensuse.org release:the following signatures couldn ' t be verified because the public key isn't available:no_p Ubkey e3757b8e0d988d6e

Reference: Http://askubuntu.com/questions/522114/cant-get-rid-of-gpg-error-http-download-opensuse-org 4. Executive Roslaunch Freenect_launch Freenect-registered-xyzrgb.launch is an error: No divices connected ... waiting for devices to be connected

The problem still hasn't been found, but on Wiki.ros it was said that the Ubuntu14.04 64-bit driver support for the Kinect 2 was not very good. After the 32-bit installed, you can see the RGB image, but do not see the depth of the diagram.
Reference: Http://www.cnblogs.com/hitcm/p/5118196.html 5, Ubuntu open SSH service

In the use of ROS, you want to use SSH service, so you want to record the configuration process:
SSH Split-client openssh-client and Openssh-server
If you just want to log on to another machine SSH only needs to install Openssh-client (Ubuntu has a default installation, if not sudo apt-get install openssh-client), If you want to make the native SSH service open, you need to install Openssh-server
sudo apt-get install Openssh-server
Then confirm that the Sshserver is started:
Ps-e |grep SSH
If you see sshd that means Ssh-server has been started.
If not, you can start this way: Sudo/etc/init.d/ssh start
The Ssh-server configuration file is located in/Etc/ssh/sshd_config, where you can define the service port for SSH, the default port is 22, and you can define yourself as another port number, such as 222.
Then restart the SSH service:
Sudo/etc/init.d/ssh stop
Sudo/etc/init.d/ssh start
Then login to SSH using the following methods:
SSH username@192.168.1.112 username is a user on the 192.168.1.112 machine and needs to enter a password.
Disconnect: Exit
Reference: http://www.cnblogs.com/xiazh/archive/2010/08/13/1798844.html

On my Ubuntu loading virtual machine (VMWARE12), the virtual machine provides the ability to use the host card directly, so that SSH clients can access the SSH service of another computer. Specific process:
Reference: http://licoolxue.iteye.com/blog/1850756 6, image_view symbol lookup error problem: Want to use Iai_ Kinect2 View the data that Kinect2 gets

$ roslaunch Kinect2_bridge Kinect2_bridge
$ rosrun image_view image_view Image:=/kinect2/qhd/image_color

However, the following error message appears:

[INFO] [1464594522.943802369]: Using Transport "Raw"

/opt/ros/indigo/lib/image_view/image_view:symbol lookup Error:/ opt/ros/indigo/lib/image_view/image_view:undefined symbol: _zn9cv_bridge18cvtcolorfordisplayerkn5boost10shared_ Ptrikns_7cvimageeeerkssbdd

Solution:

This is because the version of Cv_bridge and the version of Image_view are not quite matched, precisely because the Image_view version is too old to support newer versions of Cv_bridge. So the hint message is: undefined symbol
Then execute the following command to update Image_view:

$ sudo apt-get update 
$ sudo apt-get install Ros-indigo-image-view

7. Roslaunch turtlebot_exploration_3d/turtlebot_gfind:cannot Search ': No such file or directory question:

The no such file or directory problem occurs when you press the TAB key at home roslaunch. But the source is Devel/setup.bash.
But there is no problem with the CATKIN_WS under Roslaunch. 8, Dukto R6-Super practical free cross-platform LAN file/folder Transfer tool

Ubuntu Installation Tutorial Address: Http://software.opensuse.org/download.html?project=home:colomboem&package=dukto