English: listening, speaking, reading, writing and translating
1. Life is like tea, you must calm down to face it. Time is like water, it can be clear when it is settled.
2. The key to acquiring proficiency in any task is repetition.
document management tool
1. Mendeley: Tutorial (http://biblioteca.uoc.edu/prestatgeries/M3051/TallersMendeley_EN/html5/modul_1.html)
Mendeley is a multi-platform programme (Windows, Mac, Linux) which means that the documents stored on it can be shared, read, annotated and cited, making it extremely useful for researchers, academics and students. However, it is also a social research network that allows online documents to be shared, other articles discovered, statistics drawn up and contact with other researchers. One of the most outstanding functions of this manager is that it extracts the metadata from the documents imported into its database and indexes them automatically. It also has a powerful full text search engine, it generates automatic copies of the stored PDFs and it allows post-it notes to be made about them or the text to be underlined.
2. Learn "Mendeley" and start here! (https://zhuanlan.zhihu.com/p/30174699)
3. Zotero, a document management software that you can’t stop (https://zhuanlan.zhihu.com/p/30395323)
4. Mendeley - a free and easy to use document management software (https://zhuanlan.zhihu.com/p/28762628)
5. Mendeley Tutorial - cited references (writing papers necessary!) (https://zhuanlan.zhihu.com/p/32249499)
6. Zotero (https://www.zotero.org/support/)
7. Zotero (https://www.zotero.org/support/zh/quick_start_guide)
Paper
1. Design and Use Paradigms for Gazebo, An Open-Source Multi-Robot Simulator (http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.304.8999&rep=rep1&type=pdf) (out of date!!!)
Abstract— Simulators have played a critical role in robotics research as tools for quick and efficient testing of new concepts, strategies, and algorithms. To date, most simulators have been restricted to 2D worlds, and few have matured to the point where they are both highly capable and easily adaptable. Gazebo is designed to fill this niche by creating a 3D dynamic multi-robot environment capable of recreating the complex worlds that will be encountered by the next generation of mobile robots. Its open source status, fine grained control, and high fidelity place Gazebo in a unique position to become more than just a stepping stone between the drawing board and real hardware: data visualization, simulation of remote environments, and even reverse engineering of blackbox systems are all possible applications. Gazebo is developed in cooperation with the Player and Stage projects [1], [2], [3], and is available from http://playerstage.sourceforge.net/gazebo/ gazebo.html.
gazebo (Category: Connect to ROS)
1. ROS overview (http://gazebosim.org/tutorials?tut=ros_overview&cat=connect_ros)
To achieve ROS integration with stand-alone Gazebo, a set of ROS packages named gazebo_ros_pkgs provides wrappers around the stand-alone Gazebo. They provide the necessary interfaces to simulate a robot in Gazebo using ROS messages, services and dynamic reconfigure Some features of gazebo_ros_pkgs:
-
- Supports a stand alone system dependency of Gazebo, that has no ROS bindings on its own
- Builds with catkin
- Treats URDF and SDF as equally as possible
- Reduces code duplication with Gazebo
- Improves out of the box support for controllers using
ros_control - Integrates real time controller efficiency improvements from the DARPA Robotics Challenge
- Cleans up old code from previous versions of ROS and Gazebo
2. Using roslaunch (http://gazebosim.org/tutorials?tut=ros_roslaunch&cat=connect_ros)
There are many ways to start Gazebo, open world models and spawn robot models into the simulated environment. In this tutorial we cover the ROS-way of doing things: using rosrun and roslaunch. This includes storing your URDF files in ROS packages and keeping your various resource paths relative to your ROS workspace.
Creating your own Gazebo ROS Package
Before continuing on how to spawn robots into Gazebo, we will first go over file hierarchy standards for using ROS with Gazebo so that we can make later assumptions.
For now, we will assume your catkin workspace is named catkin_ws, though you can name this to whatever you want. Thus, your catkin workspace might be located on your computer at something like:
/home/user/catkin_ws/src
Everything concerning your robot's model and description is located, as per ROS standards, in a package named /MYROBOT_description and all the world files and launch files used with Gazebo is located in a ROS package named /MYROBOT_gazebo. Replace 'MYROBOT' with the name of your bot in lower case letters. With these two packages, your hierarchy should be as follows:
../catkin_ws/src
/MYROBOT_description
package.xml
CMakeLists.txt
/urdf
MYROBOT.urdf
/meshes
mesh1.dae
mesh2.dae
...
/materials
/cad
/MYROBOT_gazebo
/launch
MYROBOT.launch
/worlds
MYROBOT.world
/models
world_object1.dae
world_object2.stl
world_object3.urdf
/materials
/plugins
Remember that the command catkin_create_pkg is used for creating new packages, though this can also easily be adapted for rosbuild if you must. Most of these folders and files should be self explanatory.
Using roslaunch to Spawn URDF Robots
There are two ways to launch your URDF-based robot into Gazebo using roslaunch:
ROS Service Call Spawn Method
The first method keeps your robot's ROS packages more portable between computers and repository check outs. It allows you to keep your robot's location relative to a ROS package path, but also requires you to make a ROS service call using a small (python) script.
Model Database Method
The second method allows you to include your robot within the
.worldfile, which seems cleaner and more convenient but requires you to add your robot to the Gazebo model database by setting an environment variable.
We will go over both methods. Overall our recommended method is using the '''ROS Service Call Spawn Method'''
3.Installing gazebo_ros_pkgs (http://gazebosim.org/tutorials/?tut=ros_urdf)
To deal with this issue, a new format called the Simulation Description Format (SDF) was created for use in Gazebo to solve the shortcomings of URDF. SDF is a complete description for everything from the world level down to the robot level. It is scalable, and makes it easy to add and modify elements. The SDF format is itself described using XML, which facilitates a simple upgrade tool to migrate old versions to new versions. It is also self-descriptive.
It is the intention of this author to make URDFs as fully documented and supported in Gazebo as possible, but it is relevant to the reader to understand why the two formats exist and the shortcomings of both. It would be nice if more work was put into URDFs to update them to the current needs of robotics.