Abdur Rosyid's Blog
Just a few notes on mechanical engineering and robotics
In ROS, a node can publish a topic and subscribe (listen) to a topic. A topic is basically a unidirectional message in a certain data type containing some information. It is like a radio broadcast. The radio station is the topic publisher whereas the radio receiver is the topic subscriber. The topic is the radio …
A ROS package is a wrapper or container of a piece of code. By this definition, you can write any C++ or Python code and then wrap it in a ROS package in order to use it in ROS. There are two types of packages in ROS: 1) packages already built in ROS and 2) …
In ROS1, one machine/robot should serve as ROS Master whereas all the other machines/robots/devices in the same ROS network serve as ROS Clients. ROS Master can be a computer or a robot. The ROS Client can be a computer, a robot, or a device. The following is some steps to setup ROS1 network between multiple …
It is recommended to install an LTS ROS distribution, which is always to be installed on a certain LTS distribution of Linux Ubuntu. A specific ROS distribution can only be installed on a specific Linux Ubuntu distribution. ROS can be installed from either source or from binary (Debian installer). It is recommended to install the …
Based on my experience, here I summarize what to learn in Robot Operating System (ROS): 1 How to install ROS and prepare your development environment 2 How to create a ROS package and build it in your workspace 3 How to establish a ROS network between multiple machines and devices 4 Message communication in ROS: …
The main aspects of robotics can be summarized below: 1. Topology There are so many existing and possible-in-the-future body types and topologies of a robot. The existing ones include: 1) wheeled unmanned ground vehicles (UGVs), 2) track-chained UGVs, 3) biped, quadruped, and six-legged robots, 4) humanoids, 5) multi-rotor unmanned aerial vehicles (UAVs), 6) flapping aerial …
The main idea of ROS, as repetitively mentioned by their inventors and core developers, is to avoid reinventing the wheels in robotics. This is achieved by providing a platform in which various robotic algorithms are reusable in a modular manner. In this way, one can reuse a code developed by others and focus more on …
Robot Operating System (ROS) is a robot middleware. It is not the only robot middleware available. There are also some other robot middleware as briefly listed here and more extensively listed and compared to each other in this paper. The development of ROS was initiated at Stanford University. It was then developed and maintained at …
Statics analysis in robotics as commonly taught is as simple as relating the external static wrench applied to the robot’s end-effector to the joint torque through the Jacobian of the robot. By using the robot’s Jacobian, there is duality relation between statics and velocities. In other words, the robot’s Jacobian relates not only the joint …
A flexible body dynamics is commonly expressed as follows: Mxdd + (C + Cr + Cf) xd + Kx + Fg= F(t) …………………………………….(Eq. 1) where M, C, Cr, Cf, and K respectively denote the inertia, damping, Coriolis, Centrifugal, and stiffness matrices, whereas x, xd, and xdd denote the displacement, velocity, and acceleration vectors. Fg and …