Robotics is a broad interdisciplinary engineering field with immense application today. Unlike the standard classification of mobile and immobile robots, they're also classified based on applications for mobile robotics, aerial robotics, marine, and space robotics. The most common robots among them are the mobile robots that maneuver around the environment by trying to understand and learn the changes in it. They equally enjoy the environment, performing necessary actions that the application demands. Another common set of static robots that are used and are of huge demand in industries are robot arms. They were initially used to carry out lifting heavy payloads where the tasks were usually automatic and repetitive. But these manipulators have grown intelligent enough to understand the environment and objects of interest in it and perform tasks alongside humans. This category of robot arms is now called a cobot. Imagine putting together such a robot arm and a mobile robot with enough payload capabilities; this class of robots are known as mobile manipulators.

Mobile manipulators are useful in industries as they can go around carrying objects and deliver them to the respective work cells or stations as needed. This gives the robot liberty to reach almost all points in space, unlike a constrained robot arm's work volume. They are a very good addition to the flexible management systems that most industries follow for their plant automation. Apart from industries, they are useful in other fields, such as space exploration, mining, retail, and military applications. They could be either autonomously controlled, semi-autonomously controlled, or manually controlled based on the application's needs.

This is the first chapter where we will get into building robots using ROS. A list of available mobile manipulators will be introduced to provide better insight into how they can be used. Then, we will look into the prerequisites and approaches toward building the Mobile Manipulator project. Furthermore, you may model and simulate a robot base and robot arm individually and then put them together and see them in action. 

In this chapter, the following topics will be covered:

• Understanding available mobile manipulators
• Applications of mobile manipulators
• Getting started building mobile manipulators
• Units and coordinate system
• Building the robot base
• Building the robot arm
• Putting things together