Mechatronics is combination of Electrical, Mechanical, and Computer Science Engineering. Mechatronics is the closest to robotics with the slight and main difference in mechatronics systems inputs are provided whereas in robotics systems it acquires the inputs by their own.
In fact, the term “robot” means different things to different people. Even roboticists themselves have different notions about what is or isn’t a robot. And for most of us, science fiction has strongly influenced what we expect a robot to look like and be able to do.
So what makes a robot? Here’s a definition that is neither too general nor too specific:
A robot is an autonomous machine capable of sensing its environment, carrying out computations to make decisions, and performing actions in the real world.
Think of the Roomba robotic vacuum. It uses sensors to autonomously drive around a room, going around furniture and avoiding stairs; it carries out computations to make sure it covers the entire room and when deciding if a spot needs a more thorough cleaning; and it performs an action by “sucking dirt,” as roboticist Rodney Brooks, one of the Roomba creators, explains.
But no definition is perfect. You may argue, and perhaps rightly so, that the definition above could very well describe a dishwasher, a thermostat, an elevator, an automatic door, and many other systems and appliances around us. Take, for example, cruise control in cars. It senses how fast the vehicle is going, compares it to a preset speed, and accelerates or brakes as needed. Is cruise control a robot?