2.1. Major robot components and their roles

What is a robot?

In simple terms a robot can be defined as a machine that does what you design it to do. The initial purpose of robots was to provide assistance in repetitive, physically difficult or dangerous tasks that human workers performed.

What’s a robot made of?

We can separate the robot’s components in two categories:

  • mechanical components
  • electronic components

Mechanical components


An actuator is a device used to control a mechanism or a system. It converts energy – electrical, hydraulic, pneumatic - into motion. In robotics, the most common actuator is the electric motor which converts electric energy into movement. Example:

  • a four wheeled robot might use four DC motors
  • a robotic arm with six degrees of freedom might use six stepper motors

Electronic components

The microcontroller

The microcontroller represents the robot’s “brain” and acts like a command center.

Structure of a microcontroller:

  • a processor core – like a CPU but less powerful
  • volatile memory – just like RAM in a PC
  • nonvolatile memory – similar to the memory found in a USB stick
  • general purpose input/output pins – used to control or communicate with other components.
  • converters (e.g. Analog to Digital converter)
  • serial communication data lines

What differentiates the microcontroller from a microprocessor found in a PC is the fact that the microcontroller integrates all the above features on a single chip. Generally speaking, the microcontroller’s role is to provide automation for devices that perform tasks far too simple to justify the use of a CPU (e.g. microwave ovens, washing machines, ABS systems, etc.).


Sensors are the devices that convert a physical quantity to a signal which can be interpreted by a microcontroller.


  • infrared and light sensors
  • pressure sensors
  • accelerometer
  • stretch and bend sensors
  • temperature and humidity sensors
  • gyroscope
  • proximity sensors

Sensors are the linking elements between the environment and the microcontroller.


roboticsisfun/chapter2/ch2_1_major_components.txt · Last modified: 2012/11/12 16:42 by liviu.radoi