Humans have five senses, the eyes to see the tongue to taste the nose to smell, the ears to hear, and the skin to touch. The human senses are our contact to the environment. Our eyes are by far the most important input sensor we have, we perceive up to 80% of what is around us by means of our sight.
Computers, however, have no organic senses at all. Senses are difficult to reproduce, but there are other ways of letting a robot react to its environment. Without senses, a robot can only execute hard codes, which are saved in computer programs. This means every scenario must be predicted for a computer to give appropriate responses. This is an incredibly difficult task. And this is why sensors are given to robots instead. Sensors are what robots have in order to evaluate and understand the world around them. Often, these sensors are simplified versions of our own senses, like a camera for eyes, or microphones for ears. Not all human senses can be reproduced, for example, taste, but there are hundreds of sensors made today that can detect virtually anything you can think of.
To move around, basic robots such as many used in factories have proximity, positioning, and navigation sensors. All of these sensors allow the robot to be aware of its environment by receiving sound, visual and other inputs. They are referred to as input sensors, because they take information from the environment and put it into the computer program.
For a computer to understand a certain characteristic, the sensors need to measure it digitally and tell the computer program what the value of the data is. Most sensors also interpret the data they receive so the computer program can react more easily. As the name suggests, a sound sensor detects sound and returns a voltage to the robot to indicate the sound level. A simple robot can be designed to make decisions based on the sound at receive. This robot turns right for one clap, and turns left for two claps. The robot sensor takes in the sound and translates it into code, so it knows what the appropriate reaction should be. In this case, the command is to move left or right. Complex robots can use this same microphone for more complex inputs, such as speech and voice recognition.
And with the progress of technology, new sensors are still being invented. sensors allow the robot to determine sizes, shapes, space between objects and directions. They are the link between a computer program in the real world by translating central information into digital values. In the future, computers will probably be as capable as a person, if not more.