What are some of the basic sensors used in Robotics?
Sensors are everywhere, and it would be impossible to imagine modern life without them. We commonly use several sensors in various electronic devices and machines. But what exactly is a “Sensor” and what are its applications? Let’s start with understanding a few things.
What is Sensor?
A sensor is a device that detects and responds to some type of input from the physical environment. The specific input could be light, heat, motion, moisture, pressure, or any one of a great number of other environmental phenomena.
The output is generally a signal that is converted to human-readable display at the sensor location or transmitted electronically over a network for reading or further processing.
Why use Sensors?
Sensor technology can store the data in memory, from where it can be retrieved later for processing, analysis, and presentation.
Alternatively, sensor technology can display graphs of data in "real time", the graph is constructed as the data is being collected, and the graph is then modified on the screen as the data is processed.
Sensors in Robotics
The use of sensors in Robots has taken them to the next level of creativity. Most importantly, the sensors have increased the performance of robots to a large extent. It also allows the robots to perform several functions like a human being.
Some commonly used sensors along with their principle and applications are explained as follows:
#1 Light Sensor
A Light sensor is used to detect light and create a voltage difference. Photoresistors are widely used light sensors whose resistance varies with change in light intensity; more light leads to less resistance and less light leads to more resistance
Automatic Solar Tracker project is developed using the same sensor.
#2 Proximity Sensor
This sensor can detect the presence of a nearby object within a given distance, without any physical contact and working principle of a proximity sensor is very simple - Transmitter transmits an electromagnetic radiation or creates an electrostatic field and a receiver receives and then analyzes the return signal for interruptions.
Infrared (IR) Transceivers
An IR LED transmits a beam of IR light and if it finds an obstacle, the light is simply reflected back which is captured by an IR receiver. Few IR transceivers are also be used for the measurement of distance.
Ultrasonic Sensor
These sensors generate high-frequency sound waves; the received echo suggests an object interruption. Ultrasonic Sensors can also be used for distance measurement.
Photoresistor
As discussed earlier, photoresistor is a light sensor but, it can still be used as a proximity sensor. When an object comes in close proximity to the sensor, the amount of light changes which in turn changes the resistance of the photoresistor. This change can be detected and then processed.
Projects like Sensor Guided Robotics, Maze Solver Robot and 7 Robots (Combo Course) are developed using IR Sensors.
#3 Accelerometer
An accelerometer is an electromechanical device used to measure acceleration forces. Such forces may be static, like the continuous force of gravity or, as is the case with many mobile devices, dynamic to sense movement or vibrations. Smartphones and other mobile technology identify their orientation through the use of an accelerometer.
Gesture based Robot project is developed using the Accelerometer sensor.
#4 Temperature Sensor
Temperature is the most common of all physical measurements. We have temperature measurement-and-control units, called thermostats, on our home heating systems, refrigerators, air conditioners, and ovens.