Sensors in robotics

In robotics sensors are very important device. We can not think any intelligent robot without sensor. In robotics different types of sensors are used. A sensor is a transducer used to make a measurement of a physical variable. A good sensor mast have some important characteristics. Here we discuss five of them.

•  Range: This refers to the minimum and maximum change in input signal to which the sensor can respond. The sensor should possess a wide operating range.
•  Response: The sensor should be capable of responding to changes in the sensed variable in minimum time. Ideally, the response should be instantaneous.
• Accuracy: The accuracy of the measurement should be as high as possible. The output of the sensing device should properly reflect the input quantity being measured or sensed.
•   Sensitivity: It refers to the change in the output exhibited by the sensor for a unit change in input. The sensitivity should be as high as possible.
•  Linearity The sensory device should exhibit the same sensitivity over its entire operating range.

There are some other consideration to function sensory device properly. For example, The device should not disturb or have any effect upon the quantity it senses or measures. The device should be suitable for the environment in which it is to be employed. Ideally, the device should include isolation from receiving excess signals or electrical noise that could give rise to the possibility of miss operation or damage of the sensor, circuit or system. Also important are the physical size, cost and ease of operation.

Sensors in robotics may be broadly classified as contact and non-contact sensors. As the name implies, the former class of sensors respond to physical contact, such as touch, slip, force and torque. Non contact sensors on the other hand rely on the response of a detector to variations in acoustic or electromagnetic radiation. The most prominent examples of non-contact sensors are range, proximity, and vision sensors.