Sensors

Sensors

Introduction

Sensors are being used in almost every new technology and are playing the main and important role in the development of the modern and advanced world. Sensors convert physical energy like room temperature, pressure, light etc into an electrical signal that can be measured. The converted physical parameter into electrical signal is feed to the microprocessor or computer in order to manipulate, analyze and then display it (Nnaji, 1993). Hundreds of millions sensors are manufactured each year. These sensors are used in every sector of technology. Sensors are being used in medical equipments, domestic appliances, industrial control systems, aircraft, air conditioning systems, toys and satellites. In short, any technological advancement is incomplete without the use of sensors (Nnaji, 1993). Accuracy and low cost are the major factors that are focused while manufacturing the sensors. There are different sensors that are available for converting different physical parameters. Some sensors include: temperature sensors, strain gauges, nanotechnology enabled sensors, optical sensors, biosensors, motion and position sensors, pressure sensors, humidity sensors etc.

There are many important features that are necessary to consider while manufacturing and fabricating the sensors. These features are listed below:

Environmental conditions (sensors does have limitations for humidity/temperature)

Accuracy (Nnaji, 1993)

Range (limit of the sensor's measurement)

Cost

Resolution (sensitivity of the sensor or smallest change that sensor can detect)

Calibration (readings change with time thus calibration is necessary for measuring devices)

Repeatability (ability of repeatedly measuring the reading that is varying) (Nnaji, 1993)

Internal detection sensors

Internal sensors are used in automation of the robot. Internal detection sensors collect and gather all the information regarding the internal environment of the robot. Internal detection sensors control and measure each and every parameter of the robot's internal environment. Although, the measurements of the internal environment contain some noise and errors thus the information collected by the internal sensors is not entirely constant and perfect according to the real situation. Some deviations exist in the measurements of internal detection sensors (Nnaji, 1993).

Internal detection sensors possess some memory for remembering the general picture and measurement of the parameters of internal environment inside the robot in a certain span of time. Internal detection sensors are installed in the joints of the robot which are meant to measure the present velocity and position of the specific link or joint of the robot. Internal detection sensors within the robot are used to measure parameters like how much robot has traveled, battery drain and charge, how much the robot has rotated and so on (Nnaji, 1993).

Internal sensors are of two types analog and digital. By the help of encoders, digital measurement of velocity and position is accomplished. These signals are then feed to the microprocessors or microcontrollers in order to control and measure these parameters. In case of generated analog signal, signal is to be converted into the digital signal in order to make it compatible with microcontroller or microprocessor. Digital encoders are present in absolute and incremental forms, and can have either a magnetic detector or light detector, and are available in rotary as well ...