Transducers, Sensors, Location, and Navigation
The Global Positioning System (GPS) is a network of radiolocation/radionavigation apparatus that operates on a worldwide basis. The system employs several satellites, and allows determination of latitude, longitude, and altitude. All GPS satellites...
Epipolar navigation is the optoelectronic counterpart of human spatial perception. Epipolar navigation works by evaluating the way an image changes as viewed from a moving perspective. Suppose that you are piloting an aircraft over...
When conventional position sensors do not function in a particular environment for a mobile robot, a fluxgate magnetometer can be used. This system employs sensitive magnetic receptors and a microcomputer to sense the presence...
A simple direction-finding scheme (A) and an ultrasonic direction finder (B) A radio receiver, equipped with a signal-strength indicator and connected to a rotatable, directional antenna, can be used to determine the direction from...
At A, a block diagram of medium-range sonar system. At B, a sonar system can be confused by long delays. A machine or vessel can find its geographical position by comparing the signals from...
Sonar is a medium-range method of proximity sensing. The acronym derives from the words sonic navigation and ranging. The basic principle is simple: Bounce acoustic waves off of objects, and measure the time it...
A radar display. The light radial band shows the azimuth direction in which the microwave beam is currently transmitted and received. (Not all radar displays show this band.) The term radar is derived from...
A sensor employs one or more transducers to detect and/or measure phenomena such as temperature, humidity, barometric pressure, texture, proximity, and the presence of certain substances. Capacitive Pressure Sensor A capacitive pressure sensor. When...
A displacement transducer measures a distance or angle traversed, or the distance or angle separating two points. Conversely, it can convert a signal into movement over a certain distance or angle. A device that...
In electronics, wave transducers convert ac or dc into acoustic or electromagnetic (EM) waves. They can also convert these waves into ac or dc signals. Dynamic Transducer for Sound A dynamic transducer is a...