Choosing the right distance sensor for your application
ULTRASONIC DISTANCE SENSORS
An ultrasonic distance sensor measures proximity by emitting high-frequency soundwaves and recording the time elapsed before an echo reflects to the transducer. The time taken for the specific frequency to return to the signal transducer is known as the round trip time; the total distance traveled from the ultrasonic emitter to the object and back. To determine proximity to an object, the ultrasonic distance sensor multiplies the roundtrip time by the speed of sound – approximately 1129 feet per second (f/s) in ambient conditions – and halves the calculation.
BENEFITS OF ULTRASONIC DISTANCE SENSORS:
DRAWBACKS OF ULTRASONIC DISTANCE SENSORS:
IR TRIANGULATION DISTANCE SENSOR
Distance sensors equipped with IR light-emitting diodes (LEDs) often operate on the principle of triangulation: calculation of distance according to the angle of a reflected IR beam off a surface. When the LED focuses a beam of light on a surface, that light is reflected in all directions. A distance sensor adjacent to the LED source acquires a reflected signal and an integrated charge-coupled device (CCD) chip defines the angle of reflection to calculate distance.
BENEFITS OF IR TRIANGULATION DISTANCE SENSORS:
DRAWBACKS OF IR TRIANGULATION DISTANCE SENSORS:
LASER DISTANCE SENSORS
Proximity sensing with monochromatic laser light typically utilizes a laser source with integrated optics to measure the time taken for a narrow beam of pulsed light to reach an object and reflect to the sensor. The basic principle of this is known as Time-of-Flight, though laser distance sensors can adopt a choice of different measuring principles (phase comparison, etc.).
BENEFITS OF LASER DISTANCE SENSORS:
DRAWBACKS OF LASER DISTANCE SENSORS:
IR TIME-OF-FLIGHT DISTANCE SENSOR
A novel solution to the limitations of laser rangefinders, IR Time-of-Flight distance sensors measure proximity using an IR-LED according to the time-of-flight principle. This has numerous benefits with very few drawbacks, namely faster transmission-reception times, long-range (<60 meters), rapid refresh rates, fixed FOV, lower power consumption, and plug-and-play support for multi-sensor integration. While there is no one distance sensor for every application, IR time-of-flight provides the broadest range of KPIs for proximity sensing in indoor environments and specific outdoor environments.