10 Things You Should Know about Radar

Radar sensors ensure appropriate fill levels in a hopper are maintained to keep production moving. When materials such as grain or concrete mix are loaded into a hopper, dry and dusty particles fill the air. Dust will cause many optical sensors to suffer signal loss, while ultrasonic devices may give incorrect readings if debris builds up on the sensor. Radar waves, on the other hand, pass through the airborne particles to accurately measure the hopper levels.

Someone working a drive-thru window at a restaurant, bank, or pharmacy needs to respond quickly when a customer arrives. A K50R radar sensor can detect cars in snow, rain, fog, or sunlight—conditions that may cause false or no detection when using other sensing technologies. Quick and efficient vehicle recognition lets businesses analyze traffic patterns and eliminate bottlenecks, minimizing wait times and ensuring timely service. 

Extreme temperature swings, fog, steam, and water spray inside an automated car wash can make detecting a vehicle’s position problematic, even by commonly used ultrasonic sensors. Temperature variations can affect the speed of ultrasonic sound waves, which may result in false vehicle location information. Noise from equipment and changing air currents inside a wash may also interfere with ultrasonic sensors’ ability to accurately detect the edges of a vehicle. However, a single T30RW radar sensor configured for retroreflective mode can reliably determine a vehicle’s position, telling the wash system to turn each section on and off at the correct times. This makes the process more efficient by saving water and cleaning agents, prevents equipment from contacting and damaging vehicles, and ensures a high-quality wash.

In an automotive assembly plant, the leading edges of car bodies need to be detected so they can be correctly positioned in a paint tunnel. The surface may be unpainted, matte, or glossy, so they can be difficult for optical sensors to accurately recognize because the shiny, angled surface can reflect light away from the sensor’s receiver. 

Radar sensors, such as Banner’s T30R series, can identify objects that have uneven surfaces; are glossy, reflective, matte black, or any other color; or have mirrors or windows. This allows the T30R radar sensor to reliably detect the position of each body on the line, then send this location information to the robotic arms’ controllers so they know where to find each part.

By detecting any objects on the assembly line regardless of color, shape, or reflectivity, production can continue with less downtime.

Some radar sensors operate at a lower frequency, such as the QT50R which emits waves at 24 GHz. Others use a higher frequency, including the T30R which operates at 122 GHz. Then there are those, like the K50R, which operate somewhere in the middle at 60 GHz. Whether low, high, or in between, each of these frequencies has their benefits.

Most useful for detecting large objects that are far away, a lower-frequency 24 GHz sensor produces long wavelengths. Long-range detection and an ability to ignore ambient weather like heavy rain or snow make it the most effective outdoor sensing solution. Conversely, a higher-frequency 60 GHz or 122 GHz sensor produces shorter waves which can detect smaller objects, deliver superior accuracy, and are able to sense a wider range of dielectric materials.  

Monitoring liquid levels in tanks has often required a sensor mounted inside the tank. However, sometimes an external sensor solution is preferred, especially if direct contact with the liquid could damage or adversely affect the sensor. With their ability to penetrate most plastic and glass, radar sensors can be installed outside tanks where they are easier to mount and maintain.

A T30R radar sensor can be installed on a plastic tank’s outer wall or a metal tank’s sight glass. The sight glass or tank may be dusty or dirty, the plastic may be opaque, or the material inside the tank may be shrouded in mist. Even if the liquid has an uneven surface or is stored under pressure or in a vacuum, the high-frequency microwaves pass through the plastic or glass to measure the liquid level inside. When connected to an illuminated indication system, personnel can be visually alerted to the tank’s fluid level. 

To recognize vehicles entering an auto repair bay, K50R radar sensors can be mounted under heavy-duty plastic, flush-mounted with the driving surface. The radar waves penetrate dirt and debris left behind by vehicles on the repair bay’s floor and detect cars as they pull in. As part of an indication system, these sensors can let employees know a customer has arrived so they can quickly greet the customer, minimizing wait times and improving check-in efficiency.

A busy rail yard is a large-scale dynamic work environment with numerous operations occurring simultaneously. Vehicles and rail cars of different shapes and sizes, moving at varying speeds on and around multiple tracks, and carrying myriad types of materials present a serious object detection challenge. 

Trains consist of locomotives and a wide assortment of rolling stock including boxcars, flatbeds, hoppers, tankers, and more. Being able to track numerous trains and types of cargo on trailers at different distances, even while they are moving, can be handled by a radar sensor like the Q130R. The ability to detect both moving and stationary targets makes FMCW radar a more reliable solution than Doppler radar, which is only able to detect moving targets. 

Despite dust swirling around the yard or dirt building up on the Q130R sensor, the radar signal can still detect objects up to 40 meters away. The radar sensor can be set to ignore trains parked in the background on one track while recognizing other trains as they pass in front, triggering RFID antennas so operators know the precise locations of cargo in the yard. The long-range detection afforded by radar sensors, plus radar’s ability to ignore ambient weather conditions and airborne dust and dirt, make it an ideal rail yard solution.