Ultrasonic Sensors Ultrasonic Sensors for Object Detection
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Ultrasonic Sensors Ultrasonic sensors for object detection Regardless of color and surface properties BUS ultrasonic sensors can be used universally and are perfect for distance measurement or position detection of granular materi- als, liquids and powders. They measure fill levels, heights and sag without making contact as well as count and monitor the presence of objects. They do this regardless of color and surface properties. Therefore transparent objects that generate strong reflections pose no problem for them. As precision all-rounders, ultrasonic sensors are particularly suited for critical situations. Dust, dirt and steam do not impair them. Broad detection range – high precision Their detection range extends from 20 mm to 8 m, meaning that even longer object distances can be handled without problem. Their high resolution and small blind zones ensure extreme precision. Integrated synchronization means that the sensors do not interfere with one another. Switching and analog variants BUS ultrasonic sensors differ form one another in their output signal. Each series is available as a switching or analog version, whereby all analog versions are available with voltage or current output (0…10 V or 4…20 mA). The BUS M30 includes variants with two switching outputs, one switching and one analog output or two switching outputs and one analog output so that one sensor can adopt the function of a second sensor. IO-Link BUS 18M sensors with push/pull output are equipped with an IO-Link interface that enables a change from SIO mode to IO-Link mode. 402 Ultrasonic Sensors Contents Media 404 Industries, application areas 405 Application areas, sensor selection 406 Modes 407 Sound cones 408 Cylinder Designs BUS M30 410 BUS M18, BUS W18 418 BUS M12 434 Block Designs BUS R06 428 BUS Q80 436 Accessories for Ultrasonic Sensors 438 Basic information and definitions can be found on page 952. ■ www.balluff.com 403 Ultrasonic Sensors Media The all-rounders, even for difficult environments Because the distance to the object is de- value with resolution that is precise to the thin films, transparent materials and different termined via a sound transit time, ultrasonic millimeter. Some sensors to even 0.025 mm. colors. Thin deposits on the sensor mem- sensors have excellent background suppres- The sensors are able to measure in dusty brane do not affect sensor function. sion. With their travel time measurement, air or through paint spray mist. They detect ultrasonic sensors can record the measured nearly all materials that reflect sound. Even Colors Transparent layers Surfaces of bulk materials Red, green, yellow or blue—all make no Glass plates, Plexiglas and razor thin foils — Fine sand, shavings or coarse-grained mate- difference to Balluff ultrasonic sensors: They BUS ultrasonic sensors reliably detect trans- rials—in the areas of fill-level measurement, reliably detect all colors. parent layers. our ultrasonic sensors are ideal. Contrasts Liquids Material surfaces Black objects against a black background or Clear water, cloudy liquids, oils or black cof- Whether velvet, wool or leather—nearly all white on white—even with weak contrasts, fee — ultrasonic sensors can be used with clothing materials can be reliably detected our BUS ultrasonic sensors measure achieve nearly any liquid. The liquid surface should with our BUS ultrasonic sensors. the best results. have no foam. 404 Ultrasonic Sensors Industries, Application Areas BUS ultrasonic sensors are particularly well suited for the following industries ■ Handling and automation ■ Commercial vehicles ■ Specialty machine construction ■ Scales ■ Automotive industry ■ Agricultural machinery ■ Bottling and packaging ■ Food processing machinery ■ Pharmaceutical industry ■ Office and information technology ■ Plastic and rubber industry ■ Construction and ■ Timber and furniture industry building material machinery Ultrasonic ■ Paper and printing industry ■ Textile machinery Sensors ■ Conveyor technology Media Industries Application Areas Sensor Selection Operating Modes Sound Cones Cylinder Designs Block Designs Accessories for Ultrasonic Sensors Handling and automation Bottling and packaging Automotive industry Ultrasonic sensors can be used in many application areas Detection of people Foil tear monitoring Height and Presence verification Robot positioning If people need to be Ultrasonic sensors with width measurement BUS detect filled or Due to their small dimen- detected, a sensor switching output can Through the use of empty pallets and sions, BUS sensors are should be used that has be used for foil tear multiple BUS M30 or measure the content of ideally suited for exactly an operating scanning monitoring. If large waves BUS _18M ultrasonic transport containers. If a positioning robot arms: range that is considerably are formed in the foil, sensors, three-dimen- box or a container is to BUS_18M ultrasonic greater than the required the sensor should be sional measurements can be inspected with multiple sensors in a threaded measurement distance. operated as a diffuse be made for everything sensors, they can be sleeve and BUS R06K in The greater the operating reflective sensor. This from small boxes to large synchronized with each a block-shaped housing. scanning range, the lower operating mode functions cartons. other. the ultrasonic frequency. reliably even if the sound And the better absorbent is reflected by waves in pieces of clothing, such the foil. as wool, can be detected. Other applications on the next page ■ www.balluff.com 405 Ultrasonic Sensors Application areas, sensor selection Positioning Wire-breakage Stack-height detection Fill-level monitoring Object detection When scanning glass monitoring Whether wooden boards, In silos, bunkers, contain- BUS ultrasonic sensors plates or other smooth When winding and glass plates, paper or ers – for all bulk materials sort containers and parts and flat surfaces, make unwinding a wire rope, color plastic plates, BUS (e.g., sand, gravel, coal, with different heights. certain that the ultra- ultrasonic sensors with ultrasonic sensors mea- grain), our ultrasonic sen- BUS count objects. And sound strikes the surface analog output detect its sure stack heights with sors are ideal. with absolute reliability. at a right angle. position on the layer. high precision. Sensor selection Important selection criteria for an ultrasonic sensor are its sensing distance and the associated, three-dimensional detection range. Definitions ■ Blind zone The blind zone defines the smallest reliable scanning range of the sensor. There must be no objects or interfering reflections within Detection range the blind zone, as measurement errors may otherwise occur. ■ Operating scanning range The operating scanning range is the typical working range of a sensor. ■ Limiting scanning range 0 For objects with good reflective properties, the sensor can also be Object used up to its limiting scanning range. Blind zone Operating scanning range ■ Detection range Limiting scanning range The detection range is measured using various standard reflec- tors. Detection ranges The red areas are measured with a thin round rod (Ø 10 mm or 27 mm, depending on sensor type) and show the typical working range of a sensor. To obtain the blue areas, a plate is moved into the sound fields from the side. In doing so, the optimum angle of the plate to the sensor is set. This is thus the maximum detection range of the sensor. It is not possible to evaluate ultrasound reflections outside of the blue sound cones. 406 Ultrasonic Sensors Operating modes The classic operating mode of the ultrasonic sensor is as a re- flective light scanner. Compared to other sensor principles, it has Switching output Switching output superior background suppression. During operation, the switching set not set output is set as soon as the object is located within the set switch- ing distance. The switching point has a hysteresis. The operating mode is suitable for, e.g., counting objects on a conveyor belt or for performing presence verification. Set switching distance Ultrasonic Sensors Media The ultrasonic sensor in window mode is an extended function Industries Switching Switching Application of the ultrasonic reflective light scanner. In this case, the switching output Switching output output Areas not set set not set output can only be set if the object is located within a window that Sensor is defined by two window limits. This can be used to monitor, e.g., Selection Operating the correct bottle size in a bottle crate. Bottles that are too tall or too Modes short are sorted out. Window mode and the diffuse reflection ultra- Sound Cones sonic sensor can be set on all ultrasonic sensors that are equipped Cylinder with teach-in. Designs Block Designs Set window Accessories for Ultrasonic Sensors The function of the diffuse reflection ultrasonic sensor is similar to that of a photoelectric sensor. Any reflector, such as a metal sheet, is sufficient. In window mode, the ultrasonic sensor is set so Switching output set that the permanently mounted reflector lies within the window. The ultrasonic sensor returns a signal as soon as an object fully covers the reflector. It plays no role here whether the object completely absorbs or reflects away the sound. This operating mode is therefore used for materials than can be only poorly reflected, such as foam, or for scanning objects with irregular surfaces. Set Reflector window Ultrasonic sensors with analog output output the measured dis- tance value as a voltage that is proportional to distance (0...10 V) or Linear output as current that is proportional distance (4...20 mA). For the ultrasonic 20 mA sensors with analog output, the sensor-near and sensor-distant 4 mA window limits of the analog characteristic as well as a rising or falling characteristic can be set. Depending on the sensor type and window width, the resolution is between 0.025 mm and 0.36 mm. Set analog window Ultrasonic sensors with IO-Link enable gapless communication through all levels of the system architecture: from the sensor to the top fieldbus level. Transmission of the measured distance value to Digital measurement value output the controller is bit serial.