What is an ultrasonic sensor?
What is an ultrasonic sensor?
Ultrasonic sensors are electronic devices that measure the distance of a target object by sending out ultrasonic waves and converting the reflected sound into electrical signals. Basically, the sensor uses a transducer to send and get ultrasonic pulses, which in turn return information about the object's proximity. Remarkably, these ultrasound waves travel faster than audible sound. That is, these sensors emit sound waves at frequencies higher than the range of human hearing.
Ultrasonic sensors have two key components: a transmitter that emits sound using piezoelectric crystals, and a receiver that picks up the sound after it arrives and leaves the target.
How does the ultrasonic sensor work?
As mentioned earlier, the ultrasonic sensor first emits high-frequency sound waves. The transducer acts as a microphone here, sending ultrasonic pulses/sounds and receiving echoes. The sensor then extrapolates the distance to the target by measuring the time interval between the ultrasonic pulse being sent and received.
In other words, it calculates distance by measuring the time it takes for sound to travel from the transmitter to contact with the receiver. The formula is D =½T x C(where D is the distance, T is the time, and C is the speed of sound about 343 m/s). For example, if an ultrasonic sensor is aimed at a toy and it takes 0.025 seconds for the sound to bounce, then the distance between the ultrasonic sensor and the toy is:
D= 0.5 x 0.025 x 343 meters or about 4.2875 meters.
Therefore, ultrasonic sensors are very useful when it comes to detecting objects. In fact, ultrasonic sensors can detect objects of any color, surface, or material, unless it's a very soft material like wool, which the sensor may not be able to detect because wool absorbs sound. Even the detection of transparent and difficult to see objects, ultrasonic sensors can also detect.
However, to ensure the smooth operation of the sensor, it's important to avoid anything that could interfere. For example, if you are using multiple sensors in an application, you need to connect them in a way that avoids crosstalk or any other interference. It is also important to keep the surface of the ultrasonic transducer free of any obstacles; This will prevent the ultrasonic signal from the sensor from being interrupted. Some common obstacles to look out for include dirt/dust, snow/ice and any other condensation.
Application of ultrasonic sensor
Ultrasonic sensors are currently used in industrial and consumer fields. Their low cost, simple features and rugged construction make them a good bet for new products or services requiring presence detection or distance measurement. In addition, they allow changes to hardware and software configurations, making them more useful and versatile.
The most common applications of ultrasonic sensors are object detection or person detection. As a close range sensor, ultrasonic sensor is very useful in anti-collision detection, presence detection, box sorting and so on. Iot ultrasonic sensors are used for non-contact detection of solid and liquid objects. Another popular use is as a level sensor; They are commonly used for level sensing because these sensors can detect liquids of any color or opacity in a non-contact manner (without even having to come into contact with them).
A more creative way to use ultrasonic sensors is to use the one-way function of the ultrasonic transmitter and receiver separately. Thus, an ultrasonic transmitter can use its transmitter to emit/send sound, for example, to scare away birds, and an ultrasonic receiver can be used for noise detection.
Here are some of the main uses of ultrasonic sensors:
- There are tests
- The sorting box uses an ultrasonic monitoring system powered by multiple transducers
- The counting bottles on the beverage machine
- Forklift pallet inspection
- The analysis was performed using an ultrasonic system
- Cleaning and assembly vehicle inspection
- Level control/tank position control
- Cycle control
- Tension control
- The robot
- Pile height control
- Detect thread or wire breakage
Advantages of ultrasonic sensor
1.not affected by the color of the object
The color of the detected object has no effect on the function of the ultrasonic sensor. Therefore, objects can be any color, even translucent or transparent.
2. More flexibility
Ultrasonic sensors have very flexible minimum and maximum ranges. Most ultrasonic sensors can detect objects close to a few centimeters, up to about five meters. Specially configured modules can detect distances of up to 20 meters.
3. Highly reliable
Ultrasonic sensors have been around for decades, and over the years, this ultrasonic technology has become well established.
4.higher accuracy
Ultrasonic sensors provide relatively accurate measurements, usually within 1%, and even higher accuracy if needed.
5. Better ability
Ultrasonic sensors can be measured many times per second, so the refresh speed is fast.
6. Low cost
7.anti-noise
Ultrasonic sensors are resistant to electrical noise environments and most acoustic noise.
Limitations of ultrasonic sensors
1. It is not immune to temperature changes in the environment
Because the speed of sound varies with temperature and humidity, environmental conditions can interfere with the measurements made by ultrasonic sensors.
2. Other objects are detected without additional information
Ultrasonic sensors only detect the object and distance, but do not share more information about the object's characteristics, its shape, color, or even its position in the perceived area.
3. Not suitable for small embedded projects
Ultrasonic sensors may be small enough to be easily integrated into automotive or industrial applications, but are still too bulky for tiny embedded projects.
4. Regular maintenance is required
Ultrasonic sensors can get dirty, wet or icy, which in turn affects their function. Therefore, regular maintenance is necessary to avoid erratic or non-functional behavior.
5. can not be used in vacuum
Because ultrasonic sensors rely on producing sound and their bounces, they do not work in a vacuum (since sound, in turn, requires some medium to travel).
