How to wire the ultrasonic transducer sensor and ultrasonic transducer sensor ranging

How to wire the ultrasonic transducer sensor and ultrasonic transducer sensor ranging

How to wire the ultrasonic sensor

The wiring method of the piezoelectric ultrasonic transducer is related to the output. The output method of the ultrasonic sensor has 4-20Ma/0-10V analog output and NPN/PNP switch output. The line of the ultrasonic sensor is a five-core line, and the colors of the lines are brown, blue, black, white, and gray. The brown wire is generally connected to DC24V, the blue wire is generally connected to 0V, the black wire is generally connected to the corresponding output mode, the white wire is generally connected to the setting input, and the brown wire is generally connected to synchronization.

4-20Ma analog output connection mode: brown wire connects to 24V voltage, blue wire connects to 0V, black wire connects to current, white wire connects to setting input wire, gray wire does not need to be connected.

0-10V analog output wiring mode: brown wire connects to 24V voltage, blue wire connects to 0V, black wire connects to voltage, white wire connects to setting input wire, gray wire does not need to be connected.

NPN switch output wiring mode: brown wire connects to 24V voltage, blue wire connects to 0V, black wire connects to NPN, white wire connects to the setting input wire, and gray wire does not need to be connected.

The wiring method of PNP switch output: brown wire connects to 24V voltage, blue wire connects to 0V, black wire connects to PNP, white wire connects to setting input wire, and gray wire does not need to be connected.

Ultrasonic sensor ranging measurement

In daily production and life, ultrasonic range transducer is mainly used in the reversing radar of automobiles, and automatic obstacle avoidance of robots, construction sites and some industrial sites such as: liquid level, well depth, pipeline length, etc., which require automatic non-contact ranging occasion. There are currently two commonly used ultrasonic ranging solutions. One is the ultrasonic ranging system based on single chip microcomputer or embedded equipment, and the other is the ultrasonic ranging system based on CPLD (ComplexProgrammableLogicDevice). To understand the related application design of ultrasonic ranging sensors, we must first understand

The working principle of ultrasonic sensor ranging.

Working principle of ultrasonic sensor ranging

Ultrasonic sensors are sensors that convert ultrasonic signals into other energy signals (usually electrical signals). Ultrasound refers to a mechanical shock wave generated in an elastic medium with a frequency greater than 20kHz. It has the characteristics of strong directivity, slow energy consumption, and relatively long propagation distance, so it is often used for non-contact ranging measurement. Because the ultrasonic wave has a great ability to penetrate liquids and solids, especially in solids that are opaque to sunlight. When the ultrasonic wave hits the impurity or the interface, it will produce a significant reflection to form an echo, and it can produce a doppler effect when it hits a moving object. Therefore, ultrasonic ranging sensor has better adaptability to the environment. In addition, ultrasonic measurement can be a good compromise in real-time, accuracy, and price.

At present, there are many methods of 200Khz ultrasonic transducer sensor: such as round-trip time detection method, phase detection method, and acoustic wave amplitude detection method. The principle is that the ultrasonic sensor emits a certain frequency of ultrasonic waves, propagated by the air medium, and reflects back after reaching the measurement target or obstacle. After the reflection, the ultrasonic receiver sensor receives the pulse. The time experienced is the round-trip time. The round-trip time is related to the propagation of ultrasonic waves. The distance of the journey is related. Test the transmission time to get the distance, for example:

Assuming that s is the distance between the measured object and the rangefinder, the measuring time is t/s, and the ultrasonic propagation velocity is expressed by v/m·s-1, then the relationship (1) s=vt/2 ( 1) In the case of high accuracy requirements, it is necessary to consider the influence of temperature on the ultrasonic propagation speed, and the ultrasonic propagation speed should be corrected according to formula (2) to reduce the error.

v=331.4+0.607T (2) In the formula, T is the actual temperature in ℃, and v is the propagation velocity of the ultrasonic wave in the medium in m/s.