Ultrasonic level gauge in use, there are potential problems?

The ultrasonic level gauge is simple to use, easy to use and low in cost. However, the current ultrasonic level gauges have some disadvantages, such as reflection problems, noise problems and crossover problems.

Reflection problem

If the object being probed is always at the right angle, the ultrasonic level gauge will get the correct angle. Unfortunately, in actual use, very few objects to be detected can be correctly detected. There may also be errors.

Mirror reflection

The problem is the same as the reflection of light in high school physics. At a specific angle, the emitted sound is specularly reflected by a smooth object so that no echoes can be produced and distance readings can not be produced. At this time ultrasonic sensor will ignore the existence of this object.

Triangular error

When the measured object and the sensor at an angle, the detected distance and the actual distance has a triangular error.

4. Multiple reflections

This phenomenon is more common in the detection of objects in the corner or similar structures. The sound wave is received by the sensor after several bounces, so the actual sounding value is not the true distance value. These problems can be solved by using multiple satellites arranged at an angle. By detecting multiple ultrasonic return values, used to filter out the correct readings.

5. Noise

Although the majority of ultrasonic liquid level gauge working frequency of 40-45Khz, far higher than the human can hear the frequency. But the surrounding environment also produces a similar frequency of noise. For example, the motor will produce a certain high frequency during rotation, the high frequency noise generated by the rubbing of wheels on relatively hard ground, the jitter of the robot itself, and even when there are multiple robots, the sound waves emitted by other robot ultrasonic sensors , These will cause the sensor to receive the wrong signal. This problem can be solved by encoding transmitted ultrasonic waves, such as transmitting a set of sonic waves of different lengths, and only calculating the distance when the probe detects the same combination of sonic waves. This can be effectively avoided due to environmental noise caused by misreading.

Cross-cutting issues

The crossover problem is caused when multiple ultrasonic level gauges are mounted on a robot at a certain angle. The sound waves emitted by the ultrasonic X are specularly reflected and acquired by the sensors Z and Y. At this time, Z and Y calculate the distance value from this signal so that the correct measurement can not be obtained. Do you know the potential problems with these ultrasonic level gauges?