Method for reducing residual vibration of ultrasonic sensor, ultrasonic chip and ultrasonic device

Abstract

The invention discloses a method for reducing residual vibration of an ultrasonic sensor, an ultrasonic chip and an ultrasonic device.The method for reducing the residual vibration of the ultrasonic sensor can adopt a first scheme or a second scheme, the first scheme comprises the following steps that S1, an AD module is used for sampling amplitudes of n sampling points of the residual vibration of the ultrasonic sensor for the first time, and n is a natural number; then outputting voltage values with the same amplitude but opposite phases by using a DA module to offset and compensate the n sampling points of the first time; s2, sampling amplitudes of n sampling points for the second time by using the AD module, and then outputting voltage values with the same amplitude but opposite phases by using the DA module again to offset and compensate; s3, repeating the steps S1 and S2 until the residual vibration value is within a required range; according to the second scheme, after ADC sampling, the DAC is directly controlled to output signals with the same value but opposite phases to the ultrasonic sensor. According to the invention, the residual vibration can be obviously reduced, and the jump is obviously reduced.

Description

technical field [0001] The invention relates to the technical field of sensing and information processing, in particular to a method for reducing residual vibration of an ultrasonic sensor, an ultrasonic chip and an ultrasonic device. Background technique [0002] Ultrasonic sensors have many applications in various fields. For example, in detecting liquid levels, ultrasonic sensors can detect liquid levels of various liquids, detect transparent objects and materials, control tension and measure distances. In terms of reversing radar, anti-collision systems and Ultrasonic sensors are used in automatic parking assistance systems and ADAS systems. Ultrasonic sensors have a very wide range of applications in reversing radar. [0003] The key component of the ultrasonic sensor is the probe core, that is, the piezoelectric ceramic sheet. The probe core is mechanically bent under the driving of the alternating voltage to drive the air to vibrate, thereby sending out the ultrasoni...

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Problems solved by technology

[0007] 1. The residual amplitude value of each sensor is different due to discrete reasons, but the compensation pulse amplitude is fixed, so it is impossible to take into account the situation of all sensors, that is, it is impossible to fully compensate all sensors, and the compensation effect is slightly different for each sensor , large discreteness;

[0008] 2. After vibration, the front pulse amplitude is generally large and the rear pulse amplitude is small, but the compensation pulse amplitude is fixed, so the compensation amplitude of the front pulse may not be enough, and the compensation amplitude of the rear pulse is too high, and it is impossible to make good compensation for both front and rear pulses;

[0009] 3. The condition of the previous pulse after aftershock often affects the change of the following pulse. With fixed pulse compensation, it is impossible to predict how the next pulse will change after the previous pulse is compensated. However, the same compensation pulse is still used to compensate, which is a bit blind. ;

[0010] 4. Since the amplitude of the aftershock stage is generally relatively small, and the amplitude of the compensation pulse is fixed throughout, generally only the first few pulses are compensated, and the latter aftershock pulses with small amplitudes are generally not compensated, but these pulses are still after all. part of the vibration, so that the residual vibration cannot be fully compensated, that is, some residual vibration pulses are not compensated, that is, the residual vibration will only have a quantitative change, and cannot produce a sudden reduction change;

[0011] 5. From the above points 1 to 4, it can be seen that there are cases where the compensation is too much or the compensation in the front section is good but the compensation in the back section is not in place, see figure 2 As shown, such a consequence may be sharpening, that is, the overcompensated compensation pulse or the undercompensated after-vibration is mistakenly identified as an obstacle signal and falsely reported. The effect is counterproductive. In reality, many people lack experience in this area. people have suffered from this

[0012] In summary, this aftershock compensation method will only improve, but cannot produce significant reduction changes

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