Ultrasonic sensor, method for generating ultrasonic wave and application of ultrasonic sensor

Abstract

The invention discloses an ultrasonic sensor, a method for generating an ultrasonic wave and application of the ultrasonic sensor. The ultrasonic sensor comprises a metal casing with an end face at the bottom, wherein an inner cavity is defined in the metal casing; in the inner cavity, a piezoelectric ceramic plate is fixed on the inner bottom surface of the end face; the ultrasonic sensor further comprises an isolating bar arranged in the inner cavity; the isolating bar is connected and fixed on the inner bottom surface and the inner side wall to form a fixed whole body; the piezoelectric ceramic plate is fixed on the inner bottom surface on the two sides of the isolating bar. The invention further provides a corresponding method for generating the ultrasonic wave and the related application. The ultrasonic sensor provided by the invention has the characteristics of a remote ultrasonic sensor and a near field ultrasonic sensor, and can be used for forming a main lobe for remote detection and two minor lobes for near field detection.

Description

Technical field [0001] The invention relates to an ultrasonic sensor, which belongs to the field of distance measurement and signal devices, in particular to an ultrasonic sensor used for distance measurement during car parking and driving. Background technique [0002] Ultrasonic sensors have a wide range of applications, especially in distance measurement and obstacle detection. For example, the reversing radar installed on various cars now generally uses ultrasonic sensors as the signal generation and signal generation and distance measurement for obstacle detection or distance measurement. The receiving element, that is, the ultrasonic sensor is used as the probe of the reversing radar. [0003] The structure of the ultrasonic sensor 1 of the reversing radar commonly used now is as figure 1 , figure 2 As shown, it is mainly composed of a metal shell 10 and a piezoelectric ceramic sheet 20 bonded to the inner bottom surface of the bottom of the cavity (inner cavity 12) of the m...

AI Technical Summary

Problems solved by technology

In general, in order to ensure the performance, the maximum value of the main sound beam is on the normal line of the center of the end face), so that the emission angle of the main sound beam 30 is too small, and the obstacles 401 within a short distance l (0m≤l≤1.5m) cannot be detected detected (that is, the range is its dead zone)

With the development of technology, the requirements of the car factory for the detection range are gradually increasing. It is required to detect both long-distance obstacles and short-distance obstacles, but the existing technology cannot meet the requirements.

[0004] At present, very few reversing radars have the function of detecting short-range and long-distance respectively. They use two sets of ultrasonic sensors, which are respectively used to detect long-distance and short-distance ultrasonic sensors. However, this method increases the number of parts and The cost of assembly, and it is not easy to install, generally need to change the installation space of the original car, such as the adjustment of the installation hole of the bumper, so that the car manufacturer needs to improve the design; in addition, due to this, for the existing The refitting of the car is also a difficult problem, otherwise the original aesthetics of the car will be sacrificed as the price

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