Self-focusing ultrasonic transducer, floor mopping robot and acoustic impedance calculating method

Abstract

The invention discloses a self-focusing ultrasonic transducer, a floor mopping robot and an acoustic impedance calculating method. The self-focusing ultrasonic transducer comprises a supporting piece,a cross-linked polypropylene piezoelectric electret film, a shielded wire and a silver skin. A concave spherical surface is disposed at the bottom of the supporting piece. An annular flat surface isdisposed on the periphery of the concave spherical surface in a surrounding mode. A connecting joint is disposed at the upper end of the supporting piece. The upper surface and the lower surface of the cross-linked polypropylene piezoelectric electret film are each printed with conductive silver paste, and the cross-linked polypropylene piezoelectric electret film covers the interior of the concave spherical surface. One end of the shielded wire is connected with the edge of the lower surface of the cross-linked polypropylene piezoelectric electret film, and the other end of the shielded wireis connected with the connecting joint to serve as a positive electrode. The silver layer is plated on the surface of the supporting piece, and the upper surface of the cross-linked polypropylene piezoelectric electret film is connected with the connecting joint through the silver film to serve as a positive electrode. The self-focusing ultrasonic transducer can realize self-focusing of acoustic energy, recognize and detect acoustic resistance of reflectors, recognize different materials of the reflectors, and control the robot to be switched into different working modes according to the different materials.

Description

technical field [0001] The invention relates to the technical field of sweeping robots, in particular to a self-focusing ultrasonic transducer, a sweeping robot and an acoustic impedance calculation method. Background technique [0002] Sweeping robots are becoming more and more popular in society due to their efficient and intelligent cleaning methods. Sweeping robots generally use brush sweeping and vacuum methods to absorb ground debris into their own garbage storage boxes, thereby completing the function of ground cleaning. In addition, some sweeping robots are equipped with water tanks to complete the mopping function. When cleaning, if it encounters a carpet, it will change the walking path of the sweeping robot to avoid damage to the carpet. Therefore, it is necessary to detect floor materials such as carpets. [0003] At present, in the prior art, the carpet detection method of the sweeping robot is to judge whether there is a carpet according to the change of the...

AI Technical Summary

Problems solved by technology

Existing research on air-coupled ultrasonic transducers, for example, patent ZL201721476404.3 provides a self-focusing ultrasonic transducer structure, but this patent uses a piezoelectric ceramic chip as a vibration element, which has a narrow bandwidth and is fragile and easy Broken materials need to be finely processed before they can be made into a curved surface to achieve focusing

Patent ZL201811191335.0 provides a structure based on point-focused air-coupled ultrasonic transducers. This patent uses porous polypropylene ferroelectret film as a vibration element, which is glued on a curved metal backing to achieve focusing, but the metal backing The curved surface is made by fine machining of machine tools, which is difficult to make and cannot be designed

Images