A method, device, equipment and medium for sensing foreign matter based on surface acoustic waves

Abstract

The present invention relates to a method, device, equipment, and medium for sensing foreign matter based on surface acoustic waves, belonging to the field of foreign matter detection technology. The method includes: driving a signal transmitter via an electrical signal to excite a surface acoustic wave propagating along a surface to be cleaned; the signal transmitter receives the reflected wave and converts it into a first electrical signal; analyzing the first electrical signal to obtain characteristics of the foreign matter on the surface to be cleaned, including: calculating the position of the foreign matter in a first direction based on the propagation time of the first electrical signal; performing a first classification on the first electrical signal based on the position of the foreign matter in the first direction; performing a second classification based on the frequency of the first electrical signal in the first classification result; and calculating the position of the foreign matter in a second direction based on the result of the second classification to confirm the number of foreign matter and the position information of each foreign matter. The present invention improves the intelligence and anti-interference capabilities of the cleaning process.

Description

Technical Field

[0001] The present invention belongs to the technical field of foreign body detection, and in particular relates to a method, device, equipment and medium for sensing foreign bodies based on surface acoustic waves. Background Art

[0002] Transparent glass can be seen everywhere on buildings or vehicles. Due to contact with the outside atmosphere, some foreign matter will inevitably stick to the glass. In order not to affect the field of vision, the foreign matter needs to be cleaned or removed. The windshield of a vehicle is usually wiped with the help of wipers.

[0003] In the existing technology, it is usually determined manually whether to clean the windshield, which increases the probability of dangerous accidents. Some cleaning equipment is also used to clean the surface to be cleaned. For example, the windshield is automatically wiped when the optical sensor determines that there are enough raindrops on the windshield. However, only two wipers can work synchronously, and the optical sensor is greatly affected by the environment. There are technical problems such as insufficient intelligence and poor anti-interference. Summary of the Invention

[0004] In view of the above analysis, the embodiments of the present invention aim to provide a method, apparatus, device and medium for sensing foreign objects based on surface acoustic waves, so as to solve the technical problems of insufficient intelligence and poor anti-interference performance in the prior art.

[0005] The object of the present invention is achieved like this:

[0006] A first embodiment of the present invention provides a method for sensing foreign matter based on surface acoustic waves, comprising:

[0007] The signal transmitter is driven by an electrical signal to excite a surface acoustic wave propagating along the surface to be cleaned, and the signal transmitter receives the reflected wave and converts it into a first electrical signal;

[0008] Analyze the first electrical signal to obtain the characteristics of foreign matter on the surface to be cleaned, including: calculating the position of the foreign matter in a first direction based on the propagation time of the first electrical signal, performing a first classification on the first electrical signal based on the position of the foreign matter in the first direction, performing a second classification based on the frequency of the first electrical signal in the first classification result, and calculating the position of the foreign matter in a second direction based on the result of the second classification to confirm the number of foreign matter and the position information of each foreign matter.

[0009] Furthermore, the foreign body feature also includes a foreign body type, and the foreign body type is output by inputting the first electrical signal of each foreign body into a foreign body type recognition model.

[0010] Furthermore, the surface to be cleaned includes a windshield, the cleaning device includes a wiper, and the signal transmitter and the signal receiver include interdigital transducers.

[0011] Furthermore, the signal transmitter and the signal receiver are arranged relative to each other and have uneven shapes to generate surface acoustic waves of different frequencies.

[0012] Furthermore, it also includes: planning the working mode of the wiper according to the location information of each foreign object, and adjusting the wiping strength of the wiper according to the type of foreign object, specifically including: judging the coverage range of the wiper where the foreign object is located according to the location information of the foreign object, controlling the corresponding wiper to work, controlling the wiping strength of the wiper in levels according to the type of foreign object, and detecting in real time whether there is any foreign object remaining, so as to flush it by linking the water spray device.

[0013] Furthermore, it also includes: dynamically adjusting the working frequency of the wipers according to the number of foreign objects, specifically including: calculating the foreign object density per unit area according to the number of foreign objects, when the foreign object density is less than a first threshold, controlling the wipers to perform intermittent low-frequency wiping; when the foreign object density is greater than the first threshold and less than a second threshold, controlling the wipers to perform continuous low-speed wiping; when the foreign object density is greater than the second threshold, controlling the wipers to perform high-speed continuous wiping.

[0014] A second embodiment of the present invention provides a device for sensing foreign matter based on surface acoustic waves, comprising:

[0015] A signal generation and acquisition module, configured to drive a signal transmitter via an electrical signal to excite a surface acoustic wave propagating along the surface to be cleaned, wherein the signal transmitter receives the reflected wave and converts it into a first electrical signal;

[0016] The foreign body sensing module is used to analyze the first electrical signal to obtain the characteristics of the foreign body on the surface to be cleaned, including: calculating the position of the foreign body in the first direction according to the propagation time of the first electrical signal, performing a first classification on the first electrical signal according to the position of the foreign body in the first direction, performing a second classification according to the frequency of the first electrical signal in the first classification result, and calculating the position of the foreign body in the second direction according to the result of the second classification to confirm the number of foreign bodies and the position information of each foreign body.

[0017] A third aspect of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the method for sensing foreign matter based on surface acoustic waves described in any embodiment is implemented.

[0018] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for sensing foreign matter based on surface acoustic waves as described in any embodiment is implemented.

[0019] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0020] The method for sensing foreign objects based on surface acoustic waves provided by the present invention uses a signal transmitter to excite surface acoustic waves to propagate on the surface to be cleaned, and uses the characteristic that surface acoustic waves will generate reflected waves when encountering foreign objects to detect foreign objects. By analyzing the reflected wave signals, the precise location information and quantity of the foreign objects are obtained, so that the operation of the cleaning equipment can be controlled according to the characteristics of the foreign objects, thereby improving the intelligence and anti-interference ability of the cleaning process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 Flowchart of the method for sensing foreign matter based on surface acoustic waves provided in Example 1 of the present invention;

[0023] Figure 2 Schematic diagram of a device for sensing foreign matter based on surface acoustic waves provided in Example 2 of the present invention;

[0024] Figure 3 A schematic diagram of the electronic device architecture provided in Example 3 of the present invention;

[0025] Figure 4 Schematic diagram of surface acoustic wave propagation provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments disclosed in this disclosure can be combined, separated, interchanged and / or rearranged with each other. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] A specific embodiment of the present invention, as Figure 1 、 4 As shown, a method for sensing foreign matter based on surface acoustic waves is disclosed, comprising the following steps:

[0029] S1. Signal generation and acquisition

[0030] The signal transmitter is driven by an electrical signal to excite a surface acoustic wave propagating along the surface to be cleaned, and the signal transmitter receives the reflected wave and converts it into a first electrical signal.

[0031] For example, assuming that the surface to be cleaned is the windshield of a car, a layer of piezoelectric quartz film with a thickness of 10-50 μm is coated on the surface of the windshield through a magnetron sputtering process. As a surface acoustic wave propagation medium, a signal transmitter is driven by a high-frequency electrical signal to excite surface acoustic waves such as Rayleigh waves, and propagate along the windshield to the signal receiver. If there is no foreign object blocking the propagation direction, the signal receiver can successfully receive the surface acoustic wave. When there is a foreign object blocking the propagation direction, the surface acoustic wave cannot propagate to the signal receiver and is reflected back to the signal transmitter and converted into a first electrical signal.

[0032] In this embodiment, the surface to be cleaned includes a windshield, the cleaning device includes a wiper, and the signal transmitter and signal receiver include interdigital transducers; the signal transmitter and signal receiver are arranged relative to each other and have uneven shapes to generate surface acoustic waves of different frequencies.

[0033] Exemplarily, the signal transmitter and the signal receiver are configured to be thick at the top and thin at the bottom, with an operating frequency of 20-100 MHz, thereby generating surface acoustic waves of different frequencies, which facilitates the subsequent calculation of the location of the foreign object.

[0034] S2. Signal Analysis

[0035] Analyzing the first electrical signal to obtain characteristics of foreign matter on the surface to be cleaned includes:

[0036] S201, calculating the position of the foreign object in a first direction according to the propagation time of the first electrical signal;

[0037] For example, Figure 4 As shown in the figure, the signal transmitter and signal receiver are vertically installed on the left and right sides of the windshield respectively. When the surface acoustic wave is blocked by the foreign object, it forms a reflected wave and propagates back to the signal transmitter. The position of the foreign object in the X direction is calculated based on the time difference between the signal transmitter forming the surface acoustic wave (i.e., the incident wave) and forming the first electrical signal (i.e., the reflected wave), which is expressed as follows:

[0038] ,in, v represents the propagation speed of surface acoustic waves, It represents the time difference between the incident wave and the reflected wave.

[0039] S202, performing a first classification on the first electrical signal according to the position of the foreign object in the first direction, and performing a second classification according to the frequency of the first electrical signal in the first classification result;

[0040] Specifically, after calculating the X-direction position of the foreign object in step S201, first electrical signals with the same X-direction position are preliminarily classified as the same foreign object. However, considering that different foreign objects may have the same X-direction distance from the signal transmitter but different Y-direction distributions, the first classification alone cannot distinguish them, and a second classification is required.

[0041] The second classification process is as follows: based on the first classification, the frequency difference between the first electrical signals in each category is calculated to determine whether the frequency difference is less than a preset threshold. If so, it indicates that they belong to the same foreign object; otherwise, it indicates that they belong to two foreign objects with the same X-direction position but different Y-direction positions.

[0042] S203: Calculate the position of the foreign matter in the second direction according to the result of the second classification to confirm the number of foreign matter and the position information of each foreign matter.

[0043] Specifically, after step S1 obtains the position of each foreign object in the X direction, and step S202 distinguishes the first electrical signals generated by each foreign object, it is necessary to further calculate the position of each foreign object in the Y direction. Specifically, in the second classification results, the average frequency between the first electrical signals with the largest frequency and the smallest frequency in each category is calculated, and then the difference between the average frequency and the maximum frequency of all surface acoustic waves is calculated. According to the corresponding relationship between the difference and the position in the second direction, the position of the foreign object in the Y direction is obtained, thereby accurately locating the foreign object.

[0044] In this embodiment, the foreign body feature further includes the foreign body type, and the foreign body type is output by inputting the first electrical signal of each foreign body into a foreign body type recognition model.

[0045] Specifically, the pre-training steps of the foreign body type recognition model include:

[0046] Collecting samples of reflected wave signals on the surface to be cleaned under conditions of different types of foreign matter;

[0047] Label the foreign body type corresponding to each signal sample based on its frequency distribution and phase change;

[0048] The labeled signal samples are input into the classification model for training to obtain a foreign body type recognition model.

[0049] In some embodiments, the step S3 is further included, wherein the wiper operation is dynamically controlled according to the characteristics of the foreign object, specifically comprising:

[0050] S301, planning the working mode of the wipers according to the location information of each foreign object, and adjusting the wiping intensity of the wipers according to the type of foreign object, specifically including:

[0051] Based on the location information of the foreign object, the coverage range of the wiper where the foreign object is located is determined, and the corresponding wiper is controlled to work. The wiping intensity of the wiper is controlled in levels according to the type of foreign object, and whether there is any foreign object remaining is detected in real time, and the water spray device is linked to flush it.

[0052] Exemplarily, the windshield is divided into two areas according to the coverage of the two wipers. According to the foreign object position information obtained in step S2, all foreign objects are divided into the two areas. Then, according to the type of foreign objects, such as raindrops, frost, solid particles, etc., the two wipers are controlled to wipe respectively. If the foreign objects are raindrops, the corresponding wipers are controlled to perform a single gentle wipe. If the foreign objects are frost, the corresponding wipers are controlled to perform continuous and gentle wipe. If the foreign objects are solid particles, the corresponding wipers are controlled to perform a single strong wipe. If there are any residues after a single wipe, the water spray device is controlled to flush.

[0053] In some embodiments, further comprising:

[0054] S302, dynamically adjusting the operating frequency of the wipers according to the number of foreign objects, specifically including:

[0055] The density of foreign objects per unit area is calculated based on the number of foreign objects. When the foreign object density is less than a first threshold, the wipers are controlled to perform intermittent low-frequency wiping. When the foreign object density is greater than the first threshold and less than a second threshold, the wipers are controlled to perform continuous low-speed wiping. When the foreign object density is greater than the second threshold, the wipers are controlled to perform high-speed continuous wiping.

[0056] Compared with the existing technology, the method of sensing foreign objects based on surface acoustic waves provided in this embodiment uses a signal transmitter to excite surface acoustic waves to propagate on the surface to be cleaned, and uses the characteristic that surface acoustic waves will generate reflected waves when encountering foreign objects to detect foreign objects. By analyzing the reflected wave signal, the precise location information and quantity of foreign objects are obtained, so that the operation of the cleaning equipment can be controlled according to the characteristics of the foreign objects, thereby improving the intelligence and anti-interference ability of the cleaning process.

[0057] In some embodiments, further comprising:

[0058] S303: Optimize the operating frequency of the wipers according to the real-time vehicle speed and ambient temperature and humidity data.

[0059] For example, the real-time vehicle speed is obtained through the CAN bus or OBD interface, and the ambient temperature and humidity are detected by the temperature and humidity sensor. Based on 30km / h, the operating frequency of the wipers increases by 10%-15% for every 10km / h increase in the real-time vehicle speed. When the temperature is less than 5°C, the operating frequency of the wipers decreases by 30%.

[0060] Example 2

[0061] This embodiment provides a device for sensing foreign matter based on surface acoustic waves, such as Figure 2 Shown, including:

[0062] A signal generation and acquisition module, configured to drive a signal transmitter via an electrical signal to excite a surface acoustic wave propagating along the surface to be cleaned, wherein the signal transmitter receives the reflected wave and converts it into a first electrical signal;

[0063] The foreign body sensing module is used to analyze the first electrical signal to obtain the characteristics of the foreign body on the surface to be cleaned, including: calculating the position of the foreign body in the first direction according to the propagation time of the first electrical signal, performing a first classification on the first electrical signal according to the position of the foreign body in the first direction, performing a second classification according to the frequency of the first electrical signal in the first classification result, and calculating the position of the foreign body in the second direction according to the result of the second classification to confirm the number of foreign bodies and the position information of each foreign body.

[0064] Example 3

[0065] This embodiment provides an electronic device, such as Figure 3 As shown, it includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the method for sensing foreign matter based on surface acoustic waves as described in any of the above embodiments is implemented.

[0066] Example 4

[0067] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for sensing foreign matter based on surface acoustic waves as described in any of the above embodiments is implemented.

[0068] Computer-readable storage media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0069] Professionals should also be further aware that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0070] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0071] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for sensing foreign matter based on surface acoustic waves, characterized in that: include: The signal transmitter is driven by an electrical signal to excite a surface acoustic wave propagating along the surface to be cleaned, and the signal transmitter receives the reflected wave and converts it into a first electrical signal; Analyze the first electrical signal to obtain the characteristics of foreign matter on the surface to be cleaned, including: calculating the position of the foreign matter in a first direction based on the propagation time of the first electrical signal, performing a first classification on the first electrical signal based on the position of the foreign matter in the first direction, performing a second classification based on the frequency of the first electrical signal in the first classification result, and calculating the position of the foreign matter in a second direction based on the result of the second classification to confirm the number of foreign matter and the position information of each foreign matter.

2. The method for sensing foreign matter based on surface acoustic waves according to claim 1, characterized in that: The foreign body feature also includes a foreign body type, and the foreign body type is output by inputting the first electrical signal of each foreign body into a foreign body type recognition model.

3. The method for sensing foreign matter based on surface acoustic waves according to claim 2, characterized in that: The pre-training step of the foreign body type recognition model includes: Collecting samples of reflected wave signals on the surface to be cleaned under conditions of different types of foreign matter; Label the foreign body type corresponding to each signal sample based on its frequency distribution and phase change; The labeled signal samples are input into the classification model for training to obtain a foreign body type recognition model.

4. The method for sensing foreign matter based on surface acoustic waves according to claim 1, characterized in that: The surface to be cleaned includes a windshield, the cleaning device includes a wiper, and the signal transmitter and signal receiver include interdigital transducers.

5. The method for sensing foreign matter based on surface acoustic waves according to claim 1, characterized in that: The signal transmitter and the signal receiver are arranged opposite to each other and have uneven shapes so as to generate surface acoustic waves of different frequencies.

6. The method for sensing foreign matter based on surface acoustic waves according to claim 4, characterized in that: Also includes: The wiper's operating mode is planned based on the location information of each foreign object, and the wiper's wiping intensity is adjusted according to the type of foreign object. Specifically, it includes: Based on the location information of the foreign object, the coverage range of the wiper where the foreign object is located is determined, and the corresponding wiper is controlled to work. The wiping intensity of the wiper is controlled in levels according to the type of foreign object, and whether there is any foreign object remaining is detected in real time, and the water spray device is linked to flush it.

7. The method for sensing foreign matter based on surface acoustic waves according to claim 6, characterized in that: Also includes: Dynamically adjust the wiper operating frequency according to the number of foreign objects, including: Calculating the foreign object density per unit area based on the number of foreign objects, and controlling the wipers to perform intermittent low-frequency wiping when the foreign object density is less than a first threshold; When the foreign matter density is greater than the first threshold and less than the second threshold, the wipers are controlled to perform continuous low-speed wiping; when the foreign matter density is greater than the second threshold, the wipers are controlled to perform continuous high-speed wiping.

8. A device for sensing foreign matter based on surface acoustic waves, characterized in that: The device comprises: A signal generation and acquisition module, configured to drive a signal transmitter via an electrical signal to excite a surface acoustic wave propagating along the surface to be cleaned, wherein the signal transmitter receives the reflected wave and converts it into a first electrical signal; The foreign body sensing module is used to analyze the first electrical signal to obtain the characteristics of the foreign body on the surface to be cleaned, including: calculating the position of the foreign body in the first direction according to the propagation time of the first electrical signal, performing a first classification on the first electrical signal according to the position of the foreign body in the first direction, performing a second classification according to the frequency of the first electrical signal in the first classification result, and calculating the position of the foreign body in the second direction according to the result of the second classification to confirm the number of foreign bodies and the position information of each foreign body.

9. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the method for sensing foreign matter based on surface acoustic waves according to any one of claims 1 to 7 is implemented.

10. A storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the method for sensing foreign matter based on surface acoustic waves according to any one of claims 1 to 7 is implemented.

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