Method, device and equipment for sensing foreign matters based on surface acoustic waves, and medium

Abstract

The invention relates to a method, device and equipment for sensing foreign matter based on surface acoustic waves and a medium, and belongs to the technical field of foreign matter detection.The method comprises the steps that a signal emitter is driven by an electric signal to excite the surface acoustic waves propagating along a to-be-cleaned face, and the signal emitter receives reflected waves and converts the reflected waves into a first electric signal; analyzing the first electric signals to obtain foreign matter features on the to-be-cleaned surface: calculating the position of a foreign matter in a first direction according to the propagation time of the first electric signals, performing first classification on the first electric signals according to the position of the foreign matter in the first direction, and performing second classification according to the frequency of the first electric signals in a first classification result, and calculating the positions of the foreign matters in the second direction according to the result of the second classification to confirm the number of the foreign matters and the position information of each foreign matter. According to the invention, the intelligence and anti-interference capability of the cleaning process are improved.

Description

Technical Field

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

[0002] Transparent glass can be seen everywhere on buildings or vehicles. Due to contact with the external atmosphere, it is inevitable that some foreign objects will adhere to the glass. In order not to affect the vision, it is necessary to clean or remove the foreign objects. The windshield of a vehicle is usually wiped by a windshield wiper.

[0003] In the prior art, it is usually judged by humans whether to clean, which increases the probability of dangerous accidents. Some also use cleaning equipment to clean the surface to be cleaned. For example, when the number of raindrops on the windshield is determined by an optical sensor to be large enough, it will automatically wipe, but it can only make the two windshield wipers work synchronously, and the optical sensor is greatly affected by the environment, suffering from the technical problems of insufficient intelligence and poor anti-interference ability. Summary of the Invention

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

[0005] The purpose of the present invention is achieved as follows: A first aspect embodiment of the present invention provides a method for sensing foreign objects based on surface acoustic waves, including: Driving a signal transmitter by an electrical signal to excite surface acoustic waves 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 foreign object characteristics on the surface to be cleaned, including: calculating the position of the foreign object 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 object 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 object in the second direction according to the result of the second classification to confirm the number of foreign objects and the position information of each foreign object.

[0006] Further, the foreign object characteristics further include the foreign object type, and by inputting the first electrical signals of each foreign object into a foreign object type recognition model, the foreign object type is output.

[0007] Further, the surface to be cleaned includes a windshield, the cleaning equipment includes a windshield wiper, and the signal transmitter and the signal receiver include interdigital transducers.

[0008] Further, the signal transmitter and the signal receiver are oppositely arranged and have an uneven shape to generate surface acoustic waves of different frequencies.

[0009] 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 grades 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.

[0010] Furthermore, it also includes: dynamically adjusting the working frequency of the wiper according to the number of foreign objects, specifically including: calculating the density of foreign objects per unit area according to the number of foreign objects, when the foreign object density is less than a first threshold, controlling the wiper 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 wiper to perform continuous low-speed wiping; when the foreign object density is greater than the second threshold, controlling the wiper to perform high-speed continuous wiping.

[0011] A second aspect of the present invention provides a device for sensing foreign matter based on surface acoustic waves, comprising: A signal generation and acquisition module, used to drive a signal transmitter through 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; The foreign matter sensing module is used to analyze the first electrical signal to obtain the characteristics of the foreign matter on the surface to be cleaned, including: calculating the position of the foreign matter 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 matter 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 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.

[0012] 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.

[0013] 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 one of the embodiments is implemented.

[0014] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: The method for detecting foreign objects based on surface acoustic waves provided by the present invention excites surface acoustic waves to propagate on the surface to be cleaned through a signal transmitter, detects foreign objects by utilizing the characteristic that the surface acoustic waves generate reflected waves when encountering foreign objects, and obtains the precise position information and quantity of the foreign objects by analyzing the reflected wave signals, so as to control the operation of the cleaning device 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

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present specification. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a flowchart of the method for detecting foreign objects based on surface acoustic waves provided in Embodiment 1 of the present invention; Figure 2 It is a schematic diagram of the device for detecting foreign objects based on surface acoustic waves provided in Embodiment 2 of the present invention; Figure 3 It is a schematic diagram of the electronic device architecture provided in Embodiment 3 of the present invention; Figure 4 It is a schematic diagram of the propagation of surface acoustic waves provided in Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. It should be noted that, without conflict, the implementation manners and the features in the implementation manners in the present disclosure can be combined, separated, interchanged, and / or rearranged. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] Embodiment 1 A specific embodiment of the present invention, as Figure 1 、 4 shown, discloses a method for detecting foreign objects based on surface acoustic waves, including the following steps: S1. Signal generation and acquisition Drive a signal transmitter through an electrical signal to excite surface acoustic waves propagating along the surface to be cleaned, and the signal transmitter receives the reflected wave and converts it into a first electrical signal.

[0019] Exemplarily, assume that the surface to be cleaned is the windshield of a car. A piezoelectric quartz thin film with a thickness of 10 - 50 μm is deposited on the windshield surface through a magnetron sputtering process as the surface acoustic wave propagation medium. A surface acoustic wave such as a Rayleigh wave is excited by a high-frequency electrical signal driving a signal transmitter and propagates along the windshield towards the signal receiver. If there is no foreign object blocking in the propagation direction, the signal receiver can smoothly receive the surface acoustic wave. When there is a foreign object blocking in the propagation direction, the surface acoustic wave cannot propagate to the signal receiver and is reflected back to the signal transmitter, where it is converted into a first electrical signal.

[0020] In this embodiment, the surface to be cleaned includes a windshield, the cleaning device includes a windshield wiper, and the signal transmitter and the signal receiver include interdigital transducers; the signal transmitter and the signal receiver are oppositely arranged and have uneven shapes to generate surface acoustic waves with different frequencies.

[0021] Exemplarily, the signal transmitter and the signal receiver are set to be thicker at the top and thinner at the bottom, with a working frequency of 20 - 100 MHz, so as to generate surface acoustic waves with different frequencies, which is convenient for subsequent calculation of the position of foreign objects.

[0022] S2. Signal analysis Analyze the first electrical signal to obtain the foreign object characteristics on the surface to be cleaned, including: S201. Calculate the position of the foreign object in the first direction according to the propagation time of the first electrical signal; Exemplarily, as Figure 4 shown, the signal transmitter and the signal receiver are respectively vertically installed on the left and right sides of the windshield. After the surface acoustic wave is blocked by a foreign object, a reflected wave is formed and propagates back to the signal transmitter. The position of the foreign object in the X direction is calculated according to the time difference between the formation of the surface acoustic wave (i.e., the incident wave) and the formation of the first electrical signal (i.e., the reflected wave) by the signal transmitter, which is expressed as follows: , where v represents the propagation speed of the surface acoustic wave, represents the time difference between the incident wave and the reflected wave.

[0023] S202. Perform a first classification on the first electrical signal according to the position of the foreign object in the first direction, and perform a second classification according to the frequency of the first electrical signal in the first classification result; Specifically, after calculating the position of the foreign object in the X direction in step S201, the first electrical signals with the same position in the X direction are initially grouped as the same foreign object. However, considering that there may be different foreign objects with the same distance from the signal transmitter in the X direction but different distributions in the Y direction, the first classification alone cannot distinguish them, and a second classification is required; The process of the second classification is as follows: Based on the first classification, calculate the frequency difference between the first electrical signals in each category, and determine whether the frequency difference is less than a preset threshold. If it is less, it indicates that they belong to the same foreign object; otherwise, it means they are two foreign objects with the same X-direction position and different Y-direction positions.

[0024] S203. Calculate the position of the foreign object in the second direction according to the result of the second classification to confirm the number of foreign objects and the position information of each foreign object.

[0025] Specifically, after step S1 obtains the positions of each foreign object in the X direction and step S202 separates the first electrical signals generated by each foreign object, it is necessary to further calculate the positions of each foreign object in the Y direction. Specifically: In the result of the second classification, calculate the average frequency between the first electrical signals with the maximum and minimum frequencies in each category, and then calculate the difference between the average frequency and the maximum frequency among all surface acoustic waves. According to the corresponding relationship between the difference and the position in the second direction, obtain the position of the foreign object in the Y direction, so as to accurately locate the foreign object.

[0026] In this embodiment, the foreign object feature further includes the foreign object type. By inputting the first electrical signals of each foreign object into the foreign object type recognition model, the foreign object type is output.

[0027] Specifically, the pre-training steps of the foreign object type recognition model include: Collect the reflected wave signal samples on the surface to be cleaned under the conditions of different types of foreign objects; Label the foreign object type corresponding to the signal sample according to the frequency distribution and phase change of each signal sample; Input the labeled signal samples into the classification model for training to obtain the foreign object type recognition model.

[0028] In some embodiments, it further includes step S3. Dynamically control the wiper according to the foreign object feature, specifically including: S301. Plan the working mode of the wiper according to the position information of each foreign object, and adjust the wiping intensity of the wiper according to the foreign object type, specifically including: Judge the coverage range of the wiper where the foreign object is located according to the position information of the foreign object, control the corresponding wiper to work, control the wiping intensity of the wiper in grades according to the type of the foreign object, and detect in real time whether there is foreign object residue to link the water spraying device for flushing.

[0029] Exemplarily, the windshield is divided into two regions according to the coverage of two windshield wipers. Based on the foreign object position information obtained in step S2, all foreign objects are classified into the two regions, and then according to the types of foreign objects, such as raindrops, frost, solid particles, etc., the two windshield wipers are then controlled to wipe respectively. If the foreign object is a raindrop, the corresponding windshield wiper is controlled to perform a single gentle wipe. If the foreign object is frost, the corresponding windshield wiper is controlled to perform a continuous low-speed wipe. If the foreign object is a solid particle, the corresponding windshield wiper is controlled to perform a single strong wipe. If there is still residue after a single wipe, the water spraying device is controlled to perform flushing.

[0030] In some embodiments, it further includes: S302. Dynamically adjust the working frequency of the windshield wiper according to the number of foreign objects, specifically including: Calculate the density of foreign objects per unit area according to the number of foreign objects. When the density of foreign objects is less than the first threshold, control the windshield wiper to perform intermittent low-frequency wiping; when the density of foreign objects is greater than the first threshold and less than the second threshold, control the windshield wiper to perform continuous low-speed wiping; when the density of foreign objects is greater than the second threshold, control the windshield wiper to perform high-speed continuous wiping.

[0031] Compared with the prior art, the method for sensing foreign objects based on surface acoustic waves provided in this embodiment excites surface acoustic waves to propagate on the surface to be cleaned through a signal transmitter, detects foreign objects by using the characteristic that surface acoustic waves will generate reflected waves when encountering foreign objects, and obtains accurate position information and quantity of foreign objects by analyzing the reflected wave signals, so as to control the cleaning device to work according to the characteristics of foreign objects, thereby improving the intelligence and anti-interference ability of the cleaning process.

[0032] In some embodiments, it further includes: S303. Optimize the working frequency of the windshield wiper according to real-time vehicle speed and ambient temperature and humidity data.

[0033] Exemplarily, obtain the real-time vehicle speed through the CAN bus or OBD interface, detect the ambient temperature and humidity through a temperature and humidity sensor. Based on 30 km / h, for every 10 km / h increase in the real-time vehicle speed, the working frequency of the windshield wiper increases by 10%-15%. When the temperature is less than 5 °C, the working frequency of the windshield wiper decreases by 30%.

[0034] Embodiment 2 This embodiment provides a device for sensing foreign objects based on surface acoustic waves, as Figure 2 shown, including: A signal generation and acquisition module, configured to drive a signal transmitter through an electrical signal to excite surface acoustic waves propagating along the surface to be cleaned, and the signal transmitter receives the reflected wave and converts it into a first electrical signal; A foreign object sensing module, configured to analyze the first electrical signal to obtain foreign object characteristics on the surface to be cleaned, including: calculating the position of a foreign object in a 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 object 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 object in a second direction according to the result of the second classification, so as to confirm the number of foreign objects and the position information of each foreign object.

[0035] Embodiment 3 This embodiment provides an electronic device, such as Figure 3 shown, including a memory and a processor, where the memory stores a computer program, and when the computer program is executed by the processor, it implements the method for sensing foreign objects based on surface acoustic waves as described in any of the above embodiments.

[0036] Embodiment 4 This embodiment provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the method for sensing foreign objects based on surface acoustic waves as described in any of the above embodiments.

[0037] Computer-readable storage media include both permanent and non-permanent, removable and non-removable media and can be implemented by any method or technology for storing 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 technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, 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 media such as modulated data signals and carrier waves.

[0038] Those skilled in the art should also be able to further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0039] The steps of the methods or algorithms described in combination with the embodiments disclosed herein can be implemented by hardware, software modules executed by a processor, or a combination of the two. The software modules can be placed in a random access memory (RAM), memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field.

[0040] The specific embodiments described above have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for sensing foreign objects 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 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 matter 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 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.

2. The method for sensing foreign objects based on surface acoustic waves according to claim 1, wherein, 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 objects 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; Mark the foreign body type corresponding to each signal sample according to 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 objects based on surface acoustic waves according to claim 1, wherein 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.

5. The method for sensing foreign objects 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 objects based on surface acoustic waves according to claim 4, wherein Also includes: The working mode of the wipers is planned according to the location information of each foreign object, and the wiping intensity of the wipers is adjusted according to the type of foreign object, including: The coverage range of the wiper where the foreign object is located is determined based on the location information of the foreign object, 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, so that the water spray device can be linked to flush it.

7. The method for sensing foreign objects 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 density of foreign objects per unit area according to the number of foreign objects, and when the density of foreign objects is less than a first threshold, controlling the wiper to perform intermittent low-frequency wiping; When the density of foreign matter is greater than the first threshold and less than the second threshold, the wiper is controlled to perform continuous low-speed wiping; when the density of foreign matter is greater than the second threshold, the wiper is controlled to perform high-speed continuous wiping.

8. A device for sensing foreign objects based on surface acoustic waves, characterized in that, The device comprises: A signal generation and acquisition module, used to drive a signal transmitter through 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; The foreign matter sensing module is used to analyze the first electrical signal to obtain the characteristics of the foreign matter on the surface to be cleaned, including: calculating the position of the foreign matter 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 matter 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 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.

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 as described in 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 objects based on surface acoustic waves according to any one of claims 1-7 is implemented.

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