Windscreen wiper control method and system

Abstract

The windscreen wiper control method comprises the steps that first feedback current of a first light-emitting group and second feedback current of a second light-emitting group on a rainfall sensor are collected, the first feedback current is generated by exciting a photodiode through the lightened first light-emitting group, and the second feedback current is generated by exciting a photodiode through the lightened second light-emitting group; the second feedback current is generated when the photodiode is excited by the lightened second light-emitting group, and the first light-emitting group and the second light-emitting group are periodically and alternately lightened; based on the first feedback current and the second feedback current, acquiring a light difference value Tsum of the first light emitting group and the second light emitting group; based on the light difference value Tsum, a rainfall signal Tsumf is obtained; the rainfall signal Tsumf is compared with a set threshold value Th, and the number of times Cnt that the amplitude of the rainfall signal Tsumf is larger than the set threshold value Th within a set time period is obtained; and based on the frequency Cnt, the windscreen wiper is controlled to operate at the corresponding target gear. According to the invention, the first light-emitting group and the second light-emitting group are located under the same ambient light, and the rainfall sensor can achieve rainfall detection under the condition of sudden change of ambient light.

Description

Technical Field

[0001] The present application relates to the field of automobile control technology, and in particular to a wiper control method and system thereof. Background Art

[0002] The rain sensor is the core component of the entire automatic wiper system. Its function is to measure the rain on the outer surface of the windshield and output a specific signal based on the measurement results to control the wiper to work at an appropriate speed and intervals. The optical rain sensor is made based on the principle of light refraction and total reflection. It mainly consists of a transmitter module, a windshield and a receiver module. The light emitted by the transmitter module is projected onto the inner surface of the windshield at a fixed incident angle, and then the light is reflected by the windshield to the receiver module.

[0003] The receiving module of the traditional rain sensor is a photodiode. When there is rain on the outer surface of the windshield, the intensity of the light reflected to the receiving module will decrease, causing the photodiode output photocurrent to decrease. The detection of the rain on the outer surface of the windshield is achieved by measuring the output photocurrent of the receiving module. However, changes in ambient light will affect the traditional rain sensor based on photodiodes. Changes in ambient light will cause changes in the output current of the photodiode, such as passing through tunnels and bridges, which makes it difficult for traditional rain sensors to detect rain in all weather conditions and under sudden changes in ambient light. In addition, it is difficult for traditional rain sensors to measure multiple points on the windshield. Summary of the invention

[0004] The present application provides a wiper control method and system thereof, which can solve the problem in the related art that changes in ambient light will cause changes in the output current of the photodiode, making it difficult for traditional rain sensors to detect rain in all weather conditions and under sudden changes in ambient light.

[0005] In a first aspect, an embodiment of the present application provides a wiper control method, which includes:

[0006] Collecting a first feedback current of a first light-emitting group and a second feedback current of a second light-emitting group on the rain sensor, wherein the first feedback current is generated when the photodiode is excited by the first light-emitting group being lit, and the second feedback current is generated when the photodiode is excited by the second light-emitting group being lit, and the first light-emitting group and the second light-emitting group are periodically alternately lit;

[0007] Based on the first feedback current and the second feedback current, obtaining a light difference value Tsum between the first light-emitting group and the second light-emitting group;

[0008] Based on the light difference value Tsum, a rainfall signal Tsumf is obtained;

[0009] Compare the rainfall signal Tsumf with the set threshold value Th, and obtain the number of times Cnt that the amplitude of the rainfall signal Tsumf is greater than the set threshold value Th within the set time period;

[0010] Based on the number Cnt, the wiper is controlled to operate at the corresponding target gear.

[0011] In some embodiments, the first light-emitting group includes a plurality of first light-emitting diodes, the second light-emitting group includes a plurality of second light-emitting diodes, and the number of the first light-emitting diodes is the same as the number of the second light-emitting diodes.

[0012] In some embodiments, the rain sensor includes a substrate, the first light-emitting group and the second light-emitting group are arranged on the substrate, the photodiode is arranged in the middle of the substrate, and the first light-emitting group and the second light-emitting group are arranged around the photodiode;

[0013] A plurality of the first light emitting diodes are arranged on one side of the substrate, a plurality of the second light emitting diodes are arranged on the other side of the substrate, or a second light emitting diode is arranged between two first light emitting diodes adjacent to each other along the circumference of the substrate.

[0014] In some embodiments, collecting a first feedback current of a first light-emitting group and a second feedback current of a second light-emitting group on a rain sensor specifically includes:

[0015] Lighting up all first light emitting diodes of the first light emitting group to emit light beams;

[0016] After the light beam is incident on the photodiode, the response current value of the photodiode is detected and recorded as the first feedback current;

[0017] Turn off all first light emitting diodes of the first light emitting group, and light up all second light emitting diodes of the second light emitting group to emit light beams;

[0018] The response current value of the photodiode after the detection light beam enters the photodiode is recorded as the second feedback current.

[0019] In some embodiments, obtaining the light difference value Tsum of the first light-emitting group and the second light-emitting group based on the first feedback current and the second feedback current specifically includes:

[0020] Subtract the first feedback current from the second feedback current to obtain a current difference value ΔIf between the first light-emitting group and the second light-emitting group;

[0021] The current difference value ΔIf is integrated to obtain the light difference value Tsum between the first light-emitting group and the second light-emitting group.

[0022] In some embodiments, obtaining the rainfall signal Tsumf based on the light difference value Tsum specifically includes:

[0023] The light difference value Tsum is band-pass filtered to extract the signal components within the frequency range fl to fh, thereby obtaining a filtered rainfall signal Tsumf.

[0024] In some embodiments, the rainfall signal Tsumf is compared with a set threshold value Th, and the number of times Cnt that the amplitude of the rainfall signal Tsumf is greater than the set threshold value Th within a set time period is obtained, specifically including:

[0025] Set the threshold value Th;

[0026] Get the number of times Cnt when |Tsum_f|>Th in the set time period Ts.

[0027] In some embodiments, based on the number Cnt, controlling the wiper to operate at the corresponding target gear specifically includes:

[0028] Determining the wiper gear position based on the number Cnt and the mapping relationship between the number Cnt and the wiper gear position;

[0029] Control the wiper to execute the wiper gear.

[0030] In a second aspect, an embodiment of the present application provides a wiper control system, which includes: a rain sensor, a current acquisition module, a data processing module and a controller, wherein the rain sensor is provided with a light-emitting diode, a first light-emitting group and a second light-emitting group; the current acquisition module is used to collect a first feedback current of the first light-emitting group and a second feedback current of the second light-emitting group on the rain sensor, wherein the first feedback current is generated by the photodiode being excited by the lit first light-emitting group, and the second feedback current is generated by the photodiode being excited by the lit second light-emitting group, and the first light-emitting group and the second light-emitting group are periodically alternately lit; the data processing module is used to obtain a light difference value Tsum between the first light-emitting group and the second light-emitting group based on the first feedback current and the second feedback current, obtain a rain signal Tsumf based on the light difference value Tsum, compare the rain signal Tsumf with a set threshold value Th, obtain a number Cnt of times that the amplitude of the rain signal Tsumf is greater than the set threshold value Th within a set time period, and is also used to determine a target gear position of the wiper based on the number Cnt; the controller is used to control the wiper to operate at the target gear position.

[0031] In some embodiments, the wiper control system further includes a digitally controlled constant current source, and the digitally controlled constant current source is used to cyclically excite the first light-emitting group and the second light-emitting group.

[0032] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0033] The embodiment of the present application provides a wiper control method and a system thereof. Since the first light-emitting group and the second light-emitting group are under the same ambient light, the changes in ambient light have the same impact on them. Therefore, the light difference value Tsum between the first light-emitting group and the second light-emitting group will not change due to changes in ambient light, so that the rain sensor can realize rainfall detection in all weather conditions and under sudden changes in ambient light. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 A schematic diagram of a first raindrop sensor provided in an embodiment of the present application;

[0036] Figure 2 A schematic diagram of a second raindrop sensor provided in an embodiment of the present application;

[0037] Figure 3 A flow chart of the wiper control method provided in an embodiment of the present application.

[0038] In the figure: 1, substrate; 2, photodiode; 3, first light-emitting diode; 4, second light-emitting diode. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] The embodiments of the present application provide a wiper control method and system thereof, which can solve the problem in the related art that changes in ambient light will cause changes in the output current of the photodiode, making it difficult for traditional rain sensors to detect rain in all weather conditions and under sudden changes in ambient light.

[0041] In a first aspect, an embodiment of the present application provides a wiper control method, which includes:

[0042] 101: collecting a first feedback current of a first light-emitting group and a second feedback current of a second light-emitting group on the rain sensor, wherein the first feedback current is generated when the photodiode 2 is excited by the first light-emitting group being lit, and the second feedback current is generated when the photodiode 2 is excited by the second light-emitting group being lit, and the first light-emitting group and the second light-emitting group are periodically alternately lit;

[0043] 102: Obtaining a light difference value Tsum of the first light-emitting group and the second light-emitting group based on the first feedback current and the second feedback current;

[0044] 103: Obtain a rainfall signal Tsumf based on the light difference value Tsum;

[0045] 104: Compare the rainfall signal Tsumf with the set threshold value Th, and obtain the number of times Cnt that the amplitude of the rainfall signal Tsumf is greater than the set threshold value Th within the set time period;

[0046] 105: Based on the number Cnt, control the wiper to operate at the corresponding target gear.

[0047] In the present application, since the first light-emitting group and the second light-emitting group are in the same ambient light, the changes in ambient light have the same impact on them. Therefore, the light difference value Tsum between the first light-emitting group and the second light-emitting group will not change due to changes in ambient light, so that the rain sensor can realize rainfall detection in all weather conditions and under sudden changes in ambient light.

[0048] The first light-emitting group includes a plurality of first light-emitting diodes 3, and the second light-emitting group includes a plurality of second light-emitting diodes 4. In order to ensure the consistency of the detection results of the first light-emitting group and the second light-emitting group, the number of the first light-emitting diodes 3 is set to be the same as the number of the second light-emitting diodes 4.

[0049] Furthermore, the rain sensor includes a substrate 1 , the first light-emitting group and the second light-emitting group are arranged on the substrate 1 , the photodiode 2 is arranged in the middle of the substrate 1 , and the first light-emitting group and the second light-emitting group are arranged around the photodiode 2 .

[0050] There are many ways to arrange the first light emitting diode 3 and the second light emitting diode 4. Figure 1 As shown:

[0051] In some possible embodiments, a plurality of the first light emitting diodes 3 are disposed on one side of the substrate 1 , and a plurality of the second light emitting diodes 4 are disposed on the other side of the substrate 1 .

[0052] In this embodiment, two detection areas are set, namely area A and area B. A first light-emitting group is set in area A, and a second light-emitting group is set in area B. Multiple first light-emitting diodes 3 in the first light-emitting group are arranged in series, and the distance between two adjacent first light-emitting diodes 3 is the same. Multiple second light-emitting diodes 4 in the second light-emitting group are arranged in series, and the distance between two adjacent second light-emitting diodes 4 is the same.

[0053] In some other possible embodiments, see Figure 2 As shown, a second light emitting diode 4 is arranged between two first light emitting diodes 3 adjacent to each other along the circumferential direction of the substrate 1 .

[0054] That is to say, a plurality of first light emitting diodes 3 are connected in series, and a plurality of second light emitting diodes 4 are connected in series. Figure 2 In the arrangement shown, two adjacent first light emitting diodes 4 form a detection area with a difference of 120°, and two adjacent second light emitting diodes 4 form a detection area with a difference of 120°.

[0055] The above embodiments are only multiple possible implementations of the embodiments of the present application, and the embodiments of the present application are not limited thereto. In order to ensure that each monitoring point is under the same ambient light, it is preferred to adopt a configuration in which a second light emitting diode 4 is disposed between two first light emitting diodes 3 adjacent to each other along the circumference of the substrate 1 to ensure the accuracy of the monitoring results.

[0056] The wiper control system is further configured to include a digitally controlled constant current source, which is used for cyclically exciting the first light-emitting group and the second light-emitting group.

[0057] The first light-emitting group and the second light-emitting group are cyclically excited by the digitally controlled constant current source, and the response current of the photodiode 22 is recorded at that time. This value can reflect the intensity of the received light. Since each monitoring point is under the same ambient light, the impact on all detection points is the same, and it will not affect the light intensity reflecting the rainfall. And since the first light-emitting group and the second light-emitting group are arranged in a circular distribution, the rainfall detection of the circular area on the windshield can be realized.

[0058] It should be noted that the digital controlled constant current source is always in working state, and will continuously excite the first light-emitting group and the second light-emitting group at intervals to ensure that the falling of raindrops is detected in time.

[0059] On the basis of the above embodiment, in this embodiment, collecting the first feedback current of the first light-emitting group and the second feedback current of the second light-emitting group on the rain sensor specifically includes steps 1010 to 1013:

[0060] Step 1010: Light up all first light-emitting diodes 3 of the first light-emitting group to emit light beams.

[0061] In this embodiment, firstly, the digitally controlled current source is made to control the current Ia to light up all the first light emitting diodes 3 .

[0062] Step 1011: Detect the response current value of the photodiode 2 after the light beam enters the photodiode 2, and record it as the first feedback current.

[0063] After the first light-emitting diode 3 emits light, it is reflected by the glass and then enters the photodiode 2. The current acquisition module detects the current of the photodiode 2 to obtain the feedback current. After the current stabilizes, the corresponding current is collected through the internal ADC (Analog-to-Digital Converter), which is recorded as the first feedback current If1.

[0064] Step 1012: Turn off all first light-emitting diodes 3 of the first light-emitting group, and light up all second light-emitting diodes 4 of the second light-emitting group to emit light beams.

[0065] In this embodiment, after all the first light-emitting diodes 3 of the first light-emitting group are turned off, the digitally controlled current source controls the current Ia to light up all the second light-emitting diodes 4 .

[0066] Step 1013: Detect the response current value of the photodiode 2 after the light beam enters the photodiode 2, and record it as the second feedback current.

[0067] After all the second light-emitting diodes 4 emit light, it is reflected by the glass and then enters the photodiode 2. The current acquisition module detects the current of the photodiode 2 to obtain the feedback current. After the current stabilizes, the internal ADC (Analog-to-Digital Converter) collects the corresponding current, which is recorded as the second feedback current If2.

[0068] On the basis of the above embodiment, in this embodiment, based on the first feedback current and the second feedback current, obtaining the light difference value Tsum of the first light-emitting group and the second light-emitting group specifically includes steps 1020 to 1021:

[0069] Step 1020: Subtract the first feedback current from the second feedback current to obtain a current difference value ΔIf between the first light-emitting group and the second light-emitting group.

[0070] Specifically, the first feedback current If1 and the second feedback current If2 are subjected to current-voltage conversion, amplification, and filtering, and then the first feedback current If1 and the second feedback current If2 are subtracted to obtain a current difference value ΔIf between the first light-emitting group and the second light-emitting group, wherein ΔIf=If1-If2.

[0071] Step 1021: Integrate the current difference value ΔIf to obtain the light difference value Tsum between the first light-emitting group and the second light-emitting group.

[0072] Specifically, through the formula: The current difference value ΔIf is integrated to obtain the light difference value Tsum between the first light-emitting group and the second light-emitting group. Ts represents a specific time interval.

[0073] On the basis of the above embodiments, in this embodiment, based on the light difference value Tsum, a rainfall signal Tsumf is obtained, which specifically includes: performing bandpass filtering on the light difference value Tsum to extract signal components within the frequency range fl to fh to obtain a filtered rainfall signal Tsumf.

[0074] Specifically, in the rainless state, the first feedback current If1 and the second feedback current If2 of the first light-emitting group and the second light-emitting group are basically consistent, that is, ΔIf fluctuates around 0, the integrated light difference value Tsum in the Ts time period is equal to K0, and K0 is set to 0. In addition, when the absolute value of the difference between the light difference value Tsum and the set value K0 is within the set difference range, it also indicates that no raindrops are falling.

[0075] When there are raindrops on the glass, the balance between the first feedback current If1 and the second feedback current If2 of the first light-emitting group and the second light-emitting group is broken, and a deviation occurs. The light difference value Tsum will deviate from K0, that is, the absolute value of the light difference value Tsum will be greater than the set value. It should be noted that at this time, the absolute value of the difference between the light difference value Tsum and the set value K0 is outside the set difference range.

[0076] A bandpass filter is selected to perform bandpass filtering on the light difference value Tsum to obtain a filtered rainfall signal Tsumf. Bandpass filtering can be implemented using a variety of methods, such as using a digital filter (such as a FIR filter or an IIR filter).

[0077] On the basis of the above embodiment, in this embodiment, the rainfall signal Tsumf is compared with the set threshold value Th, and the number of times Cnt that the amplitude of the rainfall signal Tsumf is greater than the set threshold value Th within the set time period is obtained, specifically including steps 1041 to 1042:

[0078] Step 1041: Set the threshold value Th.

[0079] Step 1042: Obtain the number of times Cnt when |Tsum_f|>Th within the set time period Ts.

[0080] A threshold value Th is set, and based on the formula |Tsum_f|>Th, the number of times Cnt that the absolute value of the signal Tsumf exceeds the threshold value Th within the time period Ts is counted.

[0081] The larger the value of the number Cnt is, the more times the signal exceeds the set threshold Th within the time period Ts, and the greater the detected rainfall is.

[0082] On the basis of the above embodiment, in this embodiment, based on the number Cnt, the wiper is controlled to operate at the corresponding target gear, specifically including steps 1050 to 1051:

[0083] Step 1050: determining the wiper gear position based on the mapping relationship between the number Cnt, the rainfall amount, and the number Cnt and the wiper gear position;

[0084] Step 1051: Control the wiper to execute the wiper gear.

[0085] Specifically, in order to ensure a smooth transition when judging whether the rainfall is heavy, medium or small according to the number Cnt, and to control the speed of the wiper (Highspeed, Lowspeed, Interval, Stop), we can set four thresholds: the first threshold (IntervalON), the second threshold (IntervalOFF), the third threshold (LowSpeedON), the fourth threshold (LowSpeedOFF), the fifth threshold (HighSpeedON) and the sixth threshold (HighSpeedOFF). These thresholds will be used to map the amount of rainfall, or the number of times Cnt, to different wiper working states. Initialize the wiper gear state to Stop, that is, stop mode. Update the wiper gear according to the number Cnt of each time period:

[0086] When the current wiper gear is in the stop mode: the number Cnt is greater than the first threshold, and the wiper enters the intermittent mode.

[0087] When the current wiper gear is in the intermittent mode: when the number Cnt is greater than the third threshold, the wiper enters the low-speed mode; when the number Cnt is less than the second threshold, the wiper enters the stop mode.

[0088] When the current wiper gear is in the low-speed mode: when the number Cnt is greater than the fifth threshold, the wiper enters the high-speed mode; when the number Cnt is less than the fourth threshold, the wiper enters the intermittent mode.

[0089] When the current wiper gear is in the high-speed mode: the number Cnt is less than the sixth threshold, and the wiper enters the low-speed mode.

[0090] In a second aspect, an embodiment of the present application provides a wiper control system, which includes a rain sensor, a current acquisition module, a data processing module and a controller, wherein the rain sensor is provided with a light-emitting diode, a first light-emitting group and a second light-emitting group; the current acquisition module is used to collect a first feedback current of the first light-emitting group and a second feedback current of the second light-emitting group on the rain sensor, wherein the first feedback current is generated by the photodiode 2 being excited by the lit first light-emitting group, and the second feedback current is generated by the photodiode 2 being excited by the lit second light-emitting group, and the first light-emitting group and the second light-emitting group are periodically alternately lit; the data processing module is used to obtain a light difference value Tsum between the first light-emitting group and the second light-emitting group based on the first feedback current and the second feedback current, obtain a rain signal Tsumf based on the light difference value Tsum, compare the rain signal Tsumf with a set threshold value Th, obtain a number Cnt of times that the amplitude of the rain signal Tsumf is greater than the set threshold value Th within a set time period, and determine a target gear position of the wiper based on the number Cnt.

[0091] In the present application, since the first light-emitting group and the second light-emitting group are in the same ambient light, the changes in ambient light have the same impact on them. Therefore, the light difference value Tsum between the first light-emitting group and the second light-emitting group will not change due to changes in ambient light, so that the rain sensor can realize rainfall detection in all weather conditions and under sudden changes in ambient light.

[0092] The first light-emitting group includes a plurality of first light-emitting diodes 3, and the second light-emitting group includes a plurality of second light-emitting diodes 4. In order to ensure the consistency of the detection results of the first light-emitting group and the second light-emitting group, the number of the first light-emitting diodes 3 is set to be the same as the number of the second light-emitting diodes 4.

[0093] Furthermore, the rain sensor includes a substrate 1 , the first light-emitting group and the second light-emitting group are arranged on the substrate 1 , the photodiode 2 is arranged in the middle of the substrate 1 , and the first light-emitting group and the second light-emitting group are arranged around the photodiode 2 .

[0094] There are many ways to arrange the first light emitting diode 3 and the second light emitting diode 4. Figure 1 As shown:

[0095] In some possible embodiments, a plurality of the first light emitting diodes 3 are disposed on one side of the substrate 1 , and a plurality of the second light emitting diodes 4 are disposed on the other side of the substrate 1 .

[0096] In this embodiment, two detection areas are set, namely area A and area B. A first light-emitting group is set in area A, and a second light-emitting group is set in area B. Multiple first light-emitting diodes 3 in the first light-emitting group are arranged in series, and the distance between two adjacent first light-emitting diodes 3 is the same. Multiple second light-emitting diodes 4 in the second light-emitting group are arranged in series, and the distance between two adjacent second light-emitting diodes 4 is the same.

[0097] In some other possible embodiments, see Figure 2 As shown, a second light emitting diode 4 is arranged between two first light emitting diodes 3 adjacent to each other along the circumferential direction of the substrate 1 .

[0098] That is to say, a plurality of first light emitting diodes 3 are connected in series, and a plurality of second light emitting diodes 4 are connected in series. Figure 2 In the arrangement shown, two adjacent first light emitting diodes 4 form a detection area with a difference of 120°, and two adjacent second light emitting diodes 4 form a detection area with a difference of 120°.

[0099] The above embodiments are only multiple possible implementations of the embodiments of the present application, and the embodiments of the present application are not limited thereto. In order to ensure that each monitoring point is under the same ambient light, it is preferred to adopt a configuration in which a second light emitting diode 4 is disposed between two first light emitting diodes 3 adjacent to each other along the circumference of the substrate 1 to ensure the accuracy of the monitoring results.

[0100] The wiper control system is further configured to include a digitally controlled constant current source, which is used for cyclically exciting the first light-emitting group and the second light-emitting group.

[0101] The first light-emitting group and the second light-emitting group are cyclically excited by the digitally controlled constant current source, and the response current of the photodiode 22 is recorded at that time. This value can reflect the intensity of the received light. Since each monitoring point is under the same ambient light, the impact on all detection points is the same, and it will not affect the light intensity reflecting the rainfall. And since the first light-emitting group and the second light-emitting group are arranged in a circular distribution, the rainfall detection of the circular area on the windshield can be realized.

[0102] It should be noted that the digital controlled constant current source is always in working state, and will continuously excite the first light-emitting group and the second light-emitting group at intervals to ensure that the falling of raindrops is detected in time.

[0103] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0104] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0105] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A wiper control method, characterized in that: It includes: collecting a first feedback current of a first light-emitting group and a second feedback current of a second light-emitting group on the rain sensor, wherein the first feedback current is generated when the photodiode (2) is excited by the lit first light-emitting group, and the second feedback current is generated when the photodiode (2) is excited by the lit second light-emitting group, and the first light-emitting group and the second light-emitting group are alternately illuminated periodically; Based on the first feedback current and the second feedback current, obtaining a light difference value Tsum between the first light-emitting group and the second light-emitting group; Based on the light difference value Tsum, a rainfall signal Tsumf is obtained; Compare the rainfall signal Tsumf with the set threshold value Th, and obtain the number of times Cnt that the amplitude of the rainfall signal Tsumf is greater than the set threshold value Th within the set time period; Based on the number Cnt, the wiper is controlled to operate at the corresponding target gear.

2. The wiper control method according to claim 1, characterized in that: The first light-emitting group comprises a plurality of first light-emitting diodes (3), and the second light-emitting group comprises a plurality of second light-emitting diodes (4), wherein the number of the first light-emitting diodes (3) is the same as the number of the second light-emitting diodes (4).

3. The wiper control method according to claim 2, characterized in that: The rain sensor comprises a substrate (1), the first light-emitting group and the second light-emitting group are arranged on the substrate (1), the photodiode (2) is arranged in the middle of the substrate (1), and the first light-emitting group and the second light-emitting group are arranged around the photodiode (2); A plurality of the first light-emitting diodes (3) are arranged on one side of the substrate (1), and a plurality of the second light-emitting diodes (4) are arranged on the other side of the substrate, or a second light-emitting diode (4) is arranged between two first light-emitting diodes (3) adjacent to each other along the circumference of the substrate (1).

4. The wiper control method according to claim 2, characterized in that: Collecting a first feedback current of a first light-emitting group and a second feedback current of a second light-emitting group on a rain sensor specifically includes: Lighting up all first light emitting diodes (3) of the first light emitting group so that they emit light beams; After the light beam is incident on the photodiode (2), a response current value of the photodiode (2) is detected and recorded as a first feedback current; Turning off all first light-emitting diodes (3) of the first light-emitting group, and lighting up all second light-emitting diodes (4) of the second light-emitting group so that they emit light beams; The response current value of the photodiode (2) after the light beam is incident on the photodiode (2) is detected and recorded as the second feedback current.

5. The wiper control method according to claim 1, characterized in that: Based on the first feedback current and the second feedback current, obtaining a light difference value Tsum of the first light-emitting group and the second light-emitting group specifically includes: Subtract the first feedback current from the second feedback current to obtain a current difference value ΔIf between the first light-emitting group and the second light-emitting group; The current difference value ΔIf is integrated to obtain the light difference value Tsum between the first light-emitting group and the second light-emitting group.

6. The wiper control method according to claim 1, characterized in that: Based on the light difference value Tsum, the rainfall signal Tsumf is obtained, which specifically includes: The light difference value Tsum is band-pass filtered to extract the signal components within the frequency range fl to fh, thereby obtaining a filtered rainfall signal Tsumf.

7. The wiper control method according to claim 6, characterized in that: Compare the rainfall signal Tsumf with the set threshold value Th, and obtain the number of times Cnt that the amplitude of the rainfall signal Tsumf is greater than the set threshold value Th within the set time period, specifically including: Set the threshold value Th; Get the number of times Cnt when |Tsum_f|>Th in the set time period Ts.

8. The wiper control method according to claim 1, characterized in that: Based on the number Cnt, the wiper is controlled to operate at the corresponding target gear, specifically including: Determining the wiper gear position based on the number Cnt and the mapping relationship between the number Cnt and the wiper gear position; Control the wiper to execute the wiper gear.

9. A wiper control system, characterized in that: It includes: A rain sensor, wherein the rain sensor is provided with a light emitting diode (3), a first light emitting group and a second light emitting group; A current collection module, the current collection module being used to collect a first feedback current of a first light-emitting group and a second feedback current of a second light-emitting group on the rainfall sensor, the first feedback current being generated when the photodiode (2) is excited by the lit first light-emitting group, the second feedback current being generated when the photodiode (2) is excited by the lit second light-emitting group, the first light-emitting group and the second light-emitting group being periodically alternately lit; a data processing module, the data processing module being used to obtain a light difference value Tsum of the first light-emitting group and the second light-emitting group based on the first feedback current and the second feedback current, obtain a rain signal Tsumf based on the light difference value Tsum, compare the rain signal Tsumf with a set threshold value Th, obtain a number Cnt of times that the amplitude of the rain signal Tsumf is greater than the set threshold value Th within a set time period, and determine a target gear position of the wiper based on the number Cnt; A controller is used to control the wiper to operate at a target gear position.

10. The wiper control system according to claim 9, characterized in that: The wiper control system further comprises a digitally controlled constant current source, which is used for cyclically exciting the first light-emitting group and the second light-emitting group.

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