Vehicle rain sensing using modulated infrared transmission

Abstract

The invention relates to a vehicle rain sensing using modulated infrared transmission. A rain sensor in a vehicle includes a transmitter to implement pseudo-random modulation of the timing of emission of infrared transmissions toward a windshield of the vehicle. The rain sensor also includes a receiver that is active only for a specified period of time after each emission of an infrared transmission and receives reflections of the infrared transmission based on the infrared transmission encountering any material on the windshield.

Description

Technical Field

[0001] This subject matter discloses vehicle rain sensing using modulated infrared transmission. Background Technology

[0002] Vehicles (e.g., cars, construction equipment, farm equipment) are increasingly using sensors to facilitate automated or semi-automated actions. For example, radar systems, lidar systems, and / or cameras can be used to detect objects around the vehicle and facilitate automatic braking, collision avoidance, or even autonomous driving. The use of windshield wipers can be automated by using sensors to detect raindrops on the windshield. Therefore, modulated infrared transmission is expected to provide rain sensing for vehicles. Summary of the Invention

[0003] In one exemplary embodiment, the rain sensor in the vehicle includes a transmitter to implement pseudo-random modulation of the timing of the transmission of infrared light toward the vehicle's windshield. The rain sensor also includes a receiver that is active only for a specified time period after each infrared transmission and receives reflections based on any material encountered by the infrared transmission on the windshield.

[0004] In addition to one or more features described herein, the transmitter includes a pseudo-random generator and an infrared light source.

[0005] In addition to one or more features described herein, an infrared light source is triggered by a pseudo-random generator to output infrared light pulses.

[0006] In addition to one or more features described herein, the receiver is configured to provide the controller with an indication of the presence of a substance on the windshield based on the received reflection.

[0007] In addition to one or more features described herein, the receiver is configured to provide an indication of the presence of raindrops on the windshield.

[0008] In another exemplary embodiment, the system in the vehicle includes a rain sensor comprising a transmitter and a receiver. The transmitter performs pseudo-random modulation on the timing of infrared transmission toward the vehicle's windshield, and the receiver is valid only for a specified time period after each infrared transmission and receives reflections based on any material encountered by the infrared transmission on the windshield. The system also includes a controller to control the activation of the vehicle's windshield wipers based on information from the receiver.

[0009] In addition to one or more features described herein, the transmitter includes a pseudo-random generator and an infrared light source.

[0010] In addition to one or more features described herein, an infrared light source is triggered by a pseudo-random generator to output infrared light pulses.

[0011] In addition to one or more features described herein, the receiver provides the controller with an indication of the presence of a substance on the windshield based on the received reflection.

[0012] In addition to one or more features described herein, the controller activates the windshield wipers based on indications of the presence of matter.

[0013] In addition to one or more features described herein, the controller activates the windshield wipers based on an indication of the presence of raindrops on the windshield.

[0014] In yet another exemplary embodiment, a method of assembling a rain sensor in a vehicle includes configuring a transmitter to perform pseudo-random modulation of the transmission timing of infrared transmission. The method also includes configuring a receiver to be active only for a specified time period following each infrared transmission.

[0015] In addition to one or more features described herein, the method also includes positioning the transmitter in the vehicle such that each launch is directed at the vehicle's windshield.

[0016] In addition to one or more features described herein, the method also includes positioning a receiver and transmitter together to receive reflections of any material encountered on the windshield based on infrared transmission.

[0017] In addition to one or more features described herein, the receiver is configured to receive reflections of raindrops on the windshield based on infrared transmission.

[0018] In addition to one or more features described herein, the receiver is configured to include providing the controller with an indication of the presence of a substance on the windshield based on the received reflection.

[0019] In addition to one or more features described herein, the method also includes positioning the transmitter and receiver between the vehicle's rearview mirror and the vehicle's windshield.

[0020] In addition to one or more features described herein, the method also includes assembling a transmitter to include a pseudo-random generator and an infrared light source.

[0021] In addition to one or more features described herein, the method also includes configuring an infrared light source to be triggered by a pseudo-random generator to output infrared light pulses.

[0022] This invention provides the following technical solutions:

[0023] Technical Solution 1. A rain sensor for a vehicle, comprising:

[0024] The transmitter is configured to perform pseudo-random modulation of the transmission timing of infrared transmission toward the vehicle windshield; and

[0025] The receiver is configured to be effective only for a specified period of time after each infrared transmission and to receive reflections of any material on the windshield based on the infrared transmission.

[0026] Technical Solution 2. The rain sensor according to Technical Solution 1, wherein the transmitter includes a pseudo-random generator and an infrared light source.

[0027] Technical Solution 3. The rain sensor according to Technical Solution 2, wherein the infrared light source is triggered by the pseudo-random generator to output infrared light pulses.

[0028] Technical Solution 4. The rain sensor according to Technical Solution 1, wherein the receiver is configured to provide an indication to the controller of the presence of a substance on the windshield based on the received reflection.

[0029] Technical Solution 5. The rain sensor according to Technical Solution 4, wherein the receiver is configured to provide an indication of the presence of raindrops on the windshield.

[0030] Technical Solution 6. A system in a vehicle, the system comprising:

[0031] Rain sensor, comprising:

[0032] The transmitter is configured to perform pseudo-random modulation of the transmission timing of infrared transmission toward the vehicle's windshield.

[0033] A receiver configured to be effective only for a specified time period after each infrared transmission, and to receive reflections based on any material encountered by the infrared transmission on the windshield; and

[0034] A controller is configured to control the activation of the vehicle's windshield wipers based on information from the receiver.

[0035] Technical Solution 7. The system according to Technical Solution 6, wherein the transmitter includes a pseudo-random generator and an infrared light source.

[0036] Technical Solution 8. The system according to Technical Solution 7, wherein the infrared light source is triggered by the pseudo-random generator to output infrared light pulses.

[0037] Technical Solution 9. The system according to Technical Solution 6, wherein the receiver is configured to provide the controller with an indication of the presence of a substance on the windshield based on the received reflection.

[0038] Technical Solution 10. The system according to Technical Solution 9, wherein the controller is configured to activate the windshield wipers based on an indication of the presence of the substance.

[0039] Technical Solution 11. The system according to Technical Solution 10, wherein the controller is configured to activate the windshield wipers based on an indication of the presence of raindrops on the windshield.

[0040] Technical Solution 12. A method for assembling a rain sensor in a vehicle, the method comprising:

[0041] Configure the transmitter to implement pseudo-random modulation of the transmission timing for infrared transmission; and

[0042] The receiver is configured to be effective only for a specified period of time after each infrared transmission.

[0043] Technical Solution 13. The method according to Technical Solution 12 further includes arranging the transmitter in the vehicle such that each launch is directed at the windshield of the vehicle.

[0044] Technical Solution 14. The method according to Technical Solution 13 further includes positioning the receiver and the transmitter together to receive reflections from any material on the windshield based on the infrared transmission.

[0045] Technical Solution 15. The method according to Technical Solution 14, wherein the receiver is configured to receive reflections of raindrops encountered on the windshield based on infrared transmission.

[0046] Technical Solution 16. The method according to Technical Solution 12, wherein configuring the receiver includes the receiver providing an indication to the controller that the substance is present on the windshield based on receiving the reflection.

[0047] Technical Solution 17. The method according to Technical Solution 12 further includes placing the transmitter and receiver between the rearview mirror of the vehicle and the windshield of the vehicle.

[0048] Technical Solution 18. The method according to Technical Solution 12 further includes assembling the transmitter to include a pseudo-random generator and an infrared light source.

[0049] Technical Solution 19. The method according to Technical Solution 18 further includes configuring the infrared light source to be triggered by the pseudo-random generator to output infrared light pulses.

[0050] The above-described features and advantages, as well as other features and advantages, of this disclosure will become apparent from the following detailed description when taken in conjunction with the accompanying drawings. Attached Figure Description

[0051] Other features, advantages, and details appear only by way of example in the following detailed description, which refers to the accompanying drawings, wherein:

[0052] Figure 1 It is a block diagram of a vehicle including a rain sensor according to one or more embodiments;

[0053] Figure 2 This is a block diagram of a rain sensor for a vehicle according to one or more embodiments; and

[0054] Figure 3 An exemplary timeline of infrared transmission from a rain sensor according to one or more embodiments is shown. Detailed Implementation

[0055] The following description is exemplary in nature only and is not intended to limit this disclosure, its application, or use. It should be understood that throughout all the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0056] As mentioned earlier, rain sensors can be one of the sensors that facilitate automated or semi-automated actions in a vehicle. Typically, rain sensors provide infrared transmission through the windshield. Any reflection of this transmission will indicate the presence of raindrops or other particles on the windshield, since a clean windshield will transmit infrared light without any reflection. The indication of something on the windshield can trigger automatic activation of the windshield wipers. When a given vehicle has a rain sensor and another vehicle nearby is performing a lidar scan, the infrared band transmitted by the lidar may be mistakenly interpreted as a reflection by the given vehicle's rain sensor. This phantom reflection can cause the windshield wipers to be unnecessarily activated.

[0057] The system and sensor embodiments detailed herein relate to vehicle rain sensing using modulated infrared transmission. Specifically, the receiver is effective only in conjunction with the transmission of infrared light pulses, and the timing of the transmission is modulated based on a pseudo-random generator. This reduces the likelihood of time overlap between rain sensing and a scan performed by a lidar system of another vehicle, which would cause the rain sensor to detect phantom reflections.

[0058] According to an exemplary embodiment, Figure 1 This is a block diagram of a vehicle 100 including a rain sensor 110. Figure 1 The exemplary vehicle 100 shown is a car 101. Vehicle 100 is shown with a rain sensor 110 behind a rearview mirror 150. That is, the rain sensor 110 is located between the rearview mirror 150 and the windshield 140. When the windshield 140 is transparent, infrared transmission 115 from the rain sensor 110 passes through the windshield 140. When raindrops 147 ( Figure 2), debris or any other substance 145 ( Figure 2 When it is on the windshield 140, it will reflect some infrared transmission 115 as reflection 120 back to the rain sensor 110.

[0059] A controller 130 is shown in vehicle 100. Controller 130 can control the windshield wipers 135 of vehicle 100 based on reflections 120 received by rain sensor 110. Controller 130 may include processing circuitry, which may include application-specific integrated circuits (ASICs), electronic circuitry, a processor (shared, dedicated, or grouped) and memory executing one or more software or firmware programs, combinational logic circuitry, and / or other suitable components that provide the aforementioned functionality.

[0060] Figure 1 Another vehicle 160 is shown. This other vehicle 160 is shown to have a lidar system 170 on its roof. The lidar system 170 may be inside the windshield of the other vehicle 160 or in another location. Furthermore, the other vehicle 160 and vehicle 100 may include additional sensors (e.g., radar systems, cameras). As indicated, light transmission 180 from the lidar system 170 can be implemented as a 360-degree scan. This light transmission 180 may include an infrared component.

[0061] For reference Figure 2 As detailed in detail, the rain sensor 110 is designed to increase the likelihood that the infrared transmission 115 will not coincide with the light transmission 180 from the lidar system 170 to the windshield 140 of the vehicle 100, as shown in the figure. In this way, the light transmission 180 is prevented from being mistaken for a reflection 120 produced by the infrared transmission 115. By preventing this phantom reflection, the controller 130 is prevented from activating the windshield wipers 135 when there is no material 145 (e.g., raindrops 147, debris) on the windshield 140.

[0062] Figure 2This is a block diagram of a rain sensor 110 for use in a vehicle 100 according to one or more embodiments. Infrared transmission 115 directed toward the windshield 140 of the vehicle 100 and reflection 120 reflected by water droplets or any substance 145 on the windshield 140 are indicated. The infrared transmission 115 originates from a transmitter 210 of the rain sensor 110, and the reflection 120 is received by a receiver 240 of the rain sensor 110. A rain sensor controller 250, controller 130, or a combination of both may be coupled to the transmitter 210 and the receiver 240. For example, the transmitter 210 may be triggered to start or stop operation. The receiver 240 may provide information based on the received reflection 120 (e.g., amplitude) such that one or more controllers 130, 250 may determine whether there is anything on the windshield 140 that should be cleared by, for example, activating a windshield wiper 135.

[0063] As shown, a rain sensor 110 is located on one side of the windshield 140 in vehicle 100 (e.g., in the passenger compartment). A light transmission 180 is indicated on the opposite side of the windshield 140. This light transmission 180 originates from a lidar system 170 of another vehicle 160 located near vehicle 100. As previously described, this light transmission 180 may include an infrared component, which, when received by the receiver 240 of the rain sensor 110, interferes with the rain sensor 110 due to being mistaken for a reflection 120. Consequently, the rain sensor 110 may unnecessarily activate the windshield wipers 135. To mitigate this possibility, the operation of the infrared transmission 115 and the receiver 240 is controlled, as described in detail.

[0064] The transmitter 210 of the rain sensor 110 includes an infrared light source 230 and a pseudo-random generator 220 to control the output timing of the infrared light source 230. This results in pulses of infrared transmission 115 with irregular timing, which are unlikely to coincide with the scan cycle of the lidar system 170 of another vehicle 160 (i.e., unlikely to coincide with the light transmission 180 directed at vehicle 100). Figure 3 An exemplary timeline of infrared transmission 115 based on pseudo-random generator 220 is shown. The receiver 240 of rain sensor 110 is activated only to coincide with the emission of infrared transmission 115.

[0065] In other words, given the relatively small distance (e.g., on the order of a few inches) between the rain sensor 110 and the windshield 140 of the vehicle 100, the round-trip time of the infrared transmission 115 from the transmitter 210 to the windshield 140 and the reflection 120 from the windshield 140 to the receiver 240 is small (e.g., on the order of a few microseconds). Therefore, the receiver 240 (e.g., a photodetector) can be turned on only when the infrared transmission 110 is emitted or immediately after emission (i.e., activated) and turned off within a few microseconds of that time. Any light transmission 180 reaching the rain sensor 110 outside this short duration is not received by the receiver 240. Therefore, based on the pseudo-random timing of the infrared transmission 115 and the fact that the receiver 240 is ineffective at times unrelated to those infrared transmissions 115, the rain sensor 110 is unlikely to receive the light transmission 180 as a phantom reflection.

[0066] Figure 3 An exemplary timeline of infrared transmission 115 from a rain sensor 110 according to one or more embodiments is shown. Six time intervals 310 t1 to t6 are shown together with corresponding infrared transmissions 115-1 to 115-6. The duration of each time interval 310 is the same (e.g., 1 second). The time for emitting infrared transmission 115 within each interval 310 is also indicated.

[0067] like Figure 3 As shown, within the corresponding interval 310, each infrared transmission 115 is not emitted simultaneously. Instead, based on the pseudo-random generator 220, the emission time of each infrared transmission 115 within a given interval 310 varies. The irregular (i.e., non-uniform) duration between the times of the infrared transmission 115 is unlikely to overlap with the scanning interval of the lidar system 170 of another vehicle 160, which is most likely periodic.

[0068] The coupling of the receiver 240, which is only effective in relation to infrared transmission 115, makes it highly unlikely that the timing of each infrared transmission 115 coincides with the light transmission 180, based on the scan duration of the lidar system 170 of another vehicle 160. If reflection 120 is received for a specified number of consecutive infrared transmissions 115, the controller 130 can activate only the windshield wipers 135. As a result, activation of the windshield wipers 135 based on phantom reflections caused by light transmission 180 from another vehicle 160 can be avoided.

[0069] While the foregoing disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes can be made and equivalents can replace its elements without departing from its scope. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from its essential scope. Therefore, it is intended that this disclosure be limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A rain sensor for a vehicle, comprising: A transmitter configured to perform pseudo-random modulation of the emission timing of infrared transmissions toward a vehicle windshield, wherein the specific emission time of each infrared transmission varies within a given interval relative to the emission times of other infrared transmissions; and The receiver is configured to be effective only for a specified period of time after each infrared transmission and to receive reflections of any material on the windshield based on the infrared transmission.

2. The rain sensor according to claim 1, wherein, The transmitter includes a pseudo-random generator and an infrared light source.

3. The rain sensor according to claim 2, wherein, The infrared light source is triggered by the pseudo-random generator to output infrared light pulses.

4. The rain sensor according to claim 1, wherein, The receiver is configured to provide the controller with an indication of the presence of a substance on the windshield based on the received reflection.

5. The rain sensor according to claim 4, wherein, The receiver is configured to provide an indication of the presence of raindrops on the windshield.

6. A system in a vehicle, the system comprising: Rain sensor, comprising: The transmitter is configured to perform pseudo-random modulation of the transmission timing of infrared transmission toward the vehicle's windshield. A receiver configured to be effective only for a specified time period after each infrared transmission, and to receive reflections based on any material encountered by the infrared transmission on the windshield; and A controller is configured to control the activation of the vehicle's windshield wipers based on information from the receiver, wherein the vehicle's windshield wipers are activated in response to a specified number of consecutive infrared transmissions receiving reflections.

7. The system according to claim 6, wherein, The transmitter includes a pseudo-random generator and an infrared light source.

8. The system according to claim 7, wherein, The infrared light source is triggered by the pseudo-random generator to output infrared light pulses.

9. The system according to claim 6, wherein, The receiver is configured to provide the controller with an indication of the presence of a substance on the windshield based on the received reflection.

10. The system according to claim 9, wherein, The controller is configured to activate the windshield wipers based on an indication of the presence of the substance.

11. The system according to claim 10, wherein, The controller is configured to activate the windshield wipers based on an indication that raindrops are present on the windshield.

12. A method for assembling a rain sensor in a vehicle, the method comprising: The transmitter is configured to implement pseudo-random modulation of the transmission timing for infrared transmission, wherein the specific transmission time of each infrared transmission varies within a given interval relative to the transmission times of other infrared transmissions; and Configure the receiver to be effective only for a specified period of time after each infrared transmission.

13. The method of claim 12, further comprising arranging the transmitter in a vehicle such that each launch is directed at the windshield of the vehicle.

14. The method of claim 13, further comprising positioning the receiver together with the transmitter to receive reflections from any material on the windshield based on the infrared transmission.

15. The method according to claim 14, wherein, The receiver is configured to receive reflections of raindrops encountered on the windshield based on infrared transmission.

16. The method of claim 14, wherein, The receiver is configured to provide an indication to the controller, based on the received reflection, that the substance is present on the windshield.

17. The method of claim 12, further comprising positioning the transmitter and receiver between the rearview mirror of the vehicle and the windshield of the vehicle.

18. The method of claim 12, further comprising assembling the transmitter to include a pseudo-random generator and an infrared light source.

19. The method of claim 18, further comprising configuring the infrared light source to be triggered by the pseudo-random generator to output infrared light pulses.

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