Heater control device

Abstract

A heater control device controls energization of a heater provided in a manner to heat an outer surface of a vehicle, and energizes the heater when an outside air temperature around the vehicle is less than a reference temperature higher than 0°C and an actuation signal of a wiper of the vehicle is continuously received for a predetermined prescribed reference time or more.

Description

Technical Field

[0001] This invention relates to a heater control device. Background Technology

[0002] A heater system is known, comprising: a heater disposed at the rear of a vehicle; a temperature sensor for measuring the outside air temperature; and a control unit for controlling the energization of the heater based on the temperature sensor readings, to suppress snow from adhering to the rear of a vehicle equipped with lights or sensors during snowfall (Japanese Patent Application Laid-Open No. 2020-030908). In the heater system described in Japanese Patent Application Laid-Open No. 2020-030908, the control unit energizes the heater when the temperature sensor reading is -15°C or higher and less than 5°C, and de-energizes the heater when the temperature sensor reading is less than -15°C or higher than 5°C. Summary of the Invention

[0003] In the heater system described in Japanese Patent Application Publication No. 2020-030908, the heater is energized when the outside temperature is above -15°C and below 5°C. However, in such cases, dry snow may fall. If the heater is energized during dry snowfall, it may actually promote snow adhesion to the area where the heater is installed.

[0004] In view of the above-mentioned problems, the object of the present invention is to suppress snow from adhering to areas where heaters are provided.

[0005] The main points of this invention are as follows.

[0006] (1) A heater control device that controls the energization of a heater installed to heat the outer surface of a vehicle, wherein,

[0007] The heater is powered on when the ambient temperature around the vehicle is lower than a reference temperature higher than 0°C and the vehicle's windshield wiper operation signal is continuously received for a predetermined reference time.

[0008] (2) According to the heater control device described in (1) above, when the external temperature is within a specified temperature range including the reference temperature and is above the reference temperature, the heater is energized when the windshield wiper operation signal of the vehicle is received.

[0009] (3) The heater control device according to (2) above, wherein the temperature range is -5℃ to 5℃.

[0010] (4) The heater control device according to any one of (1) to (3) above, wherein the heater heats a sensor disposed on the outer surface of the vehicle or a hood covering a sensor disposed on the vehicle.

[0011] (5) The heater control device according to any one of (1) to (4) above, wherein, during the energization of the heater, when the external temperature is above the reference temperature and a stop signal of the windshield wiper is received, the energization of the heater is stopped.

[0012] According to the present invention, snow can be prevented from adhering to areas where heaters are provided. Attached Figure Description

[0013] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described, in which the same reference numerals denote the same elements, and wherein:

[0014] Figure 1 This is a front view of a vehicle equipped with a heater control device according to one embodiment.

[0015] Figure 2 It is along Figure 1 Line II-II shows a cross-sectional view of the structure around the front bumper.

[0016] Figure 3 It is a schematic block diagram representing the structure of the heater system.

[0017] Figure 4 This is a flowchart illustrating the process of starting the heater by energizing it.

[0018] Figure 5 This is a flowchart illustrating the process of shutting down the heater by stopping the power supply to it. Detailed Implementation

[0019] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Furthermore, in the following description, the same reference numerals will be used to denote the same components.

[0020] Vehicle structure

[0021] First, refer to Figure 1 A brief description will be given of a vehicle 1 equipped with a heater control device according to one embodiment. Figure 1 This is a front view of a vehicle 1 equipped with a heater control device according to one embodiment.

[0022] In this embodiment, vehicle 1 is a four-wheeled automobile with a box-shaped exterior. For example... Figure 1As shown, vehicle 1 includes a body panel 2 and a front bumper 3 as components constituting its outer body. Furthermore, a logo 4 of vehicle 1 is positioned in the center of the front bumper 3. Additionally, vehicle 1 can also be a vehicle other than a four-wheeled vehicle, such as a three-wheeled vehicle. In this embodiment, the front bumper 3 and logo 4 are made of resin, but they can also be made of other materials.

[0023] Furthermore, in this embodiment, a millimeter-wave radar 11 is disposed on the inner side of the front bumper 3 and the emblem 4 (see reference). Figure 2 and Figure 3 The millimeter-wave radar 11, located inside the front bumper 3 and emblem 4, detects objects present in front of the vehicle 1. Furthermore, the millimeter-wave radar 11 can be mounted on the rear outer panel of the vehicle, such as the rear bumper. Moreover, the millimeter-wave radar can also be installed on outer panel components other than the front bumper 3, emblem 4, and rear bumper.

[0024] In this embodiment, the millimeter-wave radar 11 is in Figure 1 The location indicated by the dotted line A is positioned inside the front bumper 3 and the emblem 4. In this embodiment, multiple (in) [unclear text - possibly referring to a specific type of emblem] are provided on the front bumper 3. Figure 1 The example shown features four millimeter-wave radars 11, which are spaced apart from each other in the width direction of the vehicle. The millimeter-wave radars 11 are also located on the rear bumper.

[0025] Figure 2 It is along Figure 1 Line II-II shows a cross-sectional view of the structure surrounding the front bumper 3. (See line II-II for details.) Figure 2 As shown, a millimeter-wave radar 11 is disposed on the inner side of the front bumper 3. In particular, in this embodiment, the millimeter-wave radar 11 is mounted on the inner side of the front bumper 3 by means of a mounting member 5 for mounting the millimeter-wave radar 11 to the front bumper 3.

[0026] Furthermore, the front bumper 3 has a through hole 6 at the location where the millimeter-wave radar 11 is installed, which extends through the front bumper 3. The through hole 6 is positioned in the direction detected by the millimeter-wave radar 11. Therefore, the millimeter-wave radar 11 detects the distance to surrounding objects through the through hole 6.

[0027] Furthermore, a wave-transmitting cover 3' is provided in the through hole 6 to block the through hole 6. The wave-transmitting cover 3' is formed of a resin with high radio wave transmittance and is formed to be thinner than the front bumper 3. The wave-transmitting cover 3' can be formed of the same material as the front bumper 3 or a different material. Furthermore, if the wave-transmitting cover 3' is formed of the same material as the front bumper 3, it can be integrally formed with the front bumper 3.

[0028] Furthermore, in this embodiment, a heater 15 is disposed on the outer surface of the radome 3' positioned in the detection direction of the millimeter-wave radar 11, in a manner that covers the millimeter-wave radar 11. In this embodiment, the heater 15 is a heat wire disposed on the outer surface of the radome 3'. The heater 15 functions to melt snow, such as when snow adheres to the outer surface of the radome 3'. Additionally, the heater 15 is capable of melting components (in the detection direction of the millimeter-wave radar 11) that are attached to the surface. Figure 2 The snow on the wave shield 3' shown in the example can be configured in any way. Therefore, for example, if the wave shield 3' has high thermal conductivity, the heater 15 can be disposed inside the wave shield 3'. Furthermore, the heater 15 can be a device that heats using radiant heat or other methods that use a different principle than heat wires.

[0029] Furthermore, the millimeter-wave radar 11 is positioned inside the emblem 4 in the same manner as the inside of the front bumper 3. Therefore, the millimeter-wave radar 11 is positioned inside the through-hole containing the emblem 4, and the emblem 4 is formed of a material with high radio wave transmittance. Additionally, a heater 15 is positioned on the outer surface of the emblem 4.

[0030] In addition, Figure 2 In the example shown, a radome 3' is provided in the detection direction of the millimeter-wave radar 11. However, the radome 3' may not be provided. In this case, the millimeter-wave radar 11 is configured such that its detection surface is exposed to the outside in the same way as the outer surface of the front bumper 3. Furthermore, in this case, the heater 15 is configured to directly heat the detection surface of the millimeter-wave radar 11. Therefore, if snow adheres to the detection surface of the millimeter-wave radar 11, the heater 15 can melt the snow adhering to the detection surface. In any case, the heater 15 is configured to heat the outer surface of the vehicle 1.

[0031] Next, refer to Figure 3 The structure of a heater system 100 equipped with a heater control device according to one embodiment will be described. The heater system 100 controls the power supply to the heater 15 provided on the outer surface of the vehicle 1. Figure 3 This is a schematic block diagram showing the structure of the heater system 100.

[0032] like Figure 3As shown, in this embodiment, the heater system 100 includes a millimeter-wave radar 11, a temperature sensor 12, a wiper operating tool 13, a heater 15, a wiper 16, and an electronic control unit (hereinafter referred to as "ECU") 20. These components—the millimeter-wave radar 11, temperature sensor 12, wiper operating tool 13, heater 15, wiper 16, and ECU 20—are communicatively connected to each other, for example, via an in-vehicle network 10. The in-vehicle network 10 is, for example, a network conforming to standards such as Controller Area Network (CAN). Alternatively, these devices may be directly connected to each other, at least partially, via signal lines without going through the in-vehicle network 10.

[0033] The millimeter-wave radar 11 is an example of a ranging sensor that detects the distance to objects located around the vehicle 1. The millimeter-wave radar 11 outputs distance measurement data to objects around the vehicle 1 (especially in front of the vehicle 1) for each predetermined period via the in-vehicle network 10 to the ECU 20. Alternatively, other ranging sensors such as LiDAR or sonar can be used instead of the millimeter-wave radar 11.

[0034] Temperature sensor 12 is a sensor that detects the external temperature around vehicle 1. Temperature sensor 12 outputs the measured external temperature around vehicle 1 to ECU 20 for each specified period via in-vehicle network 10.

[0035] The windshield wiper operating tool 13 is an operating element for controlling the windshield wipers 16 by the occupants of vehicle 1. The windshield wiper operating tool 13 switches between, for example, a wiper stop indication position that stops the operation of the wipers, a wiper intermittent operation indication position that causes the wipers to operate intermittently, and a wiper continuous operation indication position that causes the wipers to operate continuously. The windshield wiper operating tool 13 outputs a signal corresponding to the operating position to the ECU 20.

[0036] The heater 15 is configured to heat the outer surface of the vehicle 1 at the location where the millimeter-wave radar 11 is located. Specifically, in this embodiment, the heater 15 is configured to heat the radar shield 3' (including the emblem 4) located at the position corresponding to the millimeter-wave radar 11. Furthermore, as described above, when the millimeter-wave radar 11 is located on the outer surface of the vehicle 1, the heater 15 is configured to heat the millimeter-wave radar 11 located on the outer surface of the vehicle 1. The heater 15 heats the outer surface of the vehicle 1 by being energized according to an energizing signal from the ECU 20.

[0037] Windshield wiper 16 is used to wipe the windshield 7 of vehicle 1 (reference). Figure 1The wiper 16 is a device for wiping the surface of the windshield 7. When the wiper 16 is activated, raindrops or snow on the windshield 7 are wiped away. The wiper 16 is activated according to the activation signal from the ECU 20 and stopped according to the stop signal from the ECU 20.

[0038] ECU Overview

[0039] ECU20 functions as a heater control device that controls the power supply to the heater in vehicle 1. Figure 3 In the example shown, the heater system 100 has one ECU 20, but it may also have multiple ECUs 20 that are separate in function. ECU 20 has a communication interface 21, a storage unit 22, and a processor 23. Furthermore, the communication interface 21, storage unit 22, and processor 23 may be independent circuits, or they may be configured as a single integrated circuit.

[0040] Communication interface 21 is a circuit used to connect ECU 20 to the vehicle network 10. Communication interface 21 sends signals received from millimeter-wave radar 11, temperature sensor 12, and wiper operation tool 13 to processor 23. Furthermore, communication interface 21 sends signals output from processor 23 to heater 15.

[0041] Storage unit 22 stores data. Storage unit 22 may include at least one of volatile semiconductor memory, non-volatile semiconductor memory, hard disk drive (HDD), and solid-state drive (SSD). Storage unit 22 stores programs executed by processor 23. Furthermore, storage unit 22 stores data transmitted from various sensors.

[0042] Processor 23 has one or more central processing units (CPUs) and their peripheral circuitry. Processor 23 may also have other arithmetic circuitry such as logic units or numerical processing units. Processor 23 executes computer programs stored in storage unit 22.

[0043] like Figure 3 As shown, the processor 23 includes a wiper control unit 231 and a heater control unit 232. These units of the processor 23 are, for example, functional modules implemented by a computer program operating on the processor 23. Alternatively, the units of the processor 23 may be installed in the ECU 20 as independent integrated circuits, microprocessors, or firmware.

[0044] The wiper control unit 231 sends a control signal to the wiper 16 based on the signal from the wiper operating tool 13 and the output of the rain sensor (not shown) that detects rainfall. When the wiper operating tool 13 is in the wiping stop indication position, the wiper control unit 231 outputs a stop signal to the wiper 16. Furthermore, when the wiper operating tool 13 is in the intermittent wiper operation indication position, the wiper control unit 231 outputs an operation signal to the wiper 16 when raindrops or snow are detected by the rain sensor, and outputs a stop signal to the wiper 16 when no raindrops or snow are detected by the rain sensor. When the wiper operating tool 13 is in the continuous wiper operation indication position, the wiper control unit 231 outputs an operation signal to the wiper 16. Furthermore, taking the control method of the wiper 16 based on the wiper control unit 231 described above as an example, the wiper control unit 231 can control the wiper 16 in a control method different from the control method described above.

[0045] The heater control unit 232 controls the power supply to the heater 15 based on the measurement data from the millimeter-wave radar 11, the measurement data from the temperature sensor 12, and the control signal from the wiper control unit 231 to the wiper 16.

[0046] In this embodiment, the heater 15 is used to melt snow adhering to the outer surfaces of the front bumper 3 and the emblem 4. When an actuation signal is output to the wiper 16, it is generally assumed that snow or rain is falling. Therefore, the heater control unit 232 can essentially energize the heater 15 to perform heating based on the heater 15 when it receives an actuation signal to the wiper 16 and the outside temperature is within a predetermined reference temperature range. Furthermore, if the outside temperature is outside the reference temperature range or no actuation signal is output to the wiper 16, the heater control unit 232 does not energize the heater 15 and does not perform heating based on the heater 15. When the outside temperature is above the reference temperature range, it rains instead of snows, and snow does not adhere to the outer surfaces of the front bumper 3 and the emblem 4. Furthermore, when the outside temperature is below the reference temperature range, dry snow falls, but the dry snow does not generally adhere to the outer surfaces of the front bumper 3 and the emblem 4. Thus, heating based on the heater 15 is not performed when the outside temperature is outside the reference temperature range, thereby suppressing unnecessary power consumption by the heater 15.

[0047] Here, the reference temperature range is, for example, -5°C to 5°C. Therefore, when the outside temperature detected by temperature sensor 12 is less than -5°C or higher than 5°C, the heater 15 is not energized. However, the reference temperature range can be any temperature below 3°C or 7°C, rather than below 5°C, as long as it is a temperature where rainfall is likely rather than snowfall. Furthermore, the reference temperature range can be any temperature where wet snowfall is possible, rather than above -5°C, but above -3°C, -10°C, or -15°C.

[0048] Furthermore, wet snow easily adheres to the outer surfaces of the front bumper 3 and emblem 4. Therefore, when it is deduced that wet snow is falling, the heater control unit 232 energizes the heater 15 to heat it. In particular, wet snow is more likely to fall when the outside temperature is relatively high within a predetermined reference temperature range. Therefore, in this embodiment, when the outside temperature detected by the temperature sensor 12, which receives the actuation signal from the wiper 16, is above a predetermined reference temperature, the heater control unit 232 energizes the heater 15. Here, the reference temperature is, for example, 1°C. However, the reference temperature can be any temperature other than 1°C, such as 0.5°C or 2°C, as long as it is a temperature that makes it easier for wet snow to fall than dry snow. However, the reference temperature is set to a temperature higher than 0°C.

[0049] On the other hand, when the outside temperature is below the reference temperature within the reference temperature range, both dry and wet snow may fall. Therefore, in this embodiment, when the outside temperature is below the reference temperature within the reference temperature range (for example, when the outside temperature is -5°C to 1°C), in addition to the outside temperature detected by the temperature sensor 12, the power supply to the heater 15 is controlled based on the signal output from the wiper control unit 231.

[0050] Specifically, in this embodiment, regarding the heater control unit 232, when the outside temperature is below the reference temperature within the reference temperature range, the heater 15 is energized if an actuation signal is continuously received from the wiper control unit 231 for a predetermined reference time or longer. On the other hand, when the outside temperature is below the reference temperature within the reference temperature range, the heater control unit 232 does not energize the heater 15 if no actuation signal is received from the wiper control unit 231 for a period less than the reference time. Here, the reference time is, for example, 3 seconds. However, as long as the reference time is equivalent to the wiper operation time when the occupant operates the wiper 16 alone (or in small amounts) during dry snowfall, the time other than 3 seconds can be, for example, 1 second or 5 seconds.

[0051] In the case of dry snow, snow essentially does not adhere to the windshield 7, so there is no need to operate the wipers 16. Furthermore, even assuming the wipers operate, after only one or two wipes, no more snow will adhere to the windshield 7, so no further wiping is required. Therefore, in the case of dry snow, only a very short period of single (or a few) wiper operation is performed. On the other hand, in the case of wet snow, snow adheres to the windshield 7, so the wipers 16 operate continuously. Based on the above, it is assumed that when the wiper 16's operating signal output reaches a reference time or longer, wet snow is produced, and snow adheres to the outer surfaces of the front bumper 3 and emblem 4. On the other hand, it is assumed that when the wiper 16's operating signal output is only less than the reference time, it is dry snow, and snow will not adhere to the outer surfaces of the front bumper 3 and emblem 4.

[0052] In this embodiment, the heater 15 is energized when the wiper 16 actuation signal is continuously received for a reference time or longer, i.e., considering wet snowfall. On the other hand, the heater 15 is de-energized only when the wiper 16 actuation signal is received for a period shorter than the reference time, i.e., considering dry snowfall. Thus, by energizing the heater 15 only when wet snowfall requires melting, snow adhesion to the areas where the heater 15 is located, i.e., the outer surfaces of the windshield 3' and the emblem 4, can be suppressed, and unnecessary power consumption due to energization can be prevented. In particular, if the heater 15 is energized during dry snowfall, dry snow that would not normally adhere to the outer surfaces of the windshield 3' and the emblem 4 will melt on the windshield 3' and the emblem 4, causing snow to adhere to them. However, by suppressing the energization of the heater 15 during dry snowfall, the induction of such snow adhesion is suppressed.

[0053] Furthermore, in this embodiment, regarding the heater control unit 232, when the heater 15 is energized, if the outside temperature is above the reference temperature and a stop signal from the windshield wiper 16 is received, the energization of the heater 15 is stopped. Here, if there is snowfall when the outside temperature is above the reference temperature, then wet snowfall occurs. However, in this case, the windshield wiper 16 stopping means that there is no snowfall. Therefore, it is assumed that there is no snowfall when the outside temperature is above the reference temperature and a stop signal from the windshield wiper 16 is received, and thus the energization of the heater 15 is stopped. This suppresses unnecessary energization of the heater 15, thus reducing power consumption.

[0054] Control process

[0055] Next, refer to Figure 4 and Figure 5 The control process of heater 15 based on heater control device is explained. Figure 4This is a flowchart illustrating the heater start-up process, which involves energizing heater 15. (About...) Figure 4 The heater activation process shown is executed by the processor 23 at certain time intervals when the power supply to the heater 15 is stopped.

[0056] If the heater start-up process is initiated, the heater control unit 232 first determines whether the external temperature detected by the temperature sensor 12 is above -5°C and below 5°C, i.e., whether it is within the reference range (step S11). In step S11, if it is determined that the external temperature detected by the temperature sensor 12 is below -5°C or above 5°C, the heater start-up process is terminated. Therefore, power is not supplied to the heater 15.

[0057] On the other hand, in step S11, if the external temperature detected by the temperature sensor 12 is determined to be above -5°C and below 5°C, the heater control unit 232 determines whether there is snow contamination in front of the millimeter-wave radar 11 (i.e., on the radome 3' and the logo 4) (step S12). The determination of whether there is snow contamination is made, for example, based on whether there is an anomaly in the output of the millimeter-wave radar 11. In the case of snow contamination, the millimeter waves radiated from the millimeter-wave radar 11 undergo diffuse reflection, thus causing an abnormal output from the millimeter-wave radar 11. If snow contamination is determined to be present in step S12, the heater control unit 232 energizes the heater 15 (step S15).

[0058] On the other hand, if it is determined in step S12 that there is no snow pollution, the heater control unit 232 determines whether the outside temperature detected by the temperature sensor 12 is above 1°C (i.e., above the reference temperature) and whether it has received an operation signal from the windshield wiper 16 (step S13). In step S13, if it is determined that the outside temperature is above 1°C and an operation signal from the windshield wiper 16 has been received, the heater control unit 232 energizes the heater 15 (step S15).

[0059] On the other hand, if it is determined in step S13 that the external temperature is less than 1°C (i.e., less than the reference temperature), the heater control unit 232 determines whether the continuous reception time of the wiper 16's actuation signal is 3 seconds or more (i.e., more than the reference time) (step S14). In step S14, if it is determined that the continuous reception time of the wiper 16's actuation signal is less than 3 seconds, the heater start-up process ends. Therefore, the heater 15 is not energized. On the other hand, if it is determined in step S14 that the continuous reception time of the wiper 16's actuation signal is 3 seconds or more, the heater control unit 232 energizes the heater 15 (step S15).

[0060] Figure 5This is a flowchart illustrating the heater shutdown process, which involves stopping the energization of heater 15. During the energization of heater 15, the processor 23 executes the process at regular time intervals. Figure 5 The heater is shut down as shown.

[0061] If the heater shutdown process is initiated, firstly, similar to step S12, the heater control unit 232 determines whether there is snow contamination in front of the millimeter-wave radar 11 (i.e., on the radome 3' and the emblem 4) (step S21). If snow contamination is determined to exist in step S21, the heater shutdown process ends, thereby continuing to power the heater 15. On the other hand, if no snow contamination is determined in step S21, the heater control unit 232 determines whether the outside temperature is above 1°C and whether a stop signal from the windshield wiper 16 has been received (step S22). In step S22, if the outside temperature is determined to be above 1°C and a stop signal from the windshield wiper 16 has been received, the heater control unit 232 stops powering on the heater 15 (step S24).

[0062] If, in step S22, the outside temperature is determined to be less than 1°C, the heater control unit 232 determines whether the continuous reception time of the wiper 16 stop signal is more than 4 minutes (step S23). If, in step S23, the continuous reception time of the wiper 16 stop signal is less than 4 minutes, the heater shutdown process ends, and power is continued to be supplied to the heater 15. On the other hand, if, in step S23, the continuous reception time of the wiper 16 stop signal is more than 4 minutes, the heater control unit 232 stops powering to the heater 15 (step S24).

[0063] Furthermore, in the above embodiment, a ranging sensor including millimeter-wave radar 11 is used as the sensor. However, other sensors besides the ranging sensor, such as a camera, can also be used as the sensor. In this case, the heater 15 is configured, for example, to heat the outer surface of the glass disposed in front of the camera.

[0064] Furthermore, in Figure 4 and Figure 5 In the example shown, steps S12 and S21 determine whether there is snow pollution. However, this determination of snow pollution can be omitted.

[0065] The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims.

Claims

1. A heater control device that controls the energization of a heater installed for heating the outer surface of a vehicle, characterized in that... The heater is powered on when the ambient temperature around the vehicle is lower than a reference temperature higher than 0°C and the vehicle's windshield wiper operation signal is continuously received for a predetermined reference time.

2. The heater control device according to claim 1, characterized in that, When the external air temperature is within a specified temperature range including and above the reference temperature, the heater is energized upon receiving an operation signal from the vehicle's windshield wipers.

3. The heater control device according to claim 2, characterized in that, The temperature range is -5℃ to 5℃.

4. The heater control device according to any one of claims 1 to 3, characterized in that, The heater heats the sensors disposed on the outer surface of the vehicle or the shroud covering the sensors disposed on the vehicle.

5. The heater control device according to any one of claims 1 to 3, characterized in that, During the power supply to the heater, if the external air temperature is above the reference temperature and a stop signal from the windshield wipers is received, the power supply to the heater is stopped.

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