Heating control system and windshield

Abstract

A heating control system for controlling a heating element provided on a glass that separates an indoor and an outdoor of a mobile body, includes a sensor information acquisition unit that acquires sensor information from one or more sensors, and a control processing unit that controls a first heating element provided in a first region of the glass and a second heating element provided in a second region of the glass that is different from the first region based on the sensor information, the control processing unit including a temperature difference reduction processing unit that performs temperature difference reduction processing that controls at least one of the first heating element and the second heating element so that a temperature difference between a glass temperature of a third region between the first region and the second region of the glass and a glass temperature of the first region or a glass temperature of the second region does not exceed an upper limit value.

Description

Technical Field

[0001] This invention relates to a heating control system for windshields and windshields. Background Technology

[0002] A windshield is known to have heating elements installed in two separate areas of the glass.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-216193 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] However, in the aforementioned prior art, there is a possibility that a region (referred to as the "intermediate region") may be created between the two regions where the heating element is located, where the temperature difference between the glass and the two regions is large. If the temperature difference between the intermediate region and the region where the heating element is located is too large, the temperature difference may cause glass defects in the intermediate region.

[0008] Therefore, in one aspect, the present invention aims to reduce the possibility of glass defects occurring in areas between regions where heating elements are provided.

[0009] means of solving technical problems

[0010] In one aspect, there is a heating control system for controlling a heating element disposed on glass separating the interior and exterior of a moving body, comprising:

[0011] The sensor information acquisition unit acquires sensor information from one or more sensors, and

[0012] The control processing unit controls a first heating element located in a first region of the glass and a second heating element located in a second region of the glass, different from the first region, based on the sensor information.

[0013] The control processing unit includes a temperature difference reduction processing unit, which performs temperature difference reduction processing to control at least one of the first heating element and the second heating element so that the temperature difference between the glass temperature of the third region between the first region and the second region of the glass and the glass temperature of the first region or the glass temperature of the second region does not exceed an upper limit value.

[0014] The effects of the invention

[0015] In one aspect, according to the invention, the possibility of glass defects occurring in areas between areas where heating elements are provided can be reduced. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a vehicle windshield according to the first embodiment.

[0017] Figure 2 yes Figure 1 An enlarged view of part Q1.

[0018] Figure 3 It is along Figure 2 A schematic cross-sectional view taken along line AA.

[0019] Figure 4 This is a schematic diagram of the control system for a vehicle's windshield.

[0020] Figure 5 This is a functional diagram illustrating the function of the control device associated with the heating control for the windshield.

[0021] Figure 6 This is an illustration of threshold information.

[0022] Figure 7 This diagram illustrates the reasons why defects (such as cracks) may occur in the third region.

[0023] Figure 8A This is an illustration of the situation where the temperature difference reduction process is performed while only the second power-on process is being executed (Figure 1).

[0024] Figure 8B This is a diagram illustrating the situation where the temperature difference reduction process is performed while only the second power-on process is being executed (Figure 2).

[0025] Figure 8C This is a diagram illustrating the situation where the temperature difference reduction process is performed while only the second power-on process is being executed (Figure 3).

[0026] Figure 8D This is an illustration of the situation where the temperature difference reduction process is performed while only the second power-on process is being executed (Figure 4).

[0027] Figure 9A This is an illustration of the situation where the temperature difference reduction process is performed while the first and second power-on processes are being executed (Figure 1).

[0028] Figure 9B This is a diagram illustrating the situation where the temperature difference reduction process is performed while the first and second power-on processes are in progress (Figure 2).

[0029] Figure 9CThis is a diagram illustrating the situation where the temperature difference reduction process is performed while the first and second power-on processes are in progress (Figure 3).

[0030] Figure 9D This is a diagram illustrating the situation where the temperature difference reduction process is performed while the first and second power-on processes are in progress (Figure 4).

[0031] Figure 10A This is an illustration of the case where the temperature difference reduction process is performed when only the second power-on process is executed, given that the distance between the first and second regions is relatively large.

[0032] Figure 10B This is an illustration of the case where the temperature difference reduction process is performed when only the second power-on process is executed, given that the distance between the first and second regions is relatively large.

[0033] Figure 10C This is an illustration of the situation where the temperature difference reduction process is performed when only the second power-on process is executed, given that the distance between the first and second regions is relatively large. (Figure 3)

[0034] Figure 10D This is an illustration of the case where the temperature difference reduction process is performed when only the second power-on process is executed, given that the distance between the first and second regions is relatively large. (Figure 4)

[0035] Figure 11 This is a schematic flowchart illustrating an example of a process performed by the control device of this embodiment associated with the heating control of the windshield.

[0036] Figure 12 This illustrates the control process of the first heating element ( Figure 11 A schematic flowchart of an example of step S2).

[0037] Figure 13 This illustrates the control process of the second heating element ( Figure 11 A schematic flowchart of an example of step S3).

[0038] Figure 14 This is an enlarged view of a portion of the windshield 1A for a vehicle according to the second embodiment. Detailed Implementation

[0039] Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings. In the drawings, for ease of observation, sometimes only a portion of multiple parts with the same attribute are labeled. Furthermore, unless the direction is specifically stated in the drawings used to illustrate the form, the directions shown in the drawings shall be followed; the directions in each drawing correspond to the directions of the symbols and numbers. In addition, deviations in parallel, right-angled, and vertical directions are permissible without impairing the effect.

[0040] The following describes various embodiments of a vehicle windshield 1 installed at the front of a vehicle as an example. However, the vehicle windshield 1 described below can also be installed on the side or rear of the vehicle.

[0041] First Implementation Method

[0042] Figure 1 This is a schematic diagram of the windshield 1 for a vehicle according to the first embodiment. Figure 2 yes Figure 1 An enlarged view of part Q1. Figure 3 It is along Figure 2 A schematic cross-sectional view taken along line AA. Figure 3 The diagram illustrates Figure 1 and Figure 2 Cover 4, not shown in the diagram. Figure 3 The outer and inner sides (carriage side) of the vehicle are shown with the center of the window glass in the 50mm thickness direction as a reference.

[0043] Figure 1 The vehicle frame 80, which is equipped with a windshield 1, is also shown. Figure 1 This is a diagram showing the view from the front window 50, illustrating the state of the front window 50 installed on the vehicle as seen from inside the passenger compartment. Furthermore, the front window 50 is not only suitable for automobiles, but also for various moving vehicles, including trams, buses, ships, airplanes, and construction machinery.

[0044] Hereinafter, each region of the window glass 50 (first region 131, etc.) can be a region of the surface of the window glass 50 (e.g., the surface of the side of the carriage) or a region including the thickness of the window glass 50. Furthermore, the distance between each region of the window glass 50 (or such distance) is the shortest distance along the surface of the window glass 50, but when the radius of curvature of the window glass 50 is large, it can also be the shortest distance on an approximate plane. Here, as... Figure 1 As shown, the X and Y directions are defined as two mutually orthogonal directions, and the XY plane is a plane that can approximate the surface of the window glass 50. Thus, the X direction corresponds to the vehicle width direction, and the Y direction corresponds to the vertical direction (but it can also be a vertical direction inclined to the vertical direction).

[0045] like Figure 1 As shown schematically, the windshield 1 for a vehicle includes a window glass 50, a heating device 60, and a sensor device 70. Figure 1 A portion of the sensor device 70 is omitted (see [reference]). Figure 2 The illustration is shown.

[0046] Window glass 50 is a window panel covering the opening of the vehicle frame 80. The substrate of window glass 50 is not limited to glass; it can also be resin, film, etc., but all are substrates that transmit electromagnetic waves. Window glass 50 can be formed by bonding multiple substrates, and can also be fitted with films that perform various functions, and can even be formed with antennas, etc. In this embodiment, as an example, window glass 50 can be formed by overlapping two pieces of glass 51a, 51b with an intermediate film 51c (see reference). Figure 3 The laminate is made by pressurizing and heating the laminate using an autoclave or similar device.

[0047] The window glass 50 is mounted on a body flange formed on the vehicle frame 80. Figure 1 In the diagram, the outer peripheries 50a, 50b, 50c, and 50d of the window glass 50 are shown with dashed lines. The vehicle frame 80 has a body flange for forming the window opening of the vehicle body.

[0048] The windshield window glass 50 has a shielding area on its periphery. This shielding area is either an area with a black or brown shielding film 54, or an area where part of the interlayer film is colored. The shielding film 54 is formed of ceramic film such as black ceramic film or black organic ink film. This shielding film 54 improves the aesthetics when in-vehicle devices are installed, both from outside and inside the vehicle, and is a film that allows radio waves to pass through. The shielding film 54 has a portion 54a of a certain width extending approximately a certain width from the outer periphery of the window glass 50, and a protrusion 54b protruding downwards from the upper part and center (the center in the left-right direction) of the window glass 50. The protrusion 54b can be shaped such that its width decreases towards the lower left-right direction (a roughly trapezoidal shape), or conversely, its width increases towards the lower left-right direction. A portion of the protrusion 54b may also be cut out.

[0049] The heating device 60 is a device for heating the window glass 50. The heating device 60 includes a first heating device 61 and a second heating device 62.

[0050] The first heating device 61 is provided corresponding to the first region 131 of the window glass 50.

[0051] The first region 131 is a portion of the entire area of ​​the window glass 50 and is designed to correspond to the forward view of passengers, including the driver. The aforementioned blinding film 54 is configured in a manner that does not obstruct the forward view through the first region 131. The shape of the first region 131 is arbitrary, but it can also be as follows... Figure 1 As shown, it is rectangular when viewed from above (a view perpendicular to the XY plane, the same below). However, in variant examples, the shape of the first region 131 also includes a shape with a concave or convex outer periphery when viewed from above.

[0052] The first heating device 61 includes: a first heating element 610, busbars 612 and 613, and a switch 614.

[0053] The first heating element 610 is in the form of an electric heating wire or an electric heating film, and has the characteristic of generating heat when current flows through it. The first heating element 610 can, for example, be like... Figure 3 As shown, it is disposed on the outer surface of the glass 51b on the side of the car body of the window glass 50. The first heating element 610 is disposed within the first region 131. In other words, the first heating element 610 is disposed in a form that defines the first region 131. Here, the boundary of the first region 131 in the Y direction is defined by the first heating element 610. That is, the upper boundary of the first region 131 in the Y direction is the position of the uppermost first heating element 610 in the Y direction, and the lower boundary of the first region 131 in the Y direction is the position of the lowermost first heating element 610 in the Y direction. The boundary of the first region 131 in the X direction is defined by the connecting lines that connect the end positions of each first heating element 610 (the connection positions with the busbars 612 and 613) on both sides in the X direction.

[0054] The first heating element 610 is preferably arranged in a configuration density with virtually no deviation, thereby achieving uniform heating within the first region 131. Furthermore, in this embodiment, as an example, the heating wire of the first heating element 610 is... Figure 1 As shown, multiple heating elements 610 extend along the X direction with a certain spacing d1 in the Y direction. The first heating elements 610 are not continuous with each other, but they can also be formed in a shape that folds back from one end to the other and then back from the other end to one end in the X direction (a back-and-forth shape).

[0055] In this embodiment, as an example, each of the first heating elements 610 extends in the X direction and is arranged in a row in the Y direction, but it is not limited to this. For example, each heating wire constituting the first heating element 610 may also extend in the Y direction and be arranged in a row in the X direction.

[0056] Copper, silver, or tungsten can be used as the heating wire. The heating film can be a dielectric layer / silver / dielectric layer or a dielectric layer / silver / dielectric layer / silver / dielectric layer. Tin oxide, zinc oxide, silicon nitride, titanium oxide, or aluminum oxide can be used as the dielectric layer.

[0057] Busbar 612, for example, forms an electrode on the positive side and is electrically connected to the positive side of the vehicle battery (not shown). Busbar 612 can also be in the form of a film of conductive material. This is also true for other busbars such as busbar 613. Furthermore, busbar 612 can be electrically connected to the vehicle battery via a power generation unit (not shown) that generates a specified power supply voltage. Busbar 612, for example, is like... Figure 1As shown, it extends along the Y direction to the left of the X direction in the first region 131 in a manner located within a certain width portion 54a on the left side of the X direction when viewed from above.

[0058] Busbar 613, for example, forms an electrode on the negative side and is electrically connected to the negative side (ground) of the vehicle battery (not shown). Busbar 613, for example, is like... Figure 1 As shown, the busbar 613 extends along the Y direction from the right side of the X direction in the first region 131 in a shape located within a certain width portion 54a on the right side of the X direction when viewed from above. The busbar 613 can be symmetrical to the busbar 612 on both sides.

[0059] The switch unit 614 is electrically connected between the busbar 612 and the vehicle battery. The switch unit 614 includes a switch for turning the first heating element 610 energized on / off. Such a switch may be, for example, in the form of a relay or a semiconductor switch. When the switch unit 614 is controlled to be on, conduction is realized between the first heating element 610 and the vehicle battery (i.e., energizing the first heating element 610), and the heat generated by the first heating element 610 heats the window glass 50 in the first region 131.

[0060] The on / off state of the switch unit 614 is controlled by the control device 10 (see...) Figure 4 The wiring from the switch section 614 to the control device 10 is not shown. Figure 1 As shown in the accompanying drawings, it can also be formed in the same manner as the various wiring of the first heating device 61 in the area that overlaps with the certain width portion 54a when viewed from above.

[0061] The second heating device 62 is provided corresponding to the second region 132 of the window glass 50.

[0062] The second area 132 is a part of the overall area of ​​the window glass 50, corresponding to the vehicle perimeter monitoring sensor 20 (see [link]). Figure 3 The area is defined as a dashed rectangle. The vehicle perimeter monitoring sensor 20 can be a radar sensor (e.g., a millimeter-wave radar sensor), an image sensor (i.e., a camera, such as a stereo camera), etc. The second area 132 is as follows: Figure 3 As schematically shown, the side of the carriage is covered by a cover 4. The cover 4 only needs to at least partially cover the second region 132 and can be of any shape, such as a frame. In this case, for example, the space formed between the second region 132 of the window glass 50 and the cover 4 can be used to arrange radar sensors, image sensors, LiDAR (Light Detection and Ranging System), substrates, etc.

[0063] Thus, the second region 132 is set to correspond to the forward field of view of the vehicle perimeter monitoring sensor 20. Therefore, the protrusion 54b of the shielding film 54 can have an opening so as not to affect the forward field of view through the second region 132. However, if the shielding film 54 that transmits radio waves does not affect the "eye" of the vehicle perimeter monitoring sensor 20, the shielding film 54 can also be formed so that it coincides with the second region 132 when viewed from above.

[0064] The shape of the second region 132 is arbitrary, and can be as follows: Figure 2 As shown, it is rectangular when viewed from above. However, in variant examples, the shape of the second region 132 also includes a shape where the outer periphery is concave or convex when viewed from above.

[0065] The second heating device 62 includes: a second heating element 620, busbars 622 and 623, and a switch 624.

[0066] The second heating element 620 is in the form of an electric heating wire or an electric heating film, and has the characteristic of generating heat when current flows through it. The second heating element 620 can, for example, be like... Figure 3 As shown, it is installed on the surface of the glass 51b on the car side of the window glass 50. The second heating element 620 is disposed within the second region 132. In other words, the second heating element 620 is disposed in a form that defines the second region 132. Here, the boundary of the second region 132 in the Y direction is defined by the second heating element 620. That is, the upper boundary of the second region 132 in the Y direction is the position of the uppermost second heating element 620 in the Y direction, and the lower boundary of the second region 132 in the Y direction is the position of the lowermost second heating element 620 in the Y direction. The boundary of the second region 132 in the X direction is defined by the connecting lines that connect the end positions of each second heating element 620 (the connection positions with the busbars 622 and 623) on both sides in the X direction.

[0067] The second heating element 620 is preferably arranged in a configuration density with virtually no deviation, thereby achieving uniform heating within the second region 132. Furthermore, in this embodiment, as an example, the heating wire of the second heating element 620 is... Figure 2 As shown, multiple strands extend along the X direction with a certain spacing d2 in the Y direction. The spacing d2 and the spacing d1 can be the same or different. A cover 4 is provided, as in this embodiment, to cover the second area 132 from the side of the carriage (see...). Figure 3 In the case of ), the humidity in the second region 132 is prone to increase. Therefore, in order to easily prevent condensation in the second region 132, the spacing d2 can be smaller than the spacing d1.

[0068] The second heating element 620 preferably has a heat density (W / cm²) 2The temperature of the second region 132 is higher than that of the first heating element 610. In this case, the glass temperature of the second region 132 can rise more quickly. A cover 4 covering the second region 132 from the side of the carriage, as in this embodiment, is provided (see...). Figure 3 In such cases, the humidity in the second region 132 tends to be high. Therefore, by increasing the heat density of the second heating element 620, condensation in the second region 132 can be effectively suppressed.

[0069] The heating density of the second heating element 620 is preferably in the range of 1.5 to 6 times that of the heating density of the first heating element 610, more preferably in the range of 1.8 to 5 times that of the heating density of the first heating element 610, and most preferably in the range of 2 to 3 times that of the heating density of the first heating element 610. For example, the heating density of the first heating element 610 may be 400 W / cm². 2 In this case, the heat density of the second heating element 620 can be, for example, 900 W / cm². 2 ~2200 W / cm 2 Within the range.

[0070] Furthermore, in this embodiment, as an example, the second heating elements 620 are discontinuous, but they can also be configured to fold back from one end to the other and then back again in the X direction (a back-and-forth configuration). Additionally, in this embodiment, as an example, the second heating elements 620 extend in the X direction and are arranged in a row in the Y direction, but this is not a limitation. For example, the heating wires constituting the second heating elements 620 can also extend in the Y direction and be arranged in a row in the X direction.

[0071] Busbar 622, for example, forms an electrode on the positive side and is electrically connected to the positive side of the vehicle battery (not shown). Busbar 622 can be electrically connected to the vehicle battery via a power generation unit (not shown) that generates a specified power supply voltage. Busbar 622, for example, is like... Figure 2 As shown, it extends along the Y direction to the left of the X direction in the second region 132.

[0072] Busbar 623, for example, forms an electrode on the negative side and is electrically connected to the negative side (ground) of the vehicle battery (not shown). Busbar 623, for example, is like... Figure 2 As shown, it extends along the Y direction to the right of the X direction in the second region 132. The busbar 623 can be symmetrical to the busbar 622.

[0073] The switch unit 624 is electrically connected between the busbar 622 and the vehicle battery. The switch unit 624 includes a switch for turning the second heating element 620 energized on / off. Such a switch can be, for example, in the form of a relay or a semiconductor switch. When the switch unit 624 is controlled to be on, conduction is realized between the second heating element 620 and the vehicle battery (i.e., energizing the second heating element 620), and the heat generated by the second heating element 620 heats the window glass 50 in the second region 132.

[0074] The on / off state of the switch unit 624 is controlled by the control device 10 (see...) Figure 4 The wiring from the switch section 624 to the control device 10 is not shown. Figure 1 As shown in the accompanying drawings, the wiring can also be formed in the same manner as the various wirings involved in the second heating device 62, in the area that overlaps with the fixed width portion 54a and the protrusion 54b when viewed from above. Alternatively, the wiring can be implemented using a substrate that can be disposed between the second region 132 of the window glass 50 and the cover 4, without utilizing the area that overlaps with the fixed width portion 54a when viewed from above.

[0075] Furthermore, in this embodiment, the first heating element 610 of the first heating device 61 and the second heating element 620 of the second heating device 62 are electrically connected to the vehicle battery (not shown) in parallel. The switch portion 614 of the first heating device 61 is not located on the wiring between the second heating element 620 and the vehicle battery (not shown), and the switch portion 624 of the second heating device 62 is not located on the wiring between the first heating element 610 and the vehicle battery (not shown). Therefore, the first heating element 610 and the second heating element 620 can essentially operate independently of each other.

[0076] The sensor device 70 includes a first temperature sensor 71, a second temperature sensor 72, a first humidity sensor 76, and a second humidity sensor 77.

[0077] The first temperature sensor 71, for example, is in the form of a thermistor, and is provided corresponding to the first region 131. The first temperature sensor 71 is provided for detecting the glass temperature of the first region 131. For this purpose, the first temperature sensor 71 is preferably provided in or near the first region 131. Figure 1 In this example, the first temperature sensor 71 is positioned above the Y-direction on the left side of the first region 131, within a certain width 54a on the left side of the X-direction when viewed from above. Furthermore, the first temperature sensor 71 is preferably configured such that the sensing element contacts the glass surface.

[0078] The first temperature sensor 71 provides an electrical signal (an example of temperature information) representing the glass temperature of the first region 131 to the control device 10 (see [reference]). Figure 4 The wiring from the first temperature sensor 71 to the control device 10 is not shown. Figure 1 As shown in the accompanying drawings, it can also be formed in the same manner as the various wiring involved in the first heating device 61 in the area that overlaps with the certain width portion 54a when viewed from above.

[0079] The second temperature sensor 72, for example, in the form of a thermistor, is provided corresponding to the second region 132. The second temperature sensor 72 is provided for detecting the glass temperature of the second region 132. For this purpose, the second temperature sensor 72 is preferably provided within or near the second region 132. Figure 2 In this example, the second temperature sensor 72 is located in the protrusion 54b on the lower side of the second region 132 in the Y direction, as seen from above.

[0080] The second temperature sensor 72 provides an electrical signal (an example of temperature information) representing the glass temperature of the second region 132 to the control device 10 (see [reference]). Figure 4 The wiring from the second temperature sensor 72 to the control device 10 is not shown. Figure 1 As shown in the accompanying drawings, it can also be implemented in the same manner as the various wiring involved in the second heating device 62.

[0081] A first humidity sensor 76 is provided corresponding to the first region 131. The first humidity sensor 76 is provided for detecting the air humidity of the first region 131. For this purpose, the first humidity sensor 76 is preferably provided within or near the first region 131. Figure 1 In this example, the first humidity sensor 76 is positioned above the Y-direction on the left side of the first region 131 in a certain width portion 54a located to the left in the X direction when viewed from above. Furthermore, the first humidity sensor 76 is preferably positioned such that the sensing element (humidity-sensing material, etc.) is located at a distance from the glass surface that is exactly equal to the boundary layer thickness.

[0082] also, Figure 1 In this embodiment, the first humidity sensor 76 is separate from the first temperature sensor 71, but it can also be an IC (integrated circuit) that integrates the first temperature sensor 71.

[0083] The first humidity sensor 76 provides an electrical signal indicating the humidity at the set location to the control device 10 (see [link]). Figure 4 The wiring from the first humidity sensor 76 to the control device 10 can be implemented in the same way as the first temperature sensor 71.

[0084] A second humidity sensor 77 is provided corresponding to the second region 132. The second humidity sensor 77 is provided for detecting the air humidity of the second region 132. For this purpose, the second humidity sensor 77 is preferably provided within or near the second region 132. Figure 2 In this example, the second humidity sensor 77 is positioned within the second region 132 when viewed from above. Furthermore, the second humidity sensor 77 is preferably positioned such that the sensing element (humidity-sensing material, etc.) is located at a distance from the glass surface that is exactly equal to the boundary layer thickness.

[0085] also, Figure 2 In this embodiment, the second humidity sensor 77 is separate from the second temperature sensor 72, but it can also be an IC (integrated circuit) in which the second temperature sensor 72 is integrated.

[0086] The second humidity sensor 77 provides an electrical signal indicating the humidity at the set location to the control device 10 (see [link]). Figure 4 The wiring from the second humidity sensor 77 to the control device 10 can be implemented in the same way as the second temperature sensor 72.

[0087] Next, see Figures 4-7 The control system for the vehicle windshield 1 will be explained.

[0088] Figure 4 This is a schematic diagram of the control system for the vehicle's windshield 1.

[0089] The control system involved in the vehicle windshield 1 includes a control device 10. The control device 10 can be implemented as a body ECU (Electronic Control Unit) that controls the vehicle door locks, etc.

[0090] The control device 10 includes a CPU (Central Processing Unit) 11, RAM (Random Access Memory) 12, ROM (Read Only Memory) 13, auxiliary storage device 14, drive device 15, and communication interface 17 connected by a bus 19, as well as a wired transceiver unit 25 and a wireless transceiver unit 26 connected to the communication interface 17.

[0091] The auxiliary storage device 14 is, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive), which is a storage device for storing application software and other related data.

[0092] The wired transceiver unit 25 includes a transceiver unit capable of communicating using an in-vehicle network 31 that conforms to protocols such as CAN (Controller Area Network). The wired transceiver unit 25 connects to various electronic components 3 via the in-vehicle network 31.

[0093] In this embodiment, the various electronic components 3 include a brake ECU 32, a wheel speed sensor 33, an air conditioning ECU 34, an external temperature sensor 35, an internal temperature sensor 36, etc.

[0094] The brake ECU 32 controls the vehicle's braking system (not shown) based on sensor information from wheel speed sensors 33, etc. Wheel speed sensors 33 detect vehicle speed pulses corresponding to wheel speeds. The brake ECU 32 calculates the vehicle speed based on the vehicle speed pulse information from wheel speed sensors 33 and sends the vehicle speed information to the vehicle network 31. In this case, the control device 10 connected to the vehicle network 31 can obtain the vehicle speed information.

[0095] The air conditioning ECU 34 controls the vehicle's air conditioning system based on sensor information from the external temperature sensor 35, the internal temperature sensor 36, and other sensors. The external temperature sensor 35 detects the air temperature outside the vehicle (external temperature). The internal temperature sensor 36 detects the air temperature inside the vehicle cabin (internal temperature). The air conditioning ECU 34 sends the external temperature information from the external temperature sensor 35 and the internal temperature information from the internal temperature sensor 36 to the vehicle network 31.

[0096] A portion of the various electronic components 3 can be electrically connected to the bus 19 or to the wireless transceiver unit 26.

[0097] The wireless transceiver unit 26 is a transceiver unit capable of communicating using a wireless network. The wireless network may include mobile phone wireless communication networks, the Internet, VPNs (Virtual Private Networks), WANs (Wide Area Networks), etc. Furthermore, the wireless transceiver unit 26 may also include a Near Field Communication (NFC) unit, a Bluetooth (registered trademark) unit, a Wi-Fi (Wireless-Fidelity) transceiver unit, an infrared transceiver unit, etc.

[0098] The control device 10 can also be connected to the recording medium 16. The recording medium 16 stores a predetermined program. The program stored in the recording medium 16 is loaded into the auxiliary storage device 14 or the like of the control device 10 via the drive device 15. The loaded predetermined program can be executed by the CPU 11 of the control device 10. For example, the recording medium 16 can be a recording medium that records information in optical, electrical, or magnetic form, such as a CD (Compact Disc)-ROM, floppy disk, or optical disk, or a semiconductor memory that records information in electrical form, such as a ROM or flash memory.

[0099] The first temperature sensor 71, the second temperature sensor 72, the first humidity sensor 76, and the second humidity sensor 77 are electrically connected to the control device 10. Additionally, the switch unit 614 and the switch unit 624 are electrically connected to the control device 10. Figure 4 In the diagram, switch sections 614 and 624 are schematically shown together with the first heating element 610 and the second heating element 620. Furthermore, Figure 4 In this context, Vcc represents the power supply voltage supplied to the first heating element 610 and the second heating element 620.

[0100] The control device 10 performs various controls. These controls include those relating to the windshield 1 for the vehicle (hereinafter also referred to as "windshield heating control"). The windshield heating control includes controlling the first heating device 61 and the second heating device 62 based on various sensor information from the first temperature sensor 71, the second temperature sensor 72, the first humidity sensor 76, and the second humidity sensor 77.

[0101] Figure 5 This is a functional diagram showing the function of the control device 10 (heating control system) associated with the heating control of the windshield. Figure 6 This is an illustration of threshold information. Figure 7 This is an illustration of the causes of defects (such as cracks) that may occur in the third region 133 (described later).

[0102] Control device 10 (heating control system) such as Figure 5 As shown, the system includes a sensor information acquisition unit 150, a control information storage unit 151, and a control processing unit 152. The sensor information acquisition unit 150 and the control processing unit 152 can be implemented by the CPU 11 executing one or more programs stored in a storage device (e.g., ROM 13). The control information storage unit 151 can be implemented using a storage device (e.g., ROM 13 or auxiliary storage device 14, etc.).

[0103] The sensor information acquisition unit 150 acquires various sensor information associated with the window glass 50 from the first temperature sensor 71, the second temperature sensor 72, the first humidity sensor 76, and the second humidity sensor 77. The sensor information acquisition unit 150 also acquires vehicle speed information, external temperature information, and internal temperature information (hereinafter collectively referred to as "environmental information") via the vehicle network 31. Furthermore, the sensor information acquisition unit 150 can also acquire various sensor information at predetermined intervals.

[0104] The control information storage unit 151 stores control information for controlling the heating of the windshield. In this embodiment, the control information includes threshold information for setting a threshold (threshold Th, described later). Details of the threshold information will be described later.

[0105] The control processing unit 152 performs control processing on the first heating device 61 and the second heating device 62 based on various sensor information acquired by the sensor information acquisition unit 150. Specifically, the control processing unit 152 controls the switch unit 614 to switch the state of the first heating element 610 between an energized state and an inactive state based on various sensor information acquired by the sensor information acquisition unit 150. The control processing unit 152 also controls the switch unit 624 to switch the state of the second heating element 620 between an energized state and an inactive state based on various sensor information acquired by the sensor information acquisition unit 150.

[0106] Control processing unit 152, etc. Figure 5 The device includes a first power-on processing unit 1521, a second power-on processing unit 1522, a threshold setting processing unit 1523, a temperature difference parameter calculation unit 1524, a threshold determination processing unit 1525, and a temperature difference reduction processing unit 1526.

[0107] The first power-on processing unit 1521 performs a first power-on process to power on the first heating element 610 so that condensation (including fog) does not occur in the first region 131, based on sensor information from the first temperature sensor 71 and the first humidity sensor 76 respectively.

[0108] For example, the first power-on processing unit 1521 calculates the dew point temperature (hereinafter also referred to as the "first dew point temperature") at which condensation begins to form in the first region 131 based on sensor information from the first temperature sensor 71 and the first humidity sensor 76, respectively. Then, the first power-on processing unit 1521 powers on the first heating element 610 when the glass temperature of the first region 131, based on sensor information from the first temperature sensor 71, is below a first power-on start threshold corresponding to the first dew point temperature. The first power-on start threshold can be the first dew point temperature or a value only slightly higher. If power-on begins in this manner, the first power-on processing unit 1521 stops powering on the first heating element 610 when the glass temperature of the first region 131, based on sensor information from the first temperature sensor 71, reaches or exceeds a first power-on end threshold corresponding to the first dew point temperature. The first power-on end threshold can be a value slightly larger than the first dew point temperature. However, in a variation, the first power-on end threshold can also be the same as the first power-on start threshold.

[0109] The second power-on processing unit 1522 performs a second power-on process to power on the second heating element 620 so that condensation does not occur in the second region 132, based on sensor information from the second temperature sensor 72 and the second humidity sensor 77 respectively.

[0110] For example, the second power-on processing unit 1522 calculates the dew point temperature (hereinafter also referred to as the "second dew point temperature") at which condensation begins to form in the second region 132 based on sensor information from the second temperature sensor 72 and the second humidity sensor 77. Then, the second power-on processing unit 1522 powers on the second heating element 620 when the glass temperature of the second region 132, based on sensor information from the second temperature sensor 72, reaches or falls below a second power-on start threshold corresponding to the second dew point temperature. The second power-on start threshold can be the second dew point temperature or a value only slightly higher. If power-on begins in this manner, the second power-on processing unit 1522 stops powering on the second heating element 620 when the glass temperature of the second region 132, based on sensor information from the second temperature sensor 72, reaches or exceeds a second power-on end threshold corresponding to the second dew point temperature. The second power-on end threshold can be a value slightly larger than the second dew point temperature. However, in a modified example, the second power-on end threshold can also be the same as the second power-on start threshold.

[0111] The threshold setting processing unit 1523 sets a threshold (hereinafter referred to as "threshold Th" to distinguish it from other thresholds) based on environmental information (vehicle speed information, external temperature information, and internal temperature information) acquired by the sensor information acquisition unit 150. The threshold Th can be constant, but in this embodiment it is a variable value set based on the threshold information. Furthermore, when the threshold Th is constant, the threshold information in the control information storage unit 151 and the threshold setting processing unit 1523 are omitted. As detailed below, the threshold Th is a threshold related to the execution conditions of the temperature difference reduction processing unit 1526, and is compared with the value of the temperature difference parameter. An example of a specific method for setting the threshold Th will be described later.

[0112] The temperature difference parameter calculation unit 1524 calculates the value of the temperature difference parameter based on the sensor information acquired by the sensor information acquisition unit 150 from the first temperature sensor 71 and the second temperature sensor 72. The temperature difference parameter is a parameter that represents the temperature difference between the glass temperature of the third region 133 of the window glass 50 and the glass temperature of the first region 131 or the glass temperature of the second region 132.

[0113] The third region 133 includes areas that are not part of either the first region 131 or the second region 132 (i.e., areas without heating elements) and are prone to defects (e.g., cracks) in the window glass 50 due to the temperature difference (the temperature difference between the glass in the first region 131 and the glass in the second region 132 with the higher temperature) caused by the first and second power-on processes described above. Furthermore, the third region 133 is typically a region of a certain area, but it can also be a smaller area.

[0114] In this embodiment, as an example, the third region 133 is the entire region between the first region 131 and the second region 132 in the Y direction, hereinafter referred to as "the third region 133". However, in a variation, the third region 133 may also be a part of the region between the first region 131 and the second region 132. The region between the first region 131 and the second region 132 in the Y direction can be a set of positions that coincide with both the first region 131 and the second region 132 when viewed in the Y direction. In this embodiment, the X-direction boundary position of the third region 133 is substantially the same as the position of the second region 132 in the X direction.

[0115] Since the third region 133 is located between the first region 131 and the second region 132 and is not equipped with a heating element, the glass temperature is easily significantly lower than the glass temperatures of the first region 131 and the second region 132.

[0116] Unless otherwise specified, "glass temperature of the third region 133" refers to the minimum glass temperature at each location within the third region 133. Furthermore, regarding the temperature difference between the glass temperature of the third region 133 and the respective glass temperatures of the first region 131 and the second region 132, the respective glass temperatures of the first region 131 and the second region 132 refer to the glass temperatures based on sensor information from the first temperature sensor 71 and the second temperature sensor 72. The temperature difference between the glass temperature of the third region 133 and the respective glass temperatures of the first region 131 and the second region 132 refers to the temperature difference relative to the higher temperature of the first region 131 and the second region 132. This is because a larger temperature difference is more likely to cause defects (e.g., cracking) in the window glass 50. Therefore, in the following, when simply referred to as "temperature difference between the third region 133 and the first region 131 or the second region 132," it indicates the temperature difference between the glass temperature of the third region 133 and the higher temperature of the first region 131 and the second region 132.

[0117] In addition, temperature gradient (see Figure 7 The larger the temperature gradient (dT / dY), the more likely defects (such as cracks) will occur in the window glass 50 caused by the temperature difference between regions. Figure 7 In the middle, the horizontal axis represents along Figure 2 The positions of the AA line, with the vertical axis representing the glass temperature, show the positions along the AA line. Figure 2 Two examples of the temperature variation characteristics of glass in AA line (characteristic G700 and characteristic G702). Figure 7 In the diagram, the further to the right on the horizontal axis, the higher up the Y-direction. Position P1 corresponds to the boundary between the first region 131 and the third region 133, and position P2 corresponds to the boundary between the third region 133 and the second region 132. Characteristic G700 is a characteristic under conditions of essentially no temperature difference, while characteristic G702 is an example of a characteristic that produces defects (such as breakage) in the window glass 50. Furthermore, Figure 7 In this context, ΔT corresponds to the temperature difference between the third region 133 and either the first region 131 or the second region 132. Generally, when the distance between positions P1 and P2 in the Y direction is the same (i.e., when the length of the third region 133 in the Y direction is the same), the larger ΔT is, the greater the gradient dT / dY tends to be.

[0118] The method for calculating the temperature difference parameter value of the temperature difference parameter calculation unit 1524 is arbitrary. In this embodiment, the temperature difference parameter value can be calculated in any way based on the values ​​of predetermined input parameters, including sensor information from the first temperature sensor 71 and the second temperature sensor 72. For example, artificial intelligence can be used to input the values ​​of predetermined input parameters and output (generate) the temperature difference parameter value. In the case of artificial intelligence, this can be achieved by installing a convolutional neural network obtained by machine learning. In machine learning, for example, actual data related to temperature difference can be used to learn the weights of the convolutional neural network that minimize the error related to the temperature difference parameter value. In this case, the predetermined input parameters can be any parameters that affect the temperature difference between the third region 133 and the first region 131 or the second region 132, such as the glass temperature of the first region 131, the glass temperature of the second region 132, the difference between these glass temperatures, vehicle speed, external air temperature, and internal air temperature.

[0119] Furthermore, the temperature difference parameter does not necessarily have to be a parameter that directly represents the temperature difference between the third region 133 and the first region 131 or the second region 132; it can also be a parameter that indirectly represents the temperature difference. For example, the temperature difference parameter could be a gradient of glass temperature change between the third region 133 and the first region 131 or the second region 132 (the rate of change of glass temperature per unit distance, see [reference]). Figure 7 Parameters such as temperature gradient (dT / dY).

[0120] In this embodiment, as an example, the temperature difference parameter is the difference between the glass temperatures shown by the sensor information from the first temperature sensor 71 and the second temperature sensor 72, respectively. That is, the temperature difference parameter is the difference between the glass temperatures of the first region 131 and the second region 132. Furthermore, see... Figure 7 As described above, the parameter that directly causes defects (such as breakage) in the window glass 50 is the temperature gradient dT / dY. However, the temperature difference between the glass in the first region 131 and the second region 132 is a parameter related to the temperature gradient dT / dY. That is, there is a tendency that the larger the temperature difference between the glass in the first region 131 and the second region 132, the larger the temperature gradient dT / dY. However, in a modified example, the value of the temperature difference parameter can also be derived by correcting the difference in temperature between the glass in the first region 131 and the second region 132 to a value that more accurately represents the temperature gradient dT / dY.

[0121] The threshold determination processing unit 1525 determines whether the execution conditions for the temperature difference reduction processing performed by the temperature difference reduction processing unit 1526 are met. Specifically, the threshold determination processing unit 1525 determines whether the value of the temperature difference parameter calculated by the temperature difference parameter calculation unit 1524 exceeds the threshold Th set by the threshold setting processing unit 1523. At this time, the execution conditions for the temperature difference reduction processing performed by the temperature difference reduction processing unit 1526 are met if the value of the temperature difference parameter exceeds the threshold Th.

[0122] The temperature difference reduction processing unit 1526 performs temperature difference reduction processing when the execution conditions for temperature difference reduction processing are met (i.e., the value of the temperature difference parameter exceeds the threshold Th). Temperature difference reduction processing is used to ensure that the temperature difference between the glass temperature of the third region 133 and the glass temperature of the first region 131 or the glass temperature of the second region 132 (hereinafter, also simply referred to as the "local temperature difference of the window glass 50") does not exceed an upper limit value. Specifically, temperature difference reduction processing controls at least one of the first heating element 610 and the second heating element 620 to ensure that the local temperature difference of the window glass 50 does not exceed the upper limit value.

[0123] The upper limit value corresponds to the local temperature difference of the window glass 50 when a defect (e.g., crack) occurs in the third region 133 of the window glass 50. For example, when the local temperature difference of the window glass 50 is within a certain range, the upper limit value corresponds to the lower limit value of that range when a defect (e.g., crack) occurs in the third region 133 of the window glass 50.

[0124] For example, if the glass temperature in the first region 131 is significantly lower than the glass temperature in the second region 132, the temperature difference reduction processing unit 1526 can control the first heating element 610 and the second heating element 620 to raise the glass temperature in the first region 131 and / or suppress the rise in the glass temperature in the second region 132. This reduces the likelihood of defects in the window glass 50 (defects in the third region 133 of the window glass 50) arising from the significantly lower glass temperature in the first region 131 compared to the second region 132.

[0125] The temperature difference reduction treatment is performed to address the local temperature difference in the window glass 50 caused by the execution of either or both of the first and second power-on processes. This is because the first and second power-on processes are executed as described above to prevent condensation in the first region 131 and the second region 132, but due to the increase in glass temperature, there is a tendency to increase the local temperature difference in the window glass 50.

[0126] Here, as in this embodiment, a cover 4 is provided that covers the second area 132 from the side of the carriage (see...). Figure 3In the case described above, the humidity in the second region 132 tends to be high, and therefore, the second dew point temperature tends to be higher than the first dew point temperature. Consequently, at a certain point in time, the second power-on start threshold and the second power-on end threshold are almost both above the first power-on start threshold and the first power-on end threshold, respectively. Therefore, when the vehicle perimeter monitoring sensor 20 is supposed to function, a state where only the second power-on process is executed is generated, but a state where only the first power-on process is executed is not substantially generated. Therefore, in this embodiment, the execution condition for the temperature difference reduction process is basically met when the second power-on process is executed. That is, the temperature difference reduction process is executed when the second power-on process is executed to increase the glass temperature of the first region 131 and / or suppress the increase of the glass temperature of the second region 132.

[0127] For example, if the glass temperature in the first region 131 is lower than the glass temperature in the second region 132, the temperature difference reduction process may include energizing the first heating element 610 without a first energizing process (i.e., regardless of whether the glass temperature in the first region 131 is higher than the first energizing start temperature). In this case, by raising the glass temperature in the first region 131, the local temperature difference of the window glass 50 can be reduced.

[0128] Furthermore, if the glass temperature in the first region 131 is lower than the glass temperature in the second region 132, the temperature difference reduction process may include continuing to energize the first heating element 610 regardless of whether the termination condition of the first energizing process is met (i.e., regardless of whether the glass temperature in the first region 131 is higher than the first energizing termination temperature). In this case, by raising the glass temperature in the first region 131, the local temperature difference of the window glass 50 can be reduced.

[0129] In this embodiment, a temperature difference reduction process can be performed when the temperature difference parameter exceeds the threshold Th while the second power-on process is being executed, thereby reducing the local temperature difference of the window glass 50. This effectively reduces defects (e.g., cracks) in the window glass 50 caused by a significant increase in local temperature difference while the second power-on process is being executed.

[0130] The following reference Figures 8A to 9D This will illustrate the effects of this implementation method.

[0131] Figures 8A to 8D This is an explanatory diagram illustrating the case where the temperature difference reduction process is performed under the condition of only performing the second power-on process. It is an explanatory diagram showing an example of the relationship between the glass temperature of the first region 131 and the second region 132 and the glass temperature of the third region 133. Figures 8A to 8D In the middle, the horizontal axis represents the direction along... Figure 2 The positions of line AA, with the vertical axis representing glass temperature, show the positions along... Figure 2 An example of the temperature variation characteristics of glass in AA line (hereinafter referred to as "variation characteristics"). Figures 8A to 8D In the middle, the further to the right on the horizontal axis, the higher up in the Y direction. Position P1 corresponds to the boundary between the first region 131 and the third region 133, and position P2 corresponds to the boundary between the third region 133 and the second region 132.

[0132] Figures 8A to 8D The characteristics of the changes from different time points t1 to t4 are shown respectively.

[0133] Time point t1 is the initial state, corresponding to the time point when the glass temperature of the second region 132 reaches below the second power-on start threshold. Figure 8A At time t1, the glass temperature in the second region 132 is higher than that in the first region 131.

[0134] Time point t2 is a time point after time point t1, corresponding to a time point after a certain period of time after the start of the second power-on process. Thus, at time point t2, compared to time point t1, the glass temperature in the second region 132 rises more than the glass temperature in the first region 131 due to the second power-on process, resulting in a larger local temperature difference in the window glass 50.

[0135] Thus, when only the second power-on process is performed, the local temperature difference of the window glass 50 is likely to become larger. Figure 8B Immediately after time point t2, the value of the temperature difference parameter exceeds the threshold Th, and the temperature difference reduction process begins. That is, immediately after time point t2, regardless of whether the glass temperature of the first region 131 is above the first power-on start temperature, the power-on of the first heating element 610 begins immediately.

[0136] Time point t3 is a time point after time point t2, corresponding to a certain period of time after the start of the temperature difference reduction treatment. For example... Figure 8C As shown, the local temperature difference of the window glass 50 is reduced by initiating the temperature difference reduction process. Furthermore, at time point t3, the second power-on process, which began at time point t1, continues.

[0137] Time point t4 is the time point after time point t3, corresponding to the time point at which the second power-on process, which began at time point t1, normally ends (i.e., the time point when the glass temperature in the second region 132 reaches or exceeds the second power-on termination threshold). When time point t4 is reached, as... Figure 8D As shown, with the completion of the second energization process (because the possibility of a further increase in the local temperature difference of the window glass 50 is low), the temperature difference reduction process, which begins immediately after time point t2, also ends. That is, a steady state is reached. However, in a modified example, the temperature difference reduction process may also end before time point t4.

[0138] Figure 8C In the comparison example, corresponding to the change characteristic at time point t3 (solid line), the change characteristic 801, where the temperature difference reduction process that begins immediately after time point t2 is not executed, is represented by a dashed line. In such a comparison example, as shown by change characteristic 801, the local temperature difference of the window glass 50 further increases. That is to say, there is a risk of defects (e.g., cracking) occurring in the window glass 50.

[0139] In contrast, according to this embodiment, when only the second power-on process is performed as described above (when the execution conditions of the first power-on process are not met), the temperature difference reduction process is performed, thereby effectively reducing the possibility of defects (such as breakage) in the window glass 50.

[0140] Figures 9A to 9D A diagram illustrating the implementation of temperature difference reduction processing while performing the first and second power-on processes is shown. Figures 8A to 8D Similarly, the variation characteristics from different time points t11 to t14 are shown respectively. Here, as a preferred example, the second heating element 620 has a higher heat density than the first heating element 610, as described above.

[0141] Time point t11 ​​is the initial state, corresponding to the time point when the glass temperature of the first region 131 reaches below the first power-on start threshold and the glass temperature of the second region 132 reaches below the second power-on start threshold. Figure 9A At time t1, the glass temperature in the second region 132 is higher than that in the first region 131.

[0142] Time point t12 is a time point after time point t11, corresponding to a certain period of time after the start of the first and second power-on processes. At time point t12, the first and second power-on processes that started at time point t11 ​​are still continuing.

[0143] At time point t12, compared to time point t11, the glass temperature in the second region 132 rises more than that in the first region 131 because the heat density of the second heating element 620 is higher than that of the first heating element 610. Therefore, the local temperature difference of the window glass 50 becomes larger.

[0144] Thus, when the heat density of the second heating element 620 is higher than that of the first heating element 610, even when the first power-on process and the second power-on process are performed simultaneously, the local temperature difference of the window glass 50 is likely to become larger. Figure 9BImmediately after time point t12, the value of the temperature difference parameter exceeds the threshold Th, satisfying the execution condition for temperature difference reduction processing. Therefore, even if the glass temperature of the first region 131 reaches above the first power-on end temperature immediately after time point t12, the power-on of the first heating element 610 is maintained through temperature difference reduction processing. Figure 9B Immediately after time point t2, when the temperature difference parameter exceeds the threshold Th, the temperature difference reduction process, which replaces the first power-on process, is started by raising the glass temperature of the first region 131 above the first power-on end temperature.

[0145] Time point t13 is a time point after time point t12, corresponding to a certain period of time after the start of the temperature difference reduction treatment. For example... Figure 9C As shown, the local temperature difference of the window glass 50 is reduced by initiating the temperature difference reduction process. Furthermore, at time point t13, the second power-on process, which began at time point t1, continues.

[0146] Time point t14 is the time point after time point t13, corresponding to the time point at which the second power-on process, which began at time point t11, normally ends (i.e., the time point when the glass temperature of the second region 132 reaches or exceeds the second power-on termination threshold). When time point t4 is reached, as... Figure 9D As shown, with the completion of the second energization process (because the possibility of a further increase in the local temperature difference of the window glass 50 is low), the temperature difference reduction process, which begins immediately after time point t2, also ends. That is, a steady state is reached. However, in a modified example, the temperature difference reduction process may also end before time point t14.

[0147] Figure 9C In the comparison example, corresponding to the change characteristic at time point t13 (solid line), the change characteristic 901, where the temperature difference reduction process that begins immediately after time point t2 is not executed, is represented by a dashed line. In such a comparison example, as shown by change characteristic 901, the local temperature difference of the window glass 50 further increases. That is to say, there is a risk of defects (e.g., cracking) occurring in the window glass 50.

[0148] In contrast, according to this embodiment, even when the first power-on process and the second power-on process are performed as described above, the temperature difference reduction process is performed even after the first power-on process has ended (i.e., the first power-on process is substantially extended), thus effectively reducing the possibility of defects (e.g., breakage) in the window glass 50.

[0149] However, in this embodiment, as described above, the temperature difference parameter is the temperature difference between the glass in the first region 131 and the second region 132, and is not a parameter that directly represents the temperature difference between the third region 133 and the first region 131 or the second region 132. That is to say, although the temperature difference between the glass in the first region 131 and the second region 132 is related to the temperature difference between the third region 133 and the first region 131 or the second region 132, it may sometimes be inconsistent with the temperature difference between the third region 133 and the first region 131 or the second region 132.

[0150] This tendency (i.e., the tendency for the temperature difference between the glass in the first region 131 and the second region 132 to increase relative to the temperature difference between the third region 133 and the first region 131 or the second region 132) occurs when the distance between the first region 131 and the second region 132 is large. Hereinafter, this tendency will be referred to as "the tendency for the difference to increase corresponding to the increase in the distance between the first region 131 and the second region 132" or "the tendency for the difference to increase".

[0151] Figures 10A to 10D This is an explanatory diagram showing the increasing tendency of the difference between the first region 131 and the second region 132 as the distance between them increases. Figures 10A to 10D Is the same as the above Figures 8A to 8D The contrasting figures, with Figures 8A to 8D Similarly, the variation characteristics are shown when the temperature difference reduction process is performed in the state of performing only the second power-on process, from time point t1 to time point t4 as described above.

[0152] Figures 10A to 10D and Figures 8A to 8D The difference is that it shows the variation characteristics when the distance between the first region 131 and the second region 132 is large.

[0153] When the distance between the first region 131 and the second region 132 in the Y direction (i.e., the width of the third region 133 in the Y direction) is large, such as Figures 10A to 10D As shown, the glass temperature difference between the third region 133 and the first region 131 becomes larger. That is, in the central part of the third region 133 in the Y direction (see... Figure 10D Interval CT, Figure 2 In region 1331), heat from the first heating element 610 and the second heating element 620 is not easily transferred, making it difficult for the glass temperature to rise. Therefore, as Figures 10A to 10D As shown, the variation characteristics of the third region 133 decrease significantly in the central part and then increase as the position changes from the first region 131 to the second region 132. The greater the distance between the first region 131 and the second region 132, the more likely this variation characteristic in the central part becomes minimal.

[0154] Furthermore, this tendency for the variation in characteristics to become minimal in the central region also depends on the thermal conductivity of the third region 133 (e.g., the thermal conductivity from the first region 131 or the second region 132 to the central region). This thermal conductivity is not fixed, depending on the distance between the first region 131 and the second region 132, but varies with the temperature of the window glass 50. Therefore, the thermal conductivity varies with the values ​​of environmental parameters that affect the temperature of the window glass 50, such as vehicle speed, external temperature, and internal temperature (an example of specified information). For example, the higher the vehicle speed, the easier it is for the temperature of the window glass 50 to drop, and therefore, the thermal conductivity of the third region 133, etc., tends to decrease.

[0155] Therefore, the value of the aforementioned temperature difference parameter can also be corrected based on the value of the environmental parameter in a manner that takes into account the thermal conductivity. Furthermore, as an alternative or addition, the aforementioned threshold Th can also be corrected (changed) based on the value of the environmental parameter in a manner that takes into account the thermal conductivity. In this embodiment, as an example, the threshold Th is corrected (changed) based on the value of the environmental parameter.

[0156] Specifically, the threshold setting processing unit 1523 can set the threshold Th to be smaller as the vehicle speed increases, based on the vehicle speed information. This is because, as mentioned above, the higher the vehicle speed, the easier it is for the temperature of the window glass 50 to drop, and therefore the easier it is for the thermal conductivity to decrease. Similarly, the threshold setting processing unit 1523 can also set the threshold Th to be smaller as the external temperature decreases, based on the external temperature information. Furthermore, the threshold setting processing unit 1523 can also set the threshold Th to be smaller as the internal temperature decreases, based on the internal temperature information. In this way, even when the thermal conductivity of the third region 133 changes with the value of environmental parameters, the threshold Th can be set to meet the execution conditions of the temperature difference reduction processing at an appropriate time.

[0157] For example, in this embodiment, the threshold setting processing unit 1523 refers to the threshold information in the control information storage unit 151 and sets a threshold Th corresponding to the values ​​(environmental information) of the three environmental parameters: vehicle speed, external temperature, and internal temperature. In this case, the threshold information represents the relationship between the values ​​of the three environmental parameters and the threshold. Figure 6 The example shown illustrates the threshold coefficients corresponding to the values ​​of the three parameters: vehicle speed, external temperature, and internal temperature. For instance, threshold coefficient α1 corresponds to the vehicle speed range of 0–V1 (low-speed zone), threshold coefficient α2 corresponds to the vehicle speed range of V1–V2 (medium-speed zone), and so on. The number of these zones is arbitrary, and finer divisions can also be used. Figure 6In this case, the threshold setting processing unit 1523 extracts threshold coefficients corresponding to the values ​​of the three environmental parameters—vehicle speed, external temperature, and internal temperature—based on the environmental information, with reference to threshold information. Then, the threshold setting processing unit 1523 calculates the threshold Th by multiplying the extracted threshold coefficients by a predetermined reference value used for threshold Th calculation. Furthermore, each threshold coefficient can be used to adjust the calculated threshold Th to a threshold that meets the execution conditions for temperature difference reduction processing at an appropriate time.

[0158] Furthermore, in this embodiment, as an example, the threshold information is like... Figure 6 The information shown represents the threshold coefficients corresponding to the values ​​of the three environmental parameters: vehicle speed, external temperature, and internal temperature, but is not limited to this. The threshold information can also be map data (マップデータ) defining thresholds Th corresponding to various combinations of the values ​​of the three environmental parameters. Furthermore, while this embodiment utilizes three environmental parameters, it is also possible to use only one or two environmental parameters, or even four or more environmental parameters.

[0159] However, as described above, as the distance between the first region 131 and the second region 132 increases, heat from the first heating element 610 and the second heating element 620 becomes less easily transferred to the central portion between the first region 131 and the second region 132. Therefore, if the distance between the first region 131 and the second region 132 reaches a predetermined distance or more, heat from the first heating element 610 and the second heating element 620 is substantially not transferred to the central portion between the first region 131 and the second region 132. In this case, the aforementioned temperature difference reduction treatment is essentially ineffective. Therefore, in this embodiment, it is preferable that the distance between the first region 131 and the second region 132 is a distance at which the aforementioned temperature difference reduction treatment can function. The upper limit of this distance (i.e., the predetermined distance described above) depends on various characteristic values ​​of the window glass 50, and can therefore be derived through experiments or simulations.

[0160] On the other hand, as the distance between the first region 131 and the second region 132 decreases, heat from the first heating element 610 and the second heating element 620 becomes easier to transfer to the third region 133, making it less likely to generate local temperature differences in the window glass 50.

[0161] Therefore, this embodiment is applicable when the distance between the first region 131 and the second region 132 is in the range of 10mm to 200mm. Furthermore, in this embodiment, as... Figure 2As shown, the distance between the first region 131 and the second region 132 can be defined by the distance L1 in the Y direction. In other words, when the distance between the first region 131 and the second region 132 is less than 10 mm, it is possible to achieve a vehicle windshield 1 that is less prone to localized temperature differences in the window glass 50. That is, when the distance between the first region 131 and the second region 132 is less than 10 mm, it is less prone to localized temperature differences in the window glass 50. Figures 10A to 10D As explained, the tendency for the variation characteristics of the central portion to become minimal enables the realization of a vehicle windshield 1 that is less prone to defects (such as cracks). Furthermore, from the perspective of ensuring electrical insulation, it is preferable to minimize the distance between the first region 131 and the second region 132.

[0162] In this case, the planar tensile stress of the portion of window glass 50 involving the third region 133 is preferably below 5 MPa. This is because the lower the residual tensile stress originally held by the glass, the lower the risk of breakage due to thermal stress. Furthermore, the thickness of the glass in the portion involving the third region 133 of window glass 50 (e.g., the glass 51b on the side of the vehicle compartment) is preferably below 2 mm. Since such thinner glass has a smaller heat capacity, the local temperature difference of window glass 50 can be reduced. This is because the glass temperature in the third region 133 rises well during the aforementioned temperature difference reduction treatment.

[0163] Next, see Figure 11 The following flowcharts will explain an example of the operation of the control device 10 in this embodiment. Figure 11 In subsequent processing flowcharts, the processing order of each step can be changed without compromising the input and output relationships of each step.

[0164] Figure 11 This is a schematic flowchart illustrating an example of a process performed by the control device 10 of this embodiment, which is associated with the heating control of the windshield. Figure 11 The process shown can be repeated at a predetermined cycle, for example, when the vehicle’s starter switch (e.g., ignition switch) is on.

[0165] In step S1, the control device 10 acquires various information required for control. The various information required for control is associated with the sensor information acquisition unit 150, and includes various sensor information associated with the window glass 50, environmental information (vehicle speed information, external temperature information, and internal temperature information), etc.

[0166] In step S2, the control device 10 executes a first heating element control process for controlling the first heating element 610. The first heating element control process includes the aforementioned first power-on process associated with the first power-on processing unit 1521. An example of the first heating element control process is shown below. Figure 12 That will be described later.

[0167] In step S3, the control device 10 executes a second heating element control process for controlling the second heating element 620. The second heating element control process includes the aforementioned second power-on process associated with the second power-on processing unit 1522. An example of the second heating element control process is shown below. Figure 13 That will be described later.

[0168] In step S4, the control device 10 determines whether the temperature difference reduction indicator F3 is "0". The temperature difference reduction indicator F3 is marked as "1" corresponding to the execution state of the temperature difference reduction process and as "0" corresponding to the non-execution state of the temperature difference reduction process. If the determination result is "YES", proceed to step S5; otherwise, proceed to step S6.

[0169] In step S5, the control device 10 determines whether the second power-on indicator F2 is "1". The second power-on indicator F2 is marked as "1" corresponding to the power-on state of the second heating element 620, and as "0" corresponding to the non-power-on state of the second heating element 620. If the determination result is "YES", the process proceeds to step S7; otherwise, the processing of this cycle ends.

[0170] In step S6, the control device 10 determines whether the second power-on indicator F2 is "0". If the determination result is "YES", it proceeds to step S11; otherwise, it proceeds to step S7.

[0171] In step S7, the control device 10 calculates the value of the temperature difference parameter based on the various information obtained in step S1. The relationship between the temperature difference parameter and the temperature difference parameter calculation unit 1524 is as described above.

[0172] In step S8, the control device 10 calculates (sets) the threshold Th based on the various information and threshold information obtained in step S1. The association between the threshold information and the control information storage unit 151 is as described above, and the association between the threshold Th and the threshold setting processing unit 1523 is as described above.

[0173] In step S9, the control device 10 determines whether the value of the temperature difference parameter obtained in step S7 exceeds the threshold Th obtained in step S8. If the determination result is "YES", the process proceeds to step S10; otherwise, it proceeds to step S11.

[0174] In step S10, the control device 10 sets the temperature difference reduction indicator F3 to "1" or keeps it at "1".

[0175] In step S11, the control device 10 resets the temperature difference reduction indicator F3 to "0" or maintains it at "0".

[0176] In step S12, the control device 10 determines whether the first power-on indicator F1 is "1". The first power-on indicator F1 is marked as "1" corresponding to the power-on state of the first heating element 610, and marked as "0" corresponding to the non-power-on state of the first heating element 610. If the determination result is "YES", the processing of this cycle ends; otherwise, the process proceeds to step S13.

[0177] In step S13, the control device 10 sets the first power-on flag F1 to "1". That is, the control device 10 changes the first power-on flag F1 from "0" to "1".

[0178] Figure 12 This illustrates the control process of the first heating element ( Figure 11 A schematic flowchart of an example of step S2).

[0179] In step S20, the control device 10 determines whether the first power-on identifier F1 is "1". If the determination result is "YES", it proceeds to step S21; otherwise, it proceeds to step S25.

[0180] In step S21, the control device 10 turns on the first heating element 610 by turning on the switch 614.

[0181] In step S22, the control device 10 calculates the first power-on termination threshold based on the various information obtained in step S1. The first power-on termination threshold is as described above.

[0182] In step S23, the control device 10 determines whether the glass temperature of the first region 131 is above the first power-on termination threshold obtained in step S22 based on the various information obtained in step S1. If the determination result is "YES", the process proceeds to step S24; otherwise, the processing of this cycle ends.

[0183] In step S24, the control device 10 resets the first power-on flag F1 to "0".

[0184] In step S25, the control device 10 calculates the first power-on start threshold based on the various information obtained in step S1. The first power-on start threshold is as described above.

[0185] In step S26, the control device 10 determines whether the glass temperature of the first region 131 is below the first power-on start threshold obtained in step S25 based on the various information obtained in step S1. If the determination result is "YES", the process proceeds to step S27; otherwise, the processing of this cycle ends.

[0186] In step S27, the control device 10 sets the first power-on identifier F1 to "1".

[0187] Figure 13 This illustrates the control process of the second heating element ( Figure 11 A schematic flowchart of an example of step S3). Figure 13 The flowchart of the second heating element control process is relative to Figure 12 The only difference in the flowchart of the first heating element control process shown is that "first" is replaced with "second" in the following description, so detailed explanation is omitted.

[0188] according to Figures 11-13 The process shown involves the second power-on process being performed by the second power-on processing unit 1522 (step S5 "YES"). If the value of the temperature difference parameter exceeds the threshold Th (step S9 "YES"), the identifier F1 in the first power-on process changes from "0" to "1" (step S13). In this case, by energizing the first heating element 610 (step S21), the temperature difference reduction process is achieved. That is, in Figures 11-13 In the process shown, since the identifier F1 changes to "1" in the first energization in step S13, the energization of the first heating element 610 (step S21) becomes a temperature difference reduction process. Therefore, according to Figures 11-13 The process shown, in the state where the second power-on process is performed by the second power-on process unit 1522, can effectively reduce the possibility of defects (such as cracks) in the window glass 50 by realizing the temperature difference reduction process.

[0189] In addition, Figures 11-13 The temperature difference reduction process shown is achieved in step S21 by forcibly changing the state of the flag F1 in the first power-on process in step S13, but it is not limited to this. For example, if the flag F3 in the temperature difference reduction process is "1", the temperature difference reduction process can also be achieved in step S21 by correcting the first power-on end threshold calculated in step S22 to a larger value. Alternatively, if the flag F3 in the temperature difference reduction process is "1", the temperature difference reduction process can also be achieved in step S21 by correcting the first power-on start threshold calculated in step S25 to a smaller value.

[0190] In addition, Figures 11-13 The temperature difference reduction process shown ends when the temperature difference parameter value falls below the threshold Th ("NO" in step S9) or when the second heating element 620 is no longer energized ("YES" in step S6), but is not limited to these conditions. It may also end only when either of these two conditions is met, or other conditions may be added.

[0191] Second Implementation Method

[0192] In the following description of the second embodiment, components that are the same as those in the first embodiment described above are sometimes indicated by the same reference numerals and their descriptions are omitted. Components that are not specifically described may be the same as those in the first embodiment described above.

[0193] Figure 14 This is an enlarged view of a portion of the vehicle windshield 1A according to the second embodiment, showing its relationship with... Figure 1 The diagram corresponding to the Q1 part.

[0194] The difference between the vehicle windshield 1A of the second embodiment and the vehicle windshield 1 of the first embodiment is the position of the first temperature sensor 71. Specifically, in this embodiment, the first temperature sensor 71 is as follows: Figure 14 As shown, it is positioned within the third region 133. That is, the first temperature sensor 71 is located at a predetermined position away from the first region 131 and the second region 132. This predetermined position is preferably the location in the third region 133 where the temperature difference with the first region 131 or the second region 132 is the greatest (i.e., the location related to the glass temperature of the third region 133) or nearby. This predetermined position is typically located in the central part of the third region 133 (see region 1331).

[0195] According to this embodiment of the vehicle windshield 1A, the minimum glass temperature within the third region 133 can be detected with high precision by means of a first temperature sensor 71 disposed within the third region 133. This allows for the high-precision detection of the temperature difference between the third region 133 and the first region 131 or the second region 132. As a result, the possibility of defects (e.g., cracks) in the window glass 50 can be reduced more effectively.

[0196] Furthermore, in this embodiment, the function of the control device associated with the windshield heating control is omitted from the illustration, but it may be the same as that in the first embodiment described above. According to this embodiment, since the value of the temperature difference parameter calculated by the temperature difference parameter calculation unit 1524 can accurately represent the temperature difference between the third region 133 and the first region 131 or the second region 132, the reliability of the control can be improved.

[0197] Furthermore, in this embodiment, the first temperature sensor 71 of the first temperature sensor 71 and the second temperature sensor 72 is located in the third region 133, thus enabling the second power-on process to be implemented with high precision using the second temperature sensor 72. However, in a modified embodiment, the second temperature sensor 72 may be located in the third region 133, or a new third temperature sensor (not shown) may be located in the third region 133.

[0198] The embodiments have been described in detail above, but are not limited to any particular embodiment. Various modifications and alterations can be made within the scope of the claims. Furthermore, all or more of the constituent elements of the above embodiments can be combined.

[0199] For example, in the above embodiments, the temperature difference reduction process is executed as described above in the state of performing the second power-on process when the execution conditions for the temperature difference reduction process are met, but it is not limited to this. For example, the temperature difference reduction process may also be executed continuously when the second power-on process is performed. The temperature difference reduction process may also be started from an earlier stage by predicting the change in the value of the temperature difference parameter. For example, in the case where only the second power-on process is started as described above, if it is predicted that the value of the temperature difference parameter caused by the second power-on process exceeds the threshold Th, the first power-on process may be executed before the value of the temperature difference parameter exceeds the threshold Th.

[0200] Furthermore, this embodiment can also be used as a heating control program for a windshield. That is, the program in this embodiment is for controlling heating elements installed on glass separating the interior and exterior of a moving body. This program causes a computer to perform: processing to acquire sensor information from one or more sensors, and control processing to control a first heating element installed in a first region of the glass and a second heating element installed in a second region different from the first region, based on the sensor information. The control processing includes controlling at least one of the first heating element and the second heating element to reduce the temperature difference between the glass temperature in a third region between the first and second regions of the glass and the glass temperature in the first or second region, so that the temperature difference does not exceed an upper limit.

[0201] This application claims priority based on Japanese Application Special Purpose 2020-034766, filed on March 2, 2020, the entire disclosure of which is incorporated herein by reference.

[0202] Symbol Explanation

[0203] 1.1A Vehicle windshield

[0204] 3 Electronic components

[0205] 4. Cover

[0206] 10. Control device

[0207] 20 Vehicle perimeter monitoring sensors

[0208] 31. In-vehicle network

[0209] 33 Wheel speed sensor

[0210] 35 External Temperature Sensor

[0211] 36. Internal temperature sensor

[0212] 50 windows

[0213] 51a glass

[0214] 51b glass

[0215] 51c intermediate membrane

[0216] 54. Shielding film

[0217] 54a Certain width section

[0218] 54b convex part

[0219] 60 Heating device

[0220] 61 First heating device

[0221] 610 First heating element

[0222] 612 Busbar

[0223] 613 Busbar

[0224] 614 Switch Section

[0225] 62 Second heating device

[0226] 620 Second heating element

[0227] 622 Busbar

[0228] 623 Busbar

[0229] 624 Switch Section

[0230] 70 Sensor Device

[0231] 71 First Temperature Sensor

[0232] 72 Second Temperature Sensor

[0233] 76 First Humidity Sensor

[0234] 77 Second Humidity Sensor

[0235] 131 First Region

[0236] 132 Second Region

[0237] 133 Third Region

[0238] 150 Sensor Information Acquisition Department

[0239] 151 Control Information Storage Department

[0240] 152 Control Processing Unit

[0241] 1521 First Power-On Processing Department

[0242] 1522 Second Power-On Processing Department

[0243] 1523 Threshold Setting Processing Unit

[0244] 1524 Temperature Difference Parameter Calculation Department

[0245] 1525 Threshold Determination Processing Unit

[0246] 1526 Temperature Difference Reduction Treatment Department

Claims

1. A heating control system for controlling a heating element installed on glass separating the interior and exterior of a movable body, comprising: The sensor information acquisition unit acquires sensor information from one or more sensors; and The control processing unit controls a first heating element located in a first region of the glass and a second heating element located in a second region of the glass, different from the first region, based on the sensor information. The control processing unit includes a temperature difference reduction processing unit, which performs temperature difference reduction processing to control at least one of the first heating element and the second heating element so that the temperature difference between the glass temperature of the third region between the first region and the second region of the glass and the glass temperature of the first region or the glass temperature of the second region does not exceed an upper limit value. The first area is defined in relation to the forward field of vision of passengers, including the driver; the second area is defined in relation to the vehicle's perimeter monitoring sensors; and the third area is not part of either the first or the second area and is not equipped with a heating element.

2. The heating control system as described in claim 1, wherein, The temperature difference reduction processing unit performs the temperature difference reduction processing when the value of the parameter representing the temperature difference exceeds a threshold.

3. The heating control system as described in claim 2, wherein, The sensor information includes temperature information from two or more temperature sensors located at two or more locations on the glass. The control processing unit also includes a temperature difference parameter calculation unit, which calculates the value of the parameter based on the temperature information.

4. The heating control system as described in claim 2 or 3, wherein, The sensor information includes specified information that affects the thermal conductivity of the third region. The control processing unit performs a process to correct the value of the threshold or the parameter based on the specified information.

5. The heating control system as described in claim 1, wherein, The control processing unit further includes: The first power-on processing unit performs a first power-on process based on the sensor information to power on the first heating element so as to prevent condensation from forming in the first area. The second power-on processing unit performs a second power-on process based on the sensor information to power on the second heating element so that condensation does not occur in the second area. The temperature difference reduction process is performed while the second power-on process is being executed.

6. The heating control system as described in claim 5, wherein, The temperature difference reduction process includes at least one of the following: starting to energize the first heating element without the first energizing process, and continuing to energize the first heating element regardless of whether the termination condition of the first energizing process is met.

7. The heating control system as described in claim 5, wherein, The temperature difference reduction processing unit starts energizing the first heating element even when the glass temperature in the first region is lower than the glass temperature in the second region, or when the glass temperature in the first region is higher than the first energizing start temperature corresponding to the first dew point temperature of the first region.

8. The heating control system as described in claim 5, wherein, During the execution of the first power-on process, the temperature difference reduction processing unit continues to power on the first heating element even when the glass temperature in the first region is above a first power-on end threshold corresponding to the first dew point temperature of the first region.

9. The heating control system as described in claim 5, wherein, During the execution of the first power-on process, the temperature difference reduction processing unit continues to power on the first heating element even when the glass temperature in the first region reaches a temperature at which condensation does not occur in the first region.

10. The heating control system as described in claim 5, wherein, The second power-on process is performed to make the glass temperature in the second region higher than the glass temperature in the first region achieved by the first power-on process.

11. The heating control system as described in claim 1, wherein, The second heating element has a higher heat density than the first heating element.

12. The heating control system as described in claim 1, wherein, The second region is located above the first region and corresponds to the indoor sensor that acquires information about the vehicle's surroundings.

13. The heating control system as described in claim 1, wherein, The shortest distance along the glass surface between the first region and the second region is in the range of 10 mm to 200 mm.

14. A windshield comprising: The glass separating the interior and exterior of the mobile vehicle has a first region, a second region located above the first region, and a third region between the first and second regions. The first region corresponds to the forward field of vision of passengers, including the driver. The second region corresponds to the area monitored by vehicle perimeter sensors. The third region is not part of either the first or second region and is not equipped with a heating element. The first heating element is located in the first region. The second heating element is located in the second region. A first temperature sensor is provided corresponding to at least one of the first region and the second region, and A second temperature sensor is located within the third region, at a predetermined position far from the first and second regions. At least one of the first heating element and the second heating element is controlled to ensure that the temperature difference between the glass temperature of the third region and the glass temperature of the first region or the glass temperature of the second region does not exceed an upper limit.

15. The windshield as claimed in claim 14, wherein, The specified position is located in the center of the third region.

16. A windshield comprising: The glass separating the interior and exterior of the mobile vehicle has a first region, a second region located above the first region, and a third region between the first and second regions. The first region corresponds to the forward field of vision of passengers, including the driver. The second region corresponds to the area monitored by vehicle perimeter sensors. The third region is not part of either the first or second region and is not equipped with a heating element. The first heating element is located in the first region. The second heating element is located in the second region, and A temperature sensor is installed on the glass. The shortest distance along the surface of the glass between the first region and the second region is less than 10 mm. At least one of the first heating element and the second heating element is controlled to ensure that the temperature difference between the glass temperature of the third region and the glass temperature of the first region or the glass temperature of the second region does not exceed an upper limit.

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