JP2019142325A - Photographing apparatus for vehicle - Google Patents

Abstract

To provide a photographing apparatus for a vehicle which can supply electric power of a suitable quantity to heating means.SOLUTION: If a special heating necessary condition is established when an absolute value of a difference between a specific member temperature and a temperature outside the vehicle is a prescribed temperature or less in the case that a vehicle is changed from a travel impossible state to a travel possible state, a controller is so configured as to change a target value of electric energy, which is supplied to heating means in a prescribed time, to a larger value compared to the case that said special heating necessary condition is not established.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a vehicular photographing apparatus provided inside a window portion (for example, a front windshield) provided in a vehicle.

  A camera may be provided inside the front windshield of the vehicle. The camera converts reflected light (subject image) reflected by a target (for example, another vehicle) located in front of the vehicle into imaging data by an imaging element, and transmits the imaging data to a vehicle control device.

  By the way, when the vehicle outside temperature, which is the temperature of the outside air of the vehicle, is low, condensation may occur on the front windshield. If condensation occurs on the front windshield, there is a possibility that the imaging data becomes data representing a blurred subject image, or that the imaging device cannot capture a target in front of the vehicle.

  Therefore, an apparatus (hereinafter referred to as “conventional apparatus”) that prevents dew condensation by heating the front windshield has been proposed. Each of the conventional devices includes a “heater and a heated portion that applies heat received from the heater as radiant heat to the front windshield” disposed inside the front windshield. The conventional apparatus raises the temperature of the front windshield to a temperature equal to or higher than the dew point temperature by energizing the heater (supplying electric power) when the temperature outside the vehicle is low (that is, when the possibility of condensation is high). As a result, it is possible to prevent dew condensation from occurring on the front window (see, for example, Patent Document 1).

JP 2017-185896 A

  By the way, for example, when the driving source (for example, the internal combustion engine) is started after the vehicle is parked for a long time and the vehicle is started (that is, when the vehicle is started), the heater is not generating heat. Since the duration of is long, water droplets may adhere to the heated portion. When energization of the heater is started in this state, “water droplets adhering to the heated part” becomes water vapor due to the heat generated by the heater, and further condensation occurs due to this water vapor being cooled by the front windshield. There is. That is, as a result of energizing the heater at the start of vehicle operation, water droplets may adhere to the front windshield.

  Furthermore, when the temperature of the front windshield is equal to or lower than the freezing temperature of water (freezing point), water droplets attached to the front windshield may change to ice due to energization of the heater at the start of vehicle operation. In this case, it is necessary to melt the ice to form water droplets, and to dissipate the water droplets from the front windshield. At this time, since a large amount of heat is required to melt the ice, it takes a long time to clear the front windshield.

  On the other hand, the problem described above can be avoided by increasing the amount of power supplied to the heater at the start of vehicle operation. However, for example, if the same control is executed when the temperature of the front windshield is significantly higher than the freezing temperature, if no water droplets are attached to the heated portion, the front windshield and its peripheral parts (including the imaging device are included). ) May become excessively high and the parts may deteriorate.

  The present invention has been made to address the above problems. That is, one of the objects of the present invention is to provide a vehicle photographing apparatus capable of supplying an appropriate amount of power to the heating means.

In order to achieve the above object, a vehicle photographing apparatus according to the present invention comprises:
Imaging data is generated by receiving imaging light that is disposed inside a window portion (85) provided in the vehicle and that passes through the window portion using electric power supplied from a power source mounted on the vehicle. An imaging device (30);
A heating means (41a, 43b) disposed inside the window and heating the window by generating heat using electric power supplied from the power source;
An outside temperature detection means (101) for detecting an outside temperature (Tair) which is a temperature outside the vehicle;
When the vehicle is in a travelable state, the imaging device generates the imaging data, and when the vehicle is in the travelable state, this corresponds to a target value of the amount of power supplied to the heating means in a predetermined time. A control device (100) that calculates an amount based on at least the outside temperature of the vehicle and performs power supply control so that an amount of power corresponding to the target value is supplied from the power source to the heating means;
A vehicular imaging device comprising:
The specific member temperature detection means (30a, 30a, which detects, as the specific member temperature (Tc, Wt), the temperature of the specific member (30) having a temperature that approaches the outside temperature as the duration of the state where the heating means is not generating heat is longer. 103)
The control device is
When the vehicle is changed from the travel impossible state to the travelable state, special heating is required that is established when the absolute value of the difference between the specific member temperature and the outside temperature is equal to or lower than a predetermined temperature (Va1, Va2). When the condition is satisfied, the target value is changed to a larger value than when the special heating requirement is not satisfied.

As described above, in the present invention, the special heating requirement is satisfied when the absolute value of the difference between the specific member temperature, which is the temperature of the specific member, and the vehicle exterior temperature becomes equal to or lower than a predetermined temperature.
The “specific member” is, for example, cooling water for the photographing apparatus and the internal combustion engine. That is, the “specific member temperature” is, for example, the temperature of the photographing apparatus and the temperature of the cooling water. Therefore, for example, the special heating requirement is satisfied when the photographing device as the specific member is not operated for a long time due to the fact that power is not supplied.

  The control device of the present invention is configured to increase the target value of the amount of electric power supplied to the heating means when the special heating requirement is satisfied as compared with the case where the special heating requirement is not satisfied. Therefore, since the target value of the electric energy becomes large when the special heating requirement is satisfied, it is possible to reduce the possibility that water droplets attached to the window portion having a low temperature as water vapor due to the heat generated by the heating means become ice. In addition, when the special heating requirement is not satisfied, the target value of the electric energy is small, and therefore, for example, the possibility that the window portion is excessively heated by the heating means is small.

  In the above description, in order to help understanding of the present invention, names and / or symbols used in the embodiment are attached to the configuration of the invention corresponding to the embodiment described later in parentheses. However, each component of the present invention is not limited to the embodiment defined by the reference numerals.

It is the perspective view which looked at the imaging device for vehicles concerning the embodiment of the present invention, and the front windshield from the front of vehicles. It is sectional drawing which follows the II-II arrow line of FIG. It is the disassembled perspective view which looked at the light-shielding heating unit from the lower part. It is a schematic diagram of an electric circuit. It is a routine which shows the process which a control apparatus performs. It is a graph which shows duty ratio when supplying electric power to the heater calculated based on the duty ratio calculation map for special heating. It is a graph which shows duty ratio when supplying electric power to the heater calculated based on the map for low speed duty ratio calculation or the high speed duty ratio calculation.

  Hereinafter, an imaging device for a vehicle according to an embodiment of the present invention will be described with reference to the accompanying drawings.

(Constitution)
As shown in FIG. 1, a vehicle photographing apparatus 10 (hereinafter referred to as “photographing apparatus 10”) according to an embodiment is a front windshield (hereinafter referred to as “front window”) 85 of a vehicle. Provided inside the car. The front window 85 is made of translucent glass. The front window 85 may be formed of a material other than glass (for example, resin) as long as it has translucency. As shown in FIG. 2, the front window 85 is inclined with respect to the vehicle body in such a manner that the front window 85 gradually moves forward from the upper side toward the lower side.

  As shown in FIG. 1, a light shielding sheet 86 having a substantially T-shape as a whole is attached to the upper edge portion of the rear surface of the front window 85 (that is, the vehicle inner surface) and its vicinity. A front extending portion 86 a extending obliquely downward in the front direction is formed at the central portion of the light shielding sheet 86. A light transmission hole 86b having a substantially trapezoidal shape is formed in the vicinity of the front end of the front extension 86a. A portion of the front window 85 facing the light transmission hole 86b constitutes a light transmission portion 85a. The photographing apparatus 10 is disposed on the inner side of the front window 85 in a manner facing the light transmission portion 85a.

  As shown in FIG. 2, the photographing apparatus 10 includes a camera unit 30 and a light-shielding heating unit 40 as main components. The basic structure of the camera unit 30 is described in detail in Patent Document 1, and will be briefly described below.

  The camera unit 30 includes a housing 31 and an imaging unit 32. The housing 31 is an integrally molded product made of resin and constitutes the outer shape of the camera unit 30. On the upper surface of the housing 31, there is provided a hood mounting recess 31a having a substantially trapezoidal shape in plan view. The imaging unit 32 is fixed to the rear end surface of the hood mounting recess 31a. The imaging unit 32 includes a lens 32a and an imaging element 32b located immediately after the lens 32a. The imaging element 32b is a compound eye type element. The imaging element 32b receives reflected light (imaging light) reflected backward by a target located in front of the camera unit 30 and transmitted through the lens 32a to generate imaging data. A thermistor 30a (see FIG. 4) capable of detecting the temperature (camera unit temperature) Tc of the camera unit 30 is provided inside the camera unit 30.

  As shown in FIG. 3, the light shielding heating unit 40 includes a light shielding hood 41, a heater module 43, a heat insulating material 45, and a cable module 46 as main components. The basic structure of the light shielding hood 41, the heater module 43, the heat insulating material 45, and the cable module 46 is described in detail in Patent Document 1, and will be briefly described below (however, the heater module of the cable module 46 of the present embodiment). The connection mode to 43 etc. is different from Patent Document 1.)

  The light shielding hood 41 is an integrally molded product made of hard resin. The light shielding hood 41 includes a heated portion 41a and a side wall portion 41b. The heated portion 41a is a plate-like body having a regular triangle shape (that is, a regular triangle shape in a front view). The side wall portions 41b are a pair of flange portions extending upward from the left and right side edges of the heated portion 41a. The height of the side wall 41b gradually increases from the front end toward the rear end.

  The heater module 43 includes a PET sheet 43a and a heater 43b.

  The PET sheet 43a is formed of PET (polyethylene terephthalate). The outer shape of the PET sheet 43a is substantially the same shape as the heated portion 41a. The insulation property of the PET sheet 43a is good.

  The heater 43b is a heating wire made of a metal (for example, brass) that generates heat when energized. The heater 43b is formed by zigzag printing on almost the entire upper surface of the PET sheet 43a. Both end portions of the heater 43b are constituted by a pair of lands 43c and 43d having a larger area than the other portions. The lands 43c and 43d are exposed on both the upper and lower surfaces of the PET sheet 43a.

  The upper surface of the PET sheet 43a is attached to the lower surface of the heated portion 41a by a double-sided tape (not shown) having good thermal conductivity.

  The heat insulating material 45 is made of a member having an insulating property, and has an equilateral triangular shape that is substantially the same as the heated portion 41a. A pair of through holes 45 a and 45 b are formed in the heat insulating material 45. The heat conductivity of the heat insulating material 45 is low.

  The upper surface of the heat insulating material 45 is attached to the lower surface of the PET sheet 43a by a double-sided tape (not shown).

  The cable module 46 includes a first power supply cable 60 and a second power supply cable 63. The first power supply cable 60 includes an electric wire 61 made of a metal wire having good conductivity, and a covering tube 62 that covers an outer peripheral surface excluding both ends of the electric wire 61. Similarly, the second power feeding cable 63 includes an electric wire 64 made of a metal wire having good conductivity, and a covering tube 65 that covers an outer peripheral surface excluding both ends of the electric wire 64.

  One end of the electric wire 61 is inserted into the through hole 45a of the heat insulating material 45 and connected to the lower surface of the land 43c by solder (see FIG. 4). One end of the electric wire 64 is inserted into the through hole 45b and connected to the lower surface of the land 43d by solder (see FIG. 4).

  As shown in FIG. 2, the light shielding hood 41 of the light shielding heating unit 40 fits into the hood mounting recess 31a of the camera unit 30, and the front portion of the imaging unit 32 is a gap between the rear end portions of the left and right side wall portions 41b. It is located directly above the rear end of the heated part 41a.

  As shown in FIG. 2, the photographing apparatus 10 integrated in this way uses an adhesive (not shown) applied to a bracket (not shown) that supports the camera unit 30, and uses the adhesive (not shown) of the light shielding sheet 86. It is fixed to the inner surface of the front extension 86a. Then, the heated portion 41 a of the light shielding heating unit 40 and the imaging unit 32 of the camera unit 30 are located at positions facing the light transmission holes 86 b of the light shielding sheet 86. Therefore, the imaging light that has passed from the front of the front window 85 to the rear and transmitted rearward through the light transmission part 85a and the light transmission hole 86b of the light shielding sheet 86 is received by the imaging element 32b after passing through the lens 32a of the imaging part 32. The

  As shown in FIG. 4, the vehicle includes an electric control device (not shown; hereinafter referred to as “control device”) 100. The control device 100 is an ECU. The ECU is an abbreviation for Electric Control Unit, and includes a microcomputer including a storage device such as a CPU, ROM, RAM, and backup RAM. The CPU realizes various functions by executing instructions (programs) stored in the ROM. Various maps (look-up tables) described later are stored in the storage device (ROM) of the control device 100. The backup RAM holds the stored data even during a period in which power is not supplied from the IG power source to the control device 100.

  The vehicle further includes an internal combustion engine (not shown) as a drive source. This internal combustion engine has a starter motor (not shown) and is started by the power of the starter motor.

  The vehicle further includes an outside temperature sensor 101 for measuring the temperature Tair outside the vehicle. The vehicle further includes a vehicle speed sensor 102 that detects the speed of the vehicle (that is, the vehicle speed SPD), and a water temperature sensor 103 that detects the coolant temperature Wt of the internal combustion engine. The outside temperature sensor 101, the vehicle speed sensor 102, and the water temperature sensor 103 are connected to the control device 100.

  As shown in FIG. 4, the other end of the electric wire 61 is connected to the anode of an in-vehicle power source (IG power source) (battery) via a feeder line EL1 and an ignition switch (IG · SW). The cathode of the IG power supply is grounded. The other end of the electric wire 64 is connected to one end of the switch element 89. The other end of the switch element 89 is grounded. The state of the switch element 89 is switched by the control device 100 between an ON state (conductive state and connected state) and an OFF state (non-conductive state and cutoff state). In this example, the switch element 89 is a semiconductor switch element, but may be a relay switch.

  Further, one end of a power supply line EL2 is connected to the ignition switch (IG · SW). The other end of the power supply line EL2 is connected to a power supply line (not shown) of the camera control ECU 106. A ground line (not shown) of the camera control ECU 106 is grounded. Thereby, the camera control ECU 106 is supplied with electric power from the IG power source. In addition, a power line (not shown) of the camera unit 30 is connected to the power supply line EL2, and an earth line (not shown) of the camera unit 30 is grounded. As a result, the camera unit 30 is supplied with power from the IG power source. The camera control ECU 106 and the camera unit 30 are connected so that various signals can be transmitted and received. Although not shown, the control device 100 and the starter motor are also connected to the IG power source via the IG / SW, and power is supplied from the IG power source. Further, the control device 100 and the camera control ECU 106 are configured to be able to transmit / receive information to / from each other via a CAN (not shown).

  The camera control ECU 106 detects the voltage Vh of the electric power supplied to itself (potential of the power supply line EL2). This voltage Vh is substantially equal to the voltage Vp of the IG power supply. Furthermore, when the switch element 89 is in the conductive state, the voltage Vh of the power supplied to the heater 43b is substantially equal to the voltage Vp of the IG power source. Therefore, the voltage Vh detected by the camera control ECU 106 is used as the voltage (heater voltage) Vh of the power supplied to the heater 43b.

  The shading heating unit 40 and the control device 100 described above are components of the heating device 95.

(Operation)
Next, operations of the vehicle and the imaging device 10 will be described.
When the ignition switch (IG / SW) is in the OFF state, the internal combustion engine is stopped, and the vehicle is maintained in an unrunnable state. Further, as understood from FIG. 4, when the ignition switch (IG • SW) is in the OFF state, power is not supplied from the IG power source to either the camera unit 30 or the heater 43 b, so that the camera unit 30 does not operate. (Imaging data is not generated) and the heater 43b does not generate heat.

  When the driver operates an ignition key (not shown) when the vehicle starts to travel, the ignition switch (IG / SW) is switched from the OFF state to the ON state. The anode of the IG power supply is connected to the feeder line EL1, the feeder line EL2, and the control device 100. Note that a period from when the ignition switch is switched from the OFF state to the ON state until it is returned to the OFF state again is referred to as “trip”.

  When the ignition switch changes from the OFF state to the ON state, the camera ECU 106 causes the camera unit 30 to start imaging. That is, the imaging element 32b of the imaging unit 32 of the camera unit 30 is reflected backward by a target (for example, another vehicle) positioned in front of the vehicle on which the imaging device 10 is mounted every time a predetermined time elapses. The reflected light that has passed through the light transmission part 85a of the window 85, the light transmission hole 86b of the light shielding sheet 86, and the lens 32a is imaged to generate imaging data. The camera unit 30 transmits the imaging data to the camera ECU 106. The camera ECU 106 processes the imaging data received from the camera unit 30 and transmits it to the control device 100 every time a predetermined time elapses. The control device 100 acquires information (forward information) about a target (another vehicle, an obstacle, etc.) existing in front of the vehicle by analyzing the received imaging data, and controls the vehicle based on the forward information. To do.

  For example, the control device 100 executes “automatic brake control, lane keeping assist control (lane tracing assist control) and adaptive high beam control”, etc. based on the forward information, performs automatic driving, and issues an alarm. Or Hereinafter, such control based on the forward information is referred to as driving support control.

  Further, when the driver operates the ignition key to the start position (start position), the electric power of the IG power source is supplied to the starter motor, and the internal combustion engine is started.

Further, when electric power is supplied to the control device 100 and the camera control ECU 106, the control device 100 and the camera control ECU 106 perform the following operations every time a predetermined time elapses.
The control device 100 detects the vehicle outside temperature Tair using the vehicle outside temperature sensor 101, and detects the coolant temperature Wt of the internal combustion engine using the water temperature sensor 103. Furthermore, the control device 100 detects the vehicle speed SPD using the vehicle speed sensor 102.
The camera control ECU 106 detects the temperature Tc of the camera unit 30 using the thermistor 30a. The camera control ECU 106 detects the voltage value Vh of power supplied to the camera control ECU 106 itself, and transmits the detected voltage value Vh to the control device 100.

  By the way, when the outside temperature Tair is low, dew condensation may occur in the light transmission portion 85a of the front window 85. Condensation is more likely to occur when heating is used in the passenger compartment. Furthermore, when the outside temperature Tair is low, ice and / or frost may adhere to the light transmission part 85a. When such a phenomenon occurs, there is a possibility that the imaging data generated by the imaging device 32b becomes data representing a blurred subject image, or the imaging unit 32 cannot capture a target in front of the vehicle. In such a case, there is a possibility that the control device 100 cannot accurately perform the driving support control using the imaging data. Therefore, the control device 100 prevents such a situation from occurring by executing the processing (routine) shown in the flowchart of FIG. The control device 100 sets the state of the switch element 89 to the OFF state immediately after the ignition key switch is changed from the OFF state to the ON state.

  When the ignition key switch is changed from the OFF state to the ON state, the CPU of the control device 100 (hereinafter simply referred to as “CPU”) has a predetermined time T (see FIG. 7; in this embodiment, 3 minutes). 5 starts from step 1000 and proceeds to step 1001 (however, the processing of step 1095 is performed immediately after the processing of steps 1006 and 1007 described later in one routine processing). If so, the CPU starts processing a new routine immediately after the completion of step 1095).

  Then, the CPU determines whether or not the vehicle outside temperature Tair detected by the vehicle outside temperature sensor 101 at a predetermined time tp immediately before the start of the processing of this routine is lower than a predetermined threshold vehicle outside temperature Tath. When the vehicle outside temperature Tair is equal to or higher than a predetermined threshold vehicle outside temperature Tath, “the possibility of condensation or ice and / or frost adhering to the transmission part 85a” is extremely low. Accordingly, in this case, the CPU makes a “No” determination at step 1001 to proceed to step 1094 to set the state of the switch element 89 to the OFF state (stops energization of the heater 43b). Thereafter, the CPU proceeds directly to step 1095 to end the present routine tentatively. As a result, the state of the switch element 89 is maintained in the OFF state, so that the heater 43b does not generate heat.

  On the other hand, if the vehicle outside temperature Tair is lower than the predetermined threshold vehicle outside temperature Tath, the CPU makes a “Yes” determination at step 1001 to proceed to step 1002, and the vehicle speed sensor at a predetermined time tp immediately before the start of the processing of this routine. It is determined whether the vehicle speed SPD detected by the vehicle 102 is equal to or higher than a predetermined threshold speed SPDth. The control device 100 executes driving support control based on imaging data generated by the camera unit 30 when the vehicle speed SPD is equal to or higher than the threshold speed SPDth. Therefore, when the vehicle speed SPD is less than the threshold speed SPDth, the imaging data is not used, and it is not necessary to energize the heater 43b. Therefore, if the vehicle speed SPD is less than the threshold speed SPDth, the CPU makes a “No” determination at step 1002 to directly proceed to step 1095 via step 1094. As a result, the state of the switch element 89 is maintained in the OFF state, so that the heater 43b does not generate heat.

  On the other hand, when the vehicle speed SPD is equal to or higher than the threshold speed SPDth, the CPU makes a “Yes” determination at step 1002 to proceed to step 1003. Note that step 1002 may be omitted. In other words, the threshold speed SPDth may be “0 km / h”. In this case, the CPU always proceeds to step 1003 regardless of the vehicle speed SPD. In step 1003, the CPU determines that the temperature Tc of the camera unit 30 detected by the thermistor 30a at a predetermined time tp immediately before the start of the processing of this routine is within a predetermined normal temperature range (a temperature range in which the operation of the camera unit 30 is guaranteed). ). If the camera unit temperature Tc is not within the normal temperature range, the CPU makes a “No” determination at step 1003 to proceed directly to step 1095 via step 1094. As a result, the state of the switch element 89 is maintained in the OFF state, so that the heater 43b does not generate heat.

  On the other hand, if the camera unit temperature Tc is within the normal temperature range, the CPU makes a “Yes” determination at step 1003 to proceed to step 1004. In step 1004, the CPU determines whether or not the vehicle has just been switched from the untravelable state to the travelable state.

The CPU that has determined “Yes” in step 1004 proceeds to step 1005. In step 1005, the CPU determines whether both of the following conditions (a) and (b) are satisfied.
Condition (a): The absolute value | Tc−Tair | of the difference between the temperature Tc at the predetermined time tp and the outside temperature Tair at the predetermined time tp is equal to or less than the predetermined first predetermined value Va1. When the temperature Tc and the outside temperature Tair are expressed in Celsius (° C.), for example, the first predetermined value Va1 is 3.0 (° C.).
Condition (b): The absolute value | Wt−Tair | of the difference between the water temperature Wt detected by the water temperature sensor 103 at the predetermined time tp and the outside temperature Tair at the predetermined time tp is equal to or less than the predetermined second predetermined value Va2. When the water temperature Wt and the outside temperature Tair are expressed in degrees Celsius (° C.), for example, the second predetermined value Va2 is 3.0 (° C.).
When the CPU determines that both conditions (a) and (b) are satisfied, the CPU determines that the special heating requirement is satisfied. On the other hand, when at least one of the conditions (a) and (b) is not satisfied, the CPU determines that the special heating requirement is not satisfied.

  When the power of the IG power source is not supplied to the camera unit 30, when the camera unit 30 has not been operated for a long time, there is almost no difference between the temperature Tc and the outside temperature Tair (the first predetermined value Va1 or less). Become). In the present embodiment, when the ignition switch is in the OFF state, the power of the IG power source cannot be supplied to the camera unit 30, the starter motor, and the heater 43b. That is, when the IG power supply cannot be supplied to the camera unit 30 and the starter motor, the IG power supply cannot be supplied to the heater 43b. Therefore, when | Tc−Tair | is equal to or less than a predetermined first predetermined value Va1, it can be estimated that the heater 43b does not generate heat for a long time.

  Further, when the internal combustion engine has not been operated for a long time due to the fact that the power of the IG power source is not supplied to the starter motor, there is almost no difference between the water temperature Wt and the outside temperature Tair (second predetermined value Va2 or less). Become). When the IG power supply cannot be supplied to the starter motor, the IG power supply is not supplied to the heater 43b. Therefore, when | Wt−Tair | is equal to or smaller than a predetermined second predetermined value Va2, it can be estimated that the heater 43b does not generate heat for a long time.

  Therefore, when the special heating requirement is satisfied, electric power is not supplied to the heater 43b for a long time, and as a result, the predetermined temperature at which the temperature of the light transmitting portion 85a is the freezing temperature (freezing point) of water. It is considered that there is a possibility that it is Ts or less.

  The CPU that has determined “Yes” in step 1005 performs the processing of step 1006 and step 1007 described below in order, and then proceeds to step 1095 to end the present routine tentatively.

Step 1006: As shown in the following equation, the CPU calculates the duty ratio by applying the heater voltage Vh and the outside temperature Tair at the predetermined time tp as arguments to the special heating duty ratio calculation map (MapS). The heater voltage Vh is a voltage estimated as described above based on the voltage value of the power supplied to the camera control ECU 106 itself.
Duty ratio = MaPS (Vh, Tair)

As shown in FIG. 6, the duty ratio is defined as Ton when the switch element 89 is in the ON state (voltage application time), and when the switch element 89 is in the OFF state (voltage application stop time). Is a ratio (%) expressed by the following equation. In this example, if Ton + Toff is one period ΔTa, one period ΔTa of this embodiment is set to 100 sec (seconds). As the duty ratio increases, the amount of electric power (total electric energy) supplied (consumed by the heater 43b) to the heater 43b in one cycle ΔTa increases. The quantity [J]) increases.
Duty ratio = [Ton / (Ton + Toff)]. 100 (%)

  By the way, according to experiments, if the temperature of the heater 43b can be maintained within a predetermined temperature range (hereinafter referred to as “first appropriate temperature range”), “water droplets adhering to the inner side surface of the light transmitting portion 85a are iced. It has been found that there is a high possibility that the light transmitting portion 85a does not become excessively hot. This is because, when the temperature of the heater 43b is maintained within the first appropriate temperature range, the temperature of the light transmitting portion 85a is higher than the predetermined temperature Ts (freezing point) regardless of the outside temperature Tair and excessively high temperature. It is estimated that the temperature is lower than that.

  On the other hand, the temperature of the heater 43b has a strong correlation with the amount of heat generated in the heater 43b for a predetermined time (one period ΔTa in this example) and the amount of heat taken away from the heater 43b. Furthermore, the amount of heat taken away from the heater 43b has a strong correlation with the amount of heat released from the light transmission portion 85a. The amount of heat radiation of the light transmitting portion 85a in a predetermined time has a strong correlation with the “temperature outside the vehicle Tair”. Therefore, the heater voltage Vh at the predetermined time tp and the outside temperature Tair at the predetermined time tp are used as arguments of the special heating duty ratio calculation map (MapS).

  The duty ratio calculated in accordance with the special heating duty ratio calculation map (MapS) is “one cycle necessary for maintaining the temperature of the heater 43b within the first appropriate temperature range regardless of the magnitude of the outside temperature Tair. This is a value corresponding to the target value of “heat generation amount (supply power amount) of the heater 43b at ΔTa”. Therefore, the special heating duty ratio calculation map shows that the heater voltage Vh, the outside temperature Tair, and the duty ratio necessary for maintaining the temperature of the heater 43b within the first appropriate temperature range (the heater 43b is generated in one cycle ΔTa). The target value of the total amount of heat to be obtained) and a relationship obtained in advance through experiments, and stored in the ROM.

  It is possible to determine the target heat generation amount (target value of the heat generation amount) based on the outside temperature Tair, and to determine the duty ratio based on the target heat generation amount and the voltage Vh.

  When the special heating duty ratio calculation map (MapS) is used, the duty ratio decreases as the heater voltage Vh increases, and the duty ratio decreases as the vehicle outside temperature Tair increases. For example, when the heater voltage Vh and the outside temperature Tair at the predetermined time tp are respectively predetermined values, the duty ratio calculation map (MapS) calculates the duty ratio with Toff = 10 sec and Ton = 90 sec.

  The duty ratio calculated by the special heating duty ratio calculation map (MapS) under the condition that the heater voltage Vh and the outside temperature Tair at the predetermined time tp are the same is a “low speed duty ratio calculation map (MapLo), which will be described later. ) ”And“ High-speed duty ratio calculation map (Mappi) ”are larger than the calculated duty ratio. Furthermore, the Toff time calculated by the special heating duty ratio calculation map (MapS) under the condition that the heater voltage Vh and the outside temperature Tair at the predetermined time tp are the same is “the low speed duty ratio calculation map ( “MapLo)” and “High-speed duty ratio calculation map (Mapi)” are shorter than the Toff time calculated. Further, the Ton time calculated by the special heating duty ratio calculation map (MapS) under the condition that the heater voltage Vh and the outside temperature Tair at the predetermined time tp are the same is “the low speed duty ratio calculation map (MapLo). ) "And" High-speed duty ratio calculation map (Mappi) "are preferably longer than the Ton time calculated.

  Step 1007: The CPU that has completed the processing of Step 1006 proceeds to Step 1007, and executes energization control (heat generation amount control) of the heater 43b over one cycle ΔTa according to the duty ratio calculated in Step 1006. That is, as shown in FIG. 6, the CPU sets the state of the switch element 89 to the OFF state over the voltage application stop time Toff defined by the duty ratio, and then at the voltage application time Ton defined by the duty ratio. The state of the transition switch element 89 is set to the ON state. Then, while the switch element 89 is in the ON state, the electric power of the IG power source is supplied to the heater 43b and the heater 43b is heated. Therefore, there is a high possibility that the temperature of the light transmitting portion 85a is higher than the predetermined temperature Ts (freezing point) and lower than an excessively high temperature during the elapse of one cycle ΔTa (100 sec) from time t0 in FIG.

  When one cycle ΔTa (100 sec) has elapsed from time t 0, the CPU returns the state of the switch element 89 to the OFF state and restarts this routine from step 1000.

  In the second and subsequent processes of this routine, the CPU makes a “No” determination at step 1004 to execute the processes of step 1008 and step 1007 described below.

  Step 1008: The CPU first determines whether the vehicle speed SPD detected by the vehicle speed sensor 102 at a predetermined time tp is included in a predetermined low speed region or a high speed region. For example, the range of the low speed region is 0 or more and less than 50 km / h, and the range of the high speed region is 50 km / h or more.

When the vehicle speed SPD is a vehicle speed included in the low speed region, the CPU selects the low speed duty ratio calculation map (MapLo) as the duty ratio calculation map (lookup table). Then, the CPU calculates the duty ratio by applying the heater voltage Vh, the outside temperature Tair, and the vehicle speed SPD at the predetermined time tp as arguments to the map as shown in the following equation.
Duty ratio = MaPLo (Vh, Tair, SPD)

On the other hand, when the vehicle speed SPD is a vehicle speed included in the high speed region, the CPU selects the high speed duty ratio calculation map (MapHi) as the duty ratio calculation map. Then, the CPU calculates the duty ratio by applying the heater voltage Vh, the outside temperature Tair, and the vehicle speed SPD as arguments to this map as shown in the following equation.
Duty ratio = MaPHi (Vh, Tair, SPD)

  By the way, according to an experiment, if the temperature of the heater 43b can be maintained within a predetermined temperature range (hereinafter referred to as “second appropriate temperature range”), “condensation occurs in the light transmission portion 85a and light transmission occurs. It has been found that “attachment of ice, frost, etc. to the portion 85a” can be avoided. This is presumed to be because if the temperature of the heater 43b is maintained within the second appropriate temperature range, the temperature of the light transmission portion 85a can be maintained at "a temperature within a predetermined range equal to or higher than the dew point temperature".

  By the way, the heat radiation amount (and the temperature of the heater 43b) of the light transmitting portion 85a for a predetermined time has a strong correlation with not only the “vehicle outside temperature Tair” but also “vehicle speed SPD”. Therefore, the heater voltage Vh at the predetermined time tp, the outside temperature Tair at the predetermined time tp, and the vehicle speed SPD at the predetermined time tp are used as arguments of the low-speed duty ratio calculation map (MapLo) and the high-speed duty ratio calculation map (MapHpi). Used.

  The low speed duty ratio calculation map (MapLo) and the high speed duty ratio calculation map (Mapi) may be integrated into one duty ratio calculation map (MapCo (Vh, Tair, SPD)). Hereinafter, when there is no need to distinguish between the low speed duty ratio calculation map (MapLo) and the high speed duty ratio calculation map (Mapi), these maps are referred to as duty ratio calculation maps. The duty ratio calculated according to the duty ratio calculation map is a target value of “heat generation amount (supplied power amount) of the heater 43b at a predetermined time T” necessary for maintaining the temperature of the heater 43b within the second appropriate temperature range. Is a value corresponding to. Therefore, the duty ratio calculation map shows that the heater voltage Vh, the outside temperature Tair, the vehicle speed SPD, and the duty ratio necessary for maintaining the temperature of the heater 43b within the second appropriate temperature range (the heater 43b is generated at the predetermined time T). The target value of the total amount of heat to be obtained) and a relationship obtained in advance through experiments, and stored in the ROM.

  When the duty ratio calculation map is used, the target heat generation amount can be obtained based on the vehicle outside temperature Tair and the vehicle speed SPD, and the duty ratio can be obtained based on the target heat generation amount and the voltage Vh. Is possible.

  Regardless of whether the low speed duty ratio calculation map (MapLo) or the high speed duty ratio calculation map (Mapi) is used, the higher the heater voltage Vh, the smaller the duty ratio. Regardless of which one of the low speed duty ratio calculation map (MapLo) and the high speed duty ratio calculation map (MapHi) is used, the higher the vehicle outside temperature Tair, the smaller the duty ratio.

  When the heater voltage Vh and the outside temperature Tair are respectively predetermined constant values, the duty ratio obtained from the high-speed duty ratio calculation map (Mapi) is calculated from the duty ratio obtained from the low-speed duty ratio calculation map (MapLo). Also grows. Further, regardless of which one of the low speed duty ratio calculation map (MapLo) and the high speed duty ratio calculation map (MapHi) is used, the higher the vehicle speed SPD, the larger the duty ratio.

  Step 1007: The CPU executes energization control of the heater 43b for a predetermined time T according to the duty ratio. That is, as shown in FIG. 7, the CPU sets the state of the switch element 89 to the OFF state over the voltage application stop time Toff defined by the duty ratio, and then at the voltage application time Ton defined by the duty ratio. The operation of setting the transition switch element 89 to the ON state is repeated three times (see times t0 to t6). Thereafter, when a predetermined time T has elapsed from the time when the processing of step 1001 is started, the CPU restarts this routine from step 1000.

  As described above, when the special heating requirement is satisfied (when the CPU determines “Yes” in step 1005), it is considered that the heater 43b did not generate heat for a long time. That is, if the vehicle outside temperature Tair is low when the special heating requirement is satisfied, it is considered that the temperature of the light transmission part 85a may be equal to or lower than the predetermined temperature Ts (freezing point). However, when the special heating requirement is satisfied, the duty ratio calculated in step 1006 is larger than the duty calculated in step 1008, so that the heater 43b generates a large amount of heat in one cycle ΔTa. Further, the Toff time calculated in step 1006 is shorter than the Toff time calculated in step 1008. Therefore, if the processing of step 1007 is executed after step 1006, the light transmitting portion 85a is likely to immediately become a temperature higher than the predetermined temperature Ts (freezing point). Accordingly, the water droplets attached to the heated portion 41a before the power is supplied to the heater 43b become water vapor by the heat generated by the heater 43b and adhere to the inner side surface of the light transmitting portion 85a and become ice. The risk of becoming small is small. Accordingly, it is possible to cause the water droplets attached to the light transmission part 85a to disappear from the light transmission part 85a with a small amount of electric power (compared to the case where ice is generated on the inner surface of the light transmission part 85a).

  When the CPU determines “No” in step 1004 or 1005, it is considered that the heater 43b continued to generate heat for a certain period of time. That is, when the special heating requirement is not satisfied, it is considered that there is a high possibility that the temperature of the light transmission portion 85a is higher than the predetermined temperature Ts (freezing point) even when the outside temperature Tair is low. In this case, the duty ratio calculated in step 1008 is smaller than the duty ratio calculated in step 1006 when the CPU determines “Yes” in step 1005, so that the heater 43 b does not generate much heat at the predetermined time T. Does not occur. Therefore, there is little possibility that the light transmitting portion 85a is excessively heated by the heat generated by the heater 43b.

  For example, when the outside temperature Tair is extremely low, even if the CPU determines “Yes” in step 1005 in the first process of the routine shown in FIG. 5, the light transmission is completed when the first process is completed. There is a possibility that the portion 85a has a temperature equal to or lower than a predetermined temperature Ts (freezing point). However, when the energization control of the heater 43b is performed based on the duty ratio calculated using the special heating duty ratio calculation map in the first process, the temperature of the light transmission portion 85a is processed in the second and subsequent processes of the routine. Can be raised to a temperature higher than the predetermined temperature Ts (compared to the case where the processing of step 1006 is not executed in the first processing of the routine).

  As described above, the present invention has been described based on the embodiment and the modification. However, the present invention is not limited to the embodiment and the modification, and various modifications can be made without departing from the object of the present invention. .

  Only the outside temperature Tair at the predetermined time tp may be used as an argument of the special heating duty ratio calculation map (MapS). As an argument of the special heating duty ratio calculation map (MapS), an outside temperature Tair at a predetermined time tp, a heater voltage Vh at a predetermined time tp, and a vehicle speed SPD at a predetermined time tp may be used. The vehicle outside temperature Tair at the predetermined time tp and the vehicle speed SPD at the predetermined time tp may be used as arguments of the special heating duty ratio calculation map (MapS).

  Instead of using the lookup table, the duty ratio and the target heat generation amount may be obtained by a calculation formula having the lookup table argument as a variable.

  Step 1004 may be omitted from the flowchart of FIG. That is, if the CPU determines “Yes” in step 1005 in the first process of the routine shown in FIG. 5 and the CPU determines “Yes” in step 1005 in the second and subsequent processes of this routine, the CPU You may make it perform the process of step 1006 and 1007 in the process after the 2nd time.

  The vehicle photographing device may be mounted on a window part different from the front window. For example, a vehicle photographing device may be mounted on the back window of the vehicle so that an obstacle located behind the vehicle can be detected.

  The CPU may determine that the special heating requirement is satisfied when at least one of the condition (a) and the condition (b) is satisfied.

Furthermore, the CPU determines that the special heating requirement is satisfied when at least one of the following conditions (c) and (d) is satisfied in addition to at least one of the conditions (a) and (b): You may judge.
Condition (c): The elapsed time from the time when the ignition switch was returned from the ON state to the OFF state in the previous trip is equal to or longer than a predetermined first threshold time. In each trip, the time when the ignition switch is switched from the ON state to the OFF state and the time when the ignition switch is switched from the OFF state to the ON state are recorded in the backup RAM.
Condition (d): The total energization time to the heater 43b in the previous trip is not more than a predetermined second threshold time. In each trip, the total energization time to the heater 43b is recorded in the backup RAM.

The vehicle to which the present invention is applied may be any of a hybrid vehicle, an FCV (fuel cell vehicle), and an EV (electric vehicle). However, when the power sources of the hybrid vehicle, FCV, and EV cannot supply power to the electric motors that are the respective drive sources, these power sources cannot supply power to the heater 43b.
In these modifications, each specific member temperature is used instead of the water temperature Wt. That is, when the vehicle is a hybrid vehicle, the HV water temperature (the temperature of the cooling medium of the electric motor that is the drive source) is used as the specific member temperature instead of the water temperature Wt. Similarly, when the vehicle is FCV, the stack water temperature is used as the specific member temperature instead of the water temperature Wt. Similarly, when the vehicle is an EV, the battery temperature is used as the specific member temperature instead of the water temperature Wt.

  In hybrid vehicles, FCVs, and EVs, for example, when a power switch provided in the vehicle is switched from an OFF state to an ON state, the vehicle is switched from a travel impossible state to a travelable state.

  DESCRIPTION OF SYMBOLS 10 ... Shooting device for vehicles, 30 ... Camera unit, 30a ... Thermistor, 40 ... Shading heating unit, 41 ... Shading hood, 41a ... Heated part, 43 ... Heater Module, 43b ... Heater, 85 ... Front window (window), 85a ... Light transmission part, 89 ... Switch element, 95 ... Heating device, 100 ... Control device, 101. ..Outdoor temperature sensor, 102 ... vehicle speed sensor, 103 ... water temperature sensor, 106 ... camera control ECU.

Claims (1)

An imaging device that generates imaging data by receiving imaging light that is disposed inside a window provided in the vehicle and that is transmitted from the window using power supplied from a power source mounted on the vehicle; ,
A heating means that heats the window by being heated inside the window and generating heat using electric power supplied from the power source;
Vehicle outside temperature detecting means for detecting a vehicle outside temperature which is a temperature outside the vehicle;
When the vehicle is in a travelable state, the imaging device generates the imaging data, and when the vehicle is in the travelable state, this corresponds to a target value of the amount of power supplied to the heating means in a predetermined time. A control device that calculates an amount based on at least the outside temperature of the vehicle and performs power supply control so that an amount of power corresponding to the target value is supplied from the power source to the heating unit;
A vehicular imaging device comprising:
A specific member temperature detecting means for detecting, as the specific member temperature, the temperature of the specific member having a temperature approaching the outside temperature of the vehicle as the duration of the state in which the heating means is not generating heat becomes longer;
The control device is
When the vehicle is changed from being unable to run to being able to run, a special heating requirement is established that is satisfied when the absolute value of the difference between the specific member temperature and the outside temperature is equal to or lower than a predetermined temperature. The target value is configured to be changed to a larger value than when the special heating requirement is not satisfied.
An imaging device for a vehicle.

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