JP3903974B2 - Position displacement value calculation device for vehicle infrared camera, temperature correction value calculation device for vehicle infrared camera, vehicle infrared camera system - Google Patents

Description

  The present invention relates to an infrared camera system for a vehicle that acquires a thermal image of a passenger compartment and detects the position of an occupant.

  Conventionally, a technique has been proposed in which an image of the vehicle interior is captured using an infrared camera installed in the vehicle interior, and various processes are performed based on the imaging results (see, for example, Patent Document 1).

  This Patent Document 1 includes a non-contact temperature sensor that detects the temperature of a predetermined region in a non-contact manner, and a reference temperature detector that is disposed in the predetermined region and can set the temperature to the predetermined temperature. A non-contact temperature sensor that determines the correction coefficient for the current output value by comparing the initial output value of the non-contact temperature sensor obtained by detecting the temperature based on the amount of infrared rays from the body and the current output value A calibration method is disclosed.

As a result, in this non-contact temperature sensor calibration method, even if the output value of the non-contact temperature sensor changes due to deterioration of the temperature detection element or dirt on the condenser lens, The change in the output value is corrected to accurately measure the temperature of the test object.
JP 2001-349786 A

  In the technique described in Patent Document 1 described above, a reference test temperature body, which is a thermostat, is separately provided in the thermal image acquisition range, and temperature calibration is performed using the thermostat. Here, the thermal image is an imaging result obtained from the infrared camera, which indicates a temperature distribution obtained according to the amount of infrared rays emitted from the object surface within the thermal image acquisition range, which is captured by the infrared camera.

  In general, the temperature calibration method of an infrared camera detects the position of the reference temperature object from the thermal image, and obtains the difference between the actual temperature of the reference temperature object and the temperature indicated by the thermal image of the reference temperature object. The temperature of the infrared camera is calibrated based on the obtained result. Thus, the temperature-calibrated infrared camera is used in a vehicle system or the like that detects the presence or absence of an occupant or a position.

  In order to detect the position of an occupant or reference temperature object with higher accuracy, it is necessary to know the displacement of the mounting position of the infrared camera. It is necessary to prepare a separate heat source.

  However, separately installing a heat source in the vehicle interior leads to an increase in cost, and it is necessary to take measures against damage to the vehicle interior by providing the heat source.

  Therefore, the present invention has been proposed in view of the above-described problems, and provides a vehicle infrared camera system that can accurately detect a shift in the mounting position of the infrared camera without providing a separate heat source. With the goal.

In the apparatus for calculating a positional deviation value of an infrared camera for a vehicle according to the present invention, the imaging direction is directed toward the rear of the vehicle so that a window heat ray that is heated to generate heat and forms a predetermined thermal image pattern is included in the imaging region. An infrared camera that is installed and captures a thermal image of a vehicle interior, a position detection unit that detects a position of a thermal image pattern of the window heat ray based on the thermal image captured by the infrared camera, and the position detection unit The above-described problem is solved by providing a misregistration value calculating means for calculating a misalignment value of the infrared camera based on the detected position of the thermal image pattern.
In the temperature correction value calculation device for an infrared camera for a vehicle according to the present invention, the imaging direction is set toward the rear of the vehicle so that a window heat ray that is controlled by energization and generates heat to form a predetermined thermal image pattern is included in the imaging region. An infrared camera that captures a thermal image of the vehicle interior, a position detection unit that detects a position of the thermal image pattern of the window heat ray based on the thermal image captured by the infrared camera, and the position detection unit Temperature correction value calculating means for calculating a temperature correction value for correcting the temperature of the thermal image captured by the infrared camera based on the detected position of the thermal image pattern and the temperature difference appearing in the thermal image pattern. This solves the above-mentioned problem.

In addition, in the infrared camera system for a vehicle according to the present invention, a window heat ray that is heated to generate heat and forms a predetermined thermal image pattern, and an imaging direction is directed to the rear of the vehicle so that the window heat ray is included in the imaging region. An infrared camera that captures a thermal image of the vehicle interior, a position detection unit that detects a position of a thermal image pattern of the window heat ray based on the thermal image captured by the infrared camera, and the position detection The above-described problem is solved by providing a displacement value calculation means for calculating the attachment position displacement value of the infrared camera based on the position of the thermal image pattern detected by the means.
Furthermore, in the infrared camera system for a vehicle according to the present invention, the window heat ray that is forward of the vehicle interior and is heated to generate heat to form a predetermined thermal image pattern and the window heat ray are included in the imaging region. And an infrared camera that captures a thermal image in the vehicle interior, and detects the position of the thermal image pattern of the window heat ray based on the thermal image captured by the infrared camera. Based on the position detection means, and the position of the thermal image pattern detected by the position detection means and the temperature difference appearing in the thermal image pattern, a temperature correction value for correcting the temperature of the thermal image captured by the infrared camera is obtained. By providing a temperature correction value calculating means for calculating, the above-mentioned problem is solved.

  According to the vehicle infrared camera system of the present invention, it is possible to detect the displacement of the mounting position of the infrared camera without providing a separate heat source, and to reduce the cost for providing the heat source. It is possible to avoid damage to the interior of the passenger compartment due to the provision of the.

  Further, according to the vehicle infrared camera system of the present invention, the temperature correction value of the infrared camera can be acquired without providing a separate heat source, and the deterioration of the infrared camera element and the optical system can be corrected. By correcting with values, a thermal image with an accurate temperature distribution can be obtained.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

[First Embodiment]
First, a vehicle infrared camera system according to a first embodiment to which the present invention is applied will be described.

[Configuration of infrared camera system for vehicles]
As shown in FIG. 1, the infrared camera system for a vehicle according to the first embodiment includes an infrared camera 1 that captures a thermal image in a passenger compartment, and the infrared camera 1 based on the thermal image captured by the infrared camera 1. Are provided with a microcomputer 2 for calculating a mounting position deviation value and a window heat ray 3 used for defrosting the rear window.

  For example, as shown in FIG. 2, the infrared camera 1 is installed at a location that does not obstruct the driver's forward view at the center of the upper side of the window shield, such as in the vicinity of a rearview mirror. In addition, the infrared camera 1 is installed so that the imaging direction is toward the rear of the vehicle so that the window heat rays 3 provided in the driver's seat 101 and the passenger seat 102 and the rear window are included in the imaging region. A thermal image captured by the infrared camera 1 is supplied to the microcomputer 2.

  The microcomputer 2 controls the imaging operation by the infrared camera 1 and the energization operation for the window heat ray 3 and detects the position in the image of the thermal image pattern of the window heat ray 3 based on the thermal image taken by the infrared camera 1. The position information in the image of the detected thermal image pattern and the heat of the window hot wire 3 which is stored in advance in a memory (not shown) of the microcomputer 2 and will be obtained when the infrared camera 1 is correctly attached. Based on the position information of the image pattern, an attachment position deviation value of the infrared camera 1 is calculated.

  The window heat wire 3 is attached to the surface of the rear window, and is a heat source for existing equipment in the passenger compartment that is used to prevent the rear window from fogging. The window heat wire 3 is energized under the control of the microcomputer 2 to generate heat, thereby forming a predetermined heat pattern.

  In such a vehicle infrared camera system, the imaging region of the infrared camera 1 attached at the position shown in FIG. 2 is a window heat ray attached to the surface of the rear window 11 as shown in FIGS. 3 and 4, for example. 3 is a rectangular ABCD including at least a partial region. 3 is a diagram of the imaging region of the infrared camera 1 as viewed from above the vehicle, and FIG. 4 is a diagram of the imaging region of the infrared camera 1 as viewed from the front of the vehicle. Further, in this positional relationship, the thermal image pattern of the window heat ray 3 based on the thermal image obtained by imaging with the infrared camera 1 clearly shows that the window heat ray 3 is attached as shown in FIG. 5, for example. It will be understood.

  Further, in the infrared camera system for a vehicle, the imaging area of the infrared camera 1 when two passengers 12A and 12B are on the vehicle is rectangular ABCD as shown in FIGS. 6 and 7, for example. 6 is a diagram of the imaging region of the infrared camera 1 as viewed from above the vehicle, and FIG. 7 is a diagram of the imaging region of the infrared camera 1 as viewed from the front of the vehicle. Further, in this positional relationship, the thermal image pattern of the window heat ray 3 based on the thermal image obtained by imaging with the infrared camera 1 is shown in FIG. 8, for example, as the passengers 12A and 12B get on and the window heat ray. It can be clearly seen that 3 is attached.

  Such a vehicle infrared camera system functionally has a thermal image acquisition unit 21 that acquires a thermal image in the passenger compartment and a position detection unit 22 that detects the position of the thermal image pattern, as shown in FIG. And a positional deviation value calculation unit 23 that calculates an attachment positional deviation value of the infrared camera 1 based on the position of the thermal image pattern detected by the position detection unit 22. 9 is compared with the configuration shown in FIG. 1, the infrared camera 1 corresponds to the thermal image acquisition unit 21, and the program executed by the microcomputer 2 corresponds to the position detection unit 22 and the positional deviation value calculation unit 23. To do.

[Operation of infrared camera system for vehicles]
Such a vehicular infrared camera system obtains an attachment position deviation value of the infrared camera 1 through a series of processes as shown in FIG.

  First, as shown in the figure, the microcomputer 2 starts energizing the window heat wire 3 in step S1.

  Subsequently, in step S2, the microcomputer 2 controls the infrared camera 1 to capture a thermal image in the passenger compartment to acquire the thermal image. In step S3, the microcomputer 2 acquires the thermal image pattern of the acquired window hot wire 3. Perform position detection.

  Subsequently, in step S4, the microcomputer 2 detects the position information in the image of the detected thermal image pattern and the infrared camera 1 stored in the memory (not shown) of the microcomputer 2 in advance. On the basis of the position information of the thermal image pattern of the window heat ray 3 that would be obtained in the above, the attachment position deviation value of the infrared camera 1, that is, the attachment position deviation value in the vertical direction, the horizontal direction, and the rotation direction is calculated, In step S5, the calculated attachment position deviation value is stored in a memory (not shown).

  In step S6, the microcomputer 2 stops energization of the window heat wire 3 and ends the series of processes.

  The vehicle infrared camera system can obtain the attachment position deviation value of the infrared camera 1 through such a series of processes.

[Window heat ray pattern]
By the way, as shown in FIG. 4, the general window heat ray 3 has a plurality of parallel horizontal lines and has a uniform pattern in the horizontal direction. Therefore, in the vehicle infrared camera system, for example, as shown in FIG. 11, even when the mounting position of the infrared camera 1 is deviated from the normal position, the imaging region of the infrared camera 1 is normal. 12 becomes a rectangle A′B′C′D ′ shifted only in the horizontal direction from the rectangle ABCD indicating the imaging region in FIG. 12, and thus a thermal image pattern as shown in FIG. 12 is obtained, and as shown in FIG. This leads to a situation where a thermal image pattern similar to the thermal image pattern obtained at the normal attachment position is obtained. In this case, in the vehicle infrared camera system, the lateral shift of the infrared camera 1 cannot be detected based on the obtained thermal image pattern of the window heat ray 3.

  Therefore, in the vehicle infrared camera system, in order to solve this problem, a pattern that changes in the vertical direction is further added to the pattern of the window heat ray 3 that is uniform in the horizontal direction. A lateral shift can be detected.

  Specifically, in the vehicle infrared camera system, for example, as shown in FIG. 13, a pattern that further intersects the pattern of the window heat ray 3 that is uniform in the horizontal direction shown in FIG. to add. That is, the imaging area when the mounting position of the infrared camera 1 is normal is rectangular ABCD, and the imaging area when the mounting position of the infrared camera 1 is deviated from the normal position is rectangular A′B′C′D. 'Is.

  In this case, in the vehicle infrared camera system, the thermal image pattern obtained when the mounting position of the infrared camera 1 is normal is as shown in FIG. 14, and the mounting position of the infrared camera 1 is shifted from the normal position. FIG. 15 shows a thermal image pattern obtained in the case of That is, the thermal image pattern becomes different as the mounting position of the infrared camera 1 changes in the horizontal direction by adding the crossing pattern to the window heat ray 3.

  As described above, in the vehicular infrared camera system, the lateral shift of the infrared camera 1 becomes clear by adding a pattern that changes in the vertical direction to the pattern of the window heat ray 3 that is uniform in the horizontal direction. It is possible to obtain the lateral deviation value of the infrared camera 1 with high accuracy.

  Here, as shown in FIG. 13, an example in which patterns in the vertical direction and the oblique direction are added to the horizontal lines constituting the window heat ray 3 has been described. However, in the infrared camera system for vehicles, the infrared camera When the spatial resolution of 1 is low and it is difficult to capture an oblique pattern, the window heat ray 3 may be configured by only the vertical pattern and the horizontal pattern.

[Effect of the first embodiment]
As described above in detail, in the infrared camera system for a vehicle according to the first embodiment, it is installed at a location that does not obstruct the driver's front view at the center of the upper side of the window shield, and the driver's seat, passenger's seat, and rear Based on a thermal image captured by an infrared camera 1 whose imaging direction is set toward the rear of the vehicle so that a window thermal wire 3 forming a predetermined thermal image pattern attached to the surface of the window 11 is included in the imaging region. Thus, by detecting the position of the thermal image pattern of the window heat ray 3 and calculating the mounting position deviation value of the infrared camera 1 based on the detected position of the thermal image pattern, the infrared camera 1 is provided without providing a separate heat source. It is possible to detect a shift in the mounting position. Further, in this vehicle infrared camera system, the cost for providing the heat source can be reduced, and further, damage to the interior of the passenger compartment due to the provision of the heat source can be avoided.

  Moreover, in this vehicle infrared camera system, the lateral displacement of the infrared camera 1 is accurately detected by using a window heat ray 3 in which a pattern that changes in the vertical direction is further added to a uniform pattern in the horizontal direction. Can be detected well.

  More specifically, in this infrared camera system for a vehicle, the window heat ray 3 has a very simple configuration by using a pattern in which a crossing pattern is further added to a uniform pattern in the horizontal direction. However, the lateral shift of the infrared camera 1 can be accurately detected.

  Furthermore, in this vehicle infrared camera system, since the heat source of the existing equipment used for the fogging prevention of the rear window 11 is used as the window heat ray 3, it does not require any additional equipment and has an extremely simple configuration. The displacement of the mounting position of the infrared camera 1 can be accurately detected.

[Second Embodiment]
Next, a vehicle infrared camera system according to the second embodiment will be described. In the description of the second embodiment, the same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  The vehicular infrared camera system according to the second embodiment is provided with an inflection pattern with respect to a uniform pattern of window heat rays in the horizontal direction.

  Similar to the vehicle infrared camera system according to the first embodiment, the vehicle infrared camera system according to the second embodiment is configured as shown in FIGS. 1, 2, and 9. The attachment position deviation value of the infrared camera 1 is obtained through the series of processes shown.

  By the way, in the vehicle infrared camera system according to the first embodiment, the lateral shift of the infrared camera 1 is detected by adding a cross pattern to the pattern of the window heat ray 3 that is uniform in the horizontal direction. Became possible. However, since the added crossing pattern is provided so as to protrude from the main line portion composed of a plurality of horizontal lines, it can be said that peeling is likely to occur. Further, when a plurality of crossing patterns are added or the crossing pattern is enlarged, the window heat ray 3 is likely to deteriorate in appearance, and the rear view during driving may be deteriorated.

  Therefore, in the vehicle infrared camera system, in order to solve these problems, an inflection pattern is provided for the pattern of the window heat ray 3 that is uniform in the horizontal direction.

  Specifically, in the infrared camera system for a vehicle, for example, as shown in FIG. 16, it is formed integrally with the main line portion with respect to the pattern of the window heat ray 3 uniform in the horizontal direction shown in FIG. Arbitrary inflection patterns are provided. Note that the imaging area of the infrared camera 1 is a rectangular ABCD.

  In this case, the thermal image pattern is as shown in FIG. That is, the thermal image pattern is different according to the mounting position of the infrared camera 1 being changed in the lateral direction by providing an inflection pattern with respect to the window hot wire 3.

  As described above, in the vehicular infrared camera system, it is possible to accurately detect the lateral shift of the infrared camera 1 by providing the inflection pattern with respect to the pattern of the window heat ray 3 that is uniform in the horizontal direction. By forming the inflection pattern integrally with the main line portion, it is possible to secure a good field of view that is difficult to peel off and relatively good in appearance.

  As described above in detail, in the infrared camera system for vehicles according to the second embodiment, the window heat wire 3 is provided with an inflection pattern formed integrally with the main line portion with respect to a uniform pattern in the horizontal direction. By using an image sensor, it is possible to detect the displacement of the mounting position including the lateral displacement of the infrared camera 1 with high accuracy, to prevent the heat rays from being peeled off and to have a relatively good appearance, and to ensure a good field of view. .

[Third Embodiment]
Next, a vehicle infrared camera system according to a third embodiment will be described. In the description of the third embodiment, the same parts as those in the first embodiment and the second embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the infrared camera system for a vehicle according to the third embodiment, the window heat ray has a pattern having a density with respect to the spatial resolution interval of the infrared camera, and the thermal image of the window heat ray is apparently formed by the pattern having the density. It creates a temperature difference.

  Here, sparse / dense means that a plurality of window heat rays are arranged at intervals equal to or smaller than the spatial resolution of the infrared camera, and sparse means that the heat rays are arranged at intervals greater than that. When the temperature of an object in an area below the spatial resolution of the infrared camera is imaged by the infrared camera, a thermal image is obtained by averaging the temperature of the hot window heat ray and the temperature of its peripheral part at a low temperature. Therefore, if each heat ray of the window heat ray is the same temperature, a thermal image appears as a single hot wire at a high temperature in a dense pattern with many high temperature portions, and as a single hot wire at a low temperature in a sparse pattern with many lower temperature portions. In this way, an apparent temperature difference can be added to the thermal image pattern of the window heat ray.

  The vehicular infrared camera system according to the third embodiment is configured as shown in FIGS. 1, 2, and 9, similarly to the vehicular infrared camera system according to the first embodiment and the second embodiment. The attachment position deviation value of the infrared camera 1 is obtained through the series of processes shown in FIG.

  By the way, in the general thermal image pattern shown in FIG. 5 as well, it is possible to detect the vertical shift of the infrared camera 1, but when the vertical shift is large, more specifically, a plurality of horizontal lines. When the vertical deviation more than the interval occurs, a thermal image pattern similar to the thermal image pattern obtained at the normal attachment position is obtained, which leads to a situation in which it is erroneously detected.

  Therefore, in the vehicle infrared camera system, in order to solve this problem, a pattern having a sparse / dense pattern is configured as the window heat ray 3, and an apparent temperature difference is generated in a thermal image obtained by capturing the window heat ray 3 with the sparse / dense pattern. Produce. In this case, in the vehicular infrared camera system, the window heat wire 3 is only configured by densely arranging the heat rays having the same characteristics, and the design of the heat rays is relatively easy.

  Specifically, in the vehicle infrared camera system, for example, as shown in FIG. 18, a region where the distance between the heat rays is closer than the spatial resolution of the infrared camera 1 is arbitrarily provided. Note that the imaging area of the infrared camera 1 is a rectangular ABCD.

  In this case, as shown in FIG. 19, the thermal image pattern is picked up as a single hot ray having a high temperature in the region where the interval between the hot rays is smaller than the spatial resolution of the infrared camera 1, and the interval between the hot rays is infrared. A region that is sparser than the spatial resolution of the camera 1 becomes one heat ray having a low temperature. As a result, in the vehicular infrared camera system, a thermal image pattern of the window heat ray 3 in which a temperature difference is generated between a region where the heat ray interval is dense and a region where the heat ray is sparse is obtained. It becomes possible.

  As described above, in the infrared camera system for a vehicle, a pattern having a sparse / dense pattern is formed as the window heat ray 3, and an apparent temperature difference is generated in a thermal image obtained by imaging the window heat ray 3 by the sparse / dense pattern. It becomes possible to detect the vertical shift of the camera 1 with high accuracy.

  As described above in detail, in the vehicle infrared camera system according to the third embodiment, the window heat ray 3 is configured by a pattern having a density, and a thermal image obtained by capturing the window heat line 3 by the pattern having the density By using the one that produces an apparent temperature difference, it is possible to accurately detect the displacement of the mounting position including the vertical displacement of the infrared camera 1.

  More specifically, in this infrared camera system for a vehicle, a window heat ray 3 provided with a region in which the interval between the heat rays constituting the window heat ray 3 is closer than the spatial resolution of the infrared camera 1 is used. Thus, the vertical shift of the infrared camera 1 can be detected with high accuracy based on an extremely simple configuration.

[Fourth Embodiment]
Next, a vehicle infrared camera system according to a fourth embodiment will be described. In the description of the fourth embodiment, the same parts as those in the first to third embodiments described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  The infrared camera system for a vehicle according to the fourth embodiment generates a spatial temperature difference in the rear window by adjusting the energization flow rate of each heat wire constituting the window heat wire.

  The vehicular infrared camera system according to the fourth embodiment is configured as shown in FIGS. 1, 2, and 9, similarly to the vehicular infrared camera system according to the first to third embodiments. The attachment position deviation value of the infrared camera 1 is obtained through the series of processes shown in FIG.

  By the way, in the vehicle infrared camera system according to the third embodiment, a pattern having a density is formed as the window heat ray 3 and a temperature difference is generated in the rear window 11 by the pattern having the density. It is necessary to change the arrangement of the heat rays depending on the spatial resolution.

  Therefore, in the vehicle infrared camera system, as another method for generating a temperature difference in the rear window 11, for example, as shown in FIG. 20, a part of the heat rays constituting the window heat wire 3 is controlled according to the control of the microcomputer 2. A control may be made to increase the energization flow rate supplied only to the heat wires, thereby making a difference in the energization flow rates of the respective heat wires constituting the window heat wire 3. Note that the imaging area of the infrared camera 1 is a rectangular ABCD.

  In this case, the thermal image pattern is the same as that shown in FIG. 19 earlier, and a heat ray having a large energization flow rate is imaged as a single heat ray having a high temperature.

  As described above, in the vehicle infrared camera system, by adjusting the energization flow rate of each heat wire constituting the window heat wire 3, heat that causes a temperature difference without depending on the spatial resolution of the infrared camera 1. An image pattern can be acquired, and a vertical shift can be detected with higher accuracy.

  Further, in the vehicular infrared camera system, by using this method, the heat rays constituting the window heat ray 3 can be arranged at regular intervals as usual, so compared with the case where a pattern having sparse / dense is constituted, etc. Since it becomes an interval pattern, it looks good and a good field of view can be secured.

  The adjustment of the energization flow rate can be easily performed by changing the cross-sectional area of each heating wire constituting the window heating wire 3, and the window heating wire 3 according to the control of the microcomputer 2 is provided in a plurality of systems. The energization flow rate may be adjusted by making a difference in the energization flow rate to the heat wires of the system.

  As described above in detail, in the infrared camera system for a vehicle according to the fourth embodiment, the window heat wire 3 is adjusted by making a difference in the energization flow rate of each heat wire constituting the window heat wire 3. By using the window 11 that generates a spatial temperature difference, it is possible to accurately detect the mounting position shift including the vertical shift of the infrared camera 1 and to design the infrared camera 1 without spatial resolution. In addition, the appearance is improved and a good field of view can be secured.

[Fifth Embodiment]
Next, a vehicle infrared camera system according to a fifth embodiment will be described.

  The vehicle infrared camera system according to the fifth embodiment uses a heat ray pattern having the density shown in the third embodiment or the fourth embodiment, or a window heat ray having a difference in energization flow rate of each heat ray. A predetermined temperature difference is generated in the thermal image obtained by capturing the image, and a temperature correction value for correcting the infrared camera is obtained based on the temperature difference.

In a general infrared camera, infrared rays radiated from an imaging range are converted into voltages and handled as electrical signals. Now, if you take an image of the temperature T with an infrared camera,
V = AβσT ⁴ + Voff
Is obtained. Here, β is the emissivity of the heat ray, σ is the Boltzmann constant, A is the conversion efficiency, and Voff is the offset voltage of the circuit system or the like. Now, ignoring Voff,
T = (V / Aβσ) ^1/4
It can be seen that the temperature of the imaging range can be obtained by converting the temperature T by the following equation.

The conversion efficiency A is a value determined by the design of the infrared detection element assembled in the infrared camera. When the element deteriorates, A becomes smaller and the correct temperature in the imaging range cannot be obtained. If the conversion efficiency after device deterioration is A ′, the voltage obtained by the infrared camera is V ′ = A′βσT ⁴ + Voff
It has become. Here, if the hot wire is set to be the temperature Th of the high-temperature hot wire and the temperature Tc of the low-temperature hot wire, according to each temperature,
Vh ′ = A′βσTh ⁴ + Voff
Vc ′ = A′βσTc ⁴ + Voff
Is obtained, and by subtracting these voltage values,
Vd ′ = A′βσ (Th ⁴ −Tc ⁴ )
Is obtained. If the element has not deteriorated, the design value Vd = Aβσ (Th ⁴ −Tc ⁴ )
Because the difference voltage can be expected
K = Vd / Vd ′
Thus, the temperature correction value K can be calculated by taking these ratios. Using this temperature correction value, it is possible to correct the voltage value output after deterioration of the infrared detection element and convert the temperature. Therefore, even if the infrared detection element built in the infrared camera deteriorates, the heat that shows the accurate temperature An image can be obtained.

  In the description of the fifth embodiment, the same portions as those in the first to fourth embodiments described above are denoted by the same reference numerals and the same step numbers, and detailed description thereof is omitted. To do.

  The vehicle infrared camera system according to the fifth embodiment is configured as shown in FIGS. 1 and 2 in the same manner as the vehicle infrared camera system according to the first to fourth embodiments. Specifically, as shown in FIG. 21, in addition to the thermal image acquisition unit 21 and the position detection unit 22 shown in FIG. 9, the thermal image pattern detected by the position detection unit 22 instead of the positional deviation value calculation unit 23. And a temperature correction value calculation means 24 for calculating a temperature correction value for correcting the temperature of the infrared camera based on the temperature difference indicated by the information and the temperature difference appearing in the thermal image pattern. 21 is compared with the configuration shown in FIG. 1, the infrared camera 1 corresponds to the thermal image acquisition unit 21, and the program executed by the microcomputer 2 corresponds to the position detection unit 22 and the temperature correction value calculation unit 24. To do.

  Such a vehicle infrared camera system obtains a temperature correction value of the infrared camera 1 through a series of processes as shown in FIG. 22 under the control of the microcomputer 2.

  That is, as shown in the figure, the microcomputer 2 performs the processing from step S1 to step S3 shown in FIG. 10 in the same manner as in the case of obtaining the attachment position deviation value of the infrared camera 1, and then in step S11. The temperature correction value of the infrared camera 1 is calculated based on the temperature difference of the window heat ray 3 indicated by the position information of the thermal image pattern detected in step S3.

  In step S5, the microcomputer 2 stores the calculated temperature correction value in a memory (not shown). Then, in step S6, the microcomputer 2 stops energization of the window heat ray 3 and ends the series of processes.

  The vehicle infrared camera system can obtain the temperature correction value of the infrared camera 1 through such a series of processes. Therefore, even if the infrared detection element assembled in the infrared camera 1 is deteriorated, the deterioration of the element can be corrected with the temperature correction value, so that a thermal image indicating an accurate temperature can be obtained from the infrared camera 1.

  As described above in detail, in the vehicle infrared camera system according to the fifth embodiment, the vehicle is installed at a position that does not obstruct the driver's front view at the center of the upper side of the window shield, and the driver's seat, passenger's seat, and rear Based on a thermal image captured by an infrared camera 1 whose imaging direction is set toward the rear of the vehicle so that a window thermal wire 3 forming a predetermined thermal image pattern attached to the surface of the window 11 is included in the imaging region. The temperature correction value for detecting the position of the thermal image pattern of the window heat ray 3 and correcting the temperature of the infrared camera 1 based on the temperature difference of the thermal image pattern indicated by the position information of the detected thermal image pattern By calculating, the temperature correction value of the infrared camera 1 can be accurately obtained without providing a separate heat source. Further, in this vehicle infrared camera system, the cost for providing the heat source can be reduced, and further, damage to the interior of the passenger compartment due to the provision of the heat source can be avoided.

  Moreover, in this infrared camera system for vehicles, the window heat ray 3 is composed of a pattern having a density, and a pattern that generates a temperature difference in the rear window 11 by using the pattern having the density is used to vertically shift the infrared camera 1. More specifically, the window heat ray 3 is a region in which the interval between the heat rays constituting the window heat ray 3 is smaller than the spatial resolution of the infrared camera 1. By using the one provided with the above, it is possible to accurately detect the vertical shift of the infrared camera 1 based on an extremely simple configuration.

  Furthermore, in this infrared camera system for a vehicle, the window heat wire 3 is adjusted so as to make a difference in the flow rate of each heat wire constituting the window heat wire 3, thereby creating a spatial temperature difference in the rear window 11. By using this, it is possible to detect the displacement of the mounting position including the vertical displacement of the infrared camera 1 with high accuracy, and to design the infrared camera 1 without spatial resolution. Can be secured.

[Sixth Embodiment]
Next, a vehicle infrared camera system according to a sixth embodiment will be described.

  The vehicle infrared camera system according to the sixth embodiment performs both the calculation of the infrared camera mounting position deviation value shown as the first embodiment and the calculation of the temperature correction value of the infrared camera shown as the fifth embodiment. Is what you do.

  In the description of the sixth embodiment, the same parts as those in the first to fifth embodiments described above are denoted by the same reference numerals and the same step numbers, and detailed description thereof will be omitted. .

  The vehicle infrared camera system according to the sixth embodiment is configured as shown in FIGS. 1 and 2 in the same manner as the vehicle infrared camera system according to the first to fifth embodiments. Specifically, as shown in FIG. 23, together with the thermal image acquisition unit 21, the position detection unit 22, and the positional deviation value calculation unit 23 shown in FIG. 9, the temperature correction value calculation unit 24 shown in FIG. Can be represented as comprising. 23 is compared with the configuration shown in FIG. 1, the infrared camera 1 corresponds to the thermal image acquisition unit 21, and the program executed by the microcomputer 2 includes a position detection unit 22, a positional deviation value calculation unit 23, and This corresponds to the temperature correction value calculation unit 24.

  Such a vehicular infrared camera system obtains an attachment position deviation value and a temperature correction value of the infrared camera 1 through a series of processes as shown in FIG. 24 under the control of the microcomputer 2.

  In other words, as shown in the figure, the microcomputer 2 determines whether the infrared camera 1 is attached in step S1 to step S4 based on the detected position of the thermal image pattern as shown in FIG. Is calculated.

  Subsequently, in step S11, the microcomputer 2 corrects the temperature of the infrared camera 1 based on the temperature difference of the thermal image pattern indicated by the position information of the detected thermal image pattern as shown in FIG. Calculate the value.

  In step S5, the microcomputer 2 stores the calculated attachment displacement value and temperature correction value in a memory (not shown), and in step S6, stops energization of the window heat wire 3 and ends the series of processes.

  The vehicle infrared camera system can obtain both the attachment position deviation value and the temperature correction value of the infrared camera 1 through such a series of processes.

  As described above in detail, in the vehicle infrared camera system according to the sixth embodiment, the position of the thermal image pattern of the window heat ray 3 is detected and detected based on the thermal image captured by the infrared camera 1. Based on the position of the thermal image pattern, the attachment position deviation value of the infrared camera 1 is calculated, and the temperature of the infrared camera 1 is calculated based on the temperature difference indicated in the thermal image pattern indicated by the position information of the thermal image pattern. By calculating the temperature correction value for correcting the above, it is possible to accurately obtain the displacement of the mounting position of the infrared camera 1 and the temperature correction value without providing a separate heat source. Further, in this vehicle infrared camera system, the cost for providing the heat source can be reduced, and further, damage to the interior of the passenger compartment due to the provision of the heat source can be avoided.

[Seventh Embodiment]
Finally, a vehicle infrared camera system according to a seventh embodiment will be described.

  When calculating the temperature correction value of the infrared camera shown as the fifth embodiment, the vehicular infrared camera system according to the seventh embodiment creates a temperature difference in time rather than spatially, thereby calculating the temperature of the infrared camera. A temperature correction value for correcting the above is obtained.

  In the description of the seventh embodiment, the same parts as those in the first to sixth embodiments described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

  The vehicular infrared camera system according to the seventh embodiment is configured as shown in FIGS. 1 and 2 in the same manner as the vehicular infrared camera system according to the first to sixth embodiments. The temperature correction value of the infrared camera 1 is obtained through a series of processes shown in FIG.

  By the way, in the vehicle infrared camera system according to the fifth embodiment, the temperature correction value is obtained by creating a spatial temperature difference in the rear window 11. In contrast, in the vehicular infrared camera system according to the seventh embodiment, the temperature correction value is obtained by generating a temporal temperature difference in the rear window 11.

  Specifically, as shown in FIG. 25, the infrared camera system for a vehicle is a switch that is opened and closed in accordance with the control of the microcomputer 2 in the middle of a path through which the current supplied from the power source 31 is supplied to the window heat wire 3. 32, and a path downstream of the switch 32 is divided into two, and a current limiting resistor 33 is provided on one path. And in the infrared camera system for vehicles, according to the control of the microcomputer 2, the switch 32 is opened and closed every predetermined time, and the path through which the current supplied from the power source 31 flows is the path provided with the current limiting resistor 33, It switches with the path | route in which the current limiting resistance 33 is not provided.

Thereby, in the infrared camera system for vehicles , a thermal image pattern can be temporally changed according to changing the energization flow rate with respect to each hot wire constituting the window hot wire 3 temporally.

  Thus, in the vehicular infrared camera system, a temporal temperature difference can be generated in the rear window 11, and the temperature correction value of the infrared camera 1 can be accurately obtained based on this temperature difference. At this time, in the vehicle infrared camera system, a temperature difference is generated in time, so that the temperature correction value of the infrared camera 1 can be obtained with high accuracy without changing the pattern of the window heat ray 3.

  As described above in detail, in the vehicle infrared camera system according to the seventh embodiment, as the window heat wire 3, the rear window 11 is changed by temporally changing the energization flow rate for each heat wire constituting the window heat wire 3. By using the one that generates a temporal temperature difference, the temperature correction value of the infrared camera 1 can be obtained with high accuracy without changing the pattern of the window heat ray 3.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and various modifications can be made depending on the design and the like as long as the technical idea according to the present invention is not deviated from this embodiment. Of course, it is possible to change.

  For example, in the above-described embodiment, the rear window 11 has been described as the place where the window heat wire 3 is provided. However, the present invention may be configured such that a window heat wire is provided on a side window, a front window, a sunroof, or the like. The present invention can also be applied to a case where a heat ray is installed as an existing equipment in a vehicle interior such as a trim or a seat.

  Further, in the above-described embodiment, it has been described that a pattern for position detection is added to a heat ray for preventing fogging of a window. However, the present invention calculates an infrared camera mounting position deviation value and calculates a temperature correction value. You may make it install the heat ray for a separate system.

It is a block diagram which shows the structure of the infrared camera system for vehicles which concerns on 1st Embodiment of this invention. It is a principal part perspective view in a vehicle interior which shows the installation location of the infrared camera in the infrared camera system for vehicles which concerns on 1st Embodiment of this invention. FIG. 3 is a diagram illustrating an imaging region of an infrared camera attached to the position illustrated in FIG. 2, and is a diagram of the imaging region of the infrared camera viewed from above the vehicle. FIG. 3 is a diagram showing an imaging area of an infrared camera attached to the position shown in FIG. 2, and is a view of the imaging area of the infrared camera as viewed from the front of the vehicle. FIG. 5 is a diagram illustrating an example of a thermal image pattern of a window heat ray based on a thermal image obtained by imaging with an infrared camera in the positional relationship illustrated in FIGS. 3 and 4. It is a figure which shows the imaging area of the infrared camera in case two passengers are on board, and is the figure which looked at the imaging area of the said infrared camera from the vehicle upper direction. It is a figure which shows the imaging area of the infrared camera in case two passengers are on board, and is the figure which looked at the imaging area of the said infrared camera from the vehicle front. It is a figure which shows the example of the thermal image pattern of the window heat ray based on the thermal image obtained by imaging with an infrared camera in the positional relationship shown in FIG.6 and FIG.7. 1 is a block diagram showing a functional configuration of a vehicle infrared camera system according to a first embodiment of the present invention. It is a flowchart which shows a series of processes at the time of calculating | requiring the attachment position shift value of an infrared camera in the vehicle infrared camera system which concerns on 1st Embodiment of this invention. It is the figure which looked at the imaging area of the infrared camera from the vehicle front, and is a figure for explaining the difference in the imaging area when the attachment position of the infrared camera is normal and when it is deviated from the normal position. FIG. 12 is a diagram showing an example of a thermal image pattern of window heat rays based on a thermal image obtained by imaging with the infrared camera when the mounting position of the infrared camera is deviated from a normal position in the positional relationship shown in FIG. 11. . It is the figure which looked at the imaging field of the infrared camera in the infrared camera system for vehicles concerning a 1st embodiment of the present invention from the front of the vehicle, and further crosses over the pattern of a window heat ray uniform in the horizontal direction shown in FIG. FIG. 10 is a diagram for explaining a difference in imaging area between when the infrared camera is attached normally and when it is deviated from the normal position when a pattern to be added is arbitrarily added. FIG. 14 is a diagram illustrating an example of a thermal image pattern of a window heat ray based on a thermal image obtained by imaging with the infrared camera when the mounting position of the infrared camera is normal in the positional relationship illustrated in FIG. 13. FIG. 14 is a diagram illustrating an example of a thermal image pattern of window heat rays based on a thermal image obtained by imaging with the infrared camera when the mounting position of the infrared camera is deviated from a normal position in the positional relationship illustrated in FIG. 13. . It is the figure which looked at the imaging field of the infrared camera in the infrared camera system for vehicles as a 2nd embodiment of the present invention from the vehicle front, and shows an inflection pattern with respect to the pattern of a window heat ray uniform in the horizontal direction shown in FIG. It is a figure for demonstrating the imaging area in the case of providing arbitrarily. It is a figure which shows the example of the thermal image pattern of the window heat ray based on the thermal image obtained by imaging with the infrared camera in the positional relationship shown in FIG. It is the figure which looked at the imaging field of the infrared camera in the infrared camera system for vehicles concerning a 3rd embodiment of the present invention from the vehicles front, constitutes a pattern which has sparseness as a window heat ray, and it is a rear window by the pattern which has the sparseness It is a figure for demonstrating the imaging region in the case of producing a temperature difference. It is a figure which shows the example of the thermal image pattern of the window heat ray based on the thermal image obtained by imaging with the infrared camera in the positional relationship shown in FIG. It is the figure which looked at the imaging field of the infrared camera in the infrared camera system for vehicles concerning a 4th embodiment of the present invention from the vehicle front, and by adjusting so that the energization flow rate of each heat ray which constitutes a window heat ray may be made to differ. It is a figure for demonstrating the imaging area in the case of producing a spatial temperature difference in a rear window. It is a block diagram which shows the functional structure of the infrared camera system for vehicles which concerns on 5th Embodiment of this invention. It is a flowchart which shows a series of processes at the time of calculating | requiring the temperature correction value of an infrared camera in the infrared camera system for vehicles which concerns on 5th Embodiment of this invention. It is a block diagram which shows the functional structure of the infrared camera system for vehicles which concerns on 6th Embodiment of this invention. It is a flowchart which shows a series of processes at the time of calculating | requiring both the attachment position shift value of an infrared camera, and the temperature correction value of the said infrared camera in the vehicle infrared camera system which concerns on 6th Embodiment of this invention. It is the figure which looked at the imaging region of the infrared camera in the infrared camera system for vehicles concerning a 7th embodiment of the present invention from the vehicle front, the composition for producing the temperature difference in time in a rear window, and the imaging region in this case It is a figure for demonstrating. It is a figure which shows the example of the thermal image pattern of the window heat ray based on the thermal image obtained by imaging with the infrared camera in the positional relationship shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Infrared camera 2 Microcomputer 3 Window heat ray 11 Rear window 12A, 12B Crew 21 Thermal image acquisition part 22 Position detection part 23 Position shift value calculation part 24 Temperature correction value calculation part 31 Power supply 32 Switch 33 Current limiting resistance

Claims (12)

An infrared camera that captures a thermal image in the vehicle interior, the imaging direction is installed toward the rear of the vehicle so that a window heat ray that is energized and generates heat to form a predetermined thermal image pattern is included in the imaging region;
Position detection means for detecting the position of the thermal image pattern of the window heat ray based on the thermal image captured by the infrared camera;
Based on the position of the thermal image pattern detected by the position detection means, a position deviation value calculation means for calculating an attachment position deviation value of the infrared camera;
An apparatus for calculating a positional deviation value of an infrared camera for vehicles . An infrared camera that captures a thermal image in the vehicle interior, the imaging direction is installed toward the rear of the vehicle so that a window heat ray that is energized and generates heat to form a predetermined thermal image pattern is included in the imaging region;
Position detection means for detecting the position of the thermal image pattern of the window heat ray based on the thermal image captured by the infrared camera;
A temperature correction value for calculating a temperature correction value for correcting the temperature of the thermal image captured by the infrared camera based on the position of the thermal image pattern detected by the position detection means and the temperature difference appearing in the thermal image pattern. A calculation means;
A temperature correction value calculation device for an infrared camera for vehicles . A window heat ray that is energized and generates heat to form a predetermined thermal image pattern;
An infrared camera that captures a thermal image in the vehicle interior, the imaging direction is installed toward the rear of the vehicle so that the window heat ray is included in the imaging region;
Position detection means for detecting the position of the thermal image pattern of the window heat ray based on the thermal image captured by the infrared camera;
Based on the position of the thermal image pattern detected by the position detection means, a position deviation value calculation means for calculating an attachment position deviation value of the infrared camera;
A vehicle infrared camera system comprising: A window heat ray that is in front of the passenger compartment and that is energized to generate heat and form a predetermined thermal image pattern,
An infrared camera that captures a thermal image in the vehicle interior, the imaging direction is installed toward the rear of the vehicle so that the window heat ray is included in the imaging region;
Position detection means for detecting the position of the thermal image pattern of the window heat ray based on the thermal image captured by the infrared camera;
A temperature correction value for calculating a temperature correction value for correcting the temperature of the thermal image captured by the infrared camera based on the position of the thermal image pattern detected by the position detection unit and the temperature difference appearing in the thermal image pattern. A calculation means;
A vehicle infrared camera system comprising:   A temperature correction value for calculating a temperature correction value for correcting the temperature of the thermal image captured by the infrared camera based on the position of the thermal image pattern detected by the position detection unit and the temperature difference appearing in the thermal image pattern. The vehicle infrared camera system according to claim 3, further comprising a calculation unit.   6. The vehicle infrared camera system according to claim 3, wherein the window heat ray is obtained by adding a pattern that changes in the vertical direction to a uniform pattern in the horizontal direction.   The vehicle infrared camera system according to claim 6, wherein the window heat ray is obtained by adding a crossing pattern to a uniform pattern in a horizontal direction.   The infrared camera system for a vehicle according to claim 6, wherein the window heat ray is provided with an inflection pattern formed integrally with a main line portion with respect to a uniform pattern in a horizontal direction.   The said window heat ray is comprised from the pattern which has density, and produces the apparent temperature difference in the thermal image which imaged the said window heat ray by the pattern which has the said density. The vehicle infrared camera system described.   The vehicle infrared camera system according to claim 9, wherein the window heat ray is provided with a region in which a space between the heat rays constituting the window heat ray is closer than a spatial resolution of the infrared camera.   The infrared ray for a vehicle according to claim 3 or 5, wherein the window heat ray generates a temperature difference in the window heat ray by making a difference in an energization flow rate of each heat ray constituting the window heat ray. Camera system.   The said window heat ray produces the time temperature difference in the said window heat ray by changing the electricity supply flow rate with respect to each heat ray which comprises the said window heat ray temporally, The Claim 3 or Claim 5 characterized by the above-mentioned. The vehicle infrared camera system described.