JP2021021939A - Imaging unit and vehicle control unit - Google Patents

Abstract

To prevent, in a change in shape of a housing due to a change in temperature, left-right asymmetric deformation of the housing during thermal expansion.SOLUTION: An imaging unit comprises: two imaging devices 100; a circuit board on which a plurality of components related to the operation of the two imaging devices 100 are arranged; a housing 10 that holds the two imaging devices 100; two reception shape parts 11 that are provided on the housing 10 and project toward the circuit board; and two heat radiation members 40 that are respectively provided on the two reception shape parts and are respectively in contact with the components to radiate heat. The two reception shape parts are provided such that the shapes thereof and positional relationship therebetween with respect to the center part between the optical axes of the two imaging devices 100 become closer to line symmetry than the positional relationship between the two radiation members 40 with respect to the center part between the optical axes of the two imaging devices 100.SELECTED DRAWING: Figure 2

Description

The present invention relates to an imaging unit and a vehicle control unit.

Conventionally, a so-called stereo camera is known as an imaging unit capable of calculating the distance to a target object like the human eye. A stereo camera includes two monocular cameras. For example, by interlocking a stereo camera with a vehicle control unit that controls a vehicle, it is possible to calculate the distance to an object in front of the vehicle and control the operation of the vehicle according to this distance.

The two monocular cameras included in the stereo camera are arranged on the same plane and fixed so that their optical axes are parallel to each other. When these two monocular cameras simultaneously shoot the same subject, the parallax amount of the subject can be detected, and the distance to the subject can be calculated based on the parallax amount.

In order to calculate the accurate distance in a stereo camera, the characteristics of the lenses used in the two monocular cameras are matched, the focal length is the same, and the "baseline length", which is the distance between the optical axes of the two monocular cameras, is the design value. It is important that it can be fixed as it is. Furthermore, it is important that the parallelism of the optical axes of the two monocular cameras is set accurately from the time of assembly and that this is maintained.

Therefore, in Patent Document 1, in order to suppress the deterioration of the performance as a stereo camera, a plurality of heat generating structures are provided in two monocular cameras in order to cause the housing to be deformed symmetrically when the housing is thermally deformed by temperature. A technique for providing a position symmetrical with respect to a central portion between optical axes is disclosed.

By the way, a stereo camera is equipped with a plurality of heat-generating components that emit high temperatures. For example, in addition to a CPU (Central Processing Unit) that is a control unit, it is a component that performs image processing and parallax calculation such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Field-Programmable Gate Array). These plurality of heat generating components are different in type, arrangement position on the substrate, size, and the like. Therefore, there is a problem that it is very difficult to provide a plurality of heat generating components at positions symmetrical with respect to the central portion between the optical axes of the two monocular cameras as in the technique disclosed in Patent Document 1.

The present invention has been made in view of the above, and an object of the present invention is to suppress asymmetrical deformation of the housing during thermal expansion when the shape of the housing changes due to a temperature change.

In order to solve the above-mentioned problems and achieve the object, the present invention comprises two image pickup devices, a circuit board on which a plurality of components related to the operation of the two image pickup devices are arranged, and the two image pickup devices. Two housings to be held, two pick-up shapes provided in the housing and protruding toward the circuit board, and two pick-up shapes provided in the two pick-up shapes, respectively, in contact with the parts to dissipate heat. The shape and positional relationship of the two pick-up shape portions with respect to the central portion between the optical axes of the two imaging devices includes the heat radiating member, and the two heat dissipation members with respect to the central portion between the optical axes of the two imaging devices are provided. It is characterized in that it is provided so as to be closer to line symmetry than the positional relationship of the members.

According to the present invention, when the shape of the housing changes due to a temperature change, it is possible to suppress asymmetrical deformation of the housing during thermal expansion.

FIG. 1 is an exploded perspective view showing an outline of the stereo camera according to the first embodiment. FIG. 2 is a perspective view showing a state in which the housing of the stereo camera is viewed from the back side. FIG. 3 is a cross-sectional view taken along the line AA'of the stereo camera shown in FIG. FIG. 4 is a diagram showing the positional relationship between the pick-up shape portion, the heat generating component, and the heat radiating member in the stereo camera 1 shown in FIG. FIG. 5 is an overall configuration diagram schematically showing the vehicle control unit according to the second embodiment.

Hereinafter, embodiments of the imaging unit and the vehicle control unit will be described in detail with reference to the accompanying drawings.

(First Embodiment)
Here, FIG. 1 is an exploded perspective view showing an outline of the stereo camera 1 according to the first embodiment, FIG. 2 is a perspective view showing a state in which the housing 10 of the stereo camera 1 is viewed from the back side, and FIG. 3 is a view. AA'longitudinal sectional view of the stereo camera 1 shown in No. 1, FIG. 4 is a diagram showing a positional relationship between a pick-up shape portion, a heat generating component, and a heat radiating member in the stereo camera 1 shown in FIG.

As shown in FIG. 1, the stereo camera 1 which is an imaging unit includes a housing 10 which is an imaging device holding unit that holds two imaging devices (monocular cameras) 100, and a circuit board 20 to which the housing 10 is fixed. , Equipped with.

As shown in FIG. 2, the housing 10 includes a pick-up shape portion 11 having the same shape and having a symmetrical position on the circuit board 20 side. The pick-up shape portion 11 is formed in a concave shape when viewed from above the housing 10. The pick-up shape portion 11 may be formed integrally with the housing 10 or may be formed separately. Further, the pick-up shape portion 11 may be formed so as to project toward the circuit board 20 so that the concave shape cannot be seen from the outside of the housing 10.

Hereinafter, the axes in the three-dimensional Cartesian coordinate system used when the configuration of the stereo camera 1 will be described will be defined. As shown in FIG. 1, the direction in which the two image pickup devices 100 (lens 101) are arranged is defined as the X axis. The direction of the normal image of the image sensor 102 (see FIG. 2) included in the image pickup apparatus 100 is defined as the Z axis, and the height direction of the stereo camera 1 orthogonal to the X axis and the Z axis is defined as the Y axis.

Each of the two image pickup devices 100 has a lens 101, an image sensor 102, and a sensor substrate 103. The lens 101 is fitted into a hole 10b provided in the X-axis direction on the front surface of the camera stay portion 10a of the housing 10. In the state of being fitted in the camera stay portion 10a, the optical axis Lx of each lens 101 is in a state in which the baseline length (distance between the optical axes Lx of the two imaging devices 100) required for calculating the distance is secured. Further, the optical axis Lx of each lens 101 is maintained in a state parallel to the Z axis and is oriented in the same direction.

The image sensor 102 is fixed on the back surface side of each lens 101, that is, in the Z-axis direction, and is configured so that the optical axis Lx of each lens 101 and the center of the image plane of the image sensor 102 coincide with each other. The image sensor 102 is an image sensor fixed to an individual sensor substrate 103, and outputs a signal related to a subject image imaged on an imaging surface via a corresponding lens 101.

That is, the image pickup apparatus 100 is configured by fitting the lens 101 into each of the holes 10b on the front surface of the camera stay portion 10a and fixing the image sensor 102 in accordance with each optical axis Lx of the lens 101. As a result, the stereo camera 1 can detect the parallax amount from the images acquired by the two image sensors 102 and calculate the distance.

In order to accurately fix the two lenses 101 with the "baseline length", which is one of the important factors for accurately calculating the distance, the lenses 101 are accurately maintained in a predetermined position and in a predetermined posture. There must be. For that purpose, for example, the abutting surface of the lens 101 on the camera stay portion 10a is accurately processed, and the abutting portion on the lens 101 side against the camera stay portion 10a is accurately processed. Further, in the camera stay portion 10a, the position, size, and the like of the hole 10b into which the lens 101 is fitted are accurately processed, and the lens 101 is fitted therein. A lens 101 having the same optical characteristics is used to match the focal length, which is one of the important factors in calculating the distance. Further, also in the image sensor 102 that influences the camera characteristics, an image sensor having the same characteristics is used. It should be noted that the present invention is not limited to lenses / sensors having the same characteristics, and lenses / sensors having different characteristics may be used.

Further, in order to accurately calculate the distance, it is necessary to be able to maintain the parallelism of the optical axes Lx of the two lenses 101. In order to maintain these parallelisms, again, in the camera stay portion 10a, the abutting surface of the lens 101 processed with high precision and the abutting portion with the camera stay portion 10a on the lens 101 side processed with high precision are used. It is important to form. Further, the hole 10b in the camera stay portion 10a is formed by processing it with high accuracy.

On the circuit board 20, components related to the operation of the image pickup device 100, such as an arithmetic element for controlling the operation of the image pickup device 100 and calculating the distance from the parallax amount of the two images, or an element for controlling the power supply, are arranged. There is. As shown in FIG. 1, in addition to the CPU (Central Processing Unit) 21 which is a control unit, the circuit board 20 is used for image processing such as ASIC (Application Specific Integrated Circuit) and FPGA (Field-Programmable Gate Array). A processing circuit 22 that performs a parallax calculation, a power supply unit 23 that supplies an operating power source for the CPU 21 and the like, and the like are arranged. Although wiring is provided between the circuit board 20 and the image pickup apparatus 100, the illustration is omitted. Among these parts, heat-generating parts that emit high temperature are included. The heat generating components illustrated in FIG. 1 are a CPU 21 and a processing circuit 22.

The heat-generating components such as the CPU 21 and the processing circuit 22 differ in type, arrangement position on the circuit board 20, size, and the like.

In the following description, the heat generating component in the stereo camera 1 according to the present embodiment will be described only for the CPU 21. It is not necessary to limit the heat generating component to the CPU 21. For example, other components mounted on the circuit board 20, FPGA, power supply IC, and the like also correspond to heat generating components. When a plurality of heat generating components are arranged on the circuit board 20, a heat radiating member 40 described below may be provided for each heat generating component.

A heat-generating component is a component that releases heat to the surroundings during operation. For example, a heat-generating component such as the CPU 21 may cause thermal runaway and abnormal operation if heat cannot be dissipated. Therefore, a heat radiating member 40 that promotes heat radiating is attached to the CPU 21.

The heat radiating member 40 is called a TIM (Thermal Interface Material). TIM effectively increases the thermal conductivity. For example, in addition to metal, heat conductive grease, graphite sheet, or the like is applied to TIM.

One end of the heat radiating member 40 is in contact with the CPU 21 side to collect heat, and the other end is in contact with the housing 10. The heat radiating member 40 and the CPU 21 are fixed with, for example, double-sided tape.

The position of the housing 10 with which the other end of the heat radiating member 40 comes into contact is, for example, the pick-up shape portion 11 shown in FIG. More specifically, as shown in FIGS. 1 to 4, the two receiving shape portions 11 and the heat radiating member 40 are in contact with each other. Further, each heat radiating member 40 is provided on each of the two receiving-shaped portions 11 protruding toward the circuit board 20, and is in contact with two heat generating components (CPU 21 and processing circuit 22) to radiate heat.

That is, the pick-up shape portion 11 is a convex shape portion having a shape protruding in the direction (heat generating component contact direction) side of the circuit board 20. More specifically, the pick-up shape portion 11 is provided with a shape and a positional relationship closer to line symmetry than the heat radiating member 40 with respect to the central portion C between the optical axes Lx of the two image pickup devices 100. The central portion C is a surface including the optical axis Lx of the two imaging devices 100 (lens 101) and includes a center line parallel to the optical axis Lx.

As described above, the heat from the heat generating components such as the CPU 21 and the processing circuit 22 is line-symmetrical with respect to the central portion C between the optical axes Lx of the two imaging devices 100 via the heat radiating member 40. It is transmitted to one of the two pick-up shape portions 11 provided at a position close to the above, and is transmitted from the two pick-up shape portions 11 to the entire housing 10.

By the way, as described above, the heat-generating components such as the CPU 21 and the processing circuit 22 are different in type, arrangement position on the circuit board 20, size, and the like. Therefore, it is very difficult to provide a plurality of heat generating components at positions symmetrical with respect to the central portion C between the optical axes Lx of the two imaging devices 100.

However, in the present embodiment, even if the heat-generating components such as the CPU 21 and the processing circuit 22 are not line-symmetrical with respect to the central portion C between the optical axes Lx of the two imaging devices 100, the heat-generating components come into contact with each other. The shape and positional relationship of the two pick-up shape portions 11 with respect to the central portion C between the optical axes Lx of the two imaging devices 100 are two heat-generating components (CPU 21 and) with respect to the central portion C between the optical axes Lx of the two imaging devices 100. It is provided so as to be closer to line symmetry than the positional relationship of the processing circuit 22 and the like). As a result, when the shape of the housing 10 changes due to a temperature change, asymmetrical deformation during thermal expansion can be suppressed, and deterioration of the performance of the stereo camera 1 due to thermal expansion can be suppressed. Further, if the two catch-shaped portions 11 that the heat-generating parts come into contact with each have the same shape and are line-symmetrical, the effect on thermal expansion can be further obtained.

As described above, according to the present embodiment, when the shape of the housing 10 is changed due to the temperature change, the asymmetrical deformation of the 10 during thermal expansion can be suppressed, and the performance deterioration of the stereo camera 1 due to thermal expansion can be suppressed. Can be done.

As described above, it is preferable that the pick-up shape portion 11 is basically completely symmetrical. On the other hand, when the arrangement positions and sizes of the two heat-generating components (CPU 21, processing circuit 22, etc.) are significantly different, the two heat-generating components (CPU 21, processing circuit, etc.) are not completely symmetrical. By determining the arrangement position and size of the pick-up shape portion 11 based on the difference in the arrangement position and size of (22, etc.), it may be effective to prevent the housing 10 from being deformed asymmetrically.

In this embodiment, the pick-up shape portion 11, the heat generating component (CPU 21, processing circuit 22, etc.), and the heat radiating member 40 are each provided, but the present invention is not limited to this, and at least two or more of each are provided. It may be the one that can be used.

(Second Embodiment)
Next, the second embodiment will be described.

The second embodiment describes the vehicle control unit including the stereo camera 1 of the first embodiment. Hereinafter, in the description of the second embodiment, the description of the same part as that of the first embodiment will be omitted, and the parts different from the first embodiment will be described.

FIG. 5 is an overall configuration diagram schematically showing the vehicle control unit according to the second embodiment. As shown in FIG. 5, the vehicle control unit 300 is mounted on the vehicle 500 and controls the movement of the vehicle 500. The vehicle control unit 300 calculates the distance to an object existing in the traveling direction of the vehicle 500 by using the stereo camera 1 already described, and controls the movement of the vehicle according to this distance.

As shown in FIG. 5, the lens 101 included in the stereo camera 1 is installed so as to be able to capture a scene in front of the vehicle 500 in the traveling direction. The stereo camera 1 is mounted near the inner rear view mirror on the upper side (on the vehicle interior side) of the windshield of the vehicle 500. The mounting position of the stereo camera 1 is not limited to the above-mentioned position, and may be any position as long as it can detect the situation outside the vehicle in front of the vehicle 500 in the traveling direction.

The stereo camera 1 obtains the distance from the image data including the captured subject to the subject (measurement target) (acquires the distance information). The measurement target of the stereo camera 1 is another moving object, a person, an animal, or the like.

The vehicle control unit 300 includes a stereo camera 1, a control device 310, a steering wheel 320, and a brake pedal 330 installed in a vehicle interior, which is a living room space. The stereo camera 1 has a photographing function of photographing the traveling direction of the vehicle 500, and is installed near the rear-view mirror inside the front window of the vehicle 500, for example.

Here, the relationship between the stereo camera 1 and the vehicle control unit 300 will be described. The control device 310 of the vehicle control unit 300 executes various vehicle controls based on the distance information from the stereo camera 1 to the subject obtained based on the parallax image received from the stereo camera 1.

As an example of vehicle control, the control device 310 controls the steering system (control target) including the steering wheel 320 based on the parallax image received from the stereo camera 1 to execute steering control to avoid obstacles. The control device 310 also controls the brake pedal 330 (controlled object) to perform brake control and the like to decelerate and stop the vehicle 500 based on the parallax image received from the stereo camera 1. As in the vehicle control unit 300 including the stereo camera 1 and the control device 310, the driving safety of the vehicle 500 can be improved by executing vehicle control such as steering control or brake control.

As described above, the stereo camera 1 is intended to capture the front of the vehicle 500, but the present invention is not limited to this. That is, the stereo camera 1 may be installed so as to photograph the rear or side of the vehicle 500. In this case, the stereo camera 1 can detect the position of the following vehicle behind the vehicle 500, or another vehicle translating to the side. Then, the control device 310 can detect the danger at the time of changing lanes or merging lanes of the vehicle 500 and execute the above-mentioned vehicle control.

Further, when the control device 310 determines that there is a risk of collision based on the parallax image of the obstacle behind the vehicle 500 detected by the stereo camera 1 in the back operation when the vehicle 500 is parked or the like. The vehicle control described above can be performed.

As described above, according to the present embodiment, even if the heat-generating components such as the CPU 21 and the processing circuit 22 are not line-symmetrical with respect to the central portion C between the optical axes Lx of the two imaging devices 100, the heat-generating components are respectively. Since the two contacting shape portions 11 have a shape and a positional relationship closer to line symmetry, the asymmetrical deformation of the housing 10 during thermal expansion is suppressed when the shape of the housing 10 changes due to a temperature change. be able to. As a result, the deterioration of the performance of the stereo camera 1 due to thermal expansion can be suppressed, so that the influence of errors on the calculation of the distance information from the stereo camera 1 to the subject can be reduced.

The stereo camera 1 may be installed on an object whose distance from the measurement target changes. Therefore, the stereo camera 1 is not limited to the vehicle 500, and can be installed on a moving body such as a ship or a railroad, or in a fixed object such as a building in the case of FA (Factory Automation) use.

1 Imaging unit 10 Housing 11 Pick-up shape 20 Circuit board 40 Heat dissipation member 100 Imaging device 300 Vehicle control unit 310 Control device

International Publication No. 2017/163584

Claims (7)

Two imaging devices and
A circuit board on which at least two or more components related to the operation of the two image pickup devices are arranged, and
A housing that holds a plurality of the circuit boards,
Two convex-shaped portions provided in the housing so as to sandwich the central portion between the optical axes of the two imaging devices in the housing and projecting toward the circuit board.
At least two or more heat radiating members provided in each of the two convex portions and in contact with the parts to dissipate heat.
With
The shape and positional relationship of the two convex portions with respect to the central portion between the optical axes of the two imaging devices is closer to line symmetry than the positional relationship of the component with respect to the central portion between the optical axes of the two imaging devices. It is provided so that
An imaging unit characterized by this. Two imaging devices and
A circuit board on which at least two or more components related to the operation of the two image pickup devices are arranged, and
A housing that holds a plurality of the circuit boards,
Two convex portions provided at a position line-symmetrical with respect to the central portion between the optical axes of the two imaging devices in the housing and projecting toward the circuit board.
At least two or more heat radiating members provided in each of the two convex portions and in contact with the parts to dissipate heat.
An imaging unit characterized by being equipped with. The heat radiating member is called TIM (Thermal Interface Material).
The imaging unit according to claim 1 or 2. The component is an image processing circuit that processes captured images captured by the two imaging devices.
The imaging unit according to any one of claims 1 to 3, wherein the imaging unit is characterized in that. The component is a processing circuit that performs parallax calculation from captured images captured by the two imaging devices.
The imaging unit according to any one of claims 1 to 4, characterized in that. At least two or more convex parts,
At least two or more heat radiating members provided so as to be in contact with at least a part of the plurality of convex portions,
At least two or more parts provided so as to be in contact with at least a part of the plurality of heat radiating members, and
An imaging unit characterized by being equipped with. In a vehicle control unit that is mounted on a vehicle and controls the movement of the vehicle.
The imaging unit according to any one of claims 1 to 6 and the imaging unit.
A control device that executes various vehicle controls based on distance information to the subject based on the parallax image from the imaging unit, and
A vehicle control unit characterized by being equipped with.

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