In-vehicle camera control device

Abstract

To provide an on-vehicle camera control device which can eliminate the need of mounting of a thermistor of an on-vehicle camera.SOLUTION: There is provided an on-vehicle camera control device for controlling an on-vehicle camera which is installed on an inside of a windshield glass of a vehicle, and comprises: a die temperature acquiring part for acquiring a die temperature of an integrated circuit of the on-vehicle camera; a heater periphery temperature estimating part for estimating a heater periphery temperature of an anti-fog heater, on the basis of the value of current flowing in the anti-fog heater of the windshield glass corresponding to the on-vehicle camera; and a determining part for, on the basis of the die temperature and the heater periphery temperature, determining whether control of the on-vehicle camera can be continued.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an in-vehicle camera control device. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2021-115989 is a known technical document related to an in-vehicle camera control device. This publication describes a method for protecting an integrated circuit in a camera from high temperatures by measuring the die temperature of the integrated circuit and halting part of the operation of the integrated circuit when the temperature is high. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-115989 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the die temperature of the camera's integrated circuit is the only factor used for judgment, there is a risk that the integrated circuit may fail if the die temperature is not measured correctly. For this reason, in addition to measuring the die temperature, a redundancy system has traditionally been built by mounting a thermistor around the integrated circuit. However, mounting a thermistor involves the problem of increased component costs. [Means for solving the problem]

[0005] One aspect of the present invention is an in-vehicle camera control device that controls an in-vehicle camera installed on the inside of a windshield glass of a vehicle, and includes: a die temperature acquisition unit that acquires a die temperature of an integrated circuit of the in-vehicle camera; a heater peripheral temperature estimation unit that estimates a heater peripheral temperature of the defogging heater based on a current value flowing through an defogging heater of the windshield glass corresponding to the in-vehicle camera; and a determination unit that determines whether or not to continue control of the in-vehicle camera based on the die temperature of the in-vehicle camera and the heater peripheral temperature. The determination unit determines that the vehicle-mounted camera can be continuously controlled when the temperature difference between the die temperature and the heater ambient temperature is less than the control continuation threshold, and determines that the vehicle-mounted camera cannot be continuously controlled when the temperature difference is equal to or greater than the control continuation threshold. . [Effects of the Invention]

[0006] According to one aspect of the present invention, it is possible to eliminate the need for a thermistor to be mounted on an in-vehicle camera. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a block diagram showing an in-vehicle camera control device according to an embodiment; [Figure 2] 10 is a flowchart illustrating an example of a control continuation determination process for the in-vehicle camera. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] The vehicle-mounted camera control device 100 according to this embodiment shown in FIG. 1 is a device for controlling a vehicle-mounted camera 1 mounted on a vehicle. The vehicle may be a passenger car, a freight vehicle, or an autonomous vehicle. The vehicle-mounted camera control device 100 analyzes image data acquired from the vehicle-mounted camera 1, for example, to use the data for driving assistance control or autonomous driving control. The vehicle-mounted camera control device 100 may also perform object recognition processing to recognize objects such as pedestrians, vehicles, traffic lights, and signs from the image data.

[0010] The vehicle-mounted camera 1 is installed on the inside of the windshield glass of the vehicle and captures an image of the outside of the vehicle through the windshield glass. The vehicle-mounted camera 1 is provided, for example, above the windshield glass (windshield) in front of the vehicle.

[0011] The vehicle-mounted camera 1 has a hood that comes into contact with the windshield glass. The hood is a resin component that, together with the windshield glass, forms a camera imaging space where the lens of the vehicle-mounted camera 1 is exposed. As an example, the hood is composed of a fan-shaped bottom portion located below the vehicle-mounted camera 1 and side portions that rise from the left and right sides of the bottom portion. The front ends of the fan-shaped bottom portion and the front ends of the side portions are connected to the windshield glass. The hood, in cooperation with the windshield glass, which slopes toward the front of the vehicle as it goes down, forms a camera imaging space that is separated from the passenger compartment.

[0012] The hood is not limited to the above-mentioned shape. The hood may have any shape as long as it can expose the lens of the vehicle-mounted camera 1 and properly form a camera imaging space for capturing images of the outside of the vehicle. The hood may have a structure that expands in a quadrangular pyramid or cone shape from the lens side of the vehicle-mounted camera 1 toward the windshield glass. The hood may be processed to reduce reflections so that reflected light does not enter the lens of the vehicle-mounted camera 1.

[0013] As shown in FIG. 1, the vehicle-mounted camera 1 has an integrated circuit 1a and a die temperature sensor 1b. The integrated circuit 1a is a circuit that performs processes such as generating image data from the detection results of the image sensor of the vehicle-mounted camera 1. The integrated circuit 1a generates image data by, for example, converting an analog signal from the image sensor into a digital signal and then performing predetermined noise removal and correction processes. The integrated circuit 1a also performs processing to transmit the image data to the ECU 10.

[0014] The die temperature sensor 1b is disposed on the die of the integrated circuit 1a and detects the die temperature, which is the temperature of the integrated circuit 1a. The die temperature is a factor that greatly affects the camera performance. The die temperature affects the image quality and noise. The die temperature sensor 1b transmits the detected die temperature to the ECU 10.

[0015] As shown in FIG. 1, the vehicle-mounted camera control device 100 includes an ECU (Electronic Control Unit) 10 for controlling the vehicle-mounted camera 1. The ECU 10 is an electronic control unit having a CPU (Central Processing Unit) and a storage unit such as a ROM (Read Only Memory) or a RAM (Random Access Memory). The ECU 10 realizes various functions by, for example, executing programs stored in the storage unit in the CPU. The ECU 10 may be composed of multiple electronic units. Note that the vehicle-mounted camera control device 100 may not include the ECU 10, and a part of the ECU 10 may function as the vehicle-mounted camera control device 100.

[0016] In addition to the in-vehicle camera 1, the ECU 10 is also connected to an anti-fogging heater 2. The anti-fogging heater 2 is a heater for preventing fogging and condensation on the windshield glass. The anti-fogging heater 2 is a heater corresponding to the in-vehicle camera 1 and is provided to heat the camera imaging space that cannot be cleared by the vehicle's defroster. The anti-fogging heater 2 is, for example, attached to the windshield glass in front of the in-vehicle camera 1 and is made of multiple heating wires extending laterally. The current supplied to the anti-fogging heater 2 is controlled by the ECU 10.

[0017] The anti-fogging heater 2 may be a hood heater. The hood heater is configured, for example, as an electric heating wire wound around the hood of the in-vehicle camera 1. The hood heater may be provided on the back side of the bottom surface of the hood. In this case, the hood heater may be formed by forming a continuous electric heating wire into a substantially spiral-shaped plate member and attaching it to the bottom surface. The anti-fogging heater 2 may be a sticker heater.

[0018] Next, a description will be given of the functional configuration of the ECU 10. As shown in Fig. 1, the ECU 10 has a die temperature acquisition unit 11, a heater ambient temperature estimation unit 12, and a determination unit 13.

[0019] Based on the detection signal transmitted from the die temperature sensor 1b, the die temperature acquisition unit 11 acquires the die temperature of the integrated circuit 1a of the vehicle-mounted camera 1. The die temperature acquisition unit 11 acquires the die temperature at regular intervals.

[0020] The heater surrounding temperature estimator 12 estimates the heater surrounding temperature, which is the temperature around the defog heater 2 (the temperature of the space for camera imaging), based on the value of the current flowing through the defog heater 2. The resistance value of the defog heater 2 is basically temperature-dependent. Therefore, the heater surrounding temperature estimator 12 can estimate the heater surrounding temperature from the current value by measuring the value of the current flowing through the defog heater 2. The calculation formula for estimating the heater surrounding temperature from the amount of power may be set in advance for each vehicle model. Note that the control of the current of the defog heater 2 may be executed by an ECU different from the ECU 10.

[0021] The determination unit 13 determines whether or not to continue controlling the vehicle-mounted camera 1 (integrated circuit 1a) based on the die temperature of the vehicle-mounted camera 1 acquired by the die temperature acquisition unit 11 and the heater ambient temperature estimated by the heater ambient temperature estimation unit 12.

[0022] Specifically, the determination unit 13 determines that it is possible to continue controlling the vehicle-mounted camera 1 when the temperature difference between the die temperature of the vehicle-mounted camera 1 and the temperature around the heater is less than the control continuation threshold. The control continuation threshold is a threshold value that is set in advance. The control continuation threshold is set to a value that allows appropriate determination when a failure occurs in the die temperature sensor 1b.

[0023] If the temperature difference between the die temperature of the vehicle-mounted camera 1 and the temperature around the heater is equal to or greater than the control continuation threshold, the determination unit 13 determines that continued control of the vehicle-mounted camera is impossible. The determination unit 13 determines that an abnormality has occurred in the die temperature sensor 1b and makes a failure determination. The determination unit 13 stops the function of the integrated circuit 1a of the vehicle-mounted camera 1. The determination unit 13 notifies the vehicle occupants that the function of the vehicle-mounted camera 1 has been stopped by flashing an indicator, displaying a message on the display, or outputting a voice message. Note that notifying the vehicle occupants is not essential.

[0024] When it is determined that control of the vehicle-mounted camera 1 can be continued, and the die temperature of the vehicle-mounted camera 1 is equal to or higher than the high-temperature protection threshold, the determination unit 13 may stop the function of the integrated circuit 1a of the vehicle-mounted camera 1. The high-temperature protection threshold is a threshold value that is set in advance. The high-temperature protection threshold is set to a value that allows appropriate determination that the integrated circuit 1a is at a high temperature. The determination unit 13 protects the integrated circuit 1a that has become too hot by stopping the function of the integrated circuit 1a.

[0025] Next, a control method of the vehicle-mounted camera control device 100 according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a flowchart showing an example of a control continuation determination process of the vehicle-mounted camera 1.

[0026] 2, the ECU 10 of the vehicle-mounted camera control device 100 acquires the die temperature and estimates the heater ambient temperature in S10. The die temperature acquisition unit 11 of the ECU 10 acquires the die temperature of the integrated circuit 1a of the vehicle-mounted camera 1 based on the detection signal transmitted from the die temperature sensor 1b. The heater ambient temperature estimation unit 12 of the ECU 10 estimates the heater ambient temperature of the defogging heater 2 based on the value of the current flowing through the defogging heater 2. Thereafter, the ECU 10 proceeds to S11.

[0027] In S11, the ECU 10 determines whether the temperature difference between the die temperature of the vehicle-mounted camera 1 and the heater ambient temperature is less than the control continuation threshold using the determination unit 13. If the ECU 10 determines that the temperature difference between the die temperature and the heater ambient temperature is less than the control continuation threshold (S11: YES), the ECU 10 proceeds to S12. If the ECU 10 does not determine that the temperature difference between the die temperature and the heater ambient temperature is less than the control continuation threshold (S11: NO), the ECU 10 proceeds to S15.

[0028] In S12, the ECU 10 determines whether the die temperature of the vehicle-mounted camera 1 is below the high-temperature protection threshold using the determination unit 13. If the ECU 10 determines that the die temperature of the vehicle-mounted camera 1 is below the high-temperature protection threshold (S12: YES), the ECU 10 proceeds to S13. If the ECU 10 does not determine that the die temperature of the vehicle-mounted camera 1 is below the high-temperature protection threshold (S12: NO), the ECU 10 proceeds to S14.

[0029] In S13, the ECU 10 continues to control the integrated circuit 1a of the vehicle-mounted camera 1. After that, the ECU 10 repeats the process from S10 again after a certain period of time has elapsed.

[0030] In S14, the ECU 10 stops control of the integrated circuit 1a of the vehicle-mounted camera 1. This protects the overheated integrated circuit 1a. In S15, the ECU 10 determines that a failure has occurred in the die temperature sensor 1b and stops control of the integrated circuit 1a of the vehicle-mounted camera 1.

[0031] According to the in-vehicle camera control device 100 of this embodiment described above, the heater ambient temperature is estimated from the current value of the defogging heater 2, and a malfunction of the die temperature sensor 1b can be determined by comparing the die temperature with the heater ambient temperature, eliminating the need to install an additional thermistor in addition to the die temperature sensor 1b in the in-vehicle camera 1. As a result, the in-vehicle camera control device 100 can reduce the number of parts in the in-vehicle camera 1, thereby reducing costs.

[0032] Furthermore, according to the vehicle-mounted camera control device 100, if the die temperature sensor 1b is not determined to be faulty by comparing the die temperature with the temperature around the heater, the die temperature detected by the die temperature sensor 1b is used to determine whether the integrated circuit 1a is at a high temperature, thereby improving the accuracy of the high temperature determination.

[0033] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. The present invention can be embodied in various forms, including the above-described embodiments, with various modifications and improvements made based on the knowledge of those skilled in the art.

[0034] The control continuation determination process by the vehicle-mounted camera control device 100 may be applied not only to the vehicle-mounted camera 1 that captures an image in front of the vehicle, but also to a vehicle-mounted camera (rear camera) that captures an image behind the vehicle, or to a vehicle-mounted camera (side camera) that captures an image to the side of the vehicle. The rear camera and the side camera are also cameras installed on the inside of the windshield glass of the vehicle.

[0035] The vehicle-mounted camera 1 does not necessarily have to have a hood. Even if there is no hood, the anti-fogging heater 2 can be considered to be installed sufficiently close to the vehicle-mounted camera 1, so that a failure of the die temperature sensor 1b can be determined by comparing the die temperature with the temperature around the heater.

[0036] The heater surrounding temperature estimator 12 may estimate the heater surrounding temperature taking into account the outside air temperature. It can be considered that the temperature in the camera imaging space decreases as the outside air temperature decreases, even if the current value flowing through the defogging heater 2 is the same. The heater surrounding temperature estimator 12 may estimate the heater surrounding temperature to be a lower temperature as the outside air temperature decreases, even if the current value flowing through the defogging heater 2 is the same. [Explanation of symbols]

[0037] 1...In-vehicle camera, 1a...Integrated circuit, 1b...Die temperature sensor, 2...Anti-fogging heater, 11...Die temperature acquisition unit, 12...Heater ambient temperature estimation unit, 13...Determination unit, 100...In-vehicle camera control device

Claims

1. An in-vehicle camera control device that controls an in-vehicle camera installed on the inside of a windshield glass of a vehicle, a die temperature acquisition unit that acquires a die temperature of an integrated circuit of the vehicle-mounted camera; a heater peripheral temperature estimation unit that estimates a heater peripheral temperature of the defogging heater based on a current value flowing through the defogging heater of the windshield glass corresponding to the vehicle-mounted camera; a determination unit that determines whether or not to continue control of the vehicle-mounted camera based on the die temperature and the heater peripheral temperature; Equipped with The determination unit determines that control of the vehicle-mounted camera can be continued when the temperature difference between the die temperature and the heater ambient temperature is less than a control continuation threshold, and determines that control of the vehicle-mounted camera cannot be continued when the temperature difference is equal to or greater than the control continuation threshold.

2. 2. The vehicle-mounted camera control device according to claim 1, wherein when the determination unit determines that control of the vehicle-mounted camera can be continued and the die temperature is equal to or higher than a high temperature protection threshold, the vehicle-mounted camera control device stops the function of the integrated circuit of the vehicle-mounted camera.

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