Pixel headlamp dynamic thermal management method and automobile light control system

Abstract

The invention discloses a dynamic thermal management method for a pixel headlamp and an automobile light control system, and belongs to the technical field of light control. According to the second strategy, the auxiliary area is closed; the fourth strategy is overall derating, heating is reduced in a partition derating mode or a frame interpolation derating mode, and the definition and the brightness of an overall picture are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of lighting control, and in particular to a dynamic thermal management method for pixel headlights and an automobile lighting control system. Background Art

[0002] The lighting sources on traditional cars generally use halogen lamps and xenon headlights. Halogen lamps and xenon headlights are gradually replaced by LED headlights due to their low brightness, short life, high radiation energy, light pollution and safety. In addition, traditional headlights cannot meet the functional needs of projecting canvas instructions when driving at night and on complex roads. Therefore, pixel headlights are widely used as light sources in current cars. Pixel headlights are composed of a matrix of LED lamp beads, and each LED lamp bead can be controlled individually to achieve the projection of complex images. However, LED lamp beads generate a lot of heat after long-term use. Long-term projection of fixed images can easily cause thermal runaway and reduce the clarity and brightness of the projected image. Now it is necessary to perform thermal management on pixel headlights to meet the clarity and brightness requirements of the projected image.

[0003] The existing patent application with publication number CN115843137A discloses a PCBA board for intelligent car light control, which includes MCU1, LED control system, power control system, VBAT and car system. The MCU is controlled by the car system, the LED control system includes multiple groups of LED drive modules, LEDs, LED lighting detection modules, and the power control system includes a power manager, a voltage detection module, a current detection module and a bus switch. The PCBA board for intelligent car light control uses a method of reducing the number of lamp beads to improve heat dissipation capacity, which cannot meet the requirements of projecting a clear picture and maintaining brightness. Summary of the invention

[0004] One of the purposes of the present invention is to provide a dynamic thermal management method for pixel headlights, which solves the problem that existing pixel headlights cannot guarantee the clarity and brightness of the projected image under long-term illumination.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0006] A pixel headlight dynamic thermal management method comprises the following steps:

[0007] S1. Initialize the pixel headlight controller and divide the pixel units on the pixel headlight into two categories: key area and auxiliary area. Each key area and auxiliary area is equipped with a separate temperature sensor;

[0008] S2: After receiving the image data information, the pixel headlight lights up the key area and auxiliary area for image projection;

[0009] S3. Determine pixel headlight T n >T标准 Is it true, where T n is the real-time temperature of the corresponding key area and auxiliary area, T 标准 The standard temperature is set. If it is established, it will enter S4. If it is not established, it will loop through S3.

[0010] S4: The corresponding key areas and auxiliary areas begin to reduce their ratings and enter S5;

[0011] S5. Determine K 辅助 ≤K fast Is it true? If true, then the auxiliary area derating is performed, where K 辅助 is the temperature change rate of the auxiliary area adjacent to the overheated key area, K fast is the set temperature change rate. If it is established, the auxiliary area adjacent to the over-temperature key area will be derated and enter S6. If it is not established, enter S7.

[0012] S6. Judge T n ≤T 回滞 Is it established? 回滞 is the return temperature value of the area. If it is true, it returns to S2, if not, it returns to S4;

[0013] S7. Determine K 辅助 ≤K mid Is it true? If it is true, the auxiliary area is closed and the process returns to S6. If it is not true, the K 重点 ≤K slow Is it true? If it is true, the frame insertion de-rating is performed. If not, the overall de-rating is performed and then returns to S6. K 重点 is the temperature change rate of the key area, K mid and K slow For the set temperature change rate, heat is reduced by partition derating or frame insertion derating to ensure the clarity and brightness of the overall picture.

[0014] Furthermore, in S2, the image data information includes a frame header, a data segment and a frame trailer. The frame header contains the file format, file size, resolution and module area calibration information, the data segment contains the pixel information of the projected image, and the frame trailer contains CRC check data.

[0015]

[0016] Among them, K is the temperature change rate corresponding to the key area and the auxiliary area, T J is the junction temperature parameter of the pixel unit, △t is the derating interval time, △T is the derating temperature difference, and λ is the derating trend factor. The temperature changes of each partition are comprehensively judged to ensure the accuracy of temperature control.

[0017] Furthermore, in S1, the pixel headlights are controlled by the main control chip, which includes a video input unit, CAN bus, MCU, GPU, deserializer, serializer and flash memory. The video input unit receives the picture data and inputs it into the deserializer. The deserializer deserializes the data and inputs it into the MCU and GPU for decoding. The decoded picture data is input into the serializer for serialization, and then the serialized picture data is passed to each pixel unit on the pixel headlight to light up. The CAN bus is used to transmit data and is used for the conversion and transmission of picture data.

[0018] Furthermore, the pixel headlights are controlled by a main control chip and powered by a power management chip. The power management chip includes a step-down circuit and a low-voltage difference voltage regulator circuit. The input electrical energy is input into each pixel unit after passing through the step-down circuit and the low-voltage difference voltage regulator circuit to power the pixel unit.

[0019] Preferably, in S1, the display image is divided into multiple areas on the light source board composed of pixel units, and data information is calibrated in each area, with the key area calibrated as 1 and the auxiliary area calibrated as 0 to facilitate internal data recognition.

[0020] In S1, the pixel unit is controlled by PWM, which has accurate control and high refresh rate.

[0021] Preferably, in S7, the frame insertion and derating refers to inserting a certain amount of derated frames between normal frames to achieve clarity and brightness.

[0022] More preferably, in S1, the temperature sensor is a thermistor, the pixel unit is an LED, and the brightness control is accurate.

[0023] The second purpose of the present invention is to provide an automobile lighting control system to solve the problem that pixel headlights on existing automobiles are prone to overheating.

[0024] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0025] An automobile lighting control system is used to implement the pixel headlight dynamic thermal management method, which plays a role in ensuring picture clarity and brightness.

[0026] The beneficial effects of the present invention are:

[0027] (1) In the process of derating the pixel unit after overheating, the dynamic thermal management method of the pixel headlight divides the pixel unit into a key area and an auxiliary area, and sets a temperature sensor in each area. The brightness of the key area and the auxiliary area is dynamically adjusted according to the thermal change trend of each area. Under the premise of maintaining the overall temperature, the brightness and clarity of the projected image in the key area are guaranteed to remain unchanged.

[0028] (2) The pixel headlight dynamic thermal management method uses partition derating and interpolation derating to dynamically adjust the brightness of the projected image of each partition, ensuring that the key areas can project the image normally to realize the lighting and indication functions of the pixel headlight. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A system block diagram of the pixel headlight provided by the present invention;

[0030] Figure 2 A schematic diagram of the upper partitions of the pixel headlight provided by the present invention;

[0031] Figure 3 A mapping relationship diagram of the key area and the auxiliary area on the pixel headlight provided by the present invention;

[0032] Figure 4 A graph showing the temperature variation over time of each partition of the pixel headlight provided by the present invention;

[0033] Figure 5 A flow chart of the dynamic thermal management method for pixel headlights provided by the present invention;

[0034] Figure 6 This is a schematic diagram of frame insertion derating provided by the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Embodiment 1

[0037] like Figure 1-Figure 6 As shown, this embodiment discloses a dynamic thermal management method for pixel headlights, including the following:

[0038] S1. Initialize the pixel headlight controller and divide the pixel units on the pixel headlight into two categories: key area and auxiliary area. Each key area and auxiliary area is equipped with a separate temperature sensor. The temperature sensor detects the temperature and temperature change rate of the key area and auxiliary area in real time.

[0039] S2. After receiving the image data information, the pixel headlight lights up the key area and the auxiliary area for image projection, and lights up the key area and the auxiliary area through each frame of image data refreshed in real time to complete the outward projection of the image;

[0040] S3. Determine pixel headlight T n >T标准 Is it true, where T n is the real-time temperature of the corresponding key area and auxiliary area, T 标准 is the set standard temperature. If it is established, enter S4. If it is not established, loop and execute S3 to set the standard temperature according to the temperature resistance data of the pixel unit obtained by experimental test.

[0041] S4: The corresponding key areas and auxiliary areas begin to derate and enter S5 to prevent the pixel headlights from overheating and failing;

[0042] S5. Determine K 辅助 ≤K fast Is it true? If true, then the auxiliary area derating is performed, where K 辅助 is the temperature change rate of the auxiliary area adjacent to the overheated key area, K fast is the set temperature change rate. If it is established, the auxiliary area adjacent to the over-temperature key area will be derated and enter S6. If it is not established, enter S7;

[0043] S6. Judge T n ≤T 回滞 Is it established? 回滞 is the return temperature value of the area. If it is true, it returns to S2, if not, it returns to S4;

[0044] S7. Determine K 辅助 ≤K mid Is it true? If it is true, the auxiliary area is closed and the process returns to S6. If it is not true, the K 重点 ≤K slow Is it true? If it is true, the frame insertion de-rating is performed. If not, the overall de-rating is performed and then returns to S6. K 重点 is the temperature change rate of the key area, K mid and K slow is the set temperature change rate, which is selected according to the experimental data of different pixel units.

[0045] See also Figure 6 The pixel unit is dimmed by PWM to control the luminous intensity. PWM controls the luminous intensity according to the thermal trend changes of the pixel unit to achieve dynamic adjustment of the light, thereby maintaining the overall brightness while controlling the heat.

[0046] Furthermore, in S2, the image data information includes a frame header, a data segment and a frame trailer. The frame header contains the file format, file size, resolution and module area calibration information, the data segment contains the pixel information of the projected image, and the frame trailer contains CRC check data. The image data information contains the color, size and brightness information of the projected picture, which is used to realize pixel headlights.

[0047] Furthermore,

[0048]

[0049] Among them, K is the temperature change rate corresponding to the key area and the auxiliary area, T J is the junction temperature parameter of the pixel unit, △t is the derating interval time, △T is the derating temperature difference, β is the heat dissipation coefficient of the light source, α is the heat dissipation system of the lighting structure, and λ is the derating trend factor, where K fast , K mid and K slow They are fast derating rate, medium speed derating rate and low speed derating rate, which are calibrated according to the experimental data of pixel headlights.

[0050] Furthermore, in S1, the pixel headlights are controlled by the main control chip, which includes a video input unit, CAN bus, MCU, GPU, deserializer, serializer and flash memory. The video input unit receives the picture data and inputs it into the deserializer. The deserializer deserializes the data and inputs it into the MCU and GPU for decoding. The decoded picture data is input into the serializer for serialization, and then the serialized picture data is passed to each pixel unit on the pixel headlight to light up. The CAN bus is used to transmit data.

[0051] Furthermore, the pixel headlights are controlled by a main control chip and powered by a power management chip. The power management chip includes a step-down circuit and a low-voltage difference voltage regulator circuit. The input electrical energy is input to each pixel unit after passing through the step-down circuit and the low-voltage difference voltage regulator circuit.

[0052] Furthermore, in S1, the display image is divided into multiple areas on the light source board composed of pixel units, and data information is calibrated in each area, with the key area calibrated as 1 and the auxiliary area calibrated as 0.

[0053] Preferably, in S1, the pixel unit is controlled by PWM.

[0054] Preferably, in S7, the frame insertion derating refers to inserting a certain amount of derated frames between normal frames.

[0055] Preferably, in S1, the temperature sensor is a thermistor and the pixel unit is an LED.

[0056] The specific strategy of the pixel headlight dynamic thermal management method is as follows:

[0057] Strategy 1: Auxiliary area derating: When the vehicle system detects the image pre-projection area temperature T n >T 标准 When high temperature derating is triggered, if the temperature change rate K of the auxiliary area adjacent to the key area is 辅助 ≤K fastWhen the auxiliary area is derated, the PWM value of the pixel unit of the auxiliary area projecting the image is reduced. By reducing the temperature of the auxiliary area, the temperature of the key area is reduced to ensure that the brightness and clarity of the projected image in the key area remain unchanged. At this time, if T 标准 ≤T n ≤T 回滞 , then continue to perform temperature derating, select the corresponding derating mode according to different K values, until the temperature T n ≤T 回滞 When the image PWM value in the auxiliary area resumes normal output, the image is displayed normally, and the normal working state is entered.

[0058] Strategy 2: Auxiliary area closure: Based on the auxiliary area derating, the software detects the temperature change rate K of the image pre-projection area. fast <K 辅助 ≤K mid When the auxiliary area is closed, the projection image in the auxiliary area is not displayed, so as to reduce the temperature and ensure the normal display of the projection image in the key area, so as to achieve the effect of unchanged image brightness and clarity. 标准 ≤T n ≤T 回滞 , then continue to perform temperature derating, select the corresponding derating mode according to the value of K, until T n ≤T 回滞 When the auxiliary area image PWM value resumes normal output, the image is displayed normally, and returns to normal working state.

[0059] Strategy 3: Frame insertion reduction: After the auxiliary area is closed, if the pre-projection area K 重点 ≤K slow When the frame insertion derating is performed, refer to Figure 6 , if 30 frames of images need to be projected in the key area of ​​the projected image within 1 second, the PWM output of the interval frames will be dynamically adjusted according to the temperature trend to achieve the requirement of lowering the temperature while ensuring that the brightness of the projected image does not decrease. 标准 ≤T n ≤T 回滞 , then continue to perform temperature derating, select the corresponding derating mode according to different K values, until T n ≤T 回滞 , the interval frame PWM value returns to the normal frame output, the image is displayed normally, and returns to the normal working state.

[0060] Strategy 4: Overall derating: After the insertion derating strategy is executed, if the temperature change rate of the lamp board K 重点 >K slow , the overall derating is performed to reduce the frame rate of the key areas of the projected image, such as from 30 frames per second to 15 frames per second, in order to reduce the temperature of the lamp board.标准 ≤T n ≤T 回滞 , then continue to derating the temperature, select the corresponding derating mode according to different K values, until T n ≤T 回滞 , the projected image PWM value returns to normal output, the image is displayed normally, and returns to normal working state to prevent over-temperature damage to the pixel headlights.

[0061] Embodiment 2

[0062] This embodiment also discloses an automobile lighting control system for implementing a dynamic thermal management method for pixel headlights, which reduces the heat generated by automobile lights by partitioning and interpolating frames to ensure the brightness and clarity of the lighting.

[0063] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also change and modify the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes of the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A pixel headlight dynamic thermal management method, characterized in that: The following steps are involved: S1. Initialize the pixel headlight controller and divide the pixel units on the pixel headlight into two categories: key area and auxiliary area. Each key area and auxiliary area is equipped with a separate temperature sensor; S2: After receiving the image data information, the pixel headlight lights up the key area and auxiliary area for image projection; S3. Determine pixel headlight T n >T 标准 Is it true, where T n is the real-time temperature of the corresponding key area and auxiliary area, T 标准 The standard temperature is set. If it is established, it will enter S4. If it is not established, it will loop through S3. S4: The corresponding key areas and auxiliary areas begin to reduce their ratings and enter S5; S5. Determine K 辅助 ≤K fast Is it true? If true, then the auxiliary area derating is performed, where K 辅助 is the temperature change rate of the auxiliary area adjacent to the overheated key area, K fast is the set temperature change rate. If it is established, the auxiliary area adjacent to the over-temperature key area will be derated and enter S6. If it is not established, enter S7. S6. Judge T n ≤T 回滞 Is it established? 回滞 is the return temperature value of the area. If it is true, it returns to S2, if not, it returns to S4; S7. Determine K 辅助 ≤K mid Is it true? If it is true, the auxiliary area is closed and the process returns to S6. If it is not true, the K 重点 ≤K slow Is it true? If it is true, the frame insertion de-rating is performed. If not, the overall de-rating is performed and then returns to S6. K 重点 is the temperature change rate of the key area, K mid and K slow is the set temperature change rate.

2. The method for dynamic thermal management of pixel headlights according to claim 1, characterized in that: In S2, the image data information includes a frame header, a data segment and a frame trailer. The frame header contains the file format, file size, resolution and module area calibration information, the data segment contains the pixel information of the projected image, and the frame trailer contains CRC check data.

3. The method for dynamic thermal management of pixel headlights according to claim 2, characterized in that: Among them, K is the temperature change rate corresponding to the key area and the auxiliary area, T J is the junction temperature parameter of the pixel unit, △t is the derating interval time, △T is the derating temperature difference, and λ is the derating trend factor.

4. The method for dynamic thermal management of pixel headlights according to claim 3, characterized in that: In S1, the pixel headlights are controlled by the main control chip, which includes a video input unit, CAN bus, MCU, GPU, deserializer, serializer and flash memory. The video input unit receives the picture data and inputs it into the deserializer. The deserializer deserializes the data and inputs it into the MCU and GPU for decoding. The decoded picture data is input into the serializer for serialization, and then the serialized picture data is passed to each pixel unit on the pixel headlight to light up. The CAN bus is used to transmit data.

5. The method for dynamic thermal management of pixel headlights according to claim 4, characterized in that: The pixel headlights are controlled by the main control chip and powered by the power management chip. The power management chip includes a step-down circuit and a low-voltage difference voltage regulator circuit. The input electrical energy is input into each pixel unit after passing through the step-down circuit and the low-voltage difference voltage regulator circuit.

6. The method for dynamic thermal management of pixel headlights according to claim 5, characterized in that: In S1, the display image is divided into multiple areas on a light source board composed of pixel units, and data information is calibrated in each area, with the key area calibrated as 1 and the auxiliary area calibrated as 0.

7. The method for dynamic thermal management of pixel headlights according to claim 6, characterized in that: In S1, the pixel unit is controlled using PWM.

8. The method for dynamic thermal management of pixel headlights according to claim 7, characterized in that: In S7, the frame insertion derating refers to inserting a certain amount of derating frames between normal frames.

9. The method for dynamic thermal management of pixel headlights according to claim 1, characterized in that: In S1, the temperature sensor is a thermistor and the pixel unit is an LED.

10. An automobile lighting control system, characterized in that: Used to implement the dynamic thermal management method for pixel headlights as described in any one of claims 1-9.

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