Display device for vehicle
Patent Information
- Application Number
- JP2022152259
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-09-26
- Publication Date
- 2025-07-25
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing vehicle display devices are unreliable due to potential malfunctions in drawing processing means, leading to incomplete or incorrect display of vehicle information.
A vehicle display device equipped with a multi-core SOC, comprising a first processor core for normal display, a second processor core for alternative display, and a third processor core for startup effect display, ensuring redundancy and reliability by enabling alternative display control even if the primary processor core malfunctions.
The multi-core SOC configuration ensures high reliability and functional safety by allowing alternative display through a secure processor core, ensuring vehicle information is always displayed correctly, even in the event of primary processor core failures.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present disclosure relates to a vehicle display device that displays vehicle information as an image. [Background technology]
[0002] A vehicle display device that displays an information image including vehicle information is disclosed in Patent Document 1. This vehicle display device uses a drawing processing means such as a graphic controller to synthesize a plurality of layers including an information image and displays the synthesized image on an image display device. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] JP 2012-30703 A Summary of the Invention [Problem to be solved by the invention]
[0004] In the above-mentioned vehicle display device, if the drawing processing means malfunctions, the information image cannot be displayed.
[0005] In consideration of the above-mentioned problems, an object of the present disclosure is to provide a vehicle display device that is highly reliable from the viewpoint of functional safety. [Means for solving the problem]
[0006] The vehicle display device of the present disclosure includes: A display device for a vehicle includes a display for displaying an image, and a multi-core SOC for displaying an image showing vehicle information on the display, The SOC has a built-in first processor core that performs normal display control to cause the display to display the vehicle information under normal conditions, and a second processor core that performs alternative display control to cause the display to display the vehicle information when an incorrect display state occurs in which the vehicle information is not displayed on the display under the normal display control. Effect of the Invention
[0007] According to the present disclosure, it is possible to provide a vehicle display device that is highly reliable from the viewpoint of functional safety. [Brief description of the drawings]
[0008] [Figure 1] FIG. 2 is a diagram showing the configuration of a display device for a vehicle. [Diagram 2] Layer configuration diagram. [Diagram 3] 4 is an example of a display when a vehicle display device is started up. [Figure 4] 4 is an example of a display on a vehicle display device under normal conditions. [Diagram 5] 13 shows an example of a display when an illegal display state occurs on a vehicle display device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] (First embodiment) The vehicle display device M is an instrument that displays vehicle information to a vehicle occupant, and is mounted on an instrument panel of the vehicle.
[0010] Vehicle information is information related to driving the vehicle, such as the vehicle's driving speed, engine RPM, vehicle automatic control status, warning lights, remaining fuel amount (remaining energy amount), tire pressure, route guidance information, and footage from an onboard camera.
[0011] The automatic vehicle control state is an operating state of an automatic driving mode in which the vehicle automatically controls the acceleration / deceleration and steering of the vehicle. The automatic driving mode includes, for example, an autopilot mode in which the vehicle travels at a constant speed while maintaining a constant distance from the vehicle ahead, an auto lane change mode in which the vehicle controls the steering and changes lanes when the driver operates the turn signal, and an auto park mode in which the vehicle moves to a location where it determines it is possible to park and parks it.
[0012] The operating state of the autopilot mode is, for example, the target driving speed, the detection state of the vehicle ahead, the distance between the vehicle ahead, the driver's driving readiness state, the autopilot mode cancellation warning, etc. The driver's driving readiness state is determined by whether or not the driver has his / her hands on the steering wheel and is ready to immediately start manual driving.
[0013] The operating status of the auto lane change mode includes, for example, the detection status of obstacles ahead of the lane change (presence or absence of a following vehicle), guidance on the vehicle's route when changing lanes, the driver's driving preparation status, and a warning prior to the cancellation of the auto lane change.
[0014] The operating status of the autopark mode includes, for example, candidate parking locations on a map (or on an image captured by an external camera), the planned parking location, images of the area around the vehicle captured by an external camera, the driver's driving preparation status, a warning prior to the cancellation of the autopark mode, etc.
[0015] The vehicle display device M includes a SOC (System On a Chip) 1 and a display 2.
[0016] SOC1 is an integrated semiconductor chip in which all of the functions necessary for the operation of the vehicle display device M are implemented in a single integrated circuit chip. The function necessary for the operation of the vehicle display device M is a function for displaying vehicle information on the display 2 (instrument display function). SOC1 acquires a video signal capturing an image of the surroundings of the vehicle from an in-vehicle camera C that captures an image of the surroundings of the vehicle, and displays the image on the display 2 as necessary. SOC1 also displays vehicle information acquired from the in-vehicle control unit E via the in-vehicle network N on the display 2.
[0017] The display 2 is a device that displays images, such as a liquid crystal display, an organic EL display, etc. The display 2 inputs the video signal output by the SOC 1 and displays an image based on this video signal on the screen.
[0018] (SOC configuration) SOC1 incorporates a first processor core 11A, a second processor core 11B, a third processor core 11C, a PVT monitor unit 12, a communication unit 13, a video input unit 14, a display control unit 15, a ROM 16, a RAM 17, a 2D drawing unit 18, and a 3D drawing unit 19.
[0019] The first processor core 11A is an arithmetic unit that functions independently from the other cores.
[0020] The first processor core 11A starts operation by loading an OS (Operating System) stored in the ROM 16 and a program that runs on the OS into the RAM 17. Since the first processor core 11A loads the OS, it has the longest startup time among the processor cores 11A to 11C.
[0021] The first processor core 11A draws an image representing vehicle information in an area of the RAM 17 corresponding to the screen layer L1 in a normal display mode, which will be described later.
[0022] The second processor core 11B is an arithmetic unit that functions independently from the other cores. The second processor core 11B includes an internal memory 11B1. The internal memory 11B1 includes an in-core ROM and an in-core RAM.
[0023] The second processor core 11B loads a program stored in the in-core ROM into the in-core RAM and starts operation. The second processor core 11B has the shortest startup time among the processor cores 11A to 11C.
[0024] The second processor core 11B is a secure processor core that decrypts and executes encrypted instruction codes (encrypted instruction codes). The second processor core 11B includes a core-specific key storage unit that stores a unique key (core-specific key). The in-core ROM of the internal memory 11B1 stores encrypted programs in a non-rewritable format. The second processor core 11B uses the core-specific key to authenticate the encrypted instruction codes of the programs stored in the in-core ROM, and then decrypts and executes them.
[0025] The second processor core 11B draws an image representing vehicle information in an area of the RAM 17 corresponding to the screen layer L2 in an emergency display mode, which will be described later.
[0026] The third processor core 11C is an arithmetic unit that functions independently from the other cores.
[0027] The third processor core 11C loads the program stored in the ROM 16 into the RAM 17 and starts operation.
[0028] The third processor core 11C draws an image representing vehicle information in an area of the RAM 17 corresponding to the screen layer L3 in a boot performance display mode described later.
[0029] The PVT (Process, Voltage and Temperature) monitor unit 12 is a functional block that monitors whether the operation of each of the processor cores 11A to 11C is normal. The PVT monitor unit 12 monitors whether the power supply voltage and the operating clock supplied to each of the processor cores 11A to 11C are normal. The PVT monitor unit 12 also monitors whether the temperature of each of the processor cores 11A to 11C is within an operation guarantee range.
[0030] The communication unit 13 is a functional block that performs communication in accordance with a predetermined communication protocol. The predetermined communication protocol is, for example, CAN (Controller Area Network), MOST (Media Oriented Systems Transport), Ethernet, etc. The communication unit 13 communicates with the in-vehicle control unit E via the in-vehicle network N to acquire vehicle information and stores it in the RAM 17.
[0031] The video input unit 14 is a functional block that inputs a video signal of a predetermined standard. The video signal of the predetermined standard is NTSC (National Television System Committee), LVDS (Low Voltage Differential Signaling), HDMI (registered trademark) (High-Definition Multimedia Interface), etc. The video input unit 14 inputs a video signal of an image of the surroundings of the vehicle from the on-board camera C, and stores the video signal in the RAM 17.
[0032] The display control unit 15 is a functional block that outputs a video signal of a predetermined standard to the display 2 and causes an image showing vehicle information to be displayed on the display 2. The video signal of the predetermined standard is LVDS, HDMI (registered trademark), or the like.
[0033] The following description will be given with reference to Fig. 2. The display control unit 15 superimposes and composites the screen layers L1 to L3 as a composite layer L through the calculations of the processor cores 11A to 11C. The screen layers L1 to L3 are arranged in the order of L1, L3, and L2 from the bottom up. The display control unit 15 superimposes the screen layer L3 on the screen layer L1, and further superimposes the screen layer L2 on the screen layer L3, thereby superimposing and compositing the composite layer L as one screen. The display control unit 15 outputs a video signal representing the composite layer L to the display 2.
[0034] The ROM 16 is, for example, a NAND type flash memory or a NOR type flash memory.
[0035] The RAM 17 is, for example, a DDR SDRAM that transfers data by a DDR (Double Data Rate) method. The RAM 17 is a work memory that temporarily stores data calculated by each of the processor cores 11A to 11C.
[0036] The 2D drawing unit 18 is a functional block that draws two-dimensional vector graphic or raster graphic images.
[0037] The 3D drawing unit 19 is a functional block that draws three-dimensional computer graphic images.
[0038] (SOC1 startup sequence) The start-up of each of the processor cores 11A to 11C of SOC1 will be described. When power is applied to SOC1, the second processor core 11B starts up first. When the second processor core 11B completes its own start-up, it starts up the third processor core 11C. When the third processor core 11C completes its own start-up, it starts up the first processor core 11A. When the third processor core 11C has completed its start-up and until the first processor core 11A has completed its start-up, SOC1 executes a start-up presentation display mode.
[0039] (Start-up display mode: Start-up display control) The startup display mode will now be described.
[0040] The first processor core 11A does not draw anything on the screen layer L1. Similarly, the second processor core 11B does not draw anything on the screen layer L2. Drawing nothing means that the entire screen is completely transparent and colorless with maximum transparency.
[0041] The third processor core 11C controls the 2D drawing unit 18 to draw an image representing the vehicle information on the screen layer L3. The vehicle information drawn on the screen layer L3 is a warning light 31, a trademark 32 of the vehicle (or the vehicle manufacturer) in which the vehicle display device M is mounted, and an ornament 33 that decorates the start-up performance. The warning light 31 is an image that represents a symbol mark corresponding to a warning such as an abnormal voltage of the vehicle battery. The trademark 32 and the ornament 33 are an opening performance image that creates the start-up performance of the vehicle display device M. The opening performance image may be an animation that switches between multiple ornaments 33 so that, for example, a ring-shaped ornament 33 appears to rotate.
[0042] The second processor core 11B does not draw anything on the screen layer L2.
[0043] The display control unit 15 composites the screen layers L1 to L3 into a composite layer L, and displays the image shown in Fig. 4 on the display screen 20 of the display 2. In this startup performance display mode, the warning light 31 can be displayed, and the opening performance image is used to display the startup of the vehicle display device M.
[0044] When the display of this opening effect image is completed and the startup of the first processor core 11A is completed, SOC1 transitions to the normal display mode.
[0045] (Normal display mode: Normal display control) The normal display mode will now be described.
[0046] The first processor core 11A controls the 3D drawing unit 19 to draw an image representing vehicle information on the screen layer L1. The vehicle information drawn on the screen layer L1 includes a warning light 31, a driving speed 34, an engine RPM 35, and a vehicle automatic control state 36. The driving speed 34 drawn by the 3D drawing unit 19 is in the form of a pointer-type instrument having an index scale and a needle. The engine RPM 35 drawn by the 3D drawing unit 19 is in the form of a three-dimensional pointer-type instrument, similar to the driving speed 34. The vehicle automatic control state 36 drawn by the 3D drawing unit 19 is in the form of a three-dimensional instrument, with symbols indicating the control state arranged on the vehicle itself and the surrounding roads.
[0047] The third processor core 11C does not draw anything on the screen layer L3.
[0048] The first processor core 11B does not draw anything on the screen layer L2.
[0049] The display control unit 15 composites the screen layers L1 to L3 into a composite layer L, and displays the image shown in Fig. 5 on the display screen 20 of the display 2. In this normal display mode, various types of vehicle information are displayed to the driver.
[0050] During this normal display mode, the second processor core 11B monitors the first processor core 11A by the PVT monitor unit 12. When the operation of the first processor core 11A is determined to be abnormal during the normal display mode, this is an improper display state in which correct vehicle information is not displayed on the display 2 under normal display control. When the first processor core A enters the improper display state, the SOC1 transitions to the emergency display mode.
[0051] (Emergency display mode: Alternative display control) The emergency display mode will now be described. The emergency display mode is entered when it is determined that the operation of the first processor core is abnormal.
[0052] Since the first processor core is operating abnormally, the image being drawn on the screen layer L1 is unknown.
[0053] The third processor core 11C does not draw anything on the screen layer L3.
[0054] The second processor core 11B performs bit block transfer (BITBLT) of the image stored in the internal memory 11B1 to draw an image representing vehicle information on the screen layer L2. The vehicle information displayed on the screen layer L2 is a warning light 31, a driving speed 34, and a warning message 37. These vehicle information are drawn on an opaque background. The driving speed 34 drawn by bit block transfer is in the form of a digital instrument expressed by a digital value. The warning message 37 is a message expressing the reason for switching from the normal display mode to the emergency display mode and a suggestion of an action that the driver should take in the emergency display mode. The warning message 37 is, for example, a message saying "The main processor core has failed" or "Please stop the vehicle immediately in a safe place."
[0055] The display control unit 15 composites the screen layers L1 to L3 into a composite layer L, and displays the image shown in Fig. 6 on the display screen 20 of the display 2. At this time, regardless of the states of the screen layers L1 and L3, they are overwritten by the topmost screen layer L3, and the screen layer L3 is displayed.
[0056] Furthermore, the second processor core 11B restarts the first processor core 11A. The second processor core 11B monitors the first processor core 11A by the PVT monitor unit 12. When the operation of the first processor core 11A becomes normal after the restart, SOC1 returns to the normal display mode.
[0057] The second processor core 11B, which controls the alternative display, is a secure processor core with high system robustness that can prevent program tampering, so that the instrument display function can be provided safely even if the first processor core 11A is in an unauthorized display state.
[0058] The above is a description of the first embodiment of the display device for a vehicle M of the present disclosure.
[0059] The vehicle display device M of the present disclosure includes a display 2 that displays an image, and a multi-core SOC 1 that displays an image showing vehicle information on the display 2. The SOC 1 incorporates a first processor core 11A that performs normal display control to cause the display 2 to display vehicle information under normal conditions, and a second processor core 11B that performs alternative display control to cause the display 2 to display vehicle information when an incorrect display state occurs in which vehicle information is not correctly displayed on the display 2 under normal display control. With this configuration, even if an abnormality occurs in the operation of the first processor core 11A, the second processor core 11B can alternatively display vehicle information, thereby improving reliability from the viewpoint of functional safety.
[0060] (Other embodiments: Modifications) The vehicle display device M of the present disclosure may be modified as follows.
[0061] The vehicle display device M may be applied to a head-up display that displays a virtual image on the windshield in front of the driver's seat of the vehicle.
[0062] In addition to vehicle information, the SOC 1 may display entertainment information on the display 2. The entertainment information includes the operating status of the car audio (such as information about the music being played), the operating status of "CarPlay (registered trademark)" which connects to a mobile phone and operates an application on the mobile phone, etc. It is preferable that the entertainment information is drawn only on the screen layer L1 by the first processor core 11A, and is not drawn on the screen layer L2 drawn by the second processor core 11B or the screen layer L3 drawn by the third processor core 11C.
[0063] In a normal display, one screen may be constructed by the third processor core 11C of SOC1 drawing the warning light 31 on the screen layer L3, and the first processor core 11A drawing all other vehicle information on the screen layer L1 except for the warning light 31. In this configuration, the drawing load in a normal display can be distributed to the two processor cores.
[0064] The "other functions" except for the instrument display function of SOC1 may be configured as separate IC chips. In other words, the instrument display function of SOC1 may be configured as a SiP (System in a Package), and the other functions may be configured as separate IC chips. The other functions include, for example, a function to link with "CarPlay (registered trademark)", a function to control a car air conditioner, a function to control a car audio system, and a function to communicate using wireless communication standards such as "Wi Fi (registered trademark)" and "Bluetooth (registered trademark)". In other words, it is sufficient that the instrument display function, which is the main function of the vehicle display device M, is integrated into one chip.
[0065] For the purpose of expanding the capacity of the ROM 16 and RAM 17 built into the SOC 1, an external memory may be connected to the SOC 1.
[0066] When an error in the image of the screen layer L1 is detected by an error detection code such as a CRC code, it may be determined that the display is in an illegal display state. In this case, the image drawn on the screen layer L1 is incorrect, and therefore the correct vehicle information is not displayed on the display 2. In this case, it can be presumed that the cause is an abnormality in the operation of the first processor core 11A or the 3D drawing unit 19 that draws the image on the screen layer L1. The image error detection by this error detection code may detect errors in the entire screen layer L1, or may detect errors in an image representing individual vehicle information or a specified area. The image error detection by this error detection code may be executed by the display control unit 15, or may be configured by a separate functional block.
[0067] The data of the composite layer L1 stored in the RAM 17 may be compared with the data of the video signal output by the display control unit 15, and if the composite layer L1 is not correctly converted into a video signal, it may be determined that an improper display state exists. In this case, an abnormality has occurred in the operation of the display control unit 15, and the correct vehicle information is not displayed on the display 2. Whether the composite layer L1 has been correctly converted into a video signal may be determined by error detection using an error detection code such as a CRC code. It is preferable that this video signal error detection be configured in a functional block separate from the display control unit 15. [Explanation of symbols]
[0068] M … Vehicle display device 1 ... SOC (multi-core SOC) 11A ... 1st processor core 11B ... 2nd processor core 11B1…Internal memory 11C ... 3rd processor core 12 …PVT monitor section 13. Communications Department 14 ...Video input section 15 ... Display control unit 16...ROM 17. RAM 18 ... 2D drawing section 19...3D drawing section 2. Display 20…display screen 31…warning light 32 ... Trademark (Opening performance image) 33...Decoration (Opening performance image) 34 …Travel speed 35 …Engine RPM 36 ... Vehicle automatic control state 37 ... Warning message C … Car camera E…In-vehicle ECU N … In-vehicle network L ... Composite layer L1 ... Screen layer 1 (first layer) L2 ... Screen layer 2 (second layer) L3: Screen layer 3 (third layer)
Claims
1. In a vehicle display device comprising a display for displaying an image and a multi-core SOC for causing the display to display an image representing vehicle information, the SOC incorporates a first processor core for performing normal display control to display the vehicle information on the display during normal times, and a second processor core for determining whether an incorrect display state exists in which the vehicle information is not correctly displayed on the display during the normal display control. A vehicle display device.
2. When the incorrect display state exists, the second processor core performs alternative display control to display the vehicle information on the display. The vehicle display device according to Claim 1.
3. The SOC causes the display to display a screen formed by synthesizing a plurality of layers. The first processor core draws a first image representing the vehicle information on a first layer during the normal display control. The second processor core draws a second image representing the vehicle information on a second layer that is above the first layer during the alternative display. The vehicle display device according to Claim 2.
4. The first image includes a traveling speed, a warning lamp, and a vehicle automatic control state. The second image does not include the vehicle automatic control state and includes the traveling speed and the warning lamp. The vehicle display device according to Claim 3.
5. When the SOC determines the incorrect display state, it executes a restart of the first processor core. The vehicle display device according to Claim 1.
6. The SOC causes the display to display a screen formed by synthesizing a plurality of layers. The first processor core draws a first image representing the vehicle information on a first layer during the normal display control. The SOC includes a third processor core for drawing a third image representing the vehicle information on a third layer. The second processor core starts up prior to the first processor core and the third processor core when the SOC starts up. The third processor core starts up prior to the first processor core after the second processor core has started up when the SOC starts up, and draws the third image on the third layer until the first processor core starts the normal display control. The vehicle display device according to Claim 1.
7. The first image does not include an opening production image. The third image does not include the traveling speed and the vehicle automatic control state, and includes the warning lamp and the opening effect image. The vehicle display device according to claim 6.
8. The first processor core draws the first image on the first layer by 3D drawing. The third processor core draws the third image on the third layer by 2D drawing. The vehicle display device according to claim 6.
9. The SoC (i) When detecting an abnormality in the operating clock of the first processor, (ii) When detecting an error in the data drawn on the first layer, or (iii) When detecting an error in the video signal data output to the display, determines that it is in the incorrect display state. The vehicle display device according to any one of claims 1 to 8.