Display control method and device for front windshield of vehicle and vehicle

Abstract

According to the display control method and device for the front windshield of the vehicle and the vehicle, the safety assistance function and the entertainment function are integrated, intelligent switching is conducted according to the working mode of the vehicle, and therefore the maximum efficiency of a display interface, namely the maximum vehicle interior, of the front windshield is achieved. The display control method for the front windshield of the vehicle comprises the steps that the current working mode of the vehicle is recognized based on state information and environment perception information of the vehicle; when the current working mode of the vehicle is an auxiliary driving mode, the electrochromic layer is controlled to be adjusted to be in a coloring state suitable for enhanced display, and a projection device is controlled to project an augmented reality road condition image generated based on multi-sensor data fusion to the projection imaging layer; and when the current working mode of the vehicle is an entertainment mode, the electrochromic layer is controlled to be adjusted to be in a dark color state, and the projection device is controlled to project entertainment media content to the projection imaging layer.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of intelligent vehicle cockpit, in particular to a display control method and device for a front windshield of a vehicle, and a vehicle. BACKGROUND

[0002] With the continuous improvement of the intelligent level of automobiles, two major technology trends are increasingly prominent: one is the extreme pursuit of driving safety, especially the visual challenge under extreme weather conditions; the second is the growing demand for immersive entertainment experience in the cockpit. However, the existing technical solutions usually separate these two major functional fields, which has the following pain points: 1. Visual blind area problem under extreme weather: Currently, the visual perception ability of the driver is severely reduced in low-visibility environments such as heavy rain, dense fog, and nighttime. Although ADAS systems (such as millimeter wave radar, laser radar) can perceive the environment to some extent, the information is mostly presented in the form of icons or simple warning sounds on the instrument panel or small head-up displays (HUD), with limited information and unable to provide the driver with intuitive and coherent real-world images. The driver still needs to strain to observe the road conditions through the foggy windshield, with high psychological pressure and accident risk.

[0003] 2. Experience limitations of the vehicle entertainment system: To improve the front-row entertainment experience, some vehicles are equipped with large center screens or even co-pilot entertainment screens. However, the screen size is limited by physical space, and the location is usually low, requiring the driver or passenger to significantly lower their heads or shift their gaze to watch, affecting driving safety (for the driver) or immersion. The ideal immersive large-screen experience should be similar to a home theater, but the current vehicle environment cannot achieve this.

[0004] 3. Glare problem: Existing automatic anti-glare rearview and interior rearview mirrors have been popularized, but for strong light from the front (such as oncoming vehicle high beams, low-angle sunlight), the driver mainly relies on manual sun visor lowering, which is a passive approach and blocks part of the front view.

[0005] 4. Deficiencies of existing HUD technology: Traditional W-HUD (windshield-type head-up display) can project a small amount of driving information (such as speed, navigation arrows) onto a small area of the front windshield, but its display area is small, the information volume is limited, and the virtual image distance is short, making it impossible to achieve full-windshield information coverage, let alone display high-definition real-time video streams or entertainment content. While more advanced AR-HUD can provide more information and integrate with real scenes, it is costly and still limited by the projection area, making it difficult to accommodate entertainment functions.

[0006] Therefore, there is an urgent need in the field for an integrated solution that can break through the above technical barriers. SUMMARY

[0007] The application provides a display control method and device for a vehicle front windshield and a vehicle, which integrates safety assistance and entertainment functions and intelligently switches according to the working mode of the vehicle, so as to maximize the efficiency of the front windshield, which is the largest display interface in the vehicle.

[0008] The technical scheme of the application is as follows: In a first aspect, the application provides a display control method for a vehicle front windshield, characterized in that the front windshield comprises an electrochromic layer and a projection imaging layer, and the method comprises: identifying the working mode of the vehicle based on state information and environmental perception information of the vehicle; when the working mode of the vehicle is an assisted driving mode, controlling the electrochromic layer to adjust to a colored state suitable for enhanced display, and controlling a projection device to project an augmented reality road condition image generated based on multi-sensor data fusion to the projection imaging layer; when the working mode of the vehicle is an entertainment mode, controlling the electrochromic layer to adjust to a dark state, and controlling the projection device to project entertainment media content to the projection imaging layer.

[0009] The electrochromic layer and the projection imaging layer of the front windshield are cooperatively controlled, so that they can intelligently switch between different working modes based on the state information and the environmental perception information of the vehicle. Specifically, in the assisted driving mode, the front windshield is converted into a high-contrast display interface, and an augmented reality road condition image generated based on multi-sensor data fusion is projected to enhance the driver's perception ability in a complex environment with clear and intuitive visual information, thereby improving driving safety; in the entertainment mode, the front windshield is converted into an immersive projection screen with a dark background, and entertainment media content is projected to provide a cinema-level in-vehicle entertainment experience for passengers, thereby realizing intelligent integration and on-demand provision of the two core functions of safety assistance and immersive entertainment on a single physical interface.

[0010] In the assisted driving mode, an augmented reality road condition image is provided for the driver in a specific scenario. This image is not simply a picture superimposed, but is generated based on multi-sensor data fusion, which integrates the advantages of different sensors, so as to complement the sensors and overcome the limitations of a single sensor. By projecting the fused image onto the electrochromic layer which has been adjusted to a colored state suitable for enhanced display, the windshield is temporarily converted into a high-contrast digital canvas in essence, which replaces or significantly enhances the natural field of view of the driver limited by weather, light, etc., and directly presents key road condition information to the driver in a clearer and more prominent way, thereby significantly reducing cognitive load and improving driving safety.

[0011] In the entertainment mode, the front cabin space of the vehicle is temporarily converted into an immersive entertainment environment. By controlling the electrochromic layer to adjust to a dark state, the windshield is converted from a transparent viewing window to a large, dark background projection screen, effectively suppressing environmental light interference and improving the contrast and color performance of the projected image. At the same time, the projection device projects entertainment media content onto the projection imaging layer, allowing the largest in-vehicle interface to be used for playing movies, games, etc., thereby creating a cinema-level audio-visual experience for the occupants when the vehicle is stationary, greatly expanding the functionality of the in-vehicle space.

[0012] In some possible embodiments, the method further comprises: When the current working mode of the vehicle is the normal driving mode, the electrochromic layer is controlled to be in a high light transmission state, and the projection imaging layer is controlled to remain in a non-projection active state.

[0013] By controlling the electrochromic layer to be in a high light transmission state, the clarity and light transmittance of the natural field of view are maximized, meeting the fundamental needs of safe driving. At the same time, by controlling the projection imaging layer to remain in a non-projection active state, light scattering, additional glare, or image retention that may be caused by the functional layer when unnecessary are effectively avoided, thereby maintaining the purity and authenticity of the driving line of sight. This not only ensures driving safety, but also keeps the entire display solution in a low-power standby state in the normal state, providing a prerequisite for smooth and rapid switching to the auxiliary driving mode or the entertainment mode.

[0014] In some specific embodiments, the identification condition of the auxiliary driving mode comprises: determining that the current driving environment is a low-visibility driving environment based on the environmental perception information, and determining that the vehicle is in a non-parking driving state based on the state information; wherein the low-visibility driving environment is triggered by at least one of the following conditions: the wiper is in a continuous working mode, the ambient light intensity is lower than a first threshold, the camera image features meet the rain and fog weather model, and there is oncoming vehicle high beam glare.

[0015] The low-visibility driving environment caused by rain, darkness, fog, and oncoming glare in actual driving can be accurately identified, and it is ensured that only in the safety-related scenario of vehicle driving (non-parking driving state), the auxiliary driving mode that enhances the driver's visual ability is triggered. This effectively avoids the misactivation of the function in unnecessary scenarios, ensures that the projection of the augmented reality road image is timely and necessary, improves the relevance and effectiveness of driving safety assistance, and optimizes the energy consumption and user experience of the system.

[0016] In some specific embodiments, the identification condition of the entertainment mode comprises: Based on the status information, it is determined that the vehicle is in a safe parking state and has received a user-issued command to start the entertainment function.

[0017] In some specific embodiments, the projection imaging layer is a polymer-dispersed liquid crystal layer; When the vehicle is currently in assisted driving mode, the polymer-dispersed liquid crystal layer is switched to the first scattering state to form a high-contrast interface. When the vehicle is currently in entertainment mode, the polymer-dispersed liquid crystal layer is switched to a second scattering state to form a diffuse reflection projection interface; the transmittance of the second scattering state is greater than that of the first scattering state.

[0018] By leveraging the electro-controllable properties of polymer-dispersed liquid crystal layers—a smart optical material—a single projection imaging layer can provide customized optical performance for different operating modes. In assisted driving mode, the first scattering state aims to create a high-contrast interface. Its main effect is to prioritize the visual prominence and recognizability of key warning information (such as warning boxes and indicator lines) in augmented reality road condition images, sacrificing some light transmittance in exchange for higher display contrast, thereby ensuring that safety information can be quickly and accurately captured by the driver. In entertainment mode, the second scattering state aims to create a diffuse projection interface. Its higher light transmittance means that while maintaining sufficient projection brightness and color performance, more ambient light (such as interior ambient lighting) is allowed to softly pass through, helping to create a more comfortable and immersive, rather than completely isolated, cinematic viewing environment, optimizing the visual comfort of the entertainment experience. This mode-based adaptive optics adjustment allows the same hardware layer to perform differentiated optimal display assistance functions in different scenarios.

[0019] In some possible embodiments, the method further includes: During mode switching, the changes in the transmittance of the electrochromic layer, the optical state of the projection imaging layer, and the brightness of the projection device are controlled to change synchronously and gradually to avoid abrupt visual changes.

[0020] By synchronously and gradually controlling multiple key display parameters (transmittance of the electrochromic layer, optical state of the projection imaging layer, and brightness of the projection device) during mode switching, a smooth and natural transition between different operating modes is achieved. This effectively avoids visual abrupt changes such as instantaneous strong light, screen flicker, or drastic jumps in brightness caused by abrupt parameter changes, thereby significantly improving user visual comfort, reducing driver distraction or discomfort that may be caused by abrupt interface changes, and ensuring the smoothness and safety of human-computer interaction.

[0021] In some specific embodiments, the augmented reality road condition imagery includes at least visually enhanced outlines of road lane lines, warning frames that highlight obstacles ahead, and distance or collision time information related to the vehicle.

[0022] By generating and overlaying road lane outlines, augmented reality imagery reconstructs and enhances road geometry guidance in complex or ambiguous road conditions, assisting drivers in maintaining their lanes. By generating and overlaying warning boxes for obstacles ahead, it significantly separates and highlights potentially dangerous targets from the visual background, improving the driver's situational awareness and reaction speed. By providing distance or collision time-related information relevant to the vehicle, it transforms abstract sensor data into intuitive, quantifiable prompts directly related to driving decisions, assisting drivers in making more precise speed and following distance control. This comprehensive presentation of information elements transforms augmented reality road condition imagery from a mere reproduction of the environment into an intelligently processed decision-making support interface focused on key elements of driving safety.

[0023] In some possible embodiments, the method further includes: In the assisted driving mode, the projection brightness of the projection device is dynamically adjusted based on the real-time light intensity in the environmental perception information or the current coloring state of the electrochromic layer.

[0024] By dynamically adjusting the projection brightness based on real-time light intensity (such as strong daylight and low nightlight) or the current coloring state of the electrochromic layer (whose coloring depth directly affects background brightness and transmittance) in environmental perception information, the projected augmented reality road condition images can maintain optimal visual recognizability and comfort under any ambient light conditions. For example, brightness can be increased in strong light environments to counteract ambient light glare, while brightness can be reduced in low light or when the electrochromic layer is dark to avoid glare. This ensures that key driving information (such as outlines and warning boxes) remains clear, conspicuous, and non-glaring, improving the effectiveness of information delivery while guaranteeing visual safety and comfort.

[0025] Secondly, this application also provides an intelligent display control device for a vehicle windshield, the windshield comprising an electrochromic layer and a projection imaging layer, the method comprising: The pattern recognition module is used to identify the current operating mode of the vehicle based on the vehicle's status information and environmental perception information. The first control module is used to control the electrochromic layer to adjust to a color state suitable for enhanced display when the vehicle is currently in the assisted driving mode, and to control the projection device to project augmented reality road condition images generated based on multi-sensor data fusion onto the projection imaging layer. The second control module is used to control the electrochromic layer to adjust to a dark state and control the projection device to project entertainment media content onto the projection imaging layer when the vehicle's current working mode is entertainment mode.

[0026] Thirdly, this application also provides a vehicle including the aforementioned intelligent display control device for the vehicle's windshield. Attached Figure Description

[0027] Figure 1 This is a structural block diagram of the vehicle in the embodiments of this application; Figure 2 This is a structural block diagram of the windshield in an embodiment of this application; Figure 3 This is a flowchart illustrating the display control method for the vehicle windshield in an embodiment of this application. Detailed Implementation

[0028] Reference Figure 1 This application provides a vehicle 100, which can be, but is not limited to, a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), a new energy vehicle, or a fuel vehicle. The vehicle includes: a body, a smart windshield, and a multimodal imaging display system integrated into the body.

[0029] The intelligent windshield is installed at the front of the vehicle and includes at least an electrochromic layer and a projection imaging layer.

[0030] The multimodal imaging display system includes a central control unit, which is typically located behind the dashboard or in the vehicle domain controller area, serving as the core of the system's computation and control.

[0031] The projection display engine can be installed in the front of the vehicle's roof, inside the dashboard, or in the center console on the passenger side. The optical path is designed to project large-size, distortion-free images onto the projection imaging layer of the smart windshield.

[0032] The multi-sensor group includes: a front camera, typically mounted near the rearview mirror inside the windshield, for collecting visible light and / or infrared images ahead; a millimeter-wave radar, typically mounted behind the front bumper or grille, for detecting the distance and speed of objects ahead; and a light / temperature and humidity sensor, typically mounted on the upper edge of the windshield or the base of the exterior rearview mirror, for detecting ambient light intensity, temperature, and humidity.

[0033] In some embodiments, the multi-sensor group may also include lidar or low-light radar (not shown in the figures), mounted on the roof or front bumper.

[0034] The various components interact with the central control unit via a vehicle bus (such as CAN FD or vehicle Ethernet) to exchange data and control commands.

[0035] Reference Figure 2 The smart windshield in this embodiment is a functionally designed layered composite structure. Its core lies in integrating at least two key functional layers—an electrochromic layer and a projection imaging layer—within a high-strength glass substrate that meets vehicle safety standards. This enables the windshield to have dynamically adjustable light transmittance and the ability to function as a projection display interface.

[0036] Specifically, in a typical layered configuration, the windshield comprises, from the outside (facing outwards) to the inside (facing inwards), the following components: The outermost tempered glass, serving as the outermost protective layer, is typically made of high-strength soda-lime safety glass, with a thickness of approximately 2.1 to 2.5 millimeters. Its outer surface may be coated with a rain-repellent and hydrophobic coating to enhance self-cleaning capabilities and reduce glare from water droplets.

[0037] The electrochromic layer is one of the core functional layers for achieving intelligent light adjustment. This layer can be formed using electrochromic materials such as electrically controlled suspended particle film (SPD) or liquid crystal dimming film (PDLC), with a thickness of approximately 0.3 to 0.5 mm. Its transmittance can be precisely and continuously adjusted by applying a controllable external voltage (e.g., 0 to 60V DC). Typically, its transmittance is approximately 70% to 85% in a transparent state, while it can decrease to below 10% in a dark state. This layer primarily plays a dual role: when display is required, it adjusts to a specific tint to serve as a background substrate for projected displays, enhancing image contrast; during normal driving, it dynamically fine-tunes its transmittance according to ambient light, acting as an active anti-glare layer.

[0038] The projection imaging layer is a key functional layer for achieving high-definition image display. This layer can be composed of polymer-dispersed liquid crystal (PDLC) material or other optical thin films with light-scattering properties. Its function is to receive the light beam from the projection display engine and form a virtual image suitable for observation inside or on the surface of the glass through diffuse reflection or scattering of the incident light. The presence of this layer allows the projected image to overcome ambient light interference and be clearly presented using the windshield as the medium. Its optical states (such as scattering intensity and haze) can be switched electronically to adapt to the needs of different display modes.

[0039] Optional functional layers: Other functional layers can be set between or after the electrochromic layer and the projection imaging layer as needed. For example, a transparent display optional layer (such as an ITO conductive film or a nanocomposite resin film) can be added to provide additional display solutions; an anti-reflective layer (such as one composed of SiO2 / TiO2 multilayer thin films) can also be set to suppress interface reflection and further improve display clarity.

[0040] Finally, all functional layers are bonded together with the inner glass (usually high-transmittance safety glass, about 2.0 mm thick) by hot pressing with a film such as PVB (polyvinyl butyral) to form an integral sandwich structure, ensuring mechanical strength and safety performance.

[0041] The entire intelligent windshield is reliably fixed to the vehicle frame by a double layer of sealant around its perimeter, and has excellent waterproof, shockproof and high and low temperature resistance (for example, stable operation in the range of -40℃ to 85℃), meeting the stringent requirements of automotive-grade environments.

[0042] In summary, this embodiment innovatively integrates the electrochromic layer and the projection imaging layer into the composite structure of the windshield, transforming the latter from a passive light-transmitting component into an active human-computer interaction interface that can intelligently switch its optical properties (transmittance, scattering characteristics) according to the vehicle mode and display augmented reality images or entertainment content. This integrated design is the physical basis for realizing the multimodal intelligent display control method described above.

[0043] Reference Figure 3 Based on the aforementioned intelligent windshield, this application provides a display control method for a vehicle windshield, the method comprising: S101 identifies the vehicle's current operating mode based on vehicle status information and environmental perception information; S102, when the vehicle is currently in the assisted driving mode, control the electrochromic layer to adjust to a color state suitable for enhanced display, and control the projection device to project augmented reality road condition images generated based on multi-sensor data fusion onto the projection imaging layer. S103, when the vehicle is currently in entertainment mode, control the electrochromic layer to adjust to a dark state, and control the projection device to project entertainment media content onto the projection imaging layer.

[0044] Vehicle status information originates from the vehicle's internal electronic systems and bus network, and is a data set reflecting the vehicle's own operating status. Vehicle status information covers the vehicle's real-time operating conditions, including but not limited to: vehicle speed signals, gear signals (such as P, D, and R), handbrake / electronic parking status signals, and user command signals from the steering wheel or voice.

[0045] Environmental perception information originates from sensor arrays deployed inside and outside the vehicle. It is a data set reflecting the external physical environment in which the vehicle is located. Environmental perception information includes: visible light and infrared image sequences collected by forward-facing cameras, target point clouds and speed data provided by millimeter-wave radar / LiDAR, light intensity measured by ambient light sensors, and rain sensor or wiper operating status signals.

[0046] The process of identifying the operating mode is handled by a pre-defined judgment logic executed by the unit responsible for computation and processing. First, it determines whether the vehicle is in a safe parking state (e.g., in P gear with the handbrake engaged). If so, and a clear instruction from the user to activate the entertainment function is received (e.g., clicking a screen icon or a specific voice command), then it is identified as entertainment mode.

[0047] If the vehicle is in motion (e.g., in Drive with the handbrake released), the system further analyzes the environmental perception information to determine if it meets low visibility conditions. These conditions include: ambient light intensity consistently below a preset first threshold (e.g., at night); camera image features matching a rain / fog weather model after algorithmic analysis; windshield wipers in continuous operation mode (medium or high speed); or image analysis detecting glare from oncoming vehicle headlights. When any of these conditions is triggered, the system is identified as an assisted driving mode. Users can also actively request activation of this mode via a shortcut key.

[0048] When the vehicle is in motion and no low visibility triggering conditions are met, it is identified as normal driving mode.

[0049] In step S102, when it is determined that the assisted driving mode has been entered, the control unit immediately sends a command to the drive circuit connected to the electrochromic layer. The drive circuit outputs a specific voltage signal, causing the electrochromic material to react and adjust from a high-transmittance state to a predetermined, moderately colored state (e.g., light transmittance reduced to 30%-50%). This state is intended to provide a display background with significantly improved contrast for subsequent projection, while not completely blocking external light.

[0050] Simultaneously, the image processing unit initiates a multi-sensor data fusion process. This process receives synchronous data from a forward-facing camera, an infrared camera, and millimeter-wave radar / LiDAR. Through specific algorithms (such as neural networks based on cross-modal attention mechanisms), the precise 3D spatial structure and contour information provided by radar / LiDAR is deeply fused and complemented with the texture and thermal radiation information provided by visible light / infrared images. One of the core tasks of this algorithm is scene understanding and visual enhancement, such as performing defogging, deraining, and low-light enhancement. On the generated clear image stream, augmented reality layers driven by perception results are overlaid, such as highlighted lane line outlines, pedestrian or vehicle warning boxes, and distance or collision time indicators.

[0051] The generated augmented reality road condition video stream is sent to the projection device in real time. The projection device automatically adjusts its projection brightness based on the current ambient light intensity and the color depth of the electrochromic layer, and then projects the image onto the projection imaging layer on the windshield. In assisted driving mode, the projection imaging layer is typically controlled to a specific light scattering state, allowing the driver to see a clear image aligned with the real-world space ahead, with key information highlighted and enhanced, effectively compensating for natural vision loss caused by weather or lighting conditions.

[0052] In step S103, when it is determined that the entertainment mode has been entered, the control unit immediately sends an instruction to the electrochromic layer driving circuit to drive it to switch to the dark state with the lowest light transmittance (such as light transmittance <10%), turning the windshield into a dark background screen to maximize the contrast and immersion of the projected image.

[0053] The video signal source is switched to the in-vehicle infotainment system. The video stream of entertainment media content (such as movie and game footage) output by the infotainment system is transmitted to the projection device.

[0054] The projector activates and adjusts the projection brightness to a comfortable level for extended viewing, based on the dark screen environment. Simultaneously, an image geometry correction algorithm is activated, taking into account the curvature of the windshield and the driver's eye position, to ensure distortion-free image quality. The projector then projects the corrected entertainment content onto the windshield's projection layer. In this mode, the projection layer can be controlled to a different light scattering state (e.g., slightly lower haze than in assisted driving mode) to optimize image sharpness and uniformity, thereby providing occupants with a cinematic large-screen audiovisual experience. Activation of this mode is strictly limited to the vehicle being in a safe parked position.

[0055] In some embodiments, the method further includes: S104, when the vehicle is currently in normal driving mode, control the electrochromic layer to be in a high light transmittance state and control the projection imaging layer to remain in a non-projection active state.

[0056] When the unit responsible for processing determines that the vehicle is currently in normal driving mode based on continuously monitored vehicle status information and environmental perception information, it triggers the execution of step S104. The core basis for this determination is that the vehicle is in driving mode (such as in D gear and the handbrake is released), and at the same time, it does not meet any low visibility environmental conditions that would trigger the assisted driving mode (e.g., sufficient ambient light, no continuous rain, no heavy fog, no severe glare).

[0057] The control unit sends specific commands to the drive circuit connected to the electrochromic layer. The drive circuit then outputs a voltage signal that puts the electrochromic material into or restores it to a high transmittance state (e.g., a drive voltage corresponding to a transmittance greater than 70%). At this time, the electrochromic layer presents a near-colorless, high-transmittance state. Its core function is to ensure the basic optical performance of the windshield as an observation window, providing the driver with a maximized, undiminished natural field of vision and a true sense of ambient light, meeting the fundamental requirements for visual clarity in normal safe driving.

[0058] The control unit simultaneously sends commands to the drive circuitry controlling the projection imaging layer, instructing it to maintain or switch to a non-projection active state. This specifically means: If the projection imaging layer is a polymer dispersed liquid crystal (PDLC) layer, it is made into an energized transparent state by driving circuit. The liquid crystal molecules are arranged in an orderly manner, and the layered structure hardly scatters light, thereby avoiding the introduction of additional optical distortion, ghosting or haze.

[0059] If the projection imaging layer is another physical functional film layer, then control its associated drive mechanism or circuit to put it in a non-operating physical state or a state of minimal optical influence.

[0060] The core effect of this control is to ensure that this functional layer does not interfere with the driver's vision during normal driving, maintaining the purity and authenticity of the driver's vision.

[0061] In this mode, the control unit also sends commands to the projection device to turn off the light source or put it into standby / sleep mode, preventing the projection of any image content. This achieves low-power operation of the entire display solution.

[0062] Step S104 ensures that, in most conventional driving scenarios, the primary role of the smart windshield is as a high-performance, transparent safety component. By setting the electrochromic layer to a high-transmittance state and keeping the projection imaging layer in a non-projection active state, this method prioritizes and fully guarantees the most basic and important safety requirement of allowing the driver to directly observe the real world through the glass, while providing enhanced functional potential. In this mode, the entire system remains in a silent, low-power standby state, ready to respond quickly to any mode switching that may be needed (such as entering assisted driving mode in case of severe weather, or entering entertainment mode after parking), achieving a balance between functionality, safety, and energy efficiency.

[0063] In this embodiment, the projection imaging layer is a polymer-dispersed liquid crystal layer; when the vehicle is currently in the assisted driving mode, the polymer-dispersed liquid crystal layer is controlled to switch to a first scattering state to form a high-contrast interface; when the vehicle is currently in the entertainment mode, the polymer-dispersed liquid crystal layer is controlled to switch to a second scattering state to form a diffuse reflection projection interface; the transmittance corresponding to the second scattering state is greater than the transmittance corresponding to the first scattering state.

[0064] When the vehicle is detected to have entered assisted driving mode, the control unit sends a command to the driving circuit of the polymer-dispersed liquid crystal layer. The driving circuit applies a first alternating electric field with specific parameters (such as a specific voltage amplitude and frequency). Under the action of this electric field, the orientation of the liquid crystal molecules changes, causing the polymer-dispersed liquid crystal layer to switch from a transparent state to a preset first scattering state. In this state, the layer forms a microstructure interface with high haze and specific forward scattering characteristics. Through the strong light scattering effect, the visual contrast between the projected image and the background (external objects seeping through the partially colored electrochromic layer) is effectively improved, making key information in the augmented reality road condition image (such as warning boxes and guide lines) more prominent and easier to identify. This scattering state helps to moderately mix the projected light with a small amount of transmitted ambient light, reducing harsh boundary perception, allowing the generated augmented reality information to be integrated more naturally and seamlessly into the driver's field of vision of the road ahead, reducing cognitive conflict. Although in a scattering state, the first scattering state still maintains a low transmittance (for example, allowing some ambient light to pass through), so that while the driver is viewing the enhanced image, he can still have a certain degree of direct perception of changes in the light and shadow of the actual environment and emergency situations (such as abnormal lights of other vehicles). This is an important redundancy for driving safety.

[0065] When the vehicle is detected to have entered entertainment mode, the control unit switches the command. The drive circuit applies a second AC electric field with different parameters (typically a different voltage amplitude and / or frequency). This electric field drives the polymer-dispersed liquid crystal layer into a preset second scattering state. This second scattering state is designed to provide a diffuse reflective surface with more uniform optical properties, closer to that of a traditional projection screen. Its wider scattering angle more evenly disperses the light from the projection device across a wider viewing angle, improving the consistency of the viewing experience for front-seat occupants (including the front passenger).

[0066] The transmittance for the second scattering state is set to be greater than that for the first scattering state. This means that in entertainment mode, this layer allows more ambient light (mainly from inside the vehicle) to pass through softly. The technical effect is twofold: firstly, it prevents the interior environment from becoming completely dark due to the windshield blocking out light, helping to maintain the occupants' sense of spatial orientation and adequate ambient lighting, improving comfort during extended viewing, and reducing visual fatigue and a feeling of confinement. Secondly, the moderate background light transmission can combine with the projected image to create an immersive, rather than completely isolated, viewing atmosphere similar to the subtle ambient light that illuminates the screen in a high-end cinema. Simultaneously, higher transmittance usually comes with more efficient use of projected light and lower self-absorption, contributing to a brighter image at the same projection brightness.

[0067] In some embodiments, the method further includes: S105, during the mode switching process, the transmittance change of the electrochromic layer, the optical state change of the projection imaging layer, and the brightness change of the projection device are controlled to change synchronously and gradually to avoid visual abrupt changes.

[0068] Step S105 is triggered during the transition period between any two operating modes (such as between normal driving mode and assisted driving mode, between assisted driving mode and entertainment mode, or between entertainment mode and normal driving mode). Its core is to precisely coordinate the timing and unify the rate of adjustment of three key optical parameters—the transmittance of the electrochromic layer, the optical state of the projection imaging layer (such as the haze / scattering intensity of the PDLC layer), and the projection brightness of the projection device—ensuring a smooth and continuous transition from one steady-state value to another.

[0069] During synchronous gradation, a unified timer or fixed refresh cycle is used as the time base, defining the same start time (T0) and target achievement time (Tend) for the change process of all three parameters. A smooth change trajectory curve is preset for each parameter (e.g., linear gradation, S-curve gradual in and out). These curves define the expected value at each moment between the current value and the target value. For the electrochromic layer, its driving circuit adjusts the output voltage in real time according to the target transmittance curve, and fine-tunes it by monitoring the actual transmittance through a built-in or associated optical sensor (optional).

[0070] When the projection imaging layer (such as PDLC) switches from a transparent state to a scattering state (first or second scattering state), the rate of increase in its haze matches the rate of deepening of the electrochromic layer's color. For example, when entering assisted driving mode, the PDLC layer begins to scatter and the electrochromic layer begins to color almost simultaneously, jointly constructing the projection background.

[0071] The brightness changes of the projection device are closely coupled with the above two factors. When the mode is activated (e.g., from normal to assisted driving): the timing of the brightness increase from zero or a low value should slightly lag behind or synchronize with the electrochromic layer and the projection imaging layer reaching the threshold state of "effective display," avoiding glaring bright spots when the background is not ready. When the mode is deactivated (e.g., from entertainment to normal): the brightness decay should complete before or simultaneously with the final stage of the electrochromic layer and the projection imaging layer returning to a high-transparency state, ensuring that when the line of sight returns to complete transparency, there is no residual projected light interference.

[0072] In this embodiment of the application, the augmented reality road condition image includes at least the outline of the road lane lines that enhances the visual appearance, the warning box that highlights the obstacles ahead, and the distance or collision time prompt information related to the vehicle.

[0073] In this embodiment, the generation of augmented reality road condition images relies on a real-time and sophisticated multi-sensor data processing and fusion pipeline. This process begins with the simultaneous acquisition of multi-source heterogeneous data, including visible light and infrared video streams from a forward-facing camera, point cloud data from millimeter-wave radar and lidar, and the vehicle's real-time speed and heading information. All these data streams are synchronized with precise timestamps and spatial coordinate calibration to ensure consistency in both the temporal and spatial domains.

[0074] Subsequently, deep learning-based environmental perception tasks are executed in parallel. The visual model analyzes the camera images to perform lane line detection and obstacle recognition and classification. At the same time, radar point cloud data is processed by clustering and tracking algorithms to obtain the precise 3D coordinates, size, speed, and trajectory of the target ahead.

[0075] The core step lies in multi-sensor data fusion. Visually identified bounding boxes are matched with 3D point cloud targets detected by radar, thus assigning precise distance and relative speed information to each identified object. Lane information is then constructed through coordinate back-projection and spatial modeling to form a stable and continuous 3D road structure representation. This fusion mechanism particularly enhances reliability in scenarios with limited visual perception. For example, when camera images are blurred due to rain or fog, the system can primarily rely on the robust geometric and motion information provided by radar to maintain the tracking and localization of key targets, thereby guiding the visual algorithm to perform targeted compensation.

[0076] Based on the fused and accurate environmental perception results, specific augmented reality layers are generated. This includes rendering glowing outlines based on the lane line spatial model to visually enhance or reconstruct the actual lane lines; dynamically generating a highlighted warning box that matches the 3D projection of each identified obstacle, with the box color and flashing mode differentiated according to the target category and threat level; and simultaneously calculating and overlaying quantitative prompts such as the relative distance to the vehicle or the estimated collision time for key obstacles in real time.

[0077] Finally, these augmented reality layers are pixel-wise composited with the visually enhanced base environment imagery to generate a complete augmented reality road condition video stream. The resolution, refresh rate, and color space of this video stream are matched to the specifications of the projection device, ensuring that the final projected image is clear, smooth, and has extremely low latency, thus providing drivers with a visual guidance interface that has higher information density, highlights key elements, and has clearer quantitative relationships.

[0078] In this embodiment of the application, the method further includes: S106, in the assisted driving mode, the projection brightness of the projection device is dynamically adjusted according to the real-time light intensity in the environmental perception information or the current coloring state of the electrochromic layer.

[0079] When the real-time light intensity is high, such as during a sunny day, ambient light may compete with the projected image, potentially washing away the displayed content. In this case, step S106 will correspondingly increase the projection brightness of the projection device to counteract the strong ambient light and ensure that enhanced information (such as outlines and warning boxes) remains clearly visible. Conversely, in low-light environments such as at night or in tunnels, the projection brightness will be appropriately reduced to prevent overly bright images from creating glare against a dark background, which could affect the driver's dark adaptation ability and cause visual fatigue.

[0080] When the electrochromic layer is in a deep tint, it already blocks more ambient light, providing a darker background for the projection. In this case, the projection brightness can be appropriately reduced to achieve a comfortable viewing experience and save energy. If the electrochromic layer is lightly tinted and the background is bright, a higher projection brightness is needed to maintain sufficient contrast. Therefore, the projection brightness adjustment logic needs to be linked in a closed loop with the real-time transmittance of the electrochromic layer.

[0081] By implementing step S106, intelligent matching of the projection display brightness with the external and internal optical environment is achieved. This brings multiple benefits: First, it significantly improves the visibility and readability of augmented reality information in various lighting scenarios, ensuring the effectiveness of driver assistance functions; second, by avoiding outputting overly bright images in dark environments, it minimizes visual interference and potential glare for the driver, improving the safety and comfort of human-computer interaction; and third, by supplying brightness on demand, it optimizes the energy efficiency of the projection device and the entire display system. This dynamic brightness adjustment is one of the key closed-loop control links that ensures the display interface in assisted driving mode maintains optimal performance under various complex ambient light conditions.

[0082] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes according to the claims of this application still fall within the scope of this application.

Claims

1. A display control method of a vehicle front windshield, characterized by, The front windshield comprises an electrochromic layer and a projection imaging layer, and the method comprises: identifying the current working mode of the vehicle based on the state information of the vehicle and the environment perception information; when the current working mode of the vehicle is the assisted driving mode, controlling the electrochromic layer to adjust to a coloring state suitable for enhanced display, and controlling the projection device to project an augmented reality road condition image generated based on multi-sensor data fusion to the projection imaging layer; when the current working mode of the vehicle is the entertainment mode, controlling the electrochromic layer to adjust to a dark state, and controlling the projection device to project entertainment media content to the projection imaging layer.

2. The display control method of a vehicle front windshield according to claim 1, characterized by, The method further comprises: when the current working mode of the vehicle is the normal driving mode, controlling the electrochromic layer to be in a high light transmission state, and controlling the projection imaging layer to remain in a non-projection active state.

3. The display control method of a vehicle front windshield according to claim 1, characterized by, The identification conditions of the assisted driving mode include: determining that the current driving environment is low visibility based on the environment perception information, and determining that the vehicle is in a non-parking driving state based on the state information; wherein the low visibility driving environment is triggered by at least one of the following conditions: the wiper is in a continuous working mode, the ambient light intensity is lower than a first threshold, the camera image features meet the rain and fog weather model, and there is a head-on vehicle high beam glare.

4. The display control method of a vehicle front windshield glass according to claim 1, characterized by, The identification conditions of the entertainment mode include: determining that the vehicle is in a safe parking state based on the state information, and receiving an entertainment function start instruction issued by the user.

5. The display control method of a vehicle front windshield glass according to claim 1, characterized by, The projection imaging layer is a polymer dispersed liquid crystal layer; when the current working mode of the vehicle is the assisted driving mode, the polymer dispersed liquid crystal layer is controlled to switch to a first scattering state to form a high-contrast interface; when the current working mode of the vehicle is the entertainment mode, the polymer dispersed liquid crystal layer is controlled to switch to a second scattering state to form a diffuse reflection projection interface; the light transmission rate corresponding to the second scattering state is greater than the light transmission rate corresponding to the first scattering state.

6. The display control method of a vehicle front windshield glass according to claim 1, characterized by, The method further comprises: During the mode switching process, the light transmission rate of the electrochromic layer, the optical state change of the projection imaging layer, and the brightness change of the projection device are synchronized and gradually changed to avoid visual discontinuity.

7. The display control method of a vehicle front windshield glass according to claim 1 or 3, characterized by, The augmented reality road condition image at least includes a contour line for visually enhancing the road lane line, a warning box for highlighting the front obstacle, and distance or collision time prompt information related to the vehicle.

8. The display control method of a vehicle front windshield glass according to claim 1, characterized by, The method further comprises: In the assisted driving mode, the projection brightness of the projection device is dynamically adjusted according to the real-time illumination intensity in the environment perception information or the current coloring state of the electrochromic layer.

9. An intelligent display control device for a vehicle front windshield, characterized by, The front windshield comprises an electrochromic layer and a projection imaging layer, and the method comprises: a mode identification module for identifying the current working mode of the vehicle based on the state information of the vehicle and the environment perception information; a first control module for controlling the electrochromic layer to adjust to a coloring state suitable for enhanced display when the current working mode of the vehicle is the assisted driving mode, and controlling the projection device to project an augmented reality road condition image generated based on multi-sensor data fusion to the projection imaging layer; A second control module is configured to control the electrochromic layer to adjust to a dark state and control the projection device to project entertainment media content to the projection imaging layer when the vehicle is currently in an entertainment mode.

10. A vehicle characterized by The intelligent display control device of the vehicle front windshield glass according to claim 9 is provided. The intelligent display control device of the vehicle front windshield glass according to claim 9 is provided.

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