Photochromic laser radar intelligent protective glasses and protective method thereof

Abstract

The invention discloses photochromic laser radar intelligent protective glasses and a protective method thereof. The protective glasses comprise a laser radar detection module, a control module and lenses. The laser radar detection module comprises three photodiodes arranged in front, on the left side and on the right side of the mirror frame and is used for synchronously collecting optical signals in different directions, converting the optical signals into electric signals and outputting the electric signals to the control module; the control module is arranged on the mirror frame, the input end of the control module is connected with the output end of the laser radar detection module, and the control module is used for receiving and analyzing the electric signal, identifying the intensity and incident direction of the laser radar signal in the electric signal and generating corresponding control voltage based on an identification result; the lenses are provided with photochromic coating layers, the control input ends of the lenses are connected with the output end of the control module, and the lenses are used for receiving the control voltage and responding to the control voltage to adjust the color depth of the photochromic coating layers in real time. Light signal detection, light environment analysis and laser signal isolation are carried out through the protective glasses, and the purpose of protecting eyes is achieved.

Description

Technical Field

[0001] The present invention relates to the field of laser protection technology, and more particularly to a photochromic laser radar intelligent protective glasses and a protection method thereof. Background Art

[0002] According to the survey results given by the American University Association for Radiation Protection, different wavelengths of light can penetrate our eyes to different depths. Light of 180nm-315nm and 3000nm-1mm can only reach the cornea; light of 315nm-400nm and 1400nm-3000nm can irradiate the cornea, but cannot pass through the lens; 400nm-1400nm laser can penetrate the cornea and lens and irradiate the retina.

[0003] However, most current automotive LiDAR systems use lasers in the 905nm band. This 905nm laser can penetrate the cornea and rest on the retina. This localized heating and accompanying light absorption can cause retinal damage. While the eye's pupil and blinking mechanisms typically protect the retina from strong external light, 905nm LiDAR is invisible, making these protective mechanisms ineffective.

[0004] In the context of fully intelligent driving in the future, when waiting for traffic lights at traffic intersections, there will be more than a dozen or even twenty cars stopped at the intersection waiting for traffic lights. The time that pedestrians on the road are exposed to laser radar pulses will be greatly extended, which will cause serious damage to the eyes, especially for children and adolescents whose eyes are still in the development stage and the retina is most fragile. Laser radar may cause irreversible damage.

[0005] Therefore, how to provide a smarter protective glasses to isolate the light emitted by the lidar is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a photochromic lidar intelligent protective glasses and a protection method thereof, which filters the photoelectric signal, suppresses the interference of ambient light, obtains the lidar signal strength and direction, and adjusts the color depth of the photochromic coating layer in real time to attenuate the incident lidar signal and protect the eyes.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a photochromic laser radar smart protective glasses, comprising: a laser radar detection module, a control module and lenses;

[0009] The laser radar detection module includes three photodiodes placed in front, on the left and on the right of the frame, which are used to synchronously collect light signals from different directions, convert them into electrical signals and output them to the control module;

[0010] The control module is provided on the mirror frame, and its input end is connected to the output end of the laser radar detection module, and is used to receive and analyze the electrical signal, identify the intensity and incident direction of the laser radar signal in the electrical signal, and generate a corresponding control voltage based on the identification result;

[0011] The lens has a photochromic coating layer, and the control input end of the lens is connected to the output end of the control module for receiving the control voltage and adjusting the color depth of the photochromic coating layer in real time in response to the control voltage.

[0012] Furthermore, the front end of the photodiode has a multi-layer dielectric interference coating for shielding visible light and ultraviolet light.

[0013] Furthermore, the optical signal includes a lidar signal and an ambient light signal.

[0014] Furthermore, the analog signal processing unit receives the electrical signal, and the analog signal processing unit includes a transimpedance amplifier and a low-pass filter; the transimpedance amplifier converts the current signal into a voltage signal, and the low-pass filter filters out high-frequency noise in the voltage signal to obtain a valid electrical signal;

[0015] The analog-to-digital conversion unit is used to convert the effective electrical signal into a digital signal;

[0016] The digital signal processing unit is used to perform spatial differentiation on the digital signal, suppress the common-mode influence of the ambient light signal on the lidar signal, and obtain a reconstructed signal.

[0017] In a second aspect, the present invention provides a protective method for photochromic laser radar smart protective glasses, using the photochromic laser radar smart protective glasses as described in any one of the first aspects, comprising the following steps:

[0018] The three photodiodes of the laser radar detection module collect light signals from different directions in real time, convert them into electrical signals and output them to the control module;

[0019] receiving and analyzing the electrical signal through the control module, identifying the intensity and incident direction of the laser radar signal in the electrical signal, and generating a corresponding control voltage based on the identification result;

[0020] The control voltage is received through the photochromic coating layer of the lens, and the color depth of the photochromic coating layer is adjusted in real time in response to the control voltage to attenuate the incident lidar signal.

[0021] Furthermore, the control module receives and analyzes the electrical signal, specifically including:

[0022] The analog signal processing unit of the control module receives the electrical signal, converts the current signal into a voltage signal through a transimpedance amplifier, and filters out high-frequency noise through a low-pass filter to obtain a valid electrical signal;

[0023] After the analog-to-digital conversion unit performs analog-to-digital conversion on the effective electrical signal, the digital signal is input into the digital signal processing unit for spatial differentiation to suppress the common-mode influence of the ambient light signal on the laser radar signal and obtain a reconstructed signal.

[0024] Furthermore, the digital signal is input into a digital signal processing unit for spatial differentiation to suppress the common-mode influence of the ambient light signal on the lidar signal to obtain a reconstructed signal; specifically including:

[0025] The digital signal is input into the digital signal processing unit to perform signal differential calculation to suppress the common-mode influence of the ambient light signal on the lidar signal, thereby obtaining the forward differential signal and the lateral differential signal, and then obtaining the reconstructed signal;

[0026] The forward differential signal is expressed as follows:

[0027]

[0028] The lateral differential signal is expressed as follows:

[0029] S diff,lat (t)=|S left (t)-S right (t)|

[0030] The recombination signal is expressed as follows:

[0031]

[0032] Among them, S front (t) represents the digital signal corresponding to the photodiode in front of the glasses at the current moment; S left (t) represents the digital signal corresponding to the photodiode on the left side of the glasses at the current moment; S right (t) represents the digital signal corresponding to the photodiode on the right side of the glasses at the current moment; λ(t) represents the environment adaptation weight factor.

[0033] Furthermore, the environment adaptation weight factor λ(t) is expressed as follows:

[0034] λ(t)=λ0·(1-β·△ lat (t))

[0035]

[0036] Among them, λ0 is the initial weight reference; β is the sensitivity coefficient; Δ lat (t) is the lateral asymmetry index; ε is a small positive number.

[0037] Furthermore, the intensity of the laser radar signal in the recombined signal is calculated by:

[0038] A sliding window method is used to calculate the ambient light signal and the lidar signal; the formula is expressed as:

[0039]

[0040] R(t)=S value (t)-B(t)

[0041] Among them, B(t) represents the estimated value of the ambient light intensity at the current moment; N is the number of sampling points back to the current moment, i is the value of the sampling point; S value (ti) represents the reconstructed signal by looking back i sampling points at the current moment; R(t) represents the intensity of the lidar signal at the current moment.

[0042] Furthermore, generating a corresponding control voltage based on the recognition result specifically includes:

[0043] An exponential decay function is used to generate a corresponding control voltage based on the intensity of the obtained lidar signal; the formula is:

[0044] T(R)=T min +(T max -T min )·exp(-k·R(t))

[0045] Among them, T(R) represents the control voltage, k represents the adjustment coefficient, T min With T max Represent the lower and upper limits of the control voltage respectively.

[0046] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a photochromic lidar smart protective glasses and a protective method thereof, which has the following beneficial effects:

[0047] The present invention effectively detects laser signals in three directions by installing photodiodes in all directions, ensuring that any laser that may enter the range of the human eye is fully identified and isolated, thereby playing a role in protecting the human eye.

[0048] The hardware utilizes a fixed-wavelength, multi-layer dielectric infrared interference coating to eliminate most external light interference on the photodiode. Spatial differentiation during data calculation suppresses common-mode effects, accurately determining the intensity of the LiDAR signal, enabling the protective glasses to more accurately protect the wearer's eyes. The photochromic coating intelligently adjusts color depth in real time based on the LiDAR signal's intensity, accurately attenuating incoming LiDAR signals and protecting the wearer's eyes.

[0049] The smart protective glasses of this invention not only maintain a good visual field in daily life but also quickly darken to provide protection upon detecting a LiDAR radar, significantly expanding their application scenarios. They can be used not only in well-lit environments like outdoors at noon but also in relatively dark indoor environments, offering greater diversity in application scenarios.

[0050] The present invention can not only identify the intensity of the lidar signal, but also estimate its incident direction, and then locate the light source of the lidar signal, which will be helpful for the future upgrade application of intelligent protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0052] Figure 1 A schematic structural diagram of photochromic lidar smart protective glasses provided in an embodiment of the present invention.

[0053] Figure 2 A flow chart of a protective method for photochromic lidar smart protective glasses provided in an embodiment of the present invention.

[0054] Figure 3 A schematic diagram of the angle of the laser source direction provided in an embodiment of the present invention.

[0055] Figure 4 This is a comparison chart of the spectra before and after the protective glasses provided by an embodiment of the present invention isolate laser light. DETAILED DESCRIPTION

[0056] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0057] Before introducing the embodiments of the present invention, it should be clarified that light is divided into visible light (400nm-780nm), ultraviolet light (300nm-400nm) and near-infrared light (780nm-2500nm) according to its wavelength, and the pulse laser of lidar belongs to near-infrared light.

[0058] Example 1

[0059] The embodiment of the present invention discloses a photochromic laser radar smart protective glasses, referring to Figure 1 As shown, it includes: a lidar detection module, a control module and a lens;

[0060] The LiDAR detection module includes three photodiodes placed in front, on the left, and on the right side of the frame, which are used to synchronously collect light signals from different directions, convert them into electrical signals and output them to the control module;

[0061] The control module is set on the frame, and its input end is connected to the output end of the laser radar detection module. It is used to receive and analyze the electrical signal, identify the intensity and incident direction of the laser radar signal in the electrical signal, and generate a corresponding control voltage based on the identification result;

[0062] The lens has a photochromic coating layer, and the control input end of the lens is connected to the output end of the control module for receiving a control voltage and adjusting the color depth of the photochromic coating layer in real time in response to the control voltage.

[0063] The photochromic laser radar smart protective glasses of this embodiment include a laser radar detection module, a control module, lenses, a power supply, and a frame.

[0064] The LiDAR detection module of this embodiment serves as the information input terminal, responsible for detecting laser signals in the surrounding environment. It is mainly composed of three photodiodes distributed in the front, left, and right sides of the glasses. These photodiodes are fixed to the frame and face different directions to capture possible LiDAR signals in all directions. A multi-layer dielectric interference infrared filter coating is installed on the front of each photodiode to shield unnecessary light bands, ensuring that only light signals in the wavelength range of 800nm ​​to 1100nm can pass through.

[0065] The photodiode of this embodiment can generate a current corresponding to the intensity of the light it receives. When light strikes the photodiode, the energy of the photons is absorbed by the semiconductor material, generating electron-hole pairs. Under the action of an applied voltage, these electrons and holes move in opposite directions, forming a photocurrent. The magnitude of the photocurrent is proportional to the intensity of the irradiated light; that is, the stronger the light, the greater the photocurrent generated.

[0066] The optical signal of this embodiment includes a lidar signal and an ambient light signal. There are significant differences between the lidar signal and the natural ambient light in multiple dimensions. These differences provide a theoretical basis for signal detection and interference suppression. First, in terms of spatial characteristics, the lidar signal is highly directional and can only be effectively detected within a specific range of incident angles. In contrast, the ambient light is relatively uniformly distributed in space and does not change significantly with direction. Especially in outdoor or scattered environments, its impact on multi-directional detectors is highly similar. In addition, in terms of frequency characteristics, the frequency of the lidar is usually around 912nm and has a clear spectral structure. In contrast, ambient light (including sunlight and artificial lighting) covers a wide band from visible light to near-infrared. Although it has a certain radiation around 912nm, the power density is relatively dispersed. Based on this difference, this embodiment significantly suppresses background radiation in non-912nm bands by introducing a multi-layer dielectric interference coating at the front end of the photodiode, achieving optical pre-filtering of the lidar signal and reducing ambient light interference at the source.

[0067] The control module can be positioned according to design requirements. In this embodiment, it is located inside the frame, near the ear, for easy concealment while ensuring comfortable wearing. It primarily processes and analyzes data received from the LiDAR detection module and generates corresponding control instructions based on the analysis results. The control module is connected to the LiDAR detection module via wires, receiving photoelectric signals from the individual photodiodes. It is also connected to the lens via another set of wires to issue color change instructions.

[0068] The control module of this embodiment includes an analog signal processing unit, an analog-to-digital conversion unit, and a digital signal processing unit, which are connected in sequence; wherein the analog signal processing unit includes a transimpedance amplifier and a low-pass filter. After the photodiode converts the received light signal into a current signal, these weak current signals must first be converted into voltage signals through a transimpedance amplifier. This is because the subsequent electronic circuit can more easily process voltage signals. In order to remove high-frequency noise and improve signal quality, the voltage signal of this embodiment is then processed by a low-pass filter.

[0069] The voltage signal after analog signal processing will be sent to the analog-to-digital converter of this embodiment. Here, the continuous analog voltage signal is converted into a digital signal to facilitate subsequent digital processing. The digital signal processing unit of this embodiment adopts a single-chip microcomputer, which is responsible for further processing the received digital signal. This includes but is not limited to algorithmic processes such as synchronous sampling, differential calculation, background modeling, and pulse feature determination. This unit ultimately determines whether it is necessary to send a color change instruction to the electrochromic lens. The single-chip microcomputer of this embodiment integrates functions such as a central processing unit (CPU), memory, and input and output interfaces. It can efficiently process data from the analog-to-digital converter and make corresponding decisions.

[0070] The lenses utilize electrochromic technology and feature a photochromic coating that adjusts their light transmittance based on an external control voltage. Under normal circumstances, the lenses maintain high transparency, ensuring a clear field of vision for the wearer. However, if the control module detects a potentially hazardous LiDAR signal, it immediately instructs the lenses to darken accordingly, effectively shielding the wearer from harmful light. The lenses are embedded directly into the frame and connected to the control module via a thin, flexible cable, ensuring minimal impact on appearance and user experience.

[0071] The power supply, the source of energy for the entire system, utilizes a small rechargeable battery. In this embodiment, it's located discreetly inside the temple, close to the ear. This makes it convenient for users to carry and charge while minimizing the overall weight of the glasses. The power supply is connected to the control module via built-in circuitry, providing continuous and stable power.

[0072] As the carrier of all components, the frame must not only be aesthetically pleasing but also possess sufficient strength to protect the delicate electronic components within. The frame of this embodiment takes full account of ergonomic principles, ensuring comfort even after prolonged wear. Furthermore, the frame features appropriate openings and channels for routing wires and other necessary connecting components, enhancing the overall appearance of the device.

[0073] After the power is turned on, the photoelectric detection modules distributed in the left, front, and right directions continuously detect external light signals and import the converted photoelectric signals into the control module through the signal line. The control module records and analyzes the detected photoelectric signals in real time. When there is a turned-on lidar in the vicinity, the lidar detection module will detect a special signal and transmit this information to the control module, driving it to issue a "darkening" instruction to the drive circuit of the photochromic coating layer of the lens, making the color of the glass darker, which plays a role in isolating external lasers. In this way, after the external light passes through the darkened glasses, the laser signal is effectively eliminated, thereby protecting the eyes.

[0074] Example 2

[0075] The embodiment of the present invention discloses a protective method for photochromic laser radar smart protective glasses, using the photochromic laser radar smart protective glasses as described in any one of the embodiments 1, referring to Figure 2 As shown, the following steps are included:

[0076] The three photodiodes of the laser radar detection module collect light signals from different directions in real time, convert them into electrical signals and output them to the control module;

[0077] The control module receives and analyzes the electrical signal, identifies the intensity and incident direction of the lidar signal in the electrical signal, and generates a corresponding control voltage based on the identification result;

[0078] The photochromic coating layer of the lens receives a control voltage and adjusts the color depth of the photochromic coating layer in real time in response to the control voltage to attenuate the incident lidar signal.

[0079] This embodiment is applied in an urban environment where intelligent driving vehicles are widely available. A family and their children are waiting to cross the road at an intersection. Nearby are more than a dozen smart cars equipped with lidar systems, which are using lidar to scan the surrounding environment to ensure safe driving. Due to traffic lights, even during brief stops, vehicles continue to operate their lidar systems, periodically emitting invisible laser pulses in the 905nm band.

[0080] Adults have certain protective mechanisms in their eyes, such as the blink reflex and pupil constriction, that can mitigate retinal damage from strong light. However, children's eyes are still developing, and their retinas are particularly fragile and sensitive to the near-infrared lasers emitted by lidar. Prolonged exposure to these conditions can cause retinal damage or even permanent vision loss.

[0081] In order to protect the child's eyes from the influence of the laser radar, the parents let the child wear the photochromic laser radar smart protective glasses designed based on this embodiment 1.

[0082] When no LiDAR signal is detected, the protective glasses maintain high light transmittance, ensuring that children can clearly see their surroundings and enjoy the visual experience brought by natural light. Once the photoelectric detection module on the protective glasses detects a LiDAR signal from a nearby vehicle, the control module immediately analyzes whether the signal exceeds the preset safety threshold. If a threat is confirmed, the control module sends a command to the electrochromic lenses via wires, causing them to darken their color, thereby blocking harmful laser light from entering the eyes. Once the LiDAR signal disappears or its intensity drops below a safe level, the control system adjusts the voltage to restore the lenses to transparency, allowing the child to continue to observe the external environment normally.

[0083] The implementation process of this embodiment is described in detail below.

[0084] First, the three photodiodes of the lidar detection module collect light signals from different directions in real time, convert them into electrical signals and output them to the control module.

[0085] Because the light beam emitted by a LiDAR is highly directional, its energy is concentrated along a specific propagation path; while ambient light is evenly distributed in space and highly isotropic, multiple detectors arranged in different directions will receive background light of similar intensity. Based on this characteristic, this embodiment arranges photodiodes in the forward and left and right directions to synchronously sample light signals from different directions. By comparing the relative intensity differences between the channels, directional burst light signals can be identified, further eliminating the spatial common-mode ambient light background and retaining only the narrow-beam signal components consistent with the LiDAR.

[0086] Secondly, the control module receives and analyzes the collected light signal, identifies the intensity and incident direction of the lidar signal in the light signal, and generates a corresponding control voltage based on the identification result.

[0087] The analog signal processing unit of the control module in this embodiment receives the current signal from the photodiode and converts it into a voltage signal through a transimpedance amplifier. A low-pass filter processes the voltage signal generated by the previous stage to filter out high-frequency noise, thereby generating a valid electrical signal. The analog-to-digital conversion unit converts the valid electrical signal into a digital form and then inputs the digital signal into a single-chip microcontroller for spatial differentiation, suppressing the common-mode influence of the ambient light signal on the lidar signal to generate a reconstructed signal.

[0088] The spatial difference processing process performed by the single chip microcomputer in this embodiment specifically includes:

[0089] 1. Forward differential channel.

[0090] For the forward photodiode, the side photodiode is needed to realize the signal differential calculation. In this embodiment, the average value of the detection of the two side photodiodes is selected to reflect the average ambient light intensity, and the side light intensity is subtracted from the forward light intensity signal to obtain the forward differential signal:

[0091]

[0092] Among them, S front (t) represents the digital signal corresponding to the photodiode in front of the glasses at the current moment; S left (t) represents the digital signal corresponding to the photodiode on the left side of the glasses at the current moment; S right(t) represents the digital signal corresponding to the photodiode on the right side of the glasses at the current moment; λ(t) represents the weighting factor, which is adaptively adjusted to the environment. When the lateral light intensity is relatively balanced and the background interference is stable, increasing λ can better eliminate interference; when the difference between the left and right light is large or the laser intensity is incident at an oblique angle, reducing λ can avoid excessive cancellation of the useful signal. In this embodiment, the range of λ is [0.5, 1.5].

[0093] In this embodiment, the lateral asymmetry index is defined as Δlat(t), which is expressed as follows:

[0094]

[0095] Among them, ε is a small positive number used to avoid the denominator being zero, so the environment adaptive adjustment function is:

[0096] λ(t)=λ0·(1-β·△ lat (t))

[0097] Wherein, λ0 is the initial weight reference, which is set to 1.0 in this embodiment; β is the sensitivity coefficient, and the output range of λ(t) is [0.5, 1.5].

[0098] Finally, the weight expression for the differential channel is:

[0099]

[0100] 2. Lateral differential channel.

[0101] Since the ambient light levels detected by the two lateral photodiodes are substantially similar, this embodiment uses the difference calculation method by subtracting the detection values ​​of the two lateral photodiodes from each other. In this embodiment, the left side is selected as the positive direction:

[0102] S diff,lat (t)=|S left (t)-S right (t)|

[0103] Through the above processing, the differential signals in the forward and side directions effectively suppress the common-mode influence of ambient light on each channel, and also retain the directional signal component, which is beneficial for the subsequent analysis of the laser source direction.

[0104] 3. Recombination signal.

[0105] Since the LiDAR affects both the forward and side photoelectric signals at certain angles, it is necessary to consider both the forward differential channel results and the side differential channel results. In this embodiment, the root mean square is selected as the reconstructed signal, including the LiDAR signal and the ambient light signal. The formula is as follows:

[0106]

[0107] This embodiment identifies the intensity and incident direction of lidar signals in optical signals, specifically including:

[0108] Determine the ambient light signal, and use a sliding window to construct an estimate of the ambient light signal:

[0109]

[0110] This embodiment backtracks N sampling points forward from the original signal S value (t) at the current time t, and takes its average value as the estimated value B(t) of the ambient light intensity at the current time, which is used to smooth out the short-term mutation part in the signal and retain the background trend.

[0111] This embodiment needs to further analyze the estimated value B(t) of the ambient light intensity. The estimated value B(t) of the ambient light intensity is calculated iteratively based on real-time data. Since there will not always be a lidar in the environment or there is no lidar in the initial state, the estimated value B(t) of the ambient light intensity should be relatively stable and will not mutate. If a mutation occurs, it indicates that there is a laser light source at that moment. At this time, subtract the estimated ambient light B(t) from the original signal S value (t) at the current time, so as to extract the signal component that is inconsistent with the environment and is of a mutant type, and obtain the lidar signal R(t):

[0112] R(t) = S value (t) - B(t)

[0113] This embodiment determines whether there is a laser light source through R(t). Specifically, during the use of the glasses, it is required that there is no lidar signal in the initial state of the environment. When the environment changes, if the residual signal R(t) > 0, it indicates that the light intensity in a specific band in the environment is increasing. To identify whether it is environmental light interference or laser light intensity, define the laser detection threshold as a. When R(t) > a, it is determined that there is a laser light source at the current position. At this time, the value of B(t) should retain the estimated value of the ambient light intensity before iteration, which is used for the calculation of the ambient reference quantity of the lidar signal. At the same time, adjust the color depth of the variable-color glass according to the magnitude of R(t). Define the de-laser detection threshold as b. When the residual signal R(t) < b, it indicates that the light intensity in a specific band in the environment has decreased to a negligible level, and the iteration of the ambient light B(t) is restored.

[0114] This embodiment also conducts an analysis of the laser source direction. Referring to Figure 3 ?As shown, assume that the included angle of the laser source direction is θ (0° << θ << 180°), and the laser pulse light intensity is R0.

[0115] Since the ambient light intensity is relatively weak compared to the LiDAR signal, it can be ignored in the angle calculation. The laser source is generally far away, and the distance between the photodiodes of the three channels of the glasses is negligible compared to the distance of the laser source. Therefore, it can be assumed that the laser is detected by each photodiode of the glasses at the same angle and power density. At this time, the laser pulse intensity detected by the front photodiode and the side photodiode are:

[0116] S diff,front =R0sinθ

[0117] S diff,lat =R0cosθ

[0118] In the range of 0°<<θ<<180°, S diff,front Always greater than 0, indicating that it can receive the user's forward laser signal, S diff,lat The positive or negative value of S depends on the left or right source direction of the laser. If the laser comes from the left or left front, S diff,lat is positive; if the laser comes from the right or right front, then S diff,lat is negative.

[0119] Therefore, the angle calculation formula can be obtained as:

[0120]

[0121] Through the above operations, not only the laser light source identification can be achieved, but also the laser light source positioning can be achieved.

[0122] This embodiment generates a corresponding control voltage based on the identified laser radar signal strength; specifically includes:

[0123] This embodiment uses an exponential decay function to generate a corresponding control voltage T based on the real-time intensity R(t) of the sensed laser radar signal to drive the voltage-controlled electrochromic coating and achieve nonlinear dynamic adjustment of transmittance. The mapping relationship between the control voltage and the laser intensity is as follows:

[0124] T(R)=T min +(T max -T min )·exp(-k·R(t))

[0125] Where, T(R) represents the control voltage in volts (V); R(t) represents the laser intensity detected by the photoelectric sensor at time t; k is the adjustment coefficient, which reflects the system's response sensitivity to the laser intensity; T min With T max They are the lower and upper limits of the control voltage, respectively, with typical values ​​of 0.7V and 2.5V.

[0126] In this embodiment, the infrared filter coating used is a multilayer dielectric interference-type, pressure-controlled electrochromic film, whose light transmission characteristics can be finely adjusted by applying an analog control voltage. When the external control voltage varies between 0.7V and 2.5V, the coating's transmittance exhibits a reversible and controllable nonlinear change, gradually transitioning from a high-transmittance state to a low-transmittance state, thereby achieving varying degrees of optical blocking of the infrared laser emitted by the lidar.

[0127] Finally, the control voltage is received through the photochromic coating layer of the lens, and the color depth of the photochromic coating layer is adjusted in real time in response to the control voltage to attenuate the incident lidar signal.

[0128] The control voltage function of this embodiment enables the system to automatically output a higher control voltage (close to T max ), so that the electrochromic film is in a high light transmittance state; and when the laser intensity increases, the control voltage decreases in the form of exponential decay, quickly driving the coating into a low light transmittance deep color change state, thereby effectively shielding the laser.

[0129] This exponential nonlinear adjustment mechanism has better dynamic range compression capability and response sensitivity than linear mapping. It can not only quickly suppress strong lasers, but also maintain natural visual effects under safe lighting conditions, thereby improving the system's intelligent protection capabilities and wearing comfort.

[0130] This embodiment compares the wearing and not wearing of the protective glasses of the present invention. The comparison results are shown in Table 1. Figure 4 The comparison of the spectra before and after the laser is isolated is shown in Table 1.

[0131] data Before quarantine After isolation Rate of change Radiosity <![CDATA[33.2uW / cm 2 ]]> <![CDATA[3.5uW / cm 2 ]]> -89％ Near-infrared radiation <![CDATA[10.2uW / cm 2 ]]> <![CDATA[0.4uW / cm 2 ]]> -96％ Peak wavelength 912nm 568nm /

[0132] Table 1 Comparison of data before and after glasses isolation laser

[0133] Data shows that after being isolated by the glasses, the radiation intensity of the light passing through them is significantly reduced, with near-infrared radiation, which represents the intensity of the laser signal, dropping by 96%. Analyzing the wavelength of the light, the infrared signal in the laser band is also essentially eliminated after the glasses are isolated, and the isolated light is mainly visible light. These data strongly prove that protective glasses can effectively isolate lasers.

[0134] Traditional protective glasses use fixed dark lenses, which can affect daily use and limit product usage. The photochromic LiDAR children's protective glasses of the present invention use more effective detection methods. Not only can they maintain a good field of view in daily life, but they can also quickly darken to provide protection after identifying the LiDAR. This approach can greatly broaden the application scenarios of protective glasses. These protective glasses can be used not only in well-lit environments such as outdoors at noon, but also in relatively dark indoor environments, with greater application diversity.

[0135] The laser radar children's protective glasses of the present invention are equipped with photoelectric detection modules on the front, left and right sides of the frame, so that laser signals in three directions can be effectively detected, thereby ensuring that any laser that may enter the range of the human eye is fully identified and isolated, thereby playing a role in protecting the human eye.

[0136] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0137] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A photochromic laser radar smart protective glasses, characterized in that: include: LiDAR detection module, control module and lenses; The laser radar detection module includes three photodiodes placed in front, on the left and on the right of the frame, which are used to synchronously collect light signals from different directions, convert them into electrical signals and output them to the control module; The control module is provided on the mirror frame, and its input end is connected to the output end of the laser radar detection module, and is used to receive and analyze the electrical signal, identify the intensity and incident direction of the laser radar signal in the electrical signal, and generate a corresponding control voltage based on the identification result; The lens has a photochromic coating layer, and the control input end of the lens is connected to the output end of the control module for receiving the control voltage and adjusting the color depth of the photochromic coating layer in real time in response to the control voltage.

2. The photochromic laser radar smart protective glasses according to claim 1, characterized in that: The front end of the photodiode is provided with a multi-layer dielectric interference coating for shielding visible light and ultraviolet rays.

3. The photochromic laser radar smart protective glasses according to claim 1, characterized in that: The optical signal includes a lidar signal and an ambient light signal.

4. The photochromic laser radar smart protective glasses according to claim 1, characterized in that: The control module includes an analog signal processing unit, an analog-to-digital conversion unit, and a digital signal processing unit connected in sequence; The analog signal processing unit receives the electrical signal, and the analog signal processing unit includes a transimpedance amplifier and a low-pass filter; the transimpedance amplifier converts the current signal into a voltage signal, and the low-pass filter filters out high-frequency noise in the voltage signal to obtain a valid electrical signal; The analog-to-digital conversion unit is used to convert the effective electrical signal into a digital signal; The digital signal processing unit is used to perform spatial differentiation on the digital signal, suppress the common-mode influence of the ambient light signal on the lidar signal, and obtain a reconstructed signal.

5. A protective method for photochromic laser radar smart protective glasses, using the photochromic laser radar smart protective glasses according to any one of claims 1 to 4, characterized in that: The following steps are involved: The three photodiodes of the laser radar detection module collect light signals from different directions in real time, convert them into electrical signals and output them to the control module; receiving and analyzing the electrical signal through the control module, identifying the intensity and incident direction of the laser radar signal in the electrical signal, and generating a corresponding control voltage based on the identification result; The control voltage is received through the photochromic coating layer of the lens, and the color depth of the photochromic coating layer is adjusted in real time in response to the control voltage to attenuate the incident lidar signal.

6. The protective method for photochromic laser radar smart protective glasses according to claim 5, characterized in that: The control module receives and analyzes the electrical signal, specifically including: The analog signal processing unit of the control module receives the electrical signal, converts the current signal into a voltage signal through a transimpedance amplifier, and filters out high-frequency noise through a low-pass filter to obtain a valid electrical signal; After the analog-to-digital conversion unit performs analog-to-digital conversion on the effective electrical signal, the digital signal is input into the digital signal processing unit for spatial differentiation to suppress the common-mode influence of the ambient light signal on the laser radar signal and obtain a reconstructed signal.

7. The protective method for photochromic laser radar smart protective glasses according to claim 6, characterized in that: The digital signal is input into the digital signal processing unit for spatial differentiation, suppressing the common mode influence of the ambient light signal on the laser radar signal, and obtaining a reconstructed signal; specifically comprising: The digital signal is input into the digital signal processing unit to perform signal differential calculation to suppress the common-mode influence of the ambient light signal on the lidar signal, thereby obtaining the forward differential signal and the lateral differential signal, and then obtaining the reconstructed signal; The forward differential signal is expressed as follows: The lateral differential signal is expressed as follows: S diff,lat (t)=|S left (t)-S right (t)| The recombination signal is expressed as follows: Among them, S front (t) represents the digital signal corresponding to the photodiode in front of the glasses at the current moment; S left (t) represents the digital signal corresponding to the photodiode on the left side of the glasses at the current moment; S right (t) represents the digital signal corresponding to the photodiode on the right side of the glasses at the current moment; λ(t) represents the environment adaptation weight factor.

8. The protective method for photochromic laser radar smart protective glasses according to claim 7, characterized in that: The environment adaptation weight factor λ(t) is expressed as follows: λ(t)=λ0·(1-β·Δ lat (t)) Among them, λ0 is the initial weight reference; β is the sensitivity coefficient; Δ lat (t) is the lateral asymmetry index; ε is a small positive number.

9. The protective method for photochromic laser radar smart protective glasses according to claim 7, characterized in that: The intensity of the laser radar signal in the recombined signal is calculated by: A sliding window method is used to calculate the ambient light signal and the lidar signal; the formula is expressed as: R(t)=S value (t)-B(t) Among them, B(t) represents the estimated value of the ambient light intensity at the current moment; N is the number of sampling points back to the current moment, i is the value of the sampling point; S value (ti) represents the reconstructed signal by looking back i sampling points at the current moment; R(t) represents the intensity of the lidar signal at the current moment.

10. The protective method for photochromic laser radar smart protective glasses according to claim 9, characterized in that: Generating a corresponding control voltage based on the recognition result specifically includes: An exponential decay function is used to generate a corresponding control voltage based on the intensity of the obtained lidar signal; the formula is: T(R)=T min +(T max -T min )·exp(-k·R(t)) Among them, T(R) represents the control voltage, k represents the adjustment coefficient, T min With T max Represent the lower and upper limits of the control voltage respectively.

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