Laser speckle suppression device and control method thereof

Abstract

The application relates to the technical field of optical elements, and provides a laser speckle suppression device and a control method thereof. The device comprises a support, a vibration execution assembly, an electromagnetic execution assembly and a data acquisition and processing assembly. The vibration execution assembly is located above the support and the electromagnetic execution assembly. The electromagnetic execution assembly is fixedly installed on the support and is used for driving the vibration execution assembly to swing in four directions of up, down, left and right through an alternating magnetic field, and laser speckle is suppressed by driving the glass sheet to reciprocatingly swing. The data acquisition and processing assembly is used for acquiring speckle imaging data and vibration state data, and adjusting the alternating magnetic field characteristics of the electromagnetic execution assembly according to the speckle imaging data and the vibration state data, so as to realize dynamic optimization of imaging effect. The alternating magnetic field characteristics can be dynamically adjusted based on the speckle imaging and the vibration state data, so as to adapt to different laser powers and wavelengths, thereby improving the working condition adaptability of the product and the laser speckle suppression performance.

Description

Technical Field

[0001] This invention relates to the field of optical element technology, and more specifically, to a laser speckle suppression device and its control method. Background Technology

[0002] Lasers possess high monochromaticity and high coherence. When a laser beam illuminates an optical element, imaging surface, or rough medium surface, different reflected / transmitted beams coherently superimpose, forming laser speckle with alternating bright and dark areas. Speckle severely degrades the image clarity and visual uniformity of laser projection, laser television, and industrial laser imaging equipment. Therefore, laser speckle suppression is one of the core technologies in the field of laser display.

[0003] Currently, mainstream speckle suppression technologies are divided into three main categories: acousto-optic modulation, phase modulation, and mechanical vibration suppression. Among them, mechanical vibration speckle suppression devices use an electromagnetic drive structure to drive an optical glass plate to oscillate at high frequency, disrupting the coherence path of the laser beam and thus eliminating speckle.

[0004] Traditional devices typically have fixed amplitude and frequency of alternating current in the coil after leaving the factory, and the strength of the alternating magnetic field cannot be adjusted. When the power and wavelength of the laser source change, the amplitude and frequency of the glass plate vibration are prone to problems such as reduced speckle suppression effect and screen flicker because they cannot match the optimal speckle suppression conditions.

[0005] Therefore, it is necessary to develop a technology that can dynamically adjust the alternating current characteristics of a coil based on speckle imaging and vibration conditions. Summary of the Invention

[0006] To improve laser speckle suppression performance, this invention provides a laser speckle suppression device and its control method, the specific technical solution of which is as follows: A laser speckle suppression device includes a support, a vibration actuator, an electromagnetic actuator, and a data acquisition and processing component. The vibration actuator is located on the support and the electromagnetic actuator. The electromagnetic actuator is fixedly mounted on the support and is used to drive the vibration actuator to swing in four directions (up, down, left, and right) through an alternating magnetic field, thereby suppressing laser speckle by causing a glass plate to swing back and forth. The data acquisition and processing component is used to acquire speckle imaging data and vibration state data, and adjust the alternating magnetic field characteristics of the electromagnetic actuator based on the speckle imaging data and vibration state data to achieve dynamic optimization of the imaging effect.

[0007] The laser speckle suppression device acquires speckle imaging data and vibration state data, and adjusts the alternating magnetic field characteristics of the electromagnetic actuator based on the speckle imaging data and vibration state data. It can dynamically adjust the alternating magnetic field characteristics based on speckle imaging and vibration state data to adapt to different laser powers and wavelengths, thereby improving the product's adaptability to operating conditions and laser speckle suppression performance, and avoiding problems such as decreased speckle suppression effect and screen flicker caused by the glass plate vibration amplitude and frequency not matching the optimal speckle suppression conditions.

[0008] Preferably, the data acquisition and processing component is further configured to gradually reduce the upper limit of the output of the coil alternating current parameter when the real-time deformation of the spring is greater than the rated working deformation of the spring and the real-time deformation of the spring gradually approaches the fatigue safety limit deformation of the spring, and gradually increase the upper limit of the output of the coil alternating current parameter when the real-time deformation of the spring is less than the rated working deformation of the spring and the real-time deformation of the spring gradually moves away from the fatigue safety limit deformation of the spring. The vibration state data includes the real-time deformation of the spring sheet, the rated working deformation of the spring sheet, and the fatigue safety limit deformation of the spring sheet, which are preset in the data processing and control module.

[0009] Preferably, the data acquisition and processing component obtains the service time of the spring clip, calculates the cumulative fatigue damage of the spring clip that is positively correlated with the service time, and corrects the initial fatigue safety limit deformation of the spring clip based on the cumulative fatigue damage of the spring clip to obtain the fatigue safety limit deformation of the spring clip that is negatively correlated with the cumulative fatigue damage of the spring clip.

[0010] A method for controlling a laser speckle suppression device, applied to the laser speckle suppression device as described above, includes the following steps: S1, acquire speckle imaging data and vibration state data; S2 adjusts the alternating magnetic field characteristics of the electromagnetic actuator based on speckle imaging data and vibration state data to achieve dynamic optimization of imaging effect.

[0011] Preferably, the laser speckle suppression device control method further includes the following steps: S3, obtain the real-time deformation of the spring, the rated working deformation of the spring, and the fatigue safety limit deformation of the spring; S4. When the real-time deformation of the spring is greater than the rated working deformation of the spring and the real-time deformation of the spring gradually approaches the fatigue safety limit deformation of the spring, the upper limit of the output of the coil alternating current parameter is gradually reduced. S5, when the real-time deformation of the spring is less than the rated working deformation of the spring and the real-time deformation of the spring gradually moves away from the fatigue safety limit deformation of the spring, the upper limit of the output of the coil alternating current parameter is gradually increased.

[0012] Preferably, obtaining the fatigue safety limit deformation of the shrapnel specifically includes the following steps: S31, obtain the service time of the shrapnel and the initial fatigue safety limit deformation, and obtain the cumulative fatigue damage of the shrapnel that is positively correlated with the service time of the shrapnel. S32, the initial fatigue safety limit deformation of the shrapnel is corrected according to the cumulative fatigue damage of the shrapnel, and the fatigue safety limit deformation of the shrapnel is obtained which is negatively correlated with the cumulative fatigue damage of the shrapnel.

[0013] Preferably, step S2 specifically includes: S21 obtains the current speckle contrast based on the speckle imaging data, obtains the speckle contrast deviation based on the current speckle contrast and the target speckle contrast, and obtains the contrast deviation change rate based on the speckle contrast deviation. S22, obtain the vibration amplitude deviation based on the real-time deformation of the spring and the rated working deformation of the spring, and obtain the amplitude deviation change rate based on the vibration amplitude deviation. S23, obtain the speckle suppression weight and the spring safety weight, and perform weighted fusion of speckle contrast deviation and vibration amplitude deviation based on the speckle suppression weight and the spring safety weight to obtain the comprehensive static deviation. At the same time, perform weighted fusion of contrast deviation change rate and amplitude deviation change rate based on the speckle suppression weight and the spring safety weight to obtain the comprehensive trend change rate. S24, based on the comprehensive static deviation and the comprehensive trend change rate, the preset alternating magnetic field reference current amplitude is corrected to obtain the alternating current amplitude.

[0014] Preferably, in step S23, obtaining the speckle suppression weight and the shrapnel safety weight specifically includes: S231, obtain the total safety margin of the spring piece amplitude based on the fatigue safety limit deformation and the rated working deformation of the spring piece, normalize the vibration amplitude deviation based on the total safety margin of the spring piece amplitude, and obtain the current spring piece amplitude excess. S232, based on the current spatter amplitude overscalar, obtain the speckle suppression weight negatively correlated with the current spatter amplitude overscalar and the spatter safety weight positively correlated with the current spatter amplitude overscalar.

[0015] Preferably, the laser speckle suppression device control method further includes the following steps: The operational data of multiple identical laser speckle suppression devices were collected and clustered according to scene type and operating condition characteristics to obtain a group dataset; Obtain the real-time scene operating condition characteristics of the current laser speckle suppression device, and obtain the scene operating condition similarity between the current laser speckle suppression device and the centralized samples of the group data based on the real-time scene operating condition characteristics. Samples with scene condition similarity greater than a similarity threshold are selected. Weighted fusion weights are obtained based on the speckle suppression effect scores of the samples. The optimal current amplitude of the selected samples is weighted and fused to obtain the reference current amplitude of the alternating magnetic field. The operational data includes scenario operating condition characteristic values, the optimal set of control parameters, and a speckle suppression effect score. The optimal set of control parameters includes the optimal current amplitude.

[0016] Preferably, the laser speckle suppression device control method further includes the following steps: The other optimal control parameters of the selected samples are weighted and fused together, and the initial control parameter set is obtained by combining the alternating magnetic field reference current amplitude; When the current laser speckle suppression device is powered on or the scene is switched, the corresponding set of initial control parameters is loaded into the current laser speckle suppression device. The optimal control parameter set includes the optimal speckle suppression weight and the optimal spring safety weight, while the initial control parameter set includes the alternating magnetic field reference current amplitude, the initial speckle suppression weight, and the initial spring safety weight. Attached Figure Description

[0017] The invention will be further understood from the following description taken in conjunction with the accompanying drawings. The components in the drawings are not necessarily drawn to scale, but rather the emphasis is on illustrating the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0018] Figure 1 This is an exploded view of the overall structure of a laser speckle suppression device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the overall structure of a laser speckle suppression device according to an embodiment of the present invention; Figure 3 This is a schematic cross-sectional view of a laser speckle suppression device according to an embodiment of the present invention. Figure 1 ; Figure 4 This is a schematic cross-sectional view of a laser speckle suppression device according to an embodiment of the present invention. Figure 2 ; Figure 5 This is a schematic diagram of the overall process of a laser speckle suppression device control method in one embodiment of the present invention; Figure 6 This is a schematic flowchart of a laser speckle suppression device control method according to another embodiment of the present invention. Figure 1 ; Figure 7 This is a flowchart illustrating the process of taking the fatigue safety limit deformation of a shrapnel in one embodiment of the present invention; Figure 8 This is a flowchart illustrating step S2 in one embodiment of the present invention; Figure 9 This is a schematic diagram of the process for obtaining speckle suppression weight and spring safety weight in one embodiment of the present invention; Figure 10 This is a schematic flowchart of a laser speckle suppression device control method according to another embodiment of the present invention. Figure 2 ; Figure 11 This is a schematic flowchart of a laser speckle suppression device control method according to another embodiment of the present invention. Figure 3 .

[0019] Explanation of reference numerals in the attached diagram: 1. Bracket; 2. FPC board; 3. Coil; 4. Phillips head screw; 5. Magnet; 6. Glass plate; 7. Inner spring; 8. Outer spring; 9. Spring cantilever. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0021] like Figure 1 as well as Figure 2 As shown, an embodiment of the present invention provides a laser speckle suppression device, including a support 1, a vibration actuation component, an electromagnetic actuation component, and a data acquisition and processing component, wherein the vibration actuation component is located on the support 1 and the electromagnetic actuation component.

[0022] The bracket 1, serving as the load-bearing base, is generally made of lightweight rigid engineering plastic or aluminum alloy, and has reserved mounting positions and wiring channels for the coil 3, spring contacts, sensors, and main control unit. All components are fixed to the bracket 1 with Phillips head screws 4. The electromagnetic actuation component includes an enameled wire coil 3 and an FPC board 2. The FPC board 2 controls the current parameters of the input coil 3, such as amplitude, frequency, and phase, thereby changing the alternating magnetic field characteristic parameters.

[0023] Specifically, such as Figure 3 as well as Figure 4 As shown, the vibration actuator includes an inner spring 7, an outer spring 8, and a magnet 5. The inner spring 7 and the outer spring 8 are provided with spring cantilever arms 9 on their sides. The magnet 5 includes four pieces and is divided into two groups. Each group of magnets is arranged opposite to each other. The two groups of magnets are respectively installed on the spring cantilever arms 9 of the inner spring 7 and the outer spring 8 and are located directly above the coil 3.

[0024] Both the inner spring 7 and the outer spring 8 are elastic metal sheets. The spring cantilever 9 is arranged on the side to reduce the lateral space occupied by the device and achieve a narrow-edge design. The laser speckle suppression device also includes a glass plate 6, which serves as a laser-transmitting optical element. It oscillates back and forth with the inner and outer springs 8, suppressing speckle by disrupting the coherent laser path. The magnet 5 is a permanent magnet, fixed on the side of the spring near the coil 3. The two work together, relying on the magnetic attraction and repulsion to drive the spring to vibrate.

[0025] The coils 3 are arranged in independent sections, and each coil 3 is directly opposite a magnet 5. When an alternating current is passed through the coil 3, it generates an alternating magnetic field, which produces alternating attraction and repulsion forces with the magnet 5, driving the spring to swing back and forth.

[0026] More specifically, two sets of coils 3 are located directly below the spring cantilever 9 of the inner spring 7. Correspondingly, one set of magnets is installed on the spring cantilever 9 of the inner spring 7 and located directly above the corresponding coil 3, working in conjunction with the spring cantilever 9 of the outer spring 8. The other two sets of coils 3 are located directly below the spring cantilever 9 of the outer spring 8. Correspondingly, another set of magnets is installed on the spring cantilever 9 of the outer spring 8 and located directly above the corresponding coil 3, working in conjunction with the spring cantilever 9 of the inner spring 7.

[0027] The electromagnetic actuator is fixedly mounted on the bracket 1 and is used to drive the vibration actuator to swing in four directions (up, down, left, and right) through an alternating magnetic field. By driving the glass plate 6 to swing back and forth, the laser speckle is suppressed. The data acquisition and processing component is used to acquire speckle imaging data and vibration state data, and adjust the alternating magnetic field characteristics of the electromagnetic actuator according to the speckle imaging data and vibration state data to achieve dynamic optimization of the imaging effect.

[0028] The data acquisition and processing component includes a speckle image acquisition module, a vibration parameter acquisition module, and a data processing and control module. The electromagnetic execution component includes a coil 3. The speckle image acquisition module is used to acquire speckle imaging data in real time and feed it back to the data processing and control module. The vibration parameter acquisition module is used to acquire vibration state data in real time and feed it back to the data processing and control module. The data processing and control module is used to adjust the alternating current parameters of the coil 3 according to the speckle imaging data and the vibration state data, and to dynamically optimize the imaging effect by changing the characteristics of the alternating magnetic field.

[0029] Specifically, the speckle image acquisition module can be a miniature CMOS image sensor, which faces the laser emission direction. It acquires the laser image after passing through the glass plate 6 in real time and feeds it back to the data processing and control module. The data processing and control module calculates the speckle contrast, particle size, and distribution uniformity to determine the speckle suppression effect.

[0030] The vibration parameter acquisition module integrates a triaxial accelerometer and a strain sensor, which can be attached to the surface of the spring and glass plate 6. It collects the vibration amplitude, vibration frequency, and spring deformation of the device in real time and feeds them back to the data processing and control module. The data processing and control module obtains the vibration state, such as vibration amplitude and vibration amplitude change rate.

[0031] The data processing and control module can use an embedded microcontroller such as the STM32 series. It is electrically connected to the FPC board 2, the speckle image acquisition module, and the vibration parameter acquisition module. It dynamically changes the alternating magnetic field parameters by outputting adjustable alternating current to the four sets of coils 3.

[0032] The specific process of dynamically optimizing the imaging effect by adjusting the alternating current parameters of coil 3 based on speckle imaging data and vibration state data includes: if the real-time speckle contrast is less than the preset threshold, it is determined that the speckle suppression is insufficient. The vibration intensity is increased by increasing the current amplitude to enhance the speckle dispersion effect. If the speckle contrast is in the optimal range, the current parameters are maintained. If the spring deformation is greater than the safety threshold, it is determined that the vibration is overloaded. At this time, the driving current and the magnetic field strength can be appropriately reduced to avoid fatigue damage to the spring.

[0033] Based on the inherent vibration frequency of the spring, the alternating current frequency of coil 3 is dynamically matched to make the device operate in a near-resonance state, achieving the optimal vibration effect with minimal power consumption, while avoiding resonance peaks and preventing vibration overload. Regarding the current phase, the vibration timing in the up-down and left-right directions can be uniformly matched by adjusting the current phases of the four sets of coils 3 respectively, ensuring smooth four-way swing of the glass plate 6 and preventing image jitter.

[0034] In summary, the laser speckle suppression device acquires speckle imaging data and vibration state data, and adjusts the alternating magnetic field characteristics of the electromagnetic actuator based on the speckle imaging data and vibration state data. It can dynamically adjust the alternating magnetic field characteristics based on speckle imaging and vibration state data to adapt to different laser powers and wavelengths, thereby improving the product's adaptability to operating conditions and laser speckle suppression performance. This avoids problems such as decreased speckle suppression effect and screen flicker caused by the vibration amplitude and frequency of the glass plate 6 not matching the optimal speckle suppression conditions.

[0035] In one embodiment, the data acquisition and processing component is further configured to gradually reduce the upper limit of the output of the alternating current parameter of coil 3 when the real-time deformation of the spring is greater than the rated working deformation of the spring and the real-time deformation of the spring gradually approaches the fatigue safety limit deformation of the spring, and gradually increase the upper limit of the output of the alternating current parameter of coil 3 when the real-time deformation of the spring is less than the rated working deformation of the spring and the real-time deformation of the spring gradually moves away from the fatigue safety limit deformation of the spring; wherein, the vibration state data includes the real-time deformation of the spring, and the rated working deformation and the fatigue safety limit deformation of the spring are preset in the data processing and control module.

[0036] The rated working deformation of the spring is determined jointly by structural design and optical calibration, serving as a design balance point between speckle suppression effect and spring life. The fatigue safety limit deformation of the spring is the maximum allowable deformation that prevents the spring from undergoing rapid fatigue fracture. The real-time deformation of the spring can be acquired in real time by strain / displacement sensors mounted on the spring cantilever 9, characterizing the current degree of deformation of the spring and directly corresponding to the stress level and fatigue risk of the spring.

[0037] Generally, when the real-time deformation of the spring is much smaller than its rated working deformation, the upper limit of the output of the alternating current parameter of coil 3 can be adjusted based on the speckle effect. Specifically, the amplitude of the alternating current of coil 3 is adjusted, and the upper limit of the output is used as a constraint to reduce the speckle contrast. When the real-time deformation of the spring is greater than its rated working deformation and the real-time deformation of the spring gradually approaches the fatigue safety limit deformation of the spring, it is necessary to lower the upper limit of the alternating current amplitude, thereby forcibly reducing the amplitude of the alternating current and reducing vibration impact and sudden stress changes in the spring.

[0038] Specifically, the deformation offset between the real-time deformation and the rated working deformation of the spring fragment can be normalized based on the difference between the fatigue safety limit deformation and the rated working deformation of the spring fragment, i.e., the total safety margin of the fragment amplitude, to obtain the relative deformation offset. This relative deformation offset can be used to characterize the degree of deviation of the current real-time deformation of the spring fragment from the rated working deformation and the remaining proportion of the fatigue safety limit deformation of the spring fragment.

[0039] Based on the relative deformation offset, the nonlinear amplification characteristic of the natural exponential function is utilized to convert the relative deformation offset into a steeply varying gain term, and the steepness of the gain term is controlled by a corresponding steepness adjustment coefficient. After obtaining the gain term, this gain term is used as a constraint on the current amplitude output of alternating coil 3.

[0040] For example, the final alternating current amplitude output is expressed as: alternating magnetic field reference current amplitude × (1 + gain adjustment coefficient × ln(speckle contrast / target contrast) × constraint function). The constraint function is expressed as: 2 / (1 + (exp(steepness adjustment coefficient × relative deformation offset))), where the gain adjustment coefficient represents the vibration increment ratio required to improve speckle, and can be calibrated experimentally; the steepness adjustment coefficient is generally taken as 5.

[0041] When the real-time deformation of the spring is much smaller than its rated working deformation, it can be understood that the total safety margin of the spring structure is sufficient. In this case, it is permissible to use the structural safety margin to enhance the speckle suppression effect and minimize speckle contrast. Conversely, when the real-time deformation of the spring is greater than its rated working deformation and the real-time deformation gradually approaches the fatigue safety limit deformation of the spring, it is necessary to gradually reduce the current amplitude and tighten the safety boundary to avoid overload damage to the spring while preserving speckle suppression performance as much as possible.

[0042] In this way, the performance of the shrapnel can be saved from excessive conservatism in the early stages, and its fracture can be accelerated due to overload in the later stages, thus achieving a balance between laser speckle suppression performance and lifespan.

[0043] As a preferred technical solution, the data acquisition and processing component obtains the service time of the spring, calculates the cumulative fatigue damage of the spring that is positively correlated with the service time, corrects the initial fatigue safety limit deformation of the spring based on the cumulative fatigue damage, and obtains the fatigue safety limit deformation of the spring that is negatively correlated with the cumulative fatigue damage.

[0044] Specifically, the real-time deformation of the spring fragment can first be normalized using the fatigue safety limit deformation of the fragment to obtain the relative deformation. Then, a nonlinear operation with the m-th power is performed on the relative deformation to obtain the instantaneous damage rate. The value of m is generally between 6 and 8, mainly used to determine the degree of nonlinear amplification of fatigue damage by the deformation amplitude of the spring fragment. For example, when the relative deformation is 50% and the m-th power is 7, the instantaneous damage is approximately 0.78%, and the damage accumulation is slow; when the relative deformation is 90% and the m-th power is 7, the instantaneous damage is approximately 47.8%, and the damage accumulation rate is significantly increased. Finally, the instantaneous damage rate is used as the integrand, and an integral calculation is performed based on the service time of the spring fragment to obtain the cumulative fatigue damage of the spring fragment.

[0045] The accumulated fatigue damage of the spring sheet is used to quantify the total fatigue wear of the spring sheet since it left the factory. When it is 0, it corresponds to the spring sheet being in a brand new, undamaged state. When it is 1, it can be used as the theoretical fatigue life endpoint of the spring sheet. Of course, since continuous integration cannot be performed in actual embedded microcontrollers, the accumulated fatigue damage of the spring sheet can also be obtained by timed sampling and discrete recursion in practical applications. That is, the accumulated fatigue damage of the spring sheet in the current sampling period = the accumulated fatigue damage of the spring sheet in the previous sampling period + the instantaneous damage rate × the sampling period. Here, the instantaneous damage rate is expressed as (the real-time deformation of the spring sheet measured in the current sampling period / the fatigue safety limit deformation of the spring sheet) raised to the power of m.

[0046] Here, the initial fatigue safety limit deformation of the spring is modified based on the cumulative fatigue damage of the spring, and the fatigue safety limit deformation of the spring is negatively correlated with the cumulative fatigue damage of the spring. The main purpose is to make the safety boundary of the spring dynamically narrow as the spring ages, so as to achieve a balance between the life and performance of the device.

[0047] An embodiment of the present invention also provides a control method for a laser speckle suppression device, applied to the aforementioned laser speckle suppression device, such as... Figure 5 As shown, it includes the following steps: S1, acquire speckle imaging data and vibration state data.

[0048] S2 adjusts the alternating magnetic field characteristics of the electromagnetic actuator based on speckle imaging data and vibration state data to achieve dynamic optimization of imaging effect.

[0049] Specifically, if the real-time speckle contrast is less than the preset threshold, it is determined that the speckle suppression is insufficient. The vibration intensity is increased by increasing the current amplitude to enhance the speckle dispersion effect. If the speckle contrast is in the optimal range, the current parameters are maintained. If the spring deformation is greater than the safety threshold, it is determined that the vibration is overloaded. At this time, the driving current and magnetic field strength can be appropriately reduced to avoid fatigue damage to the spring.

[0050] Based on the inherent vibration frequency of the spring, the alternating current frequency of the coil is dynamically matched to make the device operate in a near-resonance state, achieving the optimal vibration effect with minimal power consumption, while avoiding resonance peaks and preventing vibration overload. For the current phase, the vibration timing in the up-down and left-right directions can be uniformly matched by adjusting the current phase of each of the four sets of coils, ensuring smooth four-way oscillation of the glass plate and preventing image jitter.

[0051] In summary, the laser speckle suppression device control method acquires speckle imaging data and vibration state data, and adjusts the alternating magnetic field characteristics of the electromagnetic actuator based on the speckle imaging data and vibration state data. It can dynamically adjust the alternating magnetic field characteristics based on speckle imaging and vibration state data to adapt to different laser powers and wavelengths, thereby improving the product's adaptability to operating conditions and laser speckle suppression performance, and avoiding problems such as decreased speckle suppression effect and screen flicker caused by the glass plate vibration amplitude and frequency not matching the optimal speckle suppression conditions.

[0052] In one embodiment, such as Figure 6 As shown, the laser speckle suppression device control method further includes the following steps: S3, obtain the real-time deformation of the spring, the rated working deformation of the spring, and the fatigue safety limit deformation of the spring.

[0053] As a preferred technical solution, such as Figure 7 As shown, obtaining the fatigue safety limit deformation of the shrapnel specifically includes the following steps: S31, obtain the service life of the shrapnel and the initial fatigue safety limit deformation, and obtain the cumulative fatigue damage of the shrapnel that is positively correlated with the service life of the shrapnel.

[0054] S32, the initial fatigue safety limit deformation of the shrapnel is corrected according to the cumulative fatigue damage of the shrapnel, and the fatigue safety limit deformation of the shrapnel is obtained which is negatively correlated with the cumulative fatigue damage of the shrapnel.

[0055] Specifically, as the cumulative fatigue damage of the shrapnel increases, the fatigue safety limit deformation of the shrapnel is gradually reduced. For example, the fatigue safety limit deformation of the shrapnel = initial fatigue safety limit deformation × (1 - cumulative fatigue damage × damage influence coefficient). The damage influence coefficient is mainly used to control the intensity of the impact of fatigue damage on the safety limit, and it determines the tightening rate of the safety boundary during aging, generally between 0.6 and 0.8. In the formula of cumulative fatigue damage × damage influence coefficient, the cumulative fatigue damage of the shrapnel is attenuated through the damage influence coefficient, which can prevent the initial fatigue safety limit deformation from returning to zero when the shrapnel reaches the end of its theoretical lifespan.

[0056] S4. When the real-time deformation of the spring is greater than the rated working deformation of the spring and the real-time deformation of the spring gradually approaches the fatigue safety limit deformation of the spring, the upper limit of the output of the coil alternating current parameter is gradually reduced.

[0057] S5, when the real-time deformation of the spring is less than the rated working deformation of the spring and the real-time deformation of the spring gradually moves away from the fatigue safety limit deformation of the spring, the upper limit of the output of the coil alternating current parameter is gradually increased.

[0058] For example, the final alternating current amplitude output is expressed as: alternating magnetic field reference current amplitude × (1 + gain adjustment coefficient × ln(speckle contrast / target contrast) × constraint function). The constraint function is expressed as: 2 / (1 + (exp(steepness adjustment coefficient × relative deformation offset))), where the gain adjustment coefficient represents the vibration increment ratio required to improve speckle, and can be calibrated experimentally; the steepness adjustment coefficient is generally taken as 5.

[0059] When the real-time deformation of the spring is much smaller than its rated working deformation, it can be understood that the spring structure has sufficient safety margin. In this case, it is permissible to use the structural safety margin to enhance the speckle suppression effect and minimize speckle contrast. Conversely, when the real-time deformation of the spring is greater than its rated working deformation and the real-time deformation gradually approaches the fatigue safety limit deformation of the spring, it is necessary to gradually reduce the current amplitude and tighten the safety boundary to avoid overload damage to the spring while preserving speckle suppression performance as much as possible.

[0060] In this way, the performance of the shrapnel can be saved from excessive conservatism in the early stages, and its fracture can be accelerated due to overload in the later stages, thus achieving a balance between laser speckle suppression performance and lifespan.

[0061] In one embodiment, such as Figure 8 As shown, step S2 specifically includes: S21 obtains the current speckle contrast based on the speckle imaging data, obtains the speckle contrast deviation based on the current speckle contrast and the target speckle contrast, and obtains the contrast deviation change rate based on the speckle contrast deviation.

[0062] Generally speaking, when the speckle contrast deviation is greater than zero, it indicates that the speckle is too heavy, and the vibration should be increased and the current increased. Conversely, it indicates that the speckle suppression is excessive, and the current can be reduced to save energy and extend the service life. If the rate of change of contrast deviation is greater than zero, it indicates that the speckle is continuously deteriorating and the trend is intensifying, and the current should be increased in advance for compensation.

[0063] S22, obtain the vibration amplitude deviation based on the real-time deformation of the spring and the rated working deformation of the spring, and obtain the amplitude deviation change rate based on the vibration amplitude deviation.

[0064] Differential calculations can be performed on the speckle contrast deviation and vibration amplitude deviation based on adjacent sampling periods to obtain the corresponding contrast deviation change rate and amplitude deviation change rate.

[0065] When the vibration amplitude deviation is greater than zero, it indicates that the amplitude is exceeding the limit and there is a risk of fatigue, requiring the current to be reduced. Conversely, it indicates that the amplitude margin is sufficient, allowing for an appropriate increase in current to optimize speckle. If the rate of change of amplitude deviation is greater than zero, it indicates that the amplitude continues to increase, and the risk of fatigue accumulates rapidly, requiring amplitude limiting in advance.

[0066] If the rate of change of contrast deviation is greater than zero and the rate of change of amplitude deviation is approximately zero, it can be considered that the speckle is continuously deteriorating. In this case, the current amplitude can be appropriately increased to suppress the deterioration of speckle in advance. If the rate of change of amplitude deviation is greater than zero and the rate of change of contrast deviation is approximately zero, it can be considered that the amplitude is continuously increasing. In this case, the current can be reduced in the opposite direction to avoid overload fatigue in advance.

[0067] S23, obtain the speckle suppression weight and the spring safety weight, and perform weighted fusion of speckle contrast deviation and vibration amplitude deviation based on the speckle suppression weight and the spring safety weight to obtain the comprehensive static deviation. At the same time, perform weighted fusion of contrast deviation change rate and amplitude deviation change rate based on the speckle suppression weight and the spring safety weight to obtain the comprehensive trend change rate.

[0068] For example, the overall static deviation = speckle suppression weight × speckle contrast deviation × first static deviation adjustment coefficient - spring safety weight × vibration amplitude deviation × second static deviation adjustment coefficient. Wherein, the first static deviation adjustment coefficient and the second static deviation adjustment coefficient are hyperparameters that can be set and adjusted according to actual conditions. They respectively represent the adjustment sensitivity of speckle suppression performance and the adjustment sensitivity of safety structural constraints.

[0069] The overall trend change rate = speckle suppression weight × contrast deviation change rate × first change rate adjustment coefficient - spring safety weight × amplitude deviation change rate × second change rate adjustment coefficient. Here, the first and second change rate adjustment coefficients are hyperparameters that can be set and adjusted according to actual conditions. They respectively represent the strength of the proactive response to speckle deterioration / improvement trends and the strength of proactive protection against rapid amplitude increases.

[0070] As a preferred technical solution, such as Figure 9 As shown, obtaining the speckle suppression weight and the shrapnel safety weight specifically includes: S231. Obtain the total safety margin of the spring's amplitude based on the fatigue safety limit deformation and the rated working deformation of the spring. Normalize the vibration amplitude deviation based on the total safety margin of the spring's amplitude to obtain the current excess amount of the spring's amplitude.

[0071] S232, based on the current spatter amplitude overscalar, obtain the speckle suppression weight negatively correlated with the current spatter amplitude overscalar and the spatter safety weight positively correlated with the current spatter amplitude overscalar.

[0072] For example, the speckle suppression weight = exp(-weight attenuation coefficient × current spring amplitude overshoot). Current spring amplitude overshoot = max(vibration amplitude deviation, 0) / total safety margin of spring amplitude, spring safety weight = 1 - speckle suppression weight, the weight attenuation coefficient can be set empirically, generally taking a value of 3-6.

[0073] When the vibration amplitude deviation is << 0, it can be understood that the amplitude margin is sufficient. At this time, the speckle suppression weight is ≈ 1, and the speckle effect can be optimized first, and the current amplitude limit can be relaxed to improve the vibration. Conversely, the amplitude should be constrained first and the current should be reduced.

[0074] Here, based on the current excessive amplitude of the spring, a speckle suppression weight negatively correlated with the current excessive amplitude of the spring and a spring safety weight positively correlated with the current excessive amplitude of the spring are obtained. The purpose is to automatically allocate the priority of performance and safety based on the current vibration amplitude deviation combined with the working condition, so as to achieve conflict balance.

[0075] S24, based on the comprehensive static deviation and the comprehensive trend change rate, the preset alternating magnetic field reference current amplitude is corrected to obtain the alternating current amplitude.

[0076] Here, the final alternating current amplitude = alternating magnetic field reference current amplitude × (1 + comprehensive static deviation + comprehensive trend change rate). The comprehensive trend change rate, as a micro-layer, has trend prediction characteristics, which can offset continuous deterioration / drift in advance, significantly reduce regulation overshoot, and shorten convergence time.

[0077] Thus, the preset alternating magnetic field reference current amplitude is corrected based on the comprehensive static deviation and the comprehensive trend change rate to obtain the alternating current amplitude. This embodiment integrates the speckle contrast deviation change rate and the amplitude deviation change rate, which can not only increase the current in advance by predicting the continuous deterioration of speckle, but also reduce the current in advance by predicting the continuous overload of amplitude, thereby realizing the trend prediction and the early correction of the alternating current amplitude, thereby reducing image flicker and spring impact stress. At the same time, the combined correction of the preset alternating magnetic field reference current amplitude based on the comprehensive static deviation and the comprehensive trend change rate can also effectively solve the control conflict between speckle performance and spring safety structure, and simultaneously balance the imaging effect and spring fatigue life.

[0078] In some cases, devices of the same model and operating conditions in the same area, such as multiple laser projectors in a cinema or multiple laser inspection devices in the same factory, have highly consistent environmental conditions and light source parameters, resulting in highly similar optimal control parameters. If each device operates independently, the optimization results cannot be shared, easily leading to redundant waste of computing power and time.

[0079] To avoid redundant optimization for devices in the same scenario and to reuse the collective experience of devices in the same region, model, and operating condition, in one embodiment, such as Figure 10 As shown, the laser speckle suppression device control method further includes the following steps: S6 collects operational data from multiple identical laser speckle suppression devices and clusters them according to scenario type and operating condition characteristics to obtain a group dataset.

[0080] Specifically, the operational data includes scene condition characteristic values, the optimal set of control parameters, and a speckle suppression effect score. The optimal set of control parameters includes the optimal current amplitude. Scene condition characteristic values ​​include, but are not limited to, scene type code, ambient temperature, laser source rated power, cumulative operating time level, and power grid voltage fluctuation level.

[0081] Multiple identical laser speckle suppression devices can be understood as laser speckle suppression devices located in the same preset area, having the same model, and operating under the same / similar conditions. The speckle suppression effect score can be calculated based on the stability and uniformity of speckle contrast. The higher the score, the better the speckle suppression effect. For example, the speckle suppression effect score can be obtained based on the standard deviation of speckle contrast and / or speckle contrast deviation over a preset time window.

[0082] S7, obtain the real-time scene operating condition characteristics of the current laser speckle suppression device, and obtain the scene operating condition similarity between the current laser speckle suppression device and the centralized samples of the group data based on the real-time scene operating condition characteristics.

[0083] For scenario operating condition similarity, it can be determined based on cosine similarity to quantify the degree of matching between operating conditions. Generally, scenario operating condition similarity is between 0 and 1. The higher the value, the closer the scenario operating conditions of the two devices are, and the stronger the transferability of the optimal control parameters.

[0084] S8. Filter samples whose scene condition similarity is greater than the similarity threshold, obtain weighted fusion weights based on the speckle suppression effect score of the samples, and perform weighted fusion on the optimal current amplitude of the filtered samples to obtain the alternating magnetic field reference current amplitude.

[0085] Samples with similarity to the operating conditions exceeding a similarity threshold are selected to obtain a set of samples meeting the similarity criteria. Generally, the more similar the operating conditions and the better the speckle effect of a device, the higher the reference weight and value of its optimal control parameters. Using the speckle suppression effect score of the similarity-compliant sample set as the weighted fusion weight, the weighted average value is calculated for each type of optimal control parameter in the optimal control parameter set to obtain the corresponding initial control parameter set. The initial control parameter set includes the alternating magnetic field reference current amplitude.

[0086] In this way, the final set of initial control parameters can be effectively adapted to the current scenario, thereby avoiding repeated optimization of devices in the same scenario, realizing the reuse of group experience of devices in the same region, model and operating condition, and reducing redundant waste of computing power and time.

[0087] In one embodiment, such as Figure 11 As shown, the laser speckle suppression device control method further includes the following steps: S9, weighted fusion of other optimal control parameters of the screened samples and combined with the alternating magnetic field reference current amplitude obtained in step S8 to obtain the initial control parameter set.

[0088] S10: When the current laser speckle suppression device is powered on or the scene is switched, the corresponding set of initial control parameters is loaded into the current laser speckle suppression device.

[0089] The optimal control parameter set includes the optimal speckle suppression weight and the optimal spring safety weight, while the initial control parameter set includes the alternating magnetic field reference current amplitude, the initial speckle suppression weight, and the initial spring safety weight.

[0090] Of course, based on the method of obtaining the comprehensive static deviation and the comprehensive trend change rate, the optimal control parameter set also includes the optimal first static deviation adjustment coefficient, the second static deviation adjustment coefficient, the first change rate adjustment coefficient, and the second change rate adjustment coefficient. Correspondingly, the initial control parameter set also includes the initial first static deviation adjustment coefficient, the second static deviation adjustment coefficient, the first change rate adjustment coefficient, and the second change rate adjustment coefficient.

[0091] When multiple devices in the region operate independently in a closed loop, if better speckle effect is obtained through local fine-tuning and optimization and the total amplitude safety margin is sufficient, the corresponding control parameters can be used as the optimal control parameters and automatically included in the optimal control parameter library, and synchronized to other devices under the same operating conditions.

[0092] When a new device is powered on or its operating conditions change abruptly, if the local closed loop is used to iterate and optimize from scratch, the speckle effect may take tens of seconds or even minutes to converge to the optimal state. The image quality is poor in the early stages of power-on, and problems such as adjustment overshoot and screen flicker are likely to occur under extreme conditions.

[0093] In this embodiment, by acquiring an initial set of control parameters and loading it into the device as feedforward reference control parameters, the problems of slow cold start and delayed switching of operating conditions in traditional adaptive control are effectively solved. For new device startup or scene switching, based on the loaded initial set of control parameters, a small-range, precise closed-loop adjustment is performed using real-time data from image sensors and strain sensors, which efficiently achieves good laser speckle suppression effects, thus improving the device's operating condition response speed and speckle effect adjustment accuracy.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A laser speckle suppression device, comprising a support, a vibration actuator, and an electromagnetic actuator, wherein the vibration actuator is located on the support and the electromagnetic actuator, and the electromagnetic actuator is fixedly mounted on the support and used to drive the vibration actuator to oscillate in four directions (up, down, left, and right) via an alternating magnetic field, thereby suppressing laser speckle by causing a glass plate to oscillate reciprocally, characterized in that, It also includes a data acquisition and processing component, which is used to acquire speckle imaging data and vibration state data, and adjust the alternating magnetic field characteristics of the electromagnetic actuator based on the speckle imaging data and vibration state data to achieve dynamic optimization of the imaging effect.

2. The laser speckle suppression device as described in claim 1, characterized in that, The data acquisition and processing component is also used to gradually reduce the upper limit of the output of the coil alternating current parameter when the real-time deformation of the spring is greater than the rated working deformation of the spring and the real-time deformation of the spring gradually approaches the fatigue safety limit deformation of the spring, and to gradually increase the upper limit of the output of the coil alternating current parameter when the real-time deformation of the spring is less than the rated working deformation of the spring and the real-time deformation of the spring gradually moves away from the fatigue safety limit deformation of the spring. The vibration state data includes the real-time deformation of the spring sheet, the rated working deformation of the spring sheet, and the fatigue safety limit deformation of the spring sheet, which are preset in the data processing and control module.

3. The laser speckle suppression device as described in claim 2, characterized in that, The data acquisition and processing component obtains the service time of the spring, calculates the cumulative fatigue damage of the spring that is positively correlated with the service time, and corrects the initial fatigue safety limit deformation of the spring based on the cumulative fatigue damage, thereby obtaining the fatigue safety limit deformation of the spring that is negatively correlated with the cumulative fatigue damage.

4. A method for controlling a laser speckle suppression device, applied to the laser speckle suppression device as described in any one of claims 1-3, characterized in that, Includes the following steps: S1, acquire speckle imaging data and vibration state data; S2 adjusts the alternating magnetic field characteristics of the electromagnetic actuator based on speckle imaging data and vibration state data to achieve dynamic optimization of imaging effect.

5. The laser speckle suppression device control method as described in claim 4, characterized in that, It also includes the following steps: S3, obtain the real-time deformation of the spring, the rated working deformation of the spring, and the fatigue safety limit deformation of the spring; S4. When the real-time deformation of the spring is greater than the rated working deformation of the spring and the real-time deformation of the spring gradually approaches the fatigue safety limit deformation of the spring, the upper limit of the output of the coil alternating current parameter is gradually reduced. S5, when the real-time deformation of the spring is less than the rated working deformation of the spring and the real-time deformation of the spring gradually moves away from the fatigue safety limit deformation of the spring, the upper limit of the output of the coil alternating current parameter is gradually increased.

6. The laser speckle suppression device control method as described in claim 5, characterized in that, Obtaining the fatigue safety limit deformation of a shrapnel specifically includes the following steps: S31, obtain the service time of the shrapnel and the initial fatigue safety limit deformation, and obtain the cumulative fatigue damage of the shrapnel that is positively correlated with the service time of the shrapnel. S32, the initial fatigue safety limit deformation of the shrapnel is corrected according to the cumulative fatigue damage of the shrapnel, and the fatigue safety limit deformation of the shrapnel is obtained which is negatively correlated with the cumulative fatigue damage of the shrapnel.

7. The laser speckle suppression device control method as described in claim 6, characterized in that, Step S2 specifically includes: S21 obtains the current speckle contrast based on the speckle imaging data, obtains the speckle contrast deviation based on the current speckle contrast and the target speckle contrast, and obtains the contrast deviation change rate based on the speckle contrast deviation. S22, obtain the vibration amplitude deviation based on the real-time deformation of the spring and the rated working deformation of the spring, and obtain the amplitude deviation change rate based on the vibration amplitude deviation. S23, obtain the speckle suppression weight and the spring safety weight, and perform weighted fusion of speckle contrast deviation and vibration amplitude deviation based on the speckle suppression weight and the spring safety weight to obtain the comprehensive static deviation. At the same time, perform weighted fusion of contrast deviation change rate and amplitude deviation change rate based on the speckle suppression weight and the spring safety weight to obtain the comprehensive trend change rate. S24, based on the comprehensive static deviation and the comprehensive trend change rate, the preset alternating magnetic field reference current amplitude is corrected to obtain the alternating current amplitude.

8. The laser speckle suppression device control method as described in claim 7, characterized in that, In step S23, obtaining the speckle suppression weight and the shrapnel safety weight specifically includes: S231, obtain the total safety margin of the spring piece amplitude based on the fatigue safety limit deformation and the rated working deformation of the spring piece, normalize the vibration amplitude deviation based on the total safety margin of the spring piece amplitude, and obtain the current spring piece amplitude excess. S232, based on the current spatter amplitude overscalar, obtain the speckle suppression weight negatively correlated with the current spatter amplitude overscalar and the spatter safety weight positively correlated with the current spatter amplitude overscalar.

9. The laser speckle suppression device control method as described in claim 7, characterized in that, It also includes the following steps: S6 collects operational data from multiple identical laser speckle suppression devices and clusters them according to scenario type and operating condition characteristics to obtain a group dataset; S7, obtain the real-time scene operating condition characteristics of the current laser speckle suppression device, and obtain the scene operating condition similarity between the current laser speckle suppression device and the centralized samples of the group data based on the real-time scene operating condition characteristics; S8. Filter samples with scene condition similarity greater than the similarity threshold, obtain weighted fusion weights based on the speckle suppression effect score of the samples, and perform weighted fusion on the optimal current amplitude of the filtered samples to obtain the alternating magnetic field reference current amplitude. The operational data includes scenario operating condition characteristic values, the optimal set of control parameters, and a speckle suppression effect score. The optimal set of control parameters includes the optimal current amplitude.

10. The laser speckle suppression device control method as described in claim 9, characterized in that, It also includes the following steps: S9, weighted and fused other optimal control parameters of the selected samples and combined with the amplitude of the alternating magnetic field reference current to obtain the initial control parameter set; S10: When the current laser speckle suppression device is powered on or the scene is switched, the corresponding set of initial control parameters is loaded into the current laser speckle suppression device. The optimal control parameter set includes the optimal speckle suppression weight and the optimal spring safety weight, while the initial control parameter set includes the alternating magnetic field reference current amplitude, the initial speckle suppression weight, and the initial spring safety weight.

Images