Radar scanning method and system

Abstract

The invention relates to the technical field of radars, in particular to a radar scanning method and system, light of a radar is controlled by an optical switch, the optical switch comprises a light source, a beam splitter, n phased array units and a modulation unit, each phased array unit comprises a waveguide, and a phase change material is arranged on the waveguide; wherein the beam splitter is used for splitting a light source into multiple beams of signal light and transmitting the signal light to the corresponding phased array units, and the modulation unit is used for applying an excitation signal to the phase change material, so that the phased array units can control the phase of the signal light passing through the waveguide; correspondingly, the signal light passing through the plurality of phased array units forms scanning light for scanning a target. The radar scanning method provided by the invention can improve the stability and reliability of the radar under large-scale and long-time scanning.

Description

Technical Field

[0001] This invention relates to the field of radar scanning technology, and specifically to a radar scanning method and system. Background Technology

[0002] Phased array radar achieves rapid electronic scanning of the beam by controlling the phase of each radiating element in the array antenna, which has advantages such as flexibility and reliability.

[0003] For example, patent application CN217820838U discloses a lidar transmitting system. This lidar transmitting system includes: a light source system, a MEMS mirror, and a metasurface modulator; the light beam emitted by the light source system is a linearly arranged beam array; the MEMS mirror is disposed on the light-emitting side of the light source to reflect the emitted light beam; the metasurface modulator is disposed on the light-emitting side of the MEMS mirror to amplify the angle of the beam reflected by the MEMS mirror and project it onto the target.

[0004] However, this launch system is only suitable for one-dimensional scanning and is difficult to achieve large-scale scanning in three-dimensional space.

[0005] For example, patent application CN118759647A discloses an on-chip phase change material optical switch-controlled optical phased array system and its control method, including a GST ultrafast optical switch module for adjusting the optical splitter, a heterogeneous integrated silicon nitride waveguide module for controlling the end-face output OPA, and a heterogeneous integrated silicon nitride waveguide module for controlling the grating output OPA. This system utilizes the optical switch module to controllably adjust the optical splitter of the input light, and the latter two modules can select the output mode and scanning mode of the OPA.

[0006] For example, patent application CN114721089A discloses a phased array radar system based on phase change material optical switches. This radar system heats the GST layer from an amorphous state to a crystalline state using short laser pulses, preventing light from passing through specific waveguides. This changes the position of the emitted light from the chip as a whole. By regularly controlling the GST optical switches of specific waveguides, spatial scanning of the output beam can be achieved.

[0007] For example, patent application CN218213445U discloses a lidar chip and a lidar. This chip uses a phase change material optical switch to control the optical path of the measurement light transmission in order to complete multi-channel beam scanning.

[0008] The radars described above utilize the on / off mechanism of optical switches during operation, that is, the 0 / 1 control (or on / off control) of the optical switch channel is achieved through phase change materials.

[0009] However, this on / off control scheme faces extremely high challenges when performing long-term, large-scale scans. For example, it is necessary to ensure that the beam power from each channel is the same; otherwise, different beams may cause significant deviations in the accuracy or orientation of the final scanned light due to interference and other reasons. Summary of the Invention

[0010] The purpose of this invention is to provide a radar scanning method that partially solves or alleviates the above-mentioned deficiencies in the prior art, and can improve the stability and reliability of radar under long-term, large-scale scanning.

[0011] To solve the aforementioned technical problems, the present invention specifically adopts the following technical solution: A first aspect of the present invention is to provide a radar scanning method, wherein the scanning light of the radar is controlled by an optical switch, and the optical switch includes: a light source, a beam splitter, n phased array units and a modulation unit, wherein the phased array unit includes: a waveguide, and a phase change material is disposed on the waveguide; The beam splitter is used to split the light provided by the light source into multiple signal beams and transmit the signal beams to the corresponding phased array units. The modulation unit is used to apply an excitation signal to the phase change material so that the phased array units can control the phase of the signal beams passing through the waveguide. Correspondingly, the signal beams passing through multiple phased array units form scanning beams for scanning the target. Correspondingly, the method includes the following steps: S100, determine whether the scanning range is less than the preset scanning threshold; If the result of S100 is yes, then the following steps are executed: S101, determine the effective optical aperture according to the scanning conditions, wherein the scanning conditions include: scanning range, and the effective optical aperture is used to determine the minimum number of elements m of the phased array combination; S102, select at least one phased array combination, wherein the phased array combination includes x phased array elements, and m≤x<n; S103, calculate the control difficulty level when the phased array combination is used to scan the scanning interval, the control difficulty level is characterized by the phase solution difficulty level and / or energy consumption level; S104, when the control difficulty level is lower than the preset difficulty level, the modulation unit corresponding to the phased array combination is set as the enabled unit, and the modulation units corresponding to the remaining phased array units are set as candidate units; wherein, during the enabling process of the phased array combination, the operating energy consumption of the candidate unit is lower than the operating energy consumption of the candidate unit.

[0012] In some embodiments, prior to S101, the following steps are included: S105, Obtain the scanning accuracy of the scanning range; S106, determine whether the scanning accuracy is greater than a preset accuracy threshold; If the result of S106 is negative, proceed to step S101.

[0013] In some embodiments, the scanning conditions further include: scanning accuracy.

[0014] In some embodiments, it also includes: Obtain at least one image after scanning; Image recognition is performed based on at least one image to identify the target; When the target recognition completion rate is greater than a preset completion threshold, the scanning accuracy of the remaining scanning interval is allowed to be reduced.

[0015] In some embodiments, it also includes: Predict the rate of change of the scanning light based on the task mode; The candidate state of the candidate unit is determined based on the rate of change, and different candidate states correspond to different operating energy consumption levels.

[0016] In some embodiments, the task mode includes: a search mode, a single-target tracking mode, or a multi-target tracking mode; wherein different task modes are configured with recommended rates of change.

[0017] In some embodiments, candidate states include: hibernation state and / or shutdown state.

[0018] In some embodiments, the excitation signal is an optical pulse signal or thermal energy.

[0019] The present invention also provides a radar scanning system, wherein the radar scanning light is controlled by an optical switch, and the optical switch includes: a light source, a beam splitter, n phased array units and a modulation unit, wherein the phased array unit includes: a waveguide, and a phase change material is disposed on the waveguide; The beam splitter is used to split the light provided by the light source into multiple signal beams and transmit the signal beams to the corresponding phased array units. The modulation unit is used to apply an excitation signal to the phase change material so that the phased array units can control the phase of the signal beams passing through the waveguide. Correspondingly, the signal beams passing through multiple phased array units form scanning beams for scanning the target. Correspondingly, the system also includes: The first judgment module is used to determine whether the scanning interval is less than the preset scanning threshold; If the result of the first judgment module is yes, then proceed to: An aperture determination module is used to determine an effective optical aperture based on scanning conditions, wherein the scanning conditions include a scanning range, and the effective optical aperture is used to determine the minimum number of elements m of the phased array combination. The selection module is used to select at least one phased array combination, wherein the phased array combination includes x phased array elements, and m≤x<n; The difficulty calculation module is used to calculate the control difficulty level when the phased array combination is used to scan the scanning interval. The control difficulty level is characterized by the phase solution difficulty level and / or energy consumption level. The setting module is used to set the modulation unit corresponding to the phased array combination as the enabled unit and set the modulation units corresponding to the remaining phased array units as candidate units when the control difficulty level is lower than the preset difficulty level; wherein, during the enabling process of the phased array combination, the operating energy consumption of the candidate units is lower than that of the candidate units.

[0020] In some embodiments, it also includes: A precision acquisition module is used to acquire the scanning precision of the scanning interval; The second judgment module is used to determine whether the scanning accuracy is greater than a preset accuracy threshold before entering the aperture determination module; If the result of the second judgment module is negative, then the aperture determination module is entered.

[0021] Beneficial technical effects: It is worth noting that, unlike the existing technology that uses optical switches to directly control the on / off state, this invention uses phase difference to control multiple paths to output beams of different phases, and then forms scanning light through the interference of multiple beams.

[0022] Furthermore, this invention provides a multi-mode switching scheme for this phase difference control mode, including local and global calls. This switching scheme can reduce overall scanning energy consumption.

[0023] It is important to understand that, unlike on / off control schemes, this invention may involve multiple, or even all, channels simultaneously outputting beams. Such synchronous output of multiple beams presents significant challenges to energy consumption control in large-scale optical switches. To address this, this invention utilizes local and global switching mechanisms to maintain stable operation of the optical switch with relatively low energy consumption.

[0024] Furthermore, for local calls, the present invention also provides a method for configuring the candidate state of the candidate unit in conjunction with the radar scanning state, thereby ensuring that the radar can also be called up more sensitively to meet the scanning requirements of temporary emergencies (such as target movement or multi-target dispersed tracking) while maintaining the low operating power consumption of the optical switch.

[0025] From another perspective, this invention, through local and global switching modes, in conjunction with low-loss methods such as candidate state configuration, can achieve a balance between reducing radar operating losses and improving radar scanning sensitivity, thereby enabling the optical switch to be suitable for large-scale, long-term radar applications. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0027] Figure 1 This is a schematic diagram of an exemplary optical switch according to the present invention; Figure 2 This is a schematic diagram of the control flow of an optical switch in an exemplary embodiment of the present invention; Figure 3 This is a schematic diagram of the control flow of an optical switch in another exemplary embodiment of the present invention; Figure 4 This is a schematic diagram of the modular architecture of a radar system in an exemplary embodiment of the present invention.

[0028] Reference numerals: 1. Light source; 2. Beam splitter; 3. Phased array element; 31. Silicon waveguide; 32. Phase change material region. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] In this document, suffixes such as "module," "part," or "unit" used to denote elements are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" may be used interchangeably.

[0031] In this document, the terms "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In this document, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] In this document, "and / or" includes any and all combinations of one or more of the listed related items.

[0034] In this article, "multiple" means two or more, that is, it includes two, three, four, five, etc.

[0035] As used in this specification, the term "about" typically means + / -5% of the value, more typically + / -4% of the value, more typically + / -3% of the value, more typically + / -2% of the value, even more typically + / -1% of the value, and even more typically + / -0.5% of the value.

[0036] In this specification, certain embodiments may be disclosed in a range-bound format. It should be understood that this "range-bound" description is merely for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered as having specifically disclosed all possible subranges and the individual numerical values ​​within those ranges. For example, a description of the range 1-6 should be considered as having specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and the individual numbers within those ranges, such as 1, 2, 3, 4, 5, and 6. This rule applies regardless of the breadth of the range.

[0037] The optical switch includes multiple output channels, and the output state of each output channel, such as on or off, can be controlled independently.

[0038] It should be noted that in existing technologies, the method of controlling phased array radar using optical switches involves using the switching action of the optical switches to make the light beam appear sequentially at different positions in space, thereby achieving discrete, step-by-step scanning. In other words, existing technologies still use the traditional control logic of optical switches, namely the 0 / 1 switching mode.

[0039] In stark contrast, this invention utilizes the characteristic of phase change materials where the refractive index changes with the state to precisely control the phase of the beam in each output channel, so that beams with different phases passing through multiple output channels can form a scanning beam. Specifically, one output channel is used as a tunable phase delayer, thereby dynamically and continuously adjusting the phase shift of each output channel, allowing beams from hundreds of channels to be output simultaneously. Multiple beams can form a high-intensity, precisely directional synthetic beam through optical interference in the far field, thus creating a huge synthetic aperture capable of producing an extremely sharp interference main lobe (i.e., scanning beam).

[0040] By controlling the formation of the main lobe of the interference beam, it is possible to achieve higher spatial resolution and target positioning accuracy. This is because differential adjustment of the phase of different output channels not only allows for the combination of different scanning beams but also enables advanced functions such as multi-beam generation, dynamic focusing, aberration correction, and anti-interference beamforming. These functions are impossible to achieve with on / off control in existing technologies.

[0041] Furthermore, from another perspective, traditional on / off control will also face greater energy consumption. On / off control means that the phase change material (PCM) must frequently transition between crystalline and amorphous states. During long-term operation, the frequent and drastic structural changes experienced by the PCM can easily lead to fatigue effects, potentially even severely impacting its service life and long-term reliability.

[0042] However, this invention chooses to approach the problem from the perspective of phase adjustment, thereby enabling minute state changes in a single adjustment process. For example, in this invention, continuous phase control only requires adjustments within a small range within the amorphous state, requiring much less adjustment energy and making it easier to achieve high-precision detection.

[0043] Example 1: See Figures 1-3 As shown, this invention provides a radar scanning method. This method uses an optical switch made of phase-change material to control the phase of the light beam and provides a partitioned scanning method to reduce the energy consumption of radar scanning to a certain extent, thereby lowering the cost of large-scale applications.

[0044] First, to introduce the partition calling method proposed in this invention, please refer to the following. Figure 1 An example illustrating the architecture of an optical switch: The radar's scanning light is controlled by an optical switch, and the optical switch includes: a light source 1, a beam splitter 2, n phased array units 3, and a modulation unit. The phased array unit 3 includes: a waveguide, on which a phase change material is disposed. The beam splitter is used to split the light provided by the light source into multiple signal beams (also called beams, or simply light), and transmit the signal beams to the corresponding phased array unit 3. The modulation unit is used to apply an excitation signal to the phase change material so that the phased array unit can control the phase of the signal beams passing through the waveguide. Correspondingly, the signal beams passing through multiple phased array units form scanning beams for scanning the target.

[0045] For example, in some embodiments, the excitation signal can be a pulse signal, such as an optical pulse or an electrical pulse.

[0046] For example, see Figure 1 As shown, phased array element 3 includes: A silicon optical waveguide 31 is used to conduct optical signals; The phase change material region 32 (referred to as the PCM region) is evanescently coupled to the silicon optical waveguide 31. This PCM region is preferably a low-loss phase change material such as SbSe (antimony selenide), which covers the top or side of the waveguide.

[0047] A modulation unit is used to adjust the phase transition state of the PCM region; For example, the modulation unit includes: Heating electrodes (such as micro-heating electrodes) are integrated near the phase change material region to apply localized, precise Joule heating pulses to the PCM region.

[0048] The control circuit is used to apply electrical pulses to the heating electrode to cause a temperature change in the heating electrode, thereby enabling the application of Joule heating pulses to the PCM region.

[0049] Specifically, the operating modes of the modulation unit may include: Reset Operation: The control circuit applies a short, strong electrical pulse (e.g., high amplitude, narrow pulse width) to the micro-heating electrode, causing the temperature of the micro-heating electrode to rise rapidly. This rapidly heats the PCM region above its melting temperature and then quickly quenches it, transforming it into an amorphous state. In this state, the PCM has little effect on the refractive index of the optical modes in the waveguide, corresponding to a reference phase state.

[0050] Setup: The control circuit applies a relatively long and moderate electrical pulse (e.g., low amplitude, wide pulse width) to the micro-heating electrode. The temperature of the micro-heating electrode gradually increases, heating the PCM region above the crystallization temperature but below the melting temperature, and maintaining this temperature for a period of time, causing it to transform into a crystalline state. In this state, the PCM has a high refractive index and absorption loss, significantly altering the effective refractive index of the waveguide, thereby introducing a fixed phase shift.

[0051] By precisely controlling the morphology of the electrical pulses, the degree of amorphization of the PCM can be precisely controlled, thereby achieving multi-order phase control, rather than just binary.

[0052] It is important to understand that, unlike traditional radar, phased array radar can provide n beams of light, and by adjusting the state of different beams (such as on / off), scanning light corresponding to different scanning areas can be formed.

[0053] In fact, one of the phased array units mentioned above is also equivalent to a channel of an optical switch, used to output signal light.

[0054] It should be noted that the architecture of the aforementioned optical switch can also be found in existing optical switches, and will not be repeated here.

[0055] Existing technologies attempt to control radar scanning light using the traditional on / off mechanism of optical switches. However, the applicant notes that this method of controlling scanning light using the traditional on / off mechanism of optical switches presents significant challenges when applied to large-scale, long-term radar scanning. For example, to accurately control the scanning accuracy or scanning area of ​​the final scanning light, it is necessary to ensure that each beam of light has the same power; otherwise, interference may cause a significant deviation between the combined beam and the standard beam (e.g., a sharp increase in beam sidelobes). Therefore, maintaining high-precision operation is difficult as the operating temperature of the optical switch changes or as the optical switch device ages.

[0056] In stark contrast, this invention breaks free from the reliance on the on / off mechanism of traditional optical switches. Instead, it utilizes multiple phased array units to provide a phase difference-based optical modulation method, where the phase difference between different light beams can be arbitrarily modulated within the range of 0-2π. Specifically, the optical modulation method utilizes coherent interference of light to combine beams into a new scanning beam, thereby tolerating differences in power between different light beams and even correcting for potential power differences by controlling the phase difference.

[0057] In other words, unlike traditional on / off control, this invention actually provides a continuous phase control mode, in which the beams of multiple output channels (i.e., phased array units) have different phases, and the multiple phases can be continuously distributed within the range of 0-2π.

[0058] This continuous phase control mode enables high-precision, dynamic phase matching, thus making it easier to meet the needs of precision scanning.

[0059] For example, in some embodiments, the light output by at least two different phased array units has different optical powers.

[0060] For example, in some embodiments, there may be a phase difference between the light output by at least two phased array units, and the selectable range of the phase difference is (0, 2π).

[0061] Correspondingly, see Figure 2 As shown, the method includes the following steps: S100, determine whether the scanning range is less than the preset scanning threshold; If the result of S100 is yes, then the following steps are executed: S101, determine the effective optical aperture according to the scanning conditions, wherein the scanning conditions include: scanning range, and the effective optical aperture is used to determine the minimum number of elements m of the phased array combination; S102, select at least one phased array combination, wherein the phased array combination includes x phased array elements, and m≤x<n; S103, calculate the control difficulty level when the phased array combination is used to scan the scanning interval, the control difficulty level is characterized by the phase solution difficulty level and / or energy consumption level; S104, when the control difficulty level is lower than the preset difficulty level, the modulation unit corresponding to the phased array combination is set as the enabled unit, and the modulation units corresponding to the remaining phased array units are set as candidate units; wherein, during the enabling process of the phased array combination, the operating energy consumption of the candidate unit is lower than the operating energy consumption of the candidate unit.

[0062] In laser detection applications using optical phased arrays (OPA), a larger effective optical aperture results in higher detection accuracy (angular resolution). Angular resolution (Δθ) ≈ wavelength (λ) / aperture diameter (D). The larger D is, the smaller Δθ is, and the higher the spatial resolution and pointing accuracy of the system.

[0063] The effective optical aperture size is related to the number of output waveguides (or phased array units) used, as well as the phase adjustment accuracy of each output waveguide. The larger the aperture, the higher the accuracy, but the smaller the scanning range.

[0064] In some embodiments, when the scanning range is large, a relatively large effective optical aperture can be selected to limit the overall scanning time to some extent.

[0065] In some embodiments, when the scanning range is small, a relatively small effective optical aperture can be selected to achieve higher scanning accuracy.

[0066] Preferably, in some embodiments, different recommended values ​​for effective optical aperture are preset for different scanning intervals of different sizes.

[0067] Preferably, to support scanning light with higher precision, multiple phased array units are used, that is, multiple beams are used to form a scanning light with a larger effective optical aperture. Conversely, when the effective optical aperture requirement of the scanning light is smaller, a smaller number of phased array units can be used, that is, a smaller number of beams are used to form a thinner scanning light.

[0068] Therefore, in some embodiments, different recommended numbers of phased array elements are provided for scanning light with different effective optical aperture sizes.

[0069] Specifically, in some embodiments, a recommended minimum number of phased array units, i.e., the minimum number of units m, is set for scanning light with different effective optical aperture sizes.

[0070] In some embodiments, the control difficulty level is characterized by the phase solution difficulty level and / or energy consumption level, including the following implementations: (1) Set the difficulty level according to the phase solution difficulty. When configuring scanning light using a phased array combination, it is necessary to solve for the required phase difference of each phased array element.

[0071] Specifically, the difficulty of solving the problem can be assessed by the number of iterations required to reach a stable solution. For example, in some embodiments, the number of phased array elements is small, making convergence difficult and potentially requiring a long period of iteration, or even leading to unstable solutions.

[0072] For example, in some embodiments, the more iterations, the greater the difficulty level of the solution. Or, in some embodiments, the greater the convergence difficulty during the solution process, the greater the difficulty level of the solution.

[0073] For example, in some embodiments, the positional distribution of multiple phased array elements (such as symmetry or regularity) may also affect the difficulty of the solution. For instance, when the phase difference and beam direction have a simple linear relationship, the difficulty level of the solution is relatively low.

[0074] (2) The control difficulty level can be determined based on the energy consumption level.

[0075] For example, in some embodiments, a larger number of phased array elements may result in a more stable solution, but this also increases the computational load and slows down the process. Therefore, the energy consumption level can also be determined from the perspective of computation time. The longer the computation time, the higher the energy consumption level.

[0076] (3) Determine the control difficulty level based on the phase solution difficulty level and energy consumption level. In some embodiments, the solution difficulty level and energy consumption level can be obtained by setting preset grading rules. Similarly, the control difficulty level and the solution difficulty level and energy consumption level can also have a preset mapping relationship.

[0077] For example, in some embodiments, the solution difficulty level is divided into at least Level 1 and Level 2, from lowest to highest; the energy consumption level is also divided into at least Level 1 and Level 2, from lowest to highest. Correspondingly, when both the solution difficulty level and the energy consumption level are Level 1, the control difficulty level is Level 1; when one of the solution difficulty level and the energy consumption level is Level 1 and the other is Level 2, the control difficulty level is Level 2; when both the solution difficulty level and the energy consumption level are Level 2, the control difficulty level is Level 3.

[0078] In some embodiments, the scanning range may refer to the scanning angle in the vertical direction.

[0079] Alternatively, in some embodiments, the scanning range may refer to the scanning angle in the lateral / horizontal direction.

[0080] Understandably, phased array radar can be used to achieve omnidirectional scanning in three-dimensional space. Taking the XYZ coordinate system as an example, the XY axes represent the horizontal direction, and the Z axis represents the vertical direction. The phase difference can be used to adjust the angular position of the scanning light in the horizontal direction, while the wavelength (e.g., by providing light sources of different wavelengths) can be used to adjust the angular position of the scanning light in the vertical direction.

[0081] Alternatively, in other embodiments, phase difference may be used to adjust the angular position of the scanning light in the vertical direction, while wavelength may be used to adjust the angular position of the scanning light in the horizontal direction.

[0082] In some embodiments, the scanning threshold can be preset by the user. For example, when the scanning angle is less than 180°, it is preferable to call the phased array unit of a local area for radar scanning (i.e., set the local call mode). As another example, it can be set to call the local area for radar scanning when the scanning angle is less than 270°.

[0083] For example, in some embodiments, when a full-range or large-range scan is required, radar scanning can be performed by calling phased array units in the global region (i.e., setting a global call mode).

[0084] For example, in some embodiments, the scanning range can be preset according to the scanning task. Here, the scanning range refers to the spatial area that the radar needs to scan sequentially according to a set time and a set direction.

[0085] In some embodiments, prior to S101, the following steps are included: S105, Obtain the scanning accuracy of the scanning range; S106, determine whether the scanning accuracy is greater than a preset accuracy threshold; If the result of S106 is negative, proceed to step S101.

[0086] In this embodiment, it is preferable to enable the global call mode when the scanning accuracy requirement is high.

[0087] In this embodiment, it is preferable to enable the local call mode when the scanning accuracy is relatively low.

[0088] For example, in some embodiments, see Figure 3 As shown, the method includes: Obtain the scanning accuracy of the scanning interval; Determine whether the scanning accuracy is greater than a preset accuracy threshold; If so, then execute: S101, determine the effective optical aperture according to the scanning conditions, wherein the scanning conditions include: scanning range, and the effective optical aperture is used to determine the minimum number of elements m of the phased array combination; S102, select at least one phased array combination, wherein the phased array combination includes x phased array elements, and m≤x<n; S103, calculate the control difficulty level when the phased array combination is used to scan the scanning interval, the control difficulty level is characterized by the phase solution difficulty level and / or energy consumption level; S104, when the control difficulty level is lower than the preset difficulty level, the modulation unit corresponding to the phased array combination is set as the enabled unit, and the modulation units corresponding to the remaining phased array units are set as candidate units; wherein, during the enabling process of the phased array combination, the operating energy consumption of the candidate unit is lower than the operating energy consumption of the candidate unit.

[0089] In other words, this invention provides different triggering mechanisms for local and global call modes, such as triggering based on the scanning area or scanning accuracy requirements. Alternatively, it can make a comprehensive judgment based on both the scanning area and scanning accuracy to trigger the call.

[0090] It is important to understand that for a given effective optical aperture, there may be a minimum requirement for the number of phased array elements that can be used. However, different numbers of elements will result in different difficulties in actual phase configuration. Therefore, this invention will comprehensively select a suitable phased array combination by considering the effective optical aperture, phase configuration difficulty, and scanning range.

[0091] It is understood that, in some embodiments, the evaluation steps for the phased array combination described above can be performed in real time during radar operation. Alternatively, in some embodiments, the evaluation steps can be pre-calculated before radar operation.

[0092] For example, in some embodiments, during the scanning process, new scanning schemes can be dynamically generated or selected for different scanning time periods or scanning stages, such as selecting new phased array combinations.

[0093] For example, in some embodiments, recommended phased array combinations are preset for different scanning conditions.

[0094] In some embodiments, the scanning conditions further include: scanning accuracy.

[0095] For example, in some embodiments, different effective optical apertures can be recommended for different scanning ranges.

[0096] For example, in some embodiments, different effective optical apertures can be recommended for different scanning accuracies.

[0097] Furthermore, in some embodiments, a suitable effective optical aperture can be selected based on a combination of the scanning range and scanning accuracy. For example, when the scanning range is small and the scanning accuracy is high, a larger aperture can be used. As another example, when the scanning range is large, the scanning accuracy is high, and the scanning time is limited, a slightly larger aperture can be used. Yet another example, when the scanning accuracy requirement is low, a smaller aperture can be used.

[0098] For example, in some embodiments, a recommended value for at least one effective optical aperture is set for a specific scanning range and / or scanning accuracy.

[0099] In some embodiments, it also includes: Obtain at least one image after scanning; Image recognition is performed based on at least one image to identify the target; When the target recognition completion rate is greater than a preset completion threshold, the scanning accuracy of the remaining scanning interval is allowed to be reduced.

[0100] For example, in some embodiments, the radar scans a drone. Once the complete shape information of the drone has been identified through the image, the scanning accuracy of the remaining scanning area can be appropriately reduced.

[0101] In some embodiments, phased array elements that are not currently activated can be set to a candidate state (the corresponding element is also referred to as a candidate element), such as a sleep state or a shutdown state. For example, the power consumption in the sleep state is greater than the power consumption in the shutdown state, but less than the power consumption in the activated state.

[0102] Furthermore, to optimize the candidate states, the goal is to minimize the power consumption of the candidate units while also reducing the frequency of state transitions. This limitation on the transition frequency reduces the control complexity of the control circuit and allows the optical switch to operate in a low-power state that can be quickly invoked. In other words, the optical switch has both low power consumption and the ability to immediately update its overall state in the event of unexpected situations (such as an increase in the number of targets or target movement), resulting in high update efficiency.

[0103] In some embodiments, it also includes: Predict the rate of change of the scanning light based on the task mode; The candidate state of the candidate unit is determined based on the rate of change.

[0104] In some embodiments, candidate states include: hibernation state and / or shutdown state.

[0105] Alternatively, in some embodiments, the candidate state can be set as a multi-level candidate state (correspondingly, a multi-level candidate unit can be set). In some embodiments, the task modes include: a search mode, a single-target tracking mode (e.g., the user specifies to track a single target, such as an aircraft), or a multi-target tracking mode (e.g., tracking multiple drones); wherein different task modes are configured with recommended rates of change.

[0106] The rate of change of the scanning direction of the scanning light (i.e., the direction update frequency) is mainly determined by the task requirements and target characteristics.

[0107] For example, the search mode scans the spatial domain according to a predetermined pattern (such as a grid). The rate of change of the scanning direction of the scanning light is usually stable, predictable, and typically slow (e.g., a few wavelengths per second). In this case, the candidate state can be selected based on its lower operating power consumption.

[0108] For example, single-target tracking mode involves closely following a single moving target. Its rate of change is high and irregular, entirely determined by the target's motion. Therefore, candidate states can be selected based on their relatively high power consumption.

[0109] For example, in multi-target tracking mode, the scanning light needs to switch rapidly between different targets (time-division multiplexing), resulting in the highest rate of change. Therefore, the candidate state can be selected based on the higher power consumption.

[0110] For example, in some embodiments, a recommended candidate ratio is selected based on the magnitude of the rate of change. The candidate ratio refers to the proportion of candidate cells in the overall phased array cells. For instance, the greater the rate of change, the greater the candidate ratio.

[0111] It should be noted that the proposed method of assigning candidate states by combining the predicted rate of change can avoid the problem of delay or transient instability introduced by low-power state switching. If the control circuit is turned off after each phase adjustment, it needs to be turned on again, a stable voltage / current needs to be re-established, and phase-locked again, which may introduce non-negligible delays and transient instability, and thus may miss the scanning opportunity.

[0112] In some embodiments, the excitation signal is a pulse signal (such as an optical pulse or an electrical pulse).

[0113] Example 2 See Figure 4 As shown, the present invention also provides a radar scanning system, wherein the radar scanning light is controlled by an optical switch, and the optical switch includes: a light source 1, a beam splitter 2, n phased array units 3 and a modulation unit, wherein the phased array unit 3 includes: a waveguide, and a phase change material is disposed on the waveguide; The beam splitter is used to split the light provided by the light source into multiple signal beams and transmit the signal beams to the corresponding phased array unit 3. The modulation unit is used to apply an excitation signal to the phase change material so that the phased array unit can control the phase of the signal beams passing through the waveguide. Correspondingly, the signal beams passing through multiple phased array units form scanning beams for scanning the target. Correspondingly, the system also includes: The first judgment module 100 is used to determine whether the scanning interval is less than the preset scanning threshold. If the result of the first judgment module is yes, then proceed to: Aperture determination module 101 is used to determine the effective optical aperture according to scanning conditions, wherein the scanning conditions include: scanning range, and the effective optical aperture is used to determine the minimum number of elements m of the phased array combination; Selection module 102 is used to select at least one phased array combination, wherein the phased array combination includes x phased array elements, and m≤x<n; The difficulty calculation module 103 is used to calculate the control difficulty level when the phased array combination is used to scan the scanning interval. The control difficulty level is characterized by the phase solution difficulty level and / or energy consumption level. Setting module 104 is used to set the modulation unit corresponding to the phased array combination as an enabled unit and set the modulation units corresponding to the remaining phased array units as candidate units when the control difficulty level is lower than a preset difficulty level; wherein, during the enabling process of the phased array combination, the operating energy consumption of the candidate units is lower than that of the candidate units.

[0114] In some embodiments, it also includes: A precision acquisition module is used to acquire the scanning precision of the scanning interval; The second judgment module is used to determine whether the scanning accuracy is greater than a preset accuracy threshold before entering the aperture determination module; If the result of the second judgment module is negative, then the aperture determination module is entered.

[0115] It is understood that the system in this embodiment can perform the methods or steps in any of the above embodiments, and will not be repeated here.

[0116] The purpose of this invention is to overcome the shortcomings of existing thermo-optical phase control technologies and provide a silicon photonic phased array chip and radar system based on phase change materials. This invention can achieve ultra-high-speed phase switching at the nanosecond level, and after phase setting, no power consumption is required to maintain it, fundamentally solving the problems of slow response and high power consumption of traditional technologies.

[0117] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0118] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a computer terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0119] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A radar scanning method, characterized in that, The scanning light of the radar is controlled by an optical switch, and the optical switch includes: a light source (1), a beam splitter (2), n phased array units (3) and a modulation unit. The phased array unit (3) includes: a waveguide, on which a phase change material is disposed; The beam splitter is used to split the light provided by the light source into multiple signal beams and transmit the signal beams to the corresponding phased array unit (3). The modulation unit is used to apply an excitation signal to the phase change material so that the phased array unit can control the phase of the signal beams passing through the waveguide. Correspondingly, the signal beams passing through multiple phased array units form scanning beams for scanning the target. Correspondingly, the method includes the following steps: S100, determine whether the scanning range is less than the preset scanning threshold; If the result of S100 is yes, then the following steps are executed: S101, determine the effective optical aperture according to the scanning conditions, wherein the scanning conditions include: scanning range, and the effective optical aperture is used to determine the minimum number of elements m of the phased array combination; S102, select at least one phased array combination, wherein the phased array combination includes x phased array elements, and m≤x<n; S103, calculate the control difficulty level when the phased array combination is used to scan the scanning interval, the control difficulty level is characterized by the phase solution difficulty level and / or energy consumption level; S104, when the control difficulty level is lower than the preset difficulty level, the modulation unit corresponding to the phased array combination is set as the enabled unit, and the modulation units corresponding to the remaining phased array units are set as candidate units; wherein, during the enabling process of the phased array combination, the operating energy consumption of the candidate unit is lower than the operating energy consumption of the candidate unit.

2. The method according to claim 1, characterized in that, Before S101, the following steps are included: S105, Obtain the scanning accuracy of the scanning range; S106, determine whether the scanning accuracy is greater than a preset accuracy threshold; If the result of S106 is negative, proceed to step S101.

3. The method according to claim 2, characterized in that, The scanning conditions include: scanning accuracy.

4. The method according to claim 2, characterized in that, Also includes: Obtain at least one image after scanning; Image recognition is performed based on at least one image to identify the target; When the target recognition completion rate is greater than a preset completion threshold, the scanning accuracy of the remaining scanning interval is allowed to be reduced.

5. The method according to claim 1, characterized in that, Also includes: Predict the rate of change of the scanning light based on the task mode; The candidate state of the candidate unit is determined based on the rate of change, and different candidate states correspond to different operating energy consumption levels.

6. The method according to claim 5, characterized in that, The task modes include: search mode, single target tracking mode, or multi-target tracking mode; wherein, different task modes are set with recommended change rates.

7. The method according to claim 5, characterized in that, The candidate states include: dormant state and / or off state.

8. The method according to claim 1, characterized in that, The excitation signal is a light pulse signal or thermal energy.

9. A radar scanning system, characterized in that, The scanning light of the radar is controlled by an optical switch, and the optical switch includes: a light source (1), a beam splitter (2), n phased array units (3) and a modulation unit. The phased array unit (3) includes: a waveguide, on which a phase change material is disposed; The beam splitter is used to split the light provided by the light source into multiple signal beams and transmit the signal beams to the corresponding phased array unit (3). The modulation unit is used to apply an excitation signal to the phase change material so that the phased array unit can control the phase of the signal beams passing through the waveguide. Correspondingly, the signal beams passing through multiple phased array units form scanning beams for scanning the target. Correspondingly, the system also includes: The first judgment module is used to determine whether the scanning interval is less than the preset scanning threshold; If the result of the first judgment module is yes, then proceed to: An aperture determination module is used to determine an effective optical aperture based on scanning conditions, wherein the scanning conditions include a scanning range, and the effective optical aperture is used to determine the minimum number of elements m of the phased array combination. The selection module is used to select at least one phased array combination, wherein the phased array combination includes x phased array elements, and m≤x<n; The difficulty calculation module is used to calculate the control difficulty level when the phased array combination is used to scan the scanning interval. The control difficulty level is characterized by the phase solution difficulty level and / or energy consumption level. The setting module is used to set the modulation unit corresponding to the phased array combination as the enabled unit and set the modulation units corresponding to the remaining phased array units as candidate units when the control difficulty level is lower than the preset difficulty level; wherein, during the enabling process of the phased array combination, the operating energy consumption of the candidate units is lower than that of the candidate units.

10. The system according to claim 9, characterized in that, Also includes: A precision acquisition module is used to acquire the scanning precision of the scanning interval; The second judgment module is used to determine whether the scanning accuracy is greater than a preset accuracy threshold before entering the aperture determination module; If the result of the second judgment module is negative, then the aperture determination module is entered.

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