A method and system for improving the tracking performance of an opto-electronic pod using a fast steering mirror

Abstract

A method and system for improving the tracking performance of an optoelectronic pod using a fast mirror. It belongs to the technical field of optoelectronic pod control. The method comprises the following steps: constructing a dual-channel tracking control system, adding a fast mirror tracking channel, and forming a decoupled dual-channel with the original servo frame channel to cooperatively achieve dynamic tracking control of the target image; obtaining target off-target information output by the image tracker, and calculating the visual axis deviation angle of the target in the horizontal X-axis and vertical Y-axis directions respectively; dividing the visual axis deviation angle into small-amplitude high-frequency signals or large-amplitude low-frequency signals according to the maximum swing angle capability of the fast mirror as a threshold; when the visual axis deviation angle is a small-amplitude high-frequency signal, the fast mirror performs tracking compensation, and the servo frame mechanism performs follow-up compensation to extend the travel of the fast mirror; when the visual axis deviation angle is a large-amplitude low-frequency signal, the fast mirror remains in the middle position, and the servo frame channel independently completes target tracking control.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optoelectronic pod control, and particularly relates to a method and system for improving the tracking performance of an optoelectronic pod by using a fast mirror. BACKGROUND

[0002] As a core optoelectronic observation device on a modern flight platform (such as a UAV, a helicopter, or a fixed-wing aircraft), an optoelectronic pod is widely used in tasks such as reconnaissance and surveillance, target identification, weapon guidance, and fire control. A high-performance optoelectronic pod is usually composed of a two-axis servo frame (for realizing azimuth and pitch motion control), a fast mirror mechanism (for image secondary stabilization and flyback compensation), an optical imaging system, a visible light / infrared detection module, an image tracker, a laser range finder or indicator, and the like.

[0003] To realize continuous and stable tracking of a target, an existing optoelectronic pod generally adopts a closed-loop control mode based on image tracking and servo attitude adjustment. An image tracker identifies and locates the position of a target in a current frame of image and outputs a target deviation signal (i.e., a miss distance). After processing, the miss distance signal is input into a servo frame control system, and the boresight direction is adjusted by controlling the attitude of the pod, so that the target is kept at the center of the boresight. However, the above tracking mechanism based on a single servo frame channel has obvious performance bottlenecks. On the one hand, the output of the image tracker is limited by the frame frequency of the detector, and the update rate is limited, which restricts the system bandwidth. On the other hand, the servo frame mechanism has a large volume and high moment of inertia, and the response speed is relatively slow, so it is difficult to effectively track a high-frequency fast-moving target, which may lead to image jitter, response lag, and even target loss. SUMMARY

[0004] To solve the technical problem of obvious performance bottlenecks in the tracking mechanism of a single servo frame channel, the application provides a method for improving the tracking performance of an optoelectronic pod by using a fast mirror. The method comprises the following steps:

[0005] S1. A dual-channel tracking control system is constructed, a fast mirror tracking channel is added, and a decoupled dual channel is formed with the original servo frame channel, so as to realize dynamic tracking control of a target image in cooperation.

[0006] S2. Target miss distance information output by an image tracker is acquired, and boresight deviation angles of the target in horizontal X-axis and vertical Y-axis directions are calculated, respectively.

[0007] S3. The maximum swing angle capability of the fast mirror is taken as a threshold value, and the boresight deviation angles are divided into small-amplitude high-frequency signals or large-amplitude low-frequency signals.

[0008] S4. When the line-of-sight deviation angle is a small-amplitude high-frequency signal, the fast reflector performs the tracking compensation function, and the servo frame mechanism performs follow-up compensation to extend the travel of the fast reflector; when the line-of-sight deviation angle is a large-amplitude low-frequency signal, the fast reflector maintains the intermediate position, and the servo frame channel independently completes the target tracking control.

[0009] Furthermore, the fast reflector tracking channel is specifically as follows: the photoelectric pod image tracker transmits the miss distance signal to the servo control system, the servo control system performs signal discrimination and calculation processing, and then transmits it to the fast reflector.

[0010] Furthermore, the target's line-of-sight deviation angle in the horizontal X-axis direction. pass:

[0011] get;

[0012] The number of pixels the target is offset from the center of the view axis on the horizontal X-axis, i.e., the miss distance;

[0013] Detector pixel size;

[0014] : Focal length of the imaging system;

[0015] : Convert radians to degrees as a unit factor.

[0016] Furthermore, the target's line-of-sight deviation angle in the vertical Y-axis direction. pass:

[0017] ;

[0018] The number of pixels the target is offset from the center of the view axis on the vertical Y-axis, i.e., the miss distance.

[0019] Furthermore, the threshold in step S3 is determined by: get;

[0020] : The threshold for determining the magnitude of the line-of-sight deviation angle;

[0021] : The maximum mechanical swing angle of the fast-reflecting mirror;

[0022] : Scaling factor of the optical system.

[0023] Furthermore, the line-of-sight deviation angle is divided into small-amplitude high-frequency signals or large-amplitude low-frequency signals, specifically as follows: [The text abruptly ends here, likely due to an incomplete sentence or a formatting error.] and The maximum value in is denoted as ,when It belongs to a small-amplitude high-frequency signal, when At that time, it belongs to a large low-frequency signal.

[0024] Furthermore, when the fast-reflecting mirror performs the tracking compensation function, the servo control system... and The data is passed to the fast reflector, which then performs the tracking task. The rotation angle is calculated by the fast reflector during tracking as follows:

[0025] ,in, This indicates the angle that the fast-reflecting mirror needs to rotate along the horizontal X-axis;

[0026] ,in, This indicates the angle that the fast-reflecting mirror needs to rotate along the vertical Y-axis.

[0027] Furthermore, when the servo frame channel independently completes target tracking control, the servo control system controls the servo frame mechanism to compensate for the target's line-of-sight deviation angle in the horizontal X-axis direction. And the target's line-of-sight deviation angle in the vertical Y-axis direction. .

[0028] Furthermore, the present invention also provides a system for improving the tracking performance of an electro-optical pod using a fast-reflecting mirror, the system comprising:

[0029] This unit is used to construct a dual-channel tracking control system, adding a fast-reflecting mirror tracking channel to form a decoupled dual channel with the original servo frame channel, which works together to achieve dynamic tracking control of the target image.

[0030] The unit is used to obtain the target miss distance information output by the image tracker and to calculate the target's line-of-sight deviation angle in the horizontal X-axis and vertical Y-axis directions, respectively.

[0031] This unit is used to divide the line-of-sight deviation angle into small-amplitude high-frequency signals or large-amplitude low-frequency signals based on the maximum swing angle capability of the fast reflector.

[0032] This unit is used when the line-of-sight deviation angle is a small-amplitude, high-frequency signal, the fast reflector performs the tracking compensation function, and the servo frame mechanism performs follow-up compensation to extend the travel of the fast reflector; when the line-of-sight deviation angle is a large-amplitude, low-frequency signal, the fast reflector maintains the intermediate position, and the servo frame channel independently completes the target tracking control.

[0033] The beneficial effects of the method described in this invention are as follows:

[0034] This method, while maintaining the existing hardware architecture of the optoelectronic pod, adds a high-speed tracking channel using a fast reflector as the actuator, forming a composite decoupled dual-channel tracking control system with the original servo-frame-based tracking channel. The target miss distance is acquired in real time by an image tracker, the line-of-sight deviation angle is calculated, and dynamic channel allocation is performed based on the deviation angle amplitude characteristics: when the line-of-sight deviation angle is below a set threshold, the fast reflector performs high-frequency, small-angle tracking, and the servo-frame system provides follow-up compensation; when the line-of-sight deviation angle is greater than or equal to the threshold, the servo-frame system independently completes the tracking task, and the fast reflector remains in a neutral position. This method fully combines the high bandwidth and low inertia characteristics of the fast reflector with the large stroke capability of the servo-frame to achieve high-precision tracking of high-speed, small targets, significantly improving the tracking speed and accuracy of the optoelectronic pod without changing the original system structure. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of constructing a fast reflector tracking loop in an embodiment of the present invention;

[0036] Figure 2 This is a flowchart illustrating a method for improving the tracking performance of an optoelectronic pod using a fast-reflecting mirror, as described in an embodiment of the present invention. Detailed Implementation

[0037] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0038] Example 1

[0039] Although existing optoelectronic pods are equipped with fast reflector devices, primarily for image stabilization and retrace compensation under attitude disturbance conditions, and possess advantages such as high bandwidth, low inertia, and fast response speed, their role in the target tracking control loop has not been fully utilized. Therefore, this embodiment proposes a dual-channel target tracking method based on the coordinated control of a fast reflector and a servo frame. Without altering the existing optoelectronic pod hardware structure and signal path, a new high-speed tracking channel is constructed by introducing a fast reflector, forming a decoupled and collaborative dual-channel tracking architecture with the original servo control channel. This method fully utilizes the high-frequency compensation capability of the fast reflector, complementing the wide-range attitude adjustment capability of the servo frame, thereby significantly improving the overall tracking response speed and image stabilization accuracy of the optoelectronic pod system.

[0040] In this embodiment, the original hardware connections of the photoelectric pod system are maintained, and a tracking loop with a fast reflector as the actuator is added to construct a dual-channel tracking control loop. For example...Figure 1 As shown, the original image tracker and servo control system consisted of a single tracking loop. When the optoelectronic pod was in tracking mode, the miss signal generated by the image tracker was transmitted to the servo frame control system. After calculation, the servo frame completed the tracking function, and the fast reflector was in the middle position at this time. The servo control system and the fast reflector consisted of an image stabilization and retrace control loop. When the pod was in image stabilization or retrace, the servo control system received the gyro residual data or retrace command and transmitted it to the fast reflector system. The fast reflector completed the two-stage image stabilization or retrace compensation function. In this invention, the original signal transmission loop remains unchanged, and an additional tracking loop is added. The miss signal from the optoelectronic pod image tracker is transmitted to the servo frame control system, which performs signal discrimination and calculation processing before transmitting it to the fast reflector system. The fast reflector completes the tracking compensation, and the servo frame mechanism performs follow-up compensation, forming a dual tracking loop with the previous tracking loop.

[0041] Example 2

[0042] This embodiment is a further explanation of Embodiment 1, such as... Figure 2 As shown, the method for improving the tracking performance of an electro-optical pod using a fast-reflecting mirror is as follows:

[0043] Step 1: Construct a dual-channel tracking control system, adding a fast-reflecting mirror tracking channel to form a decoupled dual channel with the original servo frame channel, which work together to achieve dynamic tracking control of the target image;

[0044] Step 2: Obtain the target miss distance information output by the image tracker, and calculate the target's line-of-sight deviation angle in the horizontal X-axis and vertical Y-axis directions respectively;

[0045] Step 3: Based on the maximum swing angle capability of the fast reflector as the threshold, the line deviation angle is divided into small-amplitude high-frequency signals or large-amplitude low-frequency signals;

[0046] Step 4: When the line-of-sight deviation angle is a small high-frequency signal, the fast reflector performs the tracking compensation function, and the servo frame mechanism performs follow-up compensation to extend the travel of the fast reflector; when the line-of-sight deviation angle is a large low-frequency signal, the fast reflector maintains the intermediate position, and the original servo frame channel independently completes the target tracking control.

[0047] The fast reflector tracking channel is as follows: the photoelectric pod image tracker transmits the miss distance signal to the servo control system, the servo control system performs signal discrimination and calculation processing, and then transmits it to the fast reflector system.

[0048] Target's line-of-sight deviation angle in the horizontal X-axis direction pass:

[0049] get;

[0050] The number of pixels the target is offset from the center of the line of sight along the horizontal X-axis, i.e., the miss distance, in degrees;

[0051] Detector pixel size, unit: mm;

[0052] Focal length of the imaging system, unit: mm;

[0053] : Convert radians to degrees as a unit factor.

[0054] Target's line-of-sight deviation angle in the vertical Y-axis direction pass:

[0055] ;

[0056] The number of pixels the target is offset from the center of the view axis on the vertical Y-axis, i.e., the miss distance, in degrees.

[0057] , as well as , These represent the line-of-sight deviation angle and miss distance of the tracked target in the X and Y axes, respectively.

[0058] The threshold in step S3 is passed through: get;

[0059] : Threshold for determining the magnitude of the line-of-sight deviation angle, unit: °;

[0060] : Maximum mechanical swing angle of the fast reflector, unit: °;

[0061] The scaling factor (field compression ratio) of the optical system is usually greater than 1.

[0062] The coefficient 2 is based on the double-angle principle in the law of reflection in physical optics. When the mirror rotates... At an angle, the direction of the reflected light changes. .

[0063] The change in the angle of the fast reflector corresponds to the change in the line-of-sight angle of the optical system. The scaling factor, specifically determined by the optical design, is typically greater than 1; the maximum mechanical swing angles along the X and Y axes of a fast-reflecting mirror are the same, so a scaling factor is used. express.

[0064] The eye axis deviation angle is divided into small-amplitude high-frequency signals or large-amplitude low-frequency signals, specifically as follows: [The text abruptly ends here, likely due to an incomplete sentence or a missing section.] and The maximum value in is denoted as ,when It belongs to a small-amplitude high-frequency signal, when At that time, it belongs to a large low-frequency signal.

[0065] The two tracking channels switch mutually exclusively based on threshold judgment, avoiding the fast reflector and servo frame from controlling the same line-of-sight deviation at the same time, thus ensuring system stability and control decoupling.

[0066] When the fast reflector performs the tracking compensation function, the servo control system... and The data is passed to the fast reflector, which then performs the tracking task. The rotation angle is calculated by the fast reflector during tracking as follows:

[0067] ,in, This indicates the angle that the fast-reflecting mirror needs to rotate along the horizontal X-axis;

[0068] ,in, This indicates the angle that the fast-reflecting mirror needs to rotate along the vertical Y-axis.

[0069] The rapid rotation of the reflector keeps the target at the center of the line of sight at all times, and the servo frame position is compensated for in the horizontal X-axis direction relative to the current position by approximately And the follower compensation in the vertical Y-axis direction To ensure that the angle of the fast reflector is always in the center position, the servo frame system extends the travel of the fast reflector by following its movement, allowing the line of sight controlled by the fast reflector to track the target over a wide range.

[0070] When the fast reflector performs tracking compensation, the miss angle and The data is transmitted to the fast-reflecting mirror. After the fast-reflecting mirror performs tracking, it sends a feedback value based on the real-time angle of movement of the mirror to the servo system for follow-up. Because it is a feedback value, there is an error. Therefore, the angle that the servo system follows based on the feedback value from the fast-reflecting mirror is approximately equal to... and However, it will not be exactly equal. When the servo frame channel independently performs target tracking control. Miss angle. and The data is transmitted to the servo frame mechanism, which serves as the basis for the servo system to control the movement of the servo mechanism.

[0071] When the servo frame channel independently performs target tracking control, the servo control system controls the servo frame mechanism to compensate for the target's line-of-sight deviation angle in the horizontal X-axis direction. And the target's line-of-sight deviation angle in the vertical Y-axis direction. This ensures the target is always centered on the line of sight, while the fast-reflecting mirror remains in the neutral position, preventing malfunctions and control conflicts. This state typically occurs during target acquisition when the target has a large angle of line of sight deviation.

[0072] because It only appears during the acquisition phase. Once the target is pulled back to the center of the line of sight by the servo frame system, it will switch to fast mirror tracking and servo frame system follow-up compensation state. Therefore, in actual work, the two states will not often switch or conflict with each other.

Claims

1. A method for improving the tracking performance of an electro-optical pod using a fast-reflecting mirror, characterized in that, The method includes the following steps: S1. Construct a dual-channel tracking control system, add a fast reflector tracking channel, and form a decoupled dual channel with the original servo frame channel. The two work together to achieve dynamic tracking control of the target image. S2. Obtain the target miss distance information output by the image tracker, and calculate the target's line-of-sight deviation angle in the horizontal X-axis and vertical Y-axis directions respectively; S3. Use the maximum swing angle capability of the fast-reflecting mirror as the threshold. The line-of-sight deviation angle is divided into small-amplitude high-frequency signals or large-amplitude low-frequency signals; Specifically: Take and The maximum value in is denoted as ,when It belongs to a small-amplitude high-frequency signal, when At that time, it belongs to a large low-frequency signal; in, This represents the line-of-sight deviation angle of the target in the horizontal X-axis direction. This indicates the line-of-sight deviation angle of the target in the direction perpendicular to the Y-axis; S4. When the line-of-sight deviation angle is a small-amplitude high-frequency signal, the fast reflector performs the tracking compensation function, and the servo frame mechanism performs follow-up compensation to extend the travel of the fast reflector; when the line-of-sight deviation angle is a large-amplitude low-frequency signal, the fast reflector maintains the intermediate position, and the servo frame channel independently completes the target tracking control.

2. The method for improving the tracking performance of an optoelectronic pod using a fast-reflecting mirror according to claim 1, characterized in that, The fast reflector tracking channel is as follows: the photoelectric pod image tracker transmits the miss distance signal to the servo control system, the servo control system performs signal discrimination and calculation processing, and then transmits it to the fast reflector.

3. The method for improving the tracking performance of an optoelectronic pod using a fast-reflecting mirror according to claim 2, characterized in that, Target's line-of-sight deviation angle in the horizontal X-axis direction pass: get; The number of pixels the target is offset from the center of the view axis on the horizontal X-axis, i.e., the miss distance; Detector pixel size; : Focal length of the imaging system; : Convert radians to degrees as a unit factor.

4. The method for improving the tracking performance of an optoelectronic pod using a fast-reflecting mirror according to claim 3, characterized in that, Target's line-of-sight deviation angle in the vertical Y-axis direction pass: ； The number of pixels the target is offset from the center of the view axis on the vertical Y-axis, i.e., the miss distance.

5. The method for improving the tracking performance of an optoelectronic pod using a fast-reflecting mirror according to claim 4, characterized in that, The threshold in step S3 is passed through: get; : The maximum mechanical swing angle of the fast-reflecting mirror; : Scaling factor of the optical system.

6. The method for improving the tracking performance of an optoelectronic pod using a fast-reflecting mirror according to claim 5, characterized in that, When the fast reflector performs the tracking compensation function, the servo control system... and The data is passed to the fast reflector, which then performs the tracking task. The rotation angle is calculated by the fast reflector during tracking as follows: ,in, This indicates the angle that the fast-reflecting mirror needs to rotate along the horizontal X-axis; ,in, This indicates the angle that the fast-reflecting mirror needs to rotate along the vertical Y-axis.

7. The method for improving the tracking performance of an optoelectronic pod using a fast-reflecting mirror according to claim 6, characterized in that, When the servo frame channel independently performs target tracking control, the servo control system controls the servo frame mechanism to compensate for the target's line-of-sight deviation angle in the horizontal X-axis direction. And the target's line-of-sight deviation angle in the vertical Y-axis direction. .

8. A system for improving the tracking performance of an electro-optical pod using a fast-reflecting mirror, characterized in that, The system includes: This unit is used to construct a dual-channel tracking control system, adding a fast-reflecting mirror tracking channel to form a decoupled dual channel with the original servo frame channel, which works together to achieve dynamic tracking control of the target image. The unit is used to obtain the target miss distance information output by the image tracker and to calculate the target's line-of-sight deviation angle in the horizontal X-axis and vertical Y-axis directions, respectively. This unit is used to divide the line-of-sight deviation angle into small-amplitude high-frequency signals or large-amplitude low-frequency signals based on the maximum swing angle capability of the fast reflector. Specifically: Take and The maximum value in is denoted as ,when It belongs to a small-amplitude high-frequency signal, when At that time, it belongs to a large low-frequency signal; in, This represents the line-of-sight deviation angle of the target in the horizontal X-axis direction. This indicates the line-of-sight deviation angle of the target in the direction perpendicular to the Y-axis; This unit is used when the line-of-sight deviation angle is a small-amplitude, high-frequency signal, the fast reflector performs the tracking compensation function, and the servo frame mechanism performs follow-up compensation to extend the travel of the fast reflector; when the line-of-sight deviation angle is a large-amplitude, low-frequency signal, the fast reflector maintains the intermediate position, and the servo frame channel independently completes the target tracking control.

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