Photoelectric platform frame type reverse scanning compensation control method

Abstract

The invention provides a photoelectric platform frame type reverse scanning compensation control method. The photoelectric platform frame type reverse scanning compensation control method comprises the steps of 1, initializing parameters of a frame; step 2, determining a sight line movement track in a reverse scanning period, dividing the sight line movement track into a plurality of track segments, and generating track parameters of each track segment; step 3, generating positive feedback data according to the track parameters in the step 2, and adding the track parameters and the positive feedback data into a reverse scanning controller according to time; and 4, controlling the reverse scanning compensation of the photoelectric platform frame through the positive feedback of the reverse scanning controller. According to the method, the angular position, the angular speed and the angular acceleration trajectory planning of the frame motion are generated by utilizing a positive feedback control method, the photoelectric platform frame reverse scanning compensation under the variable speed high ratio is realized, and compared with direct closed-loop control, the reverse scanning speed and frequency can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of automatic control, and in particular relates to a frame-type backscan compensation control method for an optoelectronic platform. Background Art

[0002] An optoelectronic platform installed on a fast flying platform, mainly used for photographic reconnaissance of the ground. It requires that during the exposure process of the optical sensor, backscanning compensates for the image blur caused by the high-speed movement of the flying platform, and the line of sight can stably maintain the same imaging scene to produce a clear image.

[0003] The existing backscan compensation method is to add a fast mirror in the optical path, and use the fast mirror's high precision and large bandwidth to move quickly, thereby controlling the line of sight to produce a small-angle reciprocating motion, so that the line of sight remains inertial and always aims at the same area during the sensor exposure process. However, this backscan compensation method increases the difficulty and complexity of optical design. For multi-sensor optical systems, since only one fast mirror is usually used, a multi-sensor common optical path design must be adopted. The multi-sensor common optical path has very high requirements for processing accuracy, cost, and assembly process, and the fast mirror itself is relatively expensive and large in size. Therefore, in some high-value, large-volume optoelectronic equipment, a multi-sensor common optical path solution is more commonly used.

[0004] In order to avoid complex optical design and high cost, a frame backsweep method was designed to replace the fast mirror as an actuator for backsweep compensation. However, due to the large load of the frame backsweep method and the limited torque of the actuator motor, it is difficult to achieve high-precision and fast-response frame backsweep motion with traditional control methods.

[0005] Zhang Xiaoting, an author from Harbin Institute of Technology Shenzhen Graduate School, published "Curve Motion Trajectory Control Based on Speed ​​Compensation", which proposed an adaptive real-time interpolation algorithm based on NURBS curves to control the offset between the feed speed and the planned speed to always be within an error range to ensure the smoothness of the feed speed. This algorithm is used for CNC machine tool processing parts, but it has not been used in the control field. Qu Weiran, an author from the School of Automation of Beijing University of Aeronautics and Astronautics, published "Design of Inertial Image Stabilization Control System Based on Scanning Reflector", which designed an image stabilization control algorithm for the transmission-type image stabilization configuration with inertial stabilization wheels based on the inertial stabilization platform of the scanning reflector to further improve the image stabilization accuracy.

[0006] The Chinese patent publication with publication number CN112689084 discloses an airborne optoelectronic reconnaissance imaging system and an electronic image stabilization method, which utilizes an image stabilization platform composed of inertial devices and servo control components to compensate for the relative motion of the imaging sensor. The electronic image stabilization method is mainly used to solve the image shaking problem caused by the irregular shaking of the optoelectronic detection platform with the carrier aircraft, but it does not consider the problem of periodic backscanning imaging.

[0007] How to use the frame movement of the optoelectronic platform to compensate for the image blur caused by the carrier movement during the sensor exposure time by backscanning motion without using a fast mirror. However, the existing frame control method has a slow response speed and poor control accuracy, which makes it difficult to meet the needs of fast and accurate compensation. Summary of the invention

[0008] The purpose of the present invention is to solve the problem that the frame control method in the prior art is difficult to meet the requirements of fast and accurate compensation, and to provide an optoelectronic platform frame backscan compensation control method. By using a positive feed control method, the angular position, angular velocity and angular acceleration trajectory planning of the frame movement are generated to realize the backscan compensation of the optoelectronic platform frame under a high speed ratio.

[0009] To achieve the above purpose, the technical solution provided by the present invention is:

[0010] A photoelectric platform frame type backscan compensation control method, comprising:

[0011] Step 1: Initialize the parameters of the framework, where the parameters include: maximum angular acceleration α max 、Current sight angle θ stop , the desired sight angle θ zero , the desired line of sight angular velocity ω exp , operation cycle T s , the gaze time required for imaging t k ;

[0012] Step 2: determining a sight line motion trajectory within a backscan cycle, dividing the sight line motion trajectory into a plurality of trajectory segments, and generating trajectory parameters of each trajectory segment, wherein the trajectory parameters include: sight line angle, velocity, and acceleration;

[0013] Step 3: Generate feedforward data according to the trajectory parameters of step 2, and add the trajectory parameters and the feedforward data to the backsweep controller according to time; wherein the feedforward data includes a velocity and acceleration feedforward table;

[0014] Step 4: The backsweep controller is used to feedforward control the backsweep compensation of the optoelectronic platform frame, wherein: when the backsweep start requirements are met, the backsweep controller generates a backsweep start signal; when the backsweep end requirements are met, the backsweep controller generates a backsweep end signal; when the backsweep preset requirements are met, the backsweep controller generates a backsweep initialization signal.

[0015] As a further limitation of the present invention, in step 2, dividing the sight line movement trajectory into a plurality of trajectory segments includes:

[0016] The eye movement trajectory is divided into 4 stages from S1 to S4, where:

[0017] The S1 phase includes the line of sight moving from the initial position θ stop Move to the exposure start position θ zero , In the S1 stage, the angular velocity of the line of sight decelerates from 0 to the angular velocity that needs to be compensated for the backscan;

[0018] The S2 stage includes the speed maintenance stage during the line of sight movement. In the S2 stage, the angular velocity of the line of sight remains unchanged;

[0019] Phase S3 includes the gaze movement back to the initial position θ stop In the acceleration stage, the angular velocity of the line of sight in stage S3 is accelerated from the angular velocity maintained during the backscanning in stage S2 to a suitable angular velocity;

[0020] The S4 stage includes the deceleration stage of the line of sight movement. In the S4 stage, the line of sight angle returns to the initial position θ stop , the line of sight speed is 0.

[0021] As a further limitation of the present invention, in step 2, generating trajectory parameters of each trajectory segment includes:

[0022] (21) Calculate the angle, angular velocity, and angular acceleration trajectory of the S1 stage. The S1 stage controls the uniform deceleration angular motion of the frame. When the line of sight motion in the S1 stage reaches the expected speed, the line of sight angle is also equal to the expected line of sight angle. The calculation formula is:

[0023]

[0024] In formula (1), k represents the kth calculation cycle, a(k) represents the angular acceleration at the kth calculation cycle, and w exp represents the desired line-of-sight angular velocity, θ zero represents the desired sight angle, θ stop represents the initial position of the line of sight, w(k) represents the angular velocity at the kth calculation cycle, θ(k) represents the angle at the kth calculation cycle, and t s represents the operation cycle, t1 represents the time when the S1 stage ends;

[0025] (22) Calculate the angle, angular velocity, and angular acceleration trajectory of the S2 stage. The control frame in the S2 stage moves at a uniform angular speed, and the line of sight angular velocity is equal to the expected velocity. The calculation formula is:

[0026]

[0027] In formula (2), θ2 represents the sight line position at the end of stage S1, and t2 represents the time when stage S1 ends;

[0028] (23) Calculate the angle, angular velocity, and angular acceleration trajectory of the S3 stage. In the S3 stage, the control frame uniformly accelerates the angular motion, so that the angular velocity of the line of sight changes direction and reaches ω3, so that when the angular velocity is 0 in the next deceleration stage, the angular position just returns to the preset angle of the next backscan cycle. The calculation formula is:

[0029]

[0030] In formula (3), α max represents the maximum angular acceleration, ω3 represents the line of sight velocity at the end of stage S3, t3 represents the time at the end of stage S3, and θ3 represents the line of sight position at the end of stage S3;

[0031] (24) Calculate the angle, angular velocity, and angular acceleration trajectory of the S4 stage. The S4 stage controls the uniform deceleration angular motion of the frame. When the line of sight motion in the S4 stage reaches the expected speed, the line of sight angle is also equal to the expected line of sight angle. The calculation formula is:

[0032]

[0033] Wherein, t4 represents the time when the S4 stage ends.

[0034] As a further limitation of the present invention, the step three is specifically:

[0035] According to the sight angle, velocity and acceleration of step 2, a velocity and acceleration feedforward table is generated, and the calculated angle, velocity and acceleration feedforward table is added to the backsweep controller according to time; wherein:

[0036] The frame-type backsweep compensation servo system is a three-loop closed-loop control system, which includes a current loop, a speed loop, and a position loop. GM represents a current loop controller, Gc represents a speed loop controller, Gf represents a position loop control, KI represents a current sampling gain, Kg represents a speed sampling gain, Kp represents a position sampling gain, a(k), w(k), and θ(k) represent the backsweep trajectory generated in step 2, θ(k) serves as an input command of the position loop, w(k) serves as a positive feedback input of the speed loop, and a(k) serves as a positive feedback input of the current loop.

[0037] As a further limitation of the present invention, in the step 4:

[0038] When the backsweep start requirement is met, the backsweep controller generates a backsweep start signal, including:

[0039] Determine the angle and speed values, when the expected sight angle θ meets the backscan requirement zero and the desired line-of-sight angular velocity ω exp When , a signal for the start of backsweep is generated;

[0040] When the backsweep end requirement is met, the backsweep controller generates a backsweep end signal, including:

[0041] When maintaining the desired line of sight angular velocity ω exp The gaze time t exceeds the required imaging time k After that, a backsweep end signal is generated; when the backsweep preset requirements are met, the backsweep controller generates a backsweep initialization signal, including:

[0042] When the sight angle returns to the preset angle of the backscan, the current sight angle is maintained, the backscan ends, and the next backscan start signal is waited for.

[0043] As a further limitation of the present invention, the steps 1 to 4 are executed cyclically according to a servo control cycle to complete the backscan compensation.

[0044] The advantages of the present invention are:

[0045] 1. The present invention utilizes a feedforward control method to generate trajectory planning of the angular position, angular velocity and angular acceleration of the frame motion, thereby realizing backsweep compensation of the optoelectronic platform frame under a variable speed ratio. Compared with direct closed-loop control, the speed and frequency of the backsweep can be effectively improved.

[0046] 2. The present invention does not need to add a fast-reflecting mirror, and only needs to use the frame of the optoelectronic platform itself to realize the backscan compensation function, compensate for the image blur caused by the high-speed translation of the carrier of the optoelectronic platform, simplify the optical path design and complexity, reduce the volume and weight of the optoelectronic platform, and save hardware costs.

[0047] 3. The present invention is implemented by software, has a simple algorithm, is highly portable, and is suitable for various optoelectronic systems that require backscan compensation functions.

[0048] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0050] Figure 1 : A flow chart of a photoelectric platform frame type backscan compensation control method provided by the present invention;

[0051] Figure 2 : The frame backsweep control phase diagram provided by the present invention;

[0052] Figure 3 : Schematic diagram of the reverse scanning servo control principle of the optoelectronic system provided by the present invention;

[0053] Figure 4 : The position trajectory map generated by the embodiment provided by the present invention;

[0054] Figure 5 : The speed trajectory diagram generated by the embodiment provided by the present invention;

[0055] Figure 6 : The acceleration trajectory diagram generated by the embodiment provided by the present invention. DETAILED DESCRIPTION

[0056] Embodiments of the present invention are described in detail below. The embodiments are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0057] See also Figure 1 The embodiment of the present invention provides a photoelectric platform frame type backscan compensation control method, comprising:

[0058] Step 1: Initialize the parameters of the framework, including: maximum angular acceleration α max 、Current sight angle θ stop , the desired sight angle θ zero , the desired line of sight angular velocity ω exp , operation cycle T s , the gaze time required for imaging t k .

[0059] Step 2: determine the sight line motion trajectory within a backscan cycle, divide the sight line motion trajectory into multiple trajectory segments, and generate trajectory parameters for each trajectory segment, wherein the trajectory parameters include: sight line angle, speed, and acceleration.

[0060] In step 2 of the embodiment of the present invention, dividing the sight line movement trajectory into multiple trajectory segments includes: dividing the sight line movement trajectory into four stages S1-S4, wherein:

[0061] The S1 phase includes the line of sight moving from the initial position θ stop Move to the exposure start position θ zero , In the S1 stage, the angular velocity of the line of sight decelerates from 0 to the angular velocity that needs to be compensated for the backscan;

[0062] The S2 stage includes the speed maintenance stage during the line of sight movement. In the S2 stage, the angular velocity of the line of sight remains unchanged;

[0063] Phase S3 includes the gaze movement back to the initial position θ stop In the acceleration stage, the angular velocity of the line of sight in stage S3 is accelerated from the angular velocity maintained during the backscanning in stage S2 to a suitable angular velocity;

[0064] The S4 stage includes the deceleration stage of the line of sight movement. In the S4 stage, the line of sight angle returns to the initial position θ stop, the line of sight speed is 0.

[0065] In the above step 2 of the embodiment of the present invention, generating the trajectory parameters of each trajectory segment includes:

[0066] (21) Calculate the angle, angular velocity, and angular acceleration trajectory of the S1 stage. The S1 stage controls the uniform deceleration angular motion of the frame. When the line of sight motion in the S1 stage reaches the expected speed, the line of sight angle is also equal to the expected line of sight angle. The calculation formula is:

[0067]

[0068] In formula (1), k represents the kth calculation cycle, a(k) represents the angular acceleration at the kth calculation cycle, and w exp represents the desired line-of-sight angular velocity, θ zero represents the desired sight angle, θ stop represents the initial position of the line of sight, w(k) represents the angular velocity at the kth calculation cycle, θ(k) represents the angle at the kth calculation cycle, and t s represents the operation cycle, t1 represents the time when the S1 stage ends;

[0069] (22) Calculate the angle, angular velocity, and angular acceleration trajectory of the S2 stage. The control frame in the S2 stage moves at a uniform angular speed, and the line of sight angular velocity is equal to the expected velocity. The calculation formula is:

[0070]

[0071] In formula (2), θ2 represents the sight line position at the end of stage S1, and t2 represents the time when stage S1 ends;

[0072] (23) Calculate the angle, angular velocity, and angular acceleration trajectory of the S3 stage. In the S3 stage, the control frame uniformly accelerates the angular motion, so that the angular velocity of the line of sight changes direction and reaches ω3, so that when the angular velocity is 0 in the next deceleration stage, the angular position just returns to the preset angle of the next backscan cycle. The calculation formula is:

[0073]

[0074] In formula (3), α max represents the maximum angular acceleration, ω3 represents the line of sight velocity at the end of stage S3, t3 represents the time at the end of stage S3, and θ3 represents the line of sight position at the end of stage S3;

[0075] (24) Calculate the angle, angular velocity, and angular acceleration trajectory of the S4 stage. The S4 stage controls the uniform deceleration angular motion of the frame. When the line of sight motion in the S4 stage reaches the expected speed, the line of sight angle is also equal to the expected line of sight angle. The calculation formula is:

[0076]

[0077] Wherein, t4 represents the time when the S4 stage ends.

[0078] Step three: Generate feedforward data according to the trajectory parameters of step two, and add the trajectory parameters and feedforward data to the backsweep controller according to time; wherein the feedforward data includes velocity and acceleration feedforward tables.

[0079] Step 3 of the embodiment of the present invention is specifically: according to the sight angle, speed and acceleration of step 2, a speed and acceleration feedforward table is generated, and the calculated angle, speed and acceleration feedforward table is added to the backsweep controller according to time; wherein:

[0080] The frame-type backsweep compensation servo system is a three-loop closed-loop control system, which includes a current loop, a speed loop, and a position loop. GM represents the current loop controller, Gc represents the speed loop controller, Gf represents the position loop control, KI represents the current sampling gain, Kg represents the speed sampling gain, Kp represents the position sampling gain, a(k), w(k), θ(k) represent the backsweep trajectory generated in step 2, θ(k) is used as the input command of the position loop, w(k) is used as the positive feed input of the speed loop, and a(k) is used as the positive feed input of the current loop.

[0081] Step 4: The backsweep compensation of the optoelectronic platform frame is controlled by the backsweep controller, wherein: when the backsweep start requirements are met, the backsweep controller generates a backsweep start signal; when the backsweep end requirements are met, the backsweep controller generates a backsweep end signal; when the backsweep preset requirements are met, the backsweep controller generates a backsweep initialization signal.

[0082] In the above step 4 of the embodiment of the present invention: when the backsweep start requirement is met, the backsweep controller generates a backsweep start signal, including:

[0083] Determine the angle and speed values, when the expected sight angle θ meets the backscan requirement zero and the desired line-of-sight angular velocity ω exp When the reverse sweep starts, a signal is generated.

[0084] In the above step 4 of the embodiment of the present invention: when the backsweep end requirement is met, the backsweep controller generates a backsweep end signal, including:

[0085] When maintaining the desired line of sight angular velocity ω exp The gaze time t exceeds the required imaging time k After that, a reverse scan end signal is generated.

[0086] In the above step 4 of the embodiment of the present invention: when the preset requirements for backsweeping are met, the backsweeping controller generates a backsweeping initialization signal, including:

[0087] When the sight angle returns to the preset angle of the backscan, the current sight angle is maintained, the backscan ends, and the next backscan start signal is waited for.

[0088] An optoelectronic platform frame backscan compensation control method according to an embodiment of the present invention uses the above steps 1 to 4 to be executed cyclically according to a servo control cycle to complete the backscan compensation.

[0089] See also Figures 2 to 6 The photoelectric platform frame type backsweep compensation control method of the embodiment of the present invention preferably adopts a two-axis two-frame photoelectric stabilization platform system, the system includes two sensors, a visible light sensor and an infrared sensor, the sensors are installed on the gimbal platform to form a sensor platform, the platform is driven by a servo control unit, the servo control unit includes a current loop, a speed stabilization loop and a position control loop, refer to Figure 2 .

[0090] The optoelectronic platform of the embodiment of the present invention is mainly used for photographic reconnaissance of the ground. It is required that the line of sight is perpendicular to the horizontal plane at the beginning of exposure, and the line of sight is stably pointed to the same position during the exposure process. In order to simplify the calculation process, it is assumed that the pitch angle of the carrier aircraft is 0, the roll angle is 0, the flight speed is 50m / s, and the flight height relative to the ground is 500m. According to the above steps 1 to 4, the implementation is as follows:

[0091] Step 1: Parameter initialization, calculate the angular velocity ω that needs to be compensated according to the speed-to-height ratio exp =5.71° / s, desired sight angle θ zero = -90°, leaving enough room for initial acceleration, initial sight angle θ stop =89.94°, the maximum angular acceleration of the frame α max =300° / s 2 , operation cycle T s = 0.0005s, the gaze time required for imaging t k =45ms.

[0092] Step 2: Calculate the trajectory of the line of sight in a backscan cycle, including the angle, speed and acceleration of the line of sight. The generated results are as follows: Figure 4 , Figure 5 and Figure 6 The specific steps are as follows:

[0093] Step 2.1: Calculate the angle, angular velocity, and angular acceleration trajectory of the S1 phase:

[0094]

[0095] Step 2.2: Calculate the angle, angular velocity, and angular acceleration trajectory of the S2 phase:

[0096]

[0097] Step 2.3: Calculate the angle, angular velocity, and angular acceleration trajectory of the S3 stage:

[0098]

[0099] Step 2.4: Calculate the angle, angular velocity, and angular acceleration trajectory of the S4 stage:

[0100]

[0101] Step 3: Generate a velocity and acceleration feedforward table based on the generated angle, velocity and acceleration trajectory, and add the calculated angle, velocity and acceleration feedforward table to the backsweep controller according to time, as follows: Figure 3 As shown;

[0102] Step 4: Determine the angle and speed values. When the expected sight angle θ meets the backscan requirement, zero and the desired line-of-sight angular velocity ω exp When , a signal for the start of backsweep is generated;

[0103] Step 5: While maintaining the desired line of sight angular velocity ω exp The gaze time t exceeds the required imaging time k After that, a reverse scan end signal is generated;

[0104] Step 6: When the sight angle returns to the preset angle of the backscan, the current sight angle is maintained, the backscan is ended, and the next backscan start signal is waited;

[0105] Furthermore, all steps are executed cyclically according to the servo control cycle to complete the backscan compensation.

[0106] When rotating under vibration conditions of general fixed-wing aircraft, the method of the embodiment of the present invention is adopted, through frame backsweep compensation, when the aircraft is flying at an altitude of 500m and 50m, the backsweep frequency is >5hz, the speed compensation error is <0.2° / s, and the speed linearity is <1%. If a direct position closed loop is adopted, the backsweep frequency is <2hz, the speed compensation error is >1° / s, and the speed linearity is >3%. Therefore, the method of the embodiment of the present invention is superior to the general method in both backsweep speed and accuracy.

[0107] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A photoelectric platform frame backscan compensation control method, characterized in that: include: Step 1: Initialize the parameters of the framework, where the parameters include: maximum angular acceleration α max 、Current sight angle θ stop , the desired sight angle θ zero , the desired line of sight angular velocity ω exp , operation cycle T s , the gaze time required for imaging t k ; Step 2: determining a sight line motion trajectory within a backscan cycle, dividing the sight line motion trajectory into a plurality of trajectory segments, and generating trajectory parameters of each trajectory segment, wherein the trajectory parameters include: sight line angle, velocity, and acceleration; Step 3: Generate feedforward data according to the trajectory parameters of step 2, and add the trajectory parameters and the feedforward data to the backsweep controller according to time; wherein the feedforward data includes a velocity and acceleration feedforward table; Step 4: The backsweep controller is used to feedforward control the backsweep compensation of the optoelectronic platform frame, wherein: when the backsweep start requirements are met, the backsweep controller generates a backsweep start signal; when the backsweep end requirements are met, the backsweep controller generates a backsweep end signal; when the backsweep preset requirements are met, the backsweep controller generates a backsweep initialization signal.

2. The photoelectric platform frame backsweep compensation control method according to claim 1, characterized in that: In the step 2, dividing the sight line movement trajectory into a plurality of trajectory segments includes: The eye movement trajectory is divided into 4 stages from S1 to S4, where: The S1 phase includes the line of sight moving from the initial position θ stop Move to the exposure start position θ zero , In the S1 stage, the angular velocity of the line of sight decelerates from 0 to the angular velocity that needs to be compensated for the backscan; The S2 stage includes the speed maintenance stage during the line of sight movement. In the S2 stage, the angular velocity of the line of sight remains unchanged; Phase S3 includes the gaze movement back to the initial position θ stop In the acceleration stage, the angular velocity of the line of sight in stage S3 is accelerated from the angular velocity maintained during the backscanning in stage S2 to a suitable angular velocity; The S4 stage includes the deceleration stage of the line of sight movement. In the S4 stage, the line of sight angle returns to the initial position θ stop , the line of sight speed is 0.

3. The photoelectric platform frame backsweep compensation control method according to claim 2, characterized in that: In the step 2, generating trajectory parameters of each trajectory segment includes: (21) Calculate the angle, angular velocity, and angular acceleration trajectory of the S1 stage. The S1 stage controls the uniform deceleration angular motion of the frame. When the line of sight motion in the S1 stage reaches the expected speed, the line of sight angle is also equal to the expected line of sight angle. The calculation formula is: In formula (1), k represents the kth calculation cycle, a(k) represents the angular acceleration at the kth calculation cycle, and w exp represents the desired line-of-sight angular velocity, θ zero represents the desired sight angle, θ stop represents the initial position of the line of sight, w(k) represents the angular velocity at the kth calculation cycle, θ(k) represents the angle at the kth calculation cycle, and t s represents the operation cycle, t1 represents the time when the S1 stage ends; (22) Calculate the angle, angular velocity, and angular acceleration trajectory of the S2 stage. The control frame in the S2 stage moves at a uniform angular speed, and the line of sight angular velocity is equal to the expected velocity. The calculation formula is: In formula (2), θ2 represents the sight line position at the end of stage S1, and t2 represents the time when stage S1 ends; (23) Calculate the angle, angular velocity, and angular acceleration trajectory of the S3 stage. In the S3 stage, the control frame uniformly accelerates the angular motion, so that the angular velocity of the line of sight changes direction and reaches ω3, so that when the angular velocity is 0 in the next deceleration stage, the angular position just returns to the preset angle of the next backscan cycle. The calculation formula is: In formula (3), α max represents the maximum angular acceleration, ω3 represents the line of sight velocity at the end of stage S3, t3 represents the time at the end of stage S3, and θ3 represents the line of sight position at the end of stage S3; (24) Calculate the angle, angular velocity, and angular acceleration trajectory of the S4 stage. The S4 stage controls the uniform deceleration angular motion of the frame. When the line of sight motion in the S4 stage reaches the expected speed, the line of sight angle is also equal to the expected line of sight angle. The calculation formula is: Wherein, t4 represents the time when the S4 stage ends.

4. The photoelectric platform frame backsweep compensation control method according to claim 1, characterized in that: The step three is specifically as follows: According to the sight angle, velocity and acceleration of step 2, a velocity and acceleration feedforward table is generated, and the calculated angle, velocity and acceleration feedforward table is added to the backsweep controller according to time; wherein: The frame-type backsweep compensation servo system is a three-loop closed-loop control system, which includes a current loop, a speed loop, and a position loop. GM represents a current loop controller, Gc represents a speed loop controller, Gf represents a position loop control, KI represents a current sampling gain, Kg represents a speed sampling gain, Kp represents a position sampling gain, a(k), w(k), and θ(k) represent the backsweep trajectory generated in step 2, θ(k) serves as an input command of the position loop, w(k) serves as a positive feedback input of the speed loop, and a(k) serves as a positive feedback input of the current loop.

5. The photoelectric platform frame backsweep compensation control method according to claim 1, characterized in that: In the step 4: When the backsweep start requirement is met, the backsweep controller generates a backsweep start signal, including: Determine the angle and speed values, when the expected sight angle θ meets the backscan requirement zero and the desired line-of-sight angular velocity ω exp When , a signal for the start of backsweep is generated; When the backsweep end requirement is met, the backsweep controller generates a backsweep end signal, including: When maintaining the desired line of sight angular velocity ω exp The gaze time t exceeds the required imaging time k After that, a backsweep end signal is generated; when the backsweep preset requirements are met, the backsweep controller generates a backsweep initialization signal, including: When the sight angle returns to the preset angle of the backscan, the current sight angle is maintained, the backscan ends, and the next backscan start signal is waited.

6. The photoelectric platform frame backsweep compensation control method according to claim 1, characterized in that: The steps 1 to 4 are executed cyclically according to the servo control cycle to complete the backscan compensation.

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