A method for fast acquisition of a target by an angular servo system of a mechanically scanned tracking radar

Abstract

The application discloses a kind of quick acquisition methods of machine scanning tracking radar angle servo system to target, method is: first radar receiving control console target indication command, target indication value is as boundary condition, combine radar azimuth servo performance, carry out azimuth adjustment, and the azimuth of radar antenna is turned to target indication position;Then determine the elevation scanning range, carry out elevation scanning, and form corresponding scanning pattern in radar elevation;In the process of elevation scanning, memory current target elevation position after discovering target, so that antenna is quickly braked, according to the maximum overshoot point position and memory point position form regression strategy, so that antenna is quickly to memory point position stop scanning, keep the stability of antenna elevation direction;Finally, when receiving the tracking command of control console, enter the tracking of target.The application method is simple and reliable, and the rapidity of machine scanning radar and the ability of discovering target are considered, the quick reaction ability of system is improved, without adding hardware resources, with good applicability.

Description

Technical Field

[0001] This invention relates to the field of radar target acquisition and tracking technology, and in particular to a method for rapid target acquisition by a mechanically scanned tracking radar angle servo system. Background Technology

[0002] Mechanically scanned tracking radars typically operate by scanning while tracking using a rotating mechanical turntable. For this type of radar, each rotation updates the target information; the search function is dominant, and target tracking does not consume radar resources. The radar primarily uses the target information obtained from the search to track moving targets. The radar antenna rotates with the azimuth turntable to achieve 360° spatial azimuth scanning. When the radar beam sweeps across the target, it obtains information such as the target's position coordinates. As long as the turntable rotates continuously at a fixed angular velocity, the radar can periodically and continuously scan moving targets, thus continuously tracking their trajectory. The tracking data rate is related to the turntable's rotation speed; the higher the rotation speed, the higher the tracking data rate.

[0003] Rapid target acquisition is a crucial function and key performance indicator for mechanically scanned tracking radars. After receiving target indication, the radar needs to quickly adjust its azimuth and perform an appropriate elevation scan. Once the target is detected, it must acquire it rapidly and accurately and transition to target tracking. Azimuth adjustment involves the antenna's adjustment strategy and the capabilities of the servo system itself. The elevation scan pattern needs to balance rapid scanning with the accumulation of target sweep signals. After target detection, a rapid braking maneuver based on an appropriate regression strategy is required to quickly reach the target's memorized position. These are all important factors in achieving rapid target acquisition, directly affecting the mechanically scanned radar system's reaction time to targets, reflecting the system's rapid response capability, and significantly impacting system effectiveness.

[0004] The data rate of mechanically scanned tracking radar is limited by the mechanical rotation speed and motion inertia of the turntable, resulting in low target acquisition efficiency, especially for continuously moving targets. It is necessary to design a reasonable target acquisition method to improve the radar's target acquisition efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a target acquisition method for a mechanically scanned tracking radar angle servo system that is simple, has high target acquisition efficiency, and high stability.

[0006] The technical solution for achieving the objective of this invention is: a method for rapid target acquisition by a mechanically scanned tracking radar angle servo system, comprising the following steps:

[0007] Step 1: The radar receives the target indication command from the control console, uses the target indication value as a boundary condition, and adjusts the azimuth by combining the radar azimuth servo performance, turning the radar antenna azimuth to the target indication position.

[0008] Step 2: After the radar antenna azimuth is adjusted to the correct position, determine the elevation scanning range according to the radar acquisition requirements and the radar elevation servo performance, and perform elevation scanning to form the corresponding scanning pattern at the radar elevation angle.

[0009] Step 3: During the elevation scan, the radar determines whether a target has been detected. If so, it memorizes the current target elevation position, brakes the antenna, and proceeds to step 4; otherwise, it returns to step 2 to continue scanning.

[0010] Step 4: When the radar antenna reaches the maximum overshoot point, a regression strategy is formed based on the position of the maximum overshoot point and the position of the memory point to stop scanning when the antenna reaches the position of the memory point and maintain the stability of the antenna elevation angle.

[0011] Step 5: Upon receiving the tracing command from the console, proceed with tracing the target.

[0012] Furthermore, the target indication command from the radar receiving console described in step 1 uses the target indication value as a boundary condition, and in conjunction with the radar azimuth servo performance, adjusts the radar antenna azimuth to the target indication position, as detailed below:

[0013] Step 1.1: During the orientation adjustment process, before the speed reaches the maximum value, determine whether the angle has reached half of the required adjustment angle. If it has reached half, then enter the deceleration phase until the position is adjusted to the indicated position.

[0014] Step 1.2: During the azimuth adjustment process, if the angle of adjustment has not reached half of the required angle before the speed reaches its maximum value, then the process will enter a constant speed phase after the speed reaches its maximum value.

[0015] Step 1.3: When the turning angle reaches the remaining initial acceleration phase turning angle, the deceleration phase begins until the indicated position is reached.

[0016] Furthermore, after the radar antenna azimuth is adjusted in step 2, the elevation scanning range is determined according to the radar acquisition requirements and the radar elevation servo performance. An elevation scan is then performed to form a corresponding scanning pattern at the radar elevation angle, as detailed below:

[0017] Step 2.1: Determine the maximum scanning speed based on radar requirements and elevation servo performance;

[0018] Step 2.2: After the speed reaches its maximum value, the process transitions to a constant-speed phase of scanning at the maximum speed.

[0019] Step 2.3: When the elevation angle of the scan is less than the angle scanned during the initial acceleration phase, the process transitions to the deceleration phase.

[0020] Step 2.4: If the maximum scanning angle range is reached, start retrace. The retrace process is the same as the upward scanning process.

[0021] Furthermore, in step 4, after the radar antenna reaches the maximum overshoot point, a regression strategy is formed based on the position of the maximum overshoot point and the memory point position to stop scanning when the antenna reaches the memory point position, thus maintaining the stability of the antenna elevation angle. Specifically, the strategy is as follows:

[0022] Step 4.1: Memorize the target elevation angle when the target is detected, and initiate the antenna rapid braking procedure;

[0023] Step 4.2: After the antenna reaches the maximum overshoot point, start backscanning and calculate the difference between the antenna reaching the maximum overshoot point and the target memory point position;

[0024] Step 4.3: The antenna quickly retraces to the memory point position. During the retrace process, the first half is the retrace acceleration process and the second half is the retrace deceleration process. After reaching the memory point, the antenna stops retrace and waits for the console command.

[0025] A mechanically scanned tracking radar angle servo system, wherein when the system acquires a target, it executes the steps of the rapid target acquisition method of the mechanically scanned tracking radar angle servo system.

[0026] Furthermore, in the mechanically scanned tracking radar angle servo system, the frequency synthesizer generates radio frequency excitation and local oscillator signals. After the excitation signal is amplified by the transmitter, it is focused into a needle-shaped beam by the antenna to radiate the high-power signal to the designated space.

[0027] When electromagnetic waves encounter a target, they are backscattered, forming a target echo that returns to the antenna. The echo then passes through the transceiver switch to the receiver for microwave amplification. After being mixed with the local oscillator signal, the intermediate frequency (IF) signals of each channel are obtained. These IF signals are then amplified and matched and filtered before entering the signal processing module.

[0028] The signal processing module acquires, processes, accumulates, acquires, tracks, and generates angular error signals for each channel's intermediate frequency signals, and sends target distance information and angular error information to the servo control processing module. The servo control processing module receives the target indication signal, performs antenna azimuth adjustment, elevation search, and after the target is found, it brakes and returns the antenna to the target memory point.

[0029] After target acquisition transitions to tracking, based on the angle error signal sent by the signal processing module, the angle code transmitter uses the antenna azimuth and elevation position information transmitted through the interface circuit to perform adaptive filtering to drive antenna movement, thereby completing closed-loop target angle tracking.

[0030] Compared with the prior art, the significant advantages of this invention are:

[0031] (1) Under radar servo performance conditions, boundary conditions are formed based on real-time target indication data, and an adaptive azimuth turning strategy is formed to form a suitable elevation angle scanning pattern, which takes into account both speed and the ability to detect targets.

[0032] (2) After the target is detected, the current target elevation position is memorized, the antenna is braked quickly, and the maximum overshoot point position and the memorized point position are used as boundary conditions to adaptively form a regression strategy, so that the antenna stops scanning quickly at the memorized point position. On the basis of target acquisition, the radar servo performance is fully utilized. During the azimuth turning and elevation scanning search for the target, the boundary conditions and turning and regression strategies can be adaptively adjusted, and the radar performance can be maximized.

[0033] (3) The method of rapid target acquisition is more reasonable, which can give full play to the radar performance on the basis of existing hardware resources and meet the requirements of the system's rapid response capability;

[0034] (4) The method is simple and reliable, requires no additional hardware resources, and can be widely used in the rapid target acquisition process of two-dimensional target-guided mechanical scanning radar, with good applicability. Attached Figure Description

[0035] Figure 1 This is a structural block diagram of the mechanically scanned tracking radar in this invention.

[0036] Figure 2 This is a flowchart illustrating the rapid target acquisition method of the mechanically scanned tracking radar angle servo system of the present invention.

[0037] Figure 3 This is a timing diagram of orientation reversal in an embodiment of the present invention.

[0038] Figure 4 This is a timing diagram of elevation angle scan search and capture in an embodiment of the present invention. Detailed Implementation

[0039] Combination Figure 1 The present invention discloses a method for rapid target acquisition by a mechanically scanned tracking radar angle servo system, comprising the following steps:

[0040] Step 1: The radar receives the target indication command from the control console, uses the target indication value as a boundary condition, and adjusts the azimuth by combining the radar azimuth servo performance, turning the radar antenna azimuth to the target indication position.

[0041] Step 2: After the radar antenna azimuth is adjusted to the correct position, determine the elevation scanning range according to the radar acquisition requirements and the radar elevation servo performance, and perform elevation scanning to form the corresponding scanning pattern at the radar elevation angle.

[0042] Step 3: During the elevation scan, the radar determines whether a target has been detected. If so, it memorizes the current target elevation position, brakes the antenna, and proceeds to step 4; otherwise, it returns to step 2 to continue scanning.

[0043] Step 4: When the radar antenna reaches the maximum overshoot point, a regression strategy is formed based on the position of the maximum overshoot point and the position of the memory point to stop scanning when the antenna reaches the position of the memory point and maintain the stability of the antenna elevation angle.

[0044] Step 5: Upon receiving the tracing command from the console, proceed with tracing the target.

[0045] As a specific example, the target indication command from the radar receiving console in step 1 uses the target indication value as a boundary condition, combined with the radar azimuth servo performance, to adjust the radar antenna azimuth to the target indication position, as follows:

[0046] Step 1.1: During the orientation adjustment process, before the speed reaches the maximum value, determine whether the angle has reached half of the required adjustment angle. If it has reached half, then enter the deceleration phase until the position is adjusted to the indicated position.

[0047] Step 1.2: During the azimuth adjustment process, if the angle of adjustment has not reached half of the required angle before the speed reaches its maximum value, then the process will enter a constant speed phase after the speed reaches its maximum value.

[0048] Step 1.3: When the turning angle reaches the remaining initial acceleration phase turning angle, the deceleration phase begins until the indicated position is reached.

[0049] As a specific example, after the radar antenna azimuth is adjusted in step 2, the elevation scanning range is determined according to the radar acquisition requirements and the radar elevation servo performance. An elevation scan is then performed to form a corresponding scanning pattern at the radar elevation angle, as detailed below:

[0050] Step 2.1: Determine the maximum scanning speed based on radar requirements and elevation servo performance;

[0051] Step 2.2: After the speed reaches its maximum value, the process transitions to a constant-speed phase of scanning at the maximum speed.

[0052] Step 2.3: When the elevation angle of the scan is less than the angle scanned during the initial acceleration phase, the process transitions to the deceleration phase.

[0053] Step 2.4: If the maximum scanning angle range is reached, start retrace. The retrace process is the same as the upward scanning process.

[0054] As a specific example, in step 4, after the radar antenna reaches the maximum overshoot point, a regression strategy is formed based on the position of the maximum overshoot point and the memory point position to stop scanning when the antenna reaches the memory point position, thus maintaining the stability of the antenna elevation angle. Specifically, the strategy is as follows:

[0055] Step 4.1: Memorize the target elevation angle when the target is detected, and initiate the antenna rapid braking procedure;

[0056] Step 4.2: After the antenna reaches the maximum overshoot point, start backscanning and calculate the difference between the antenna reaching the maximum overshoot point and the target memory point position;

[0057] Step 4.3: The antenna quickly retraces to the memory point position. During the retrace process, the first half is the retrace acceleration process and the second half is the retrace deceleration process. After reaching the memory point, the antenna stops retrace and waits for the console command.

[0058] The present invention also relates to a mechanically scanned tracking radar angle servo system, which, when acquiring a target, executes the steps of the rapid target acquisition method of the mechanically scanned tracking radar angle servo system.

[0059] Combination Figure 2 In the mechanically scanned tracking radar angle servo system, the frequency synthesizer generates radio frequency excitation and local oscillator signals. The excitation signal is amplified by the transmitter and then focused into a needle-shaped beam by the antenna to radiate a high-power signal to a designated space. When the electromagnetic wave encounters the target, it generates backscattering, forming a target echo that returns to the antenna. After passing through the transceiver switch, it is amplified by the receiver's microwave amplifier and mixed with the local oscillator signal to obtain the intermediate frequency (IF) signals of each channel. These signals are then amplified by the IF signal, matched and filtered, and enter the signal processing module. The signal processing module collects, processes, accumulates, acquires, tracks, and generates angle error signals for each channel's IF signals. It generates target range information and angle error information, which are sent to the servo control processing module. The servo control processing module receives the target indication signal, performs antenna azimuth adjustment, elevation search, and after target detection, brakes and returns the antenna to the target memory point. After target acquisition and transition to tracking, based on the angle error signal sent by the signal processing module, the angle code transmitter uses the antenna azimuth and elevation position information transmitted through the interface circuit to perform adaptive filtering to drive the antenna movement, completing the target angle closed-loop tracking.

[0060] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0061] Example

[0062] This embodiment employs a rapid target acquisition method for a mechanically scanned tracking radar angle servo system according to the present invention, to rapidly acquire the target, in comparison with... Figure 3 The midline segment a1b1c1d1 represents the azimuth reversal process. Figure 4The midline segment a2b2c'2d'2e'2f2' represents the target acquisition process during elevation angle scanning. The specific steps are as follows:

[0063] Step 1, Combining Figure 3 The radar received a target indication command from the receiving console. The target indication azimuth is 135°, and the radar is currently pointing at 45°. The radar needs to be turned 90°. The maximum azimuth acceleration of the radar is 300° / s². 2 The maximum speed is 90° / s. Following the acceleration, constant speed scanning, and deceleration strategy, the radar accelerates to 90° / s in 0.3s and turns 13.5°. Similarly, it decelerates from 90° / s to 0° / s in 0.3s and turns 13.5°. The acceleration and deceleration together turn 27°. The constant speed scanning takes 63° and 0.7s. The total time to turn 90° is 1.3s to get the target to the target position.

[0064] Step 2, Combining Figure 4 After the azimuth is adjusted to the correct position, based on the radar acquisition requirements and elevation servo performance, the elevation scanning range is determined to be 0° to 20°, with a maximum acceleration of 200° / s². 2 The maximum speed is 30° / s. The scanning pattern follows an acceleration, uniform horizontal scan, and deceleration strategy. The radar accelerates to a speed of 30° / s in 0.15s, and the angle scans 2.25°. Similarly, the deceleration phase also takes 0.15s, and the angle scans 2.25°. The uniform horizontal scan phase takes 15°, taking 0.5s. The retrace process is the same as the upward scan process, and the total scanning cycle is 1.6s.

[0065] Step 3: If the target is detected when the elevation angle is scanned to 10°, proceed to step 4.

[0066] Step 4: Memorize the current target elevation angle position, and quickly brake the antenna in 0.15s, sweeping the maximum overshoot angle of 2.25°. Based on the maximum overshoot angle of 2.25°, follow the acceleration and deceleration return strategy: acceleration phase 1.125°, taking 0.106s, deceleration phase 1.125°, taking 0.106s, quickly bringing the antenna back to the memorized position and stopping the sweep, maintaining the stability of the antenna elevation angle.

[0067] Step 5: Upon receiving the tracking command, proceed with tracking the target.

[0068] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for rapid target acquisition by a mechanically scanned tracking radar angle servo system, characterized in that, Includes the following steps: Step 1: The radar receives the target indication command from the control console, uses the target indication value as a boundary condition, and adjusts the azimuth by combining the radar azimuth servo performance, turning the radar antenna azimuth to the target indication position. Step 2: After the radar antenna azimuth is adjusted to the correct position, determine the elevation scanning range according to the radar acquisition requirements and the radar elevation servo performance, and perform elevation scanning to form the corresponding scanning pattern at the radar elevation angle. Step 3: During the elevation scan, the radar determines whether a target has been detected. If so, it memorizes the current elevation position of the target, brakes the antenna, and proceeds to step 4. Otherwise, return to step 2 and continue scanning; Step 4: When the radar antenna reaches the maximum overshoot point, a regression strategy is formed based on the location of the maximum overshoot point and the memory point location to stop scanning when the antenna reaches the memory point location, thus maintaining the stability of the antenna elevation angle, as follows: Step 4.1: Memorize the target elevation angle when the target is detected, and initiate the antenna rapid braking procedure; Step 4.2: After the antenna reaches the maximum overshoot point, start backscanning and calculate the difference between the antenna reaching the maximum overshoot point and the target memory point position; Step 4.3: The antenna quickly scans back to the memory point position. During the scan process, the first half is the scan acceleration process and the second half is the scan deceleration process. Once the memory point is reached, the antenna stops scanning and waits for commands from the control console. Step 5: Upon receiving the tracing command from the console, proceed with tracing the target.

2. The method for rapid target acquisition by the mechanically scanned tracking radar angle servo system according to claim 1, characterized in that, Step 1 involves using the target indication command from the radar receiving console as a boundary condition, and combining it with the radar azimuth servo performance to adjust the radar antenna azimuth to the target indication position, as detailed below: Step 1.1: During the orientation adjustment process, before the speed reaches the maximum value, determine whether the angle has reached half of the required adjustment angle. If it has reached half, then enter the deceleration phase until the position is adjusted to the indicated position. Step 1.2: During the azimuth adjustment process, if the angle of adjustment has not reached half of the required angle before the speed reaches its maximum value, then the process will enter a constant speed phase after the speed reaches its maximum value. Step 1.3: When the turning angle reaches the remaining initial acceleration phase turning angle, the deceleration phase begins until the indicated position is reached.

3. The method for rapid target acquisition by the mechanically scanned tracking radar angle servo system according to claim 1, characterized in that, After the radar antenna azimuth is adjusted in step 2, the elevation scanning range is determined according to the radar acquisition requirements and the radar elevation servo performance. An elevation scan is then performed to form the corresponding scanning pattern at the radar elevation angle, as detailed below: Step 2.1: Determine the maximum scanning speed based on radar requirements and elevation servo performance; Step 2.2: After the speed reaches its maximum value, the process transitions to a constant-speed phase of scanning at the maximum speed. Step 2.3: When the elevation angle of the scan is less than the angle scanned during the initial acceleration phase, the process transitions to the deceleration phase. Step 2.4: If the maximum scanning angle range is reached, start retrace. The retrace process is the same as the upward scanning process.

4. A mechanically scanned tracking radar angle servo system, characterized in that, When the system acquires a target, it performs the steps of the rapid target acquisition method of the mechanically scanned tracking radar angle servo system as described in any one of claims 1 to 3.

5. The mechanically scanned tracking radar angle servo system according to claim 4, characterized in that, In the mechanically scanned tracking radar angle servo system, the frequency synthesizer generates radio frequency excitation and local oscillator signals. After the excitation signal is amplified by the transmitter, it is focused into a needle beam by the antenna to radiate the high-power signal to the designated space. When electromagnetic waves encounter a target, they are backscattered, forming a target echo that returns to the antenna. The echo then passes through the transceiver switch to the receiver for microwave amplification. After being mixed with the local oscillator signal, the intermediate frequency (IF) signals of each channel are obtained. These IF signals are then amplified and matched and filtered before entering the signal processing module. The signal processing module acquires, processes, accumulates, acquires, tracks, and generates angular error signals for each channel's intermediate frequency signals, and sends target distance information and angular error information to the servo control processing module. The servo control processing module receives the target indication signal, performs antenna azimuth adjustment, elevation search, and after the target is found, it brakes and returns the antenna to the target memory point. After target acquisition transitions to tracking, based on the angle error signal sent by the signal processing module, the angle code transmitter uses the antenna azimuth and elevation position information transmitted through the interface circuit to perform adaptive filtering to drive antenna movement, thereby completing closed-loop target angle tracking.

Images