Cooperative target identification system based on corner reflecting prism

Abstract

The invention discloses a cooperative target recognition system based on a corner reflecting prism, and belongs to the technical field of target recognition, and the recognition system comprises a control processing unit, a light wave transmitting device, a reflected light receiving device, a corner reflecting prism and a rotation control device of the corner reflecting prism. The control unit can control the light wave emitting device to emit a light wave band with a specific frequency, then a receiver is provided with a circle of eight corner reflecting prisms capable of rotating along with a rotating shaft in the middle, and light waves generated by a sender are reflected to the receiver. The reflected light receiving device can identify different rotation frequencies of the corner reflecting prism by receiving reflected light waves, so that cooperative target identification can be accurately carried out, the reflecting prism of the device reflects signals with high reflectivity, 360-degree omnidirectional identification is realized, the system reliability is improved, on one hand, an invisible light identification technology can be adopted, and on the other hand, the system reliability is improved. Therefore, the recognition efficiency and accuracy are greatly improved, and the cooperative target recognition capability is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of target recognition. Background Art

[0002] The cooperative target recognition system is a technical system specially designed to identify specific targets in complex environments. It usually relies on multiple sensor data and advanced algorithms to process and analyze information in order to accurately identify and track targets amidst numerous potential interferences. This system usually consists of two parts: an interrogator and a transponder, which can effectively identify cooperative targets in the air or on the ground.

[0003] Cooperative target recognition technology continues to develop and has become an indispensable part of military and civilian use. This technology integrates the Automatic Dependent Surveillance-Broadcast (ADS-B) technology and is divided into two methods: active recognition (such as radio recognition technology and radar imaging recognition technology) and passive recognition (monitoring the radiation signals of electronic devices on the target platform).

[0004] Generally speaking, traditional radio frequency (RF) cooperative target recognition systems face some challenges in practical applications. Since RF signals are susceptible to interference, non-cooperative parties may use electronic means to disrupt the interrogation and response system, thereby reducing the recognition efficiency of the system. In addition, when multiple transponders are located within the effective beam range of the interrogation antenna and close to each other, interference will occur; and the side lobes of the interrogation antenna may also cause some transponders to fail to respond correctly, causing crosstalk. Importantly, cooperative target recognition systems for RF signals usually have low directivity, which means that the radiation direction of the signal is not fixed, which increases the risk of interception and interference by non-cooperative parties. These problems will have a negative impact on the recognition efficiency and accuracy of the system. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] In view of the deficiencies of the prior art, the present invention provides a cooperative target recognition system based on corner reflection prisms, which solves the problems raised in the above background technology.

[0007] (II) Technical solution

[0008] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0009] A cooperative target recognition system based on corner reflector prisms includes: a control processing unit, a noise filtering and decoding function, a target automatic tracking function, a light wave transmitting device, a horizontal and vertical direction motor, a reflected light wave receiving device, a key input and target feature display, a wireless interference shielding device and a corner reflector prism group and a rotation control device thereof;

[0010] The control processing unit is connected to the light wave transmitting device, the reflected light wave receiving device, the horizontal and vertical direction motors and installed together in the wireless interference shielding device, the optical lens group is installed on the wireless interference shielding device, the wireless interference shielding device is installed on the detector, and the corner reflection prism group and its rotation control device are installed on the target;

[0011] The light wave transmitting device amplifies the power of the control processing unit signal, drives four infrared laser diodes to emit detection light waves, and controls the angles of the horizontal and vertical direction motors;

[0012] The corner reflection prism group and its rotation control device are equipped with 8 corner reflection prisms of the same size installed on a horizontal plane, which can change the propagation path of the light wave so that the light is reflected back to the reflected light wave receiving device, and change the receiving frequency of the reflected light through the rotation speed of the corner reflection prism, perform light wave modulation, and realize the recognition of the target;

[0013] The reflected light wave receiving device uses a silicon photodetection diode for three-input diversity reception to receive the light waves reflected from the corner reflection prism of the target, and enters the analog-to-digital (ADC) conversion through the signal amplification unit, and the sum of these information is sent to the control unit for analysis through AD conversion;

[0014] Furthermore, the control processing unit is characterized in that the wireless interference shielding device includes: using conductive paint containing copper and silver composite particles as conductive particles, spraying and brushing it on a nickel-iron alloy shell with a nickel content of 80% and an iron content of 20%, so that the surface has stronger metal electromagnetic wave absorption, conduction and attenuation characteristics, and connecting the device to the ground.

[0015] Furthermore, the control processing unit is characterized in that the noise filtering and decoding functions include: using the control processing unit and the analog-to-digital conversion circuit, the frequency of the electrical signal of the reflected light receiving device can be processed and detected. At the same time, an extended Kalman filter is used to perform a Taylor series expansion on the nonlinear function, and high-order terms are discarded to obtain a first-order approximation. In the prediction step, a first-order approximation is used to describe the change in the system state. In the update step, these nonlinear equations are linearized and calculated using the Kalman filter formula.

[0016] Furthermore, the light wave emitting device is characterized in that the power control and capture functions include: power control is achieved by adjusting the number of four infrared laser diodes, and the altitude angle and azimuth angle can be controlled by changing the horizontal and vertical direction motors to capture and track the target.

[0017] Furthermore, the corner reflection prism group is characterized in that the light wave is modulated by the speed of the rotating control device, the duration of the light wave in the reflection prism is the effective time t1 of the light wave, the time of the light wave outside the reflection prism is the invalid time t2, the total duration t=t1+t2, and the modulation frequency of the reflected light wave is 1 / t.

[0018] Furthermore, the described reflected light wave receiving device is characterized in that the described diversity reception includes: using three silicon photodetection diodes equipped with 1550nm band filters, each silicon photodetection diode receives light waves and outputs one signal, through AD conversion, weighted summation is performed in the control processing unit, and PWMI is used to measure the frequency and duty cycle of the signal for feature comparison.

[0019] Furthermore, the control processing unit is characterized in that the target automatic tracking function (9) includes: using a fuzzy PID method to control the light wave transmitting device and the reflected light receiving device, and performing target tracking when the target frequency is captured. The initialization tracking device can also manually select the tracking target. After the tracking target is determined, the proportional, integral and differential parameters are adjusted in real time through the fuzzy PID method.

[0020] (III) Beneficial effects

[0021] Compared with the prior art, the present invention provides a cooperative target recognition method based on corner reflection prism, which has the following beneficial effects:

[0022] (1) The present invention provides three wireless signal shielding methods, which can protect the system from wireless signal interference and always maintain the best operating state in the absence of other shielding equipment. The nickel-iron alloy has good electrical conductivity and magnetism, and the nickel-iron alloy shell coated with conductive paint is connected to the ground to form a complete electromagnetic shielding system.

[0023] (2) The present invention sets up a light wave transmitter, which can control the light wave transmitting device to emit a light band of 1550nm through a control unit, and can change the power, emission altitude angle and azimuth angle. On the one hand, the invisible light band is used for recognition, which can reduce the characteristic value of reflected light matching and greatly improve the recognition efficiency and success rate. On the other hand, this method has a long transmission distance, and can effectively improve the recognition effect of cooperative targets.

[0024] (3) The present invention reflects the light waves emitted by the sender to the receiver through the corner reflection prism group and its rotation control device. The reflection prism of the device modulates the light waves and reflects the signal with high reflectivity to achieve 360-degree omnidirectional recognition and resist electromagnetic interference. This system has high directivity and high security. Radio frequency instruments cannot detect the reflected light waves because the laser beam is highly directional and has a narrow beam divergence in space optical communication. Therefore, any form of interception is very difficult, and for a given transmitter power, due to its narrow beam divergence angle, the light intensity at the receiver is greater, there are less power and weight requirements, and the communication distance is farther, all of which improve the reliability and practicality of the system.

[0025] (4) The present invention provides higher channel capacity and better signal reliability by setting up this diversity transmission and diversity reception device, thereby achieving efficient spectrum utilization. When some of the three communications are interfered, other communications can still be maintained, reducing the risk of data packet loss.

[0026] (5) The present invention adopts the extended Kalman filter technology to optimize the processing of noisy measurement data. By introducing the Jacobian matrix of the nonlinear system, the technology can effectively remove the noise in the data and provide a faster and more accurate response, thereby ensuring the quality of information extraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the system composition structure of the present invention;

[0028] Figure 2 Schematic diagram of the optical lens structure of the present invention

[0029] In the figure: 1. Control processing unit; 2. Light wave transmitting device; 3. Reflected light wave receiving device; 4. Key input and target feature display device; 5. Corner reflection prism group; 6. Rotation control device; 7. Wireless interference shielding device; 8. Noise filtering and decoding function; 9. Target automatic tracking function; 10. Horizontal and vertical direction motors; 20. Optical lens group; 21. Infrared laser diode; 22. Silicon photodetection diode. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] See also Figure 1 and Figure 2, a cooperative target recognition system based on corner reflection prism, the system can recognize cooperative targets, increase the recognition efficiency and accuracy in practical applications, and has certain practical significance;

[0032] The device comprises a control processing unit 1, a noise filtering and decoding function 8, a target automatic tracking function 9, a light wave transmitting device 2, a horizontal and vertical direction motor 10, a reflected light wave receiving device 3, a key input and target feature display 4, a wireless interference shielding device 7 and a corner reflector prism group 5 and a rotation control device 6 thereof;

[0033] The control processing unit 1 is connected to the light wave transmitting device 2, the reflected light wave receiving device 3, the horizontal and vertical direction motors 10 and are installed together in the wireless interference shielding device 7, the optical lens group 20 is installed on the wireless interference shielding device 7, the wireless interference shielding device 7 is installed on the detector, and the corner reflection prism group 5 and its rotation control device 6 are installed on the target;

[0034] The light wave transmitting device 2 amplifies the power of the control processing unit signal and drives four infrared laser diodes 21 to transmit detection light waves, which are controlled by the horizontal and vertical direction motors 10;

[0035] The corner reflection prism group 5 and its rotation control device 6 are equipped with 8 corner reflection prisms of the same size installed on a horizontal plane, which can change the propagation path of the light wave so that the light is reflected back to the reflected light wave receiving device 3, and the receiving frequency of the reflected light is changed by the rotation speed of the corner reflection prism, and the light wave is modulated to realize the recognition of the target with the advantages of high reflectivity, 360-degree omnidirectional reflection, and anti-electromagnetic interference compared with other methods;

[0036] The reflected light wave receiving device 3 uses a silicon photodetection diode 22 for three-input diversity reception, receives the light waves reflected from the corner reflection prism of the target, enters the analog-to-digital (ADC) conversion through the linear amplification unit, and sums the information through AD conversion and sends it to the control unit for analysis;

[0037] The control processing unit 1 is characterized in that the wireless interference shielding device 7 comprises: using conductive paint containing copper and silver composite particles as conductive particles, spraying and brushing on a nickel-iron alloy shell with a nickel content of 80% and an iron content of 20%, so that the surface has stronger metal electromagnetic wave absorption, conduction and attenuation characteristics, and connecting the device to the ground, which can effectively shield electromagnetic wave interference;

[0038] The control processing unit 1 is characterized in that the noise filtering and decoding function 8 includes: using the control processing unit and the analog-to-digital conversion circuit, the frequency of the electrical signal of the reflected light receiving device can be processed and detected. At the same time, the extended Kalman filter is used to perform Taylor series expansion on the nonlinear function, and the high-order terms are discarded to obtain the first-order approximation. In the prediction step, the first-order approximation is used to describe the change of the system state. In the update step, these nonlinear equations are linearized and calculated using the Kalman filter formula, which can control the error in the transmission process and ensure the accuracy of the signal;

[0039] The light wave transmitting device 2 is characterized in that the power control and capture functions include: power control is achieved by adjusting the number of four infrared laser diodes 21, and the altitude angle and azimuth angle can be controlled by changing the horizontal and vertical direction motors 10 to capture and track the target;

[0040] The corner reflector prism set 5 and its rotation control device 6 are characterized in that the functions of the corner reflector prism set 5 include: modulating the light wave by the speed of the rotation control device 6, the duration of the light wave in the reflector prism is the effective time t1 of the light wave, the time of the light wave outside the reflector prism is the invalid time t2, the total duration t=t1+t2, and the modulation frequency f of the reflected light wave is 1 / t. The corner reflector prism is very insensitive to position and movement, and this characteristic makes cooperative target recognition easier than other methods;

[0041] The reflected light wave receiving device 3 and its noise filtering and decoding function 8 are characterized in that the diversity receiving step includes: using three silicon photodetection diodes with 1550nm band filters arranged compactly horizontally and vertically, the fixed band of light can improve the recognition efficiency and success rate, each silicon photodetection diode receives the light wave and outputs a signal, through AD conversion, weighted summation is performed in the control processing unit, PWMI is used to measure the frequency and duty cycle of the signal, and feature comparison is performed. This method can effectively improve the recognition effect of cooperative targets;

[0042] The control processing unit 1 is characterized in that the target automatic tracking function 9 includes: using the fuzzy PID method to control the light wave transmitting device and the reflected light receiving device, performing target tracking when the target frequency is captured, initializing the tracking device, or manually selecting the tracking target. After determining the tracking target, the proportional, integral and differential parameters are adjusted in real time through the fuzzy PID method, so that the system can maintain good control effects under different conditions and enhance the stability of the system.

Claims

1. A cooperative target recognition system based on corner reflection prism, comprising: A control processing unit (1), a noise filtering and decoding function (8), an automatic target tracking function (9), a light wave transmitting device (2), a horizontal and vertical direction motor (10), a reflected light wave receiving device (3), a key input and target feature display (4), a wireless interference shielding device (7) and a corner reflection prism group (5) and a rotation control device (6) thereof; The control processing unit (1) is connected to the light wave transmitting device (2), the reflected light wave receiving device (3), the horizontal and vertical direction motors (10) and are installed together in the wireless interference shielding device (7), the optical lens group (20) is installed on the wireless interference shielding device (7), the wireless interference shielding device (7) is installed on the detector, and the corner reflection prism group (5) and its rotation control device (6) are installed on the target; The light wave transmitting device (2) amplifies the power of the control processing unit signal and drives four infrared laser diodes (21) to emit detection light waves, and the horizontal and vertical direction motors (10) perform angle control; A corner reflection prism group (5) and a rotation control device (6) thereof are provided. Eight corner reflection prisms of the same size are installed on a horizontal plane. The propagation path of light waves can be changed to reflect the light back to the reflected light wave receiving device (3). The receiving frequency of the reflected light can be changed by the rotation speed of the corner reflection prisms to perform light wave modulation and realize target recognition. The reflected light wave receiving device (3) uses a silicon photodetection diode (22) to perform three-input diversity reception, receives the light waves reflected from the corner reflection prism of the target, enters the analog-to-digital (ADC) conversion through a linear amplification unit, and sums the information through AD conversion and sends it to the control unit for analysis.

2. The control processing unit (1) according to claim 1, characterized in that: The wireless interference shielding device (7) comprises: using conductive paint containing copper and silver composite particles as conductive particles, spraying and brushing on a nickel-iron alloy shell with a nickel content of 80% and an iron content of 20%, so that the surface has stronger metal electromagnetic wave absorption, conduction and attenuation characteristics, and connecting the device to the ground.

3. The control processing unit (1) according to claim 1, characterized in that: The noise filtering and decoding function (8) includes: using a control processing unit and an analog-to-digital conversion circuit to process and detect the frequency of the electrical signal of the reflected light receiving device, and at the same time, using an extended Kalman filter (Extended Kalman Filter, EKF) to perform Taylor series expansion on the nonlinear function, discarding high-order terms to obtain a first-order approximation, and in the prediction step, using the first-order approximation to describe the change of the system state. In the update step, these nonlinear equations are linearized and calculated using the Kalman filter formula.

4. A light wave emitting device (2) according to claim 1, characterized in that: The power regulation and capture functions include: power regulation is achieved by adjusting the number of four infrared laser diodes (21), and target capture and tracking can be achieved by changing the horizontal and vertical direction motors (10) to control the altitude angle and azimuth angle.

5. A corner reflection prism assembly (5) and a rotation control device (6) thereof according to claim 1, characterized in that: The functions of the corner reflection prism group (5) include: modulating the light wave by the speed of the rotation control device (6), the duration of the light wave in the reflection prism is the effective time t1 of the light wave, the time of the light wave outside the reflection prism is the invalid time t2, the total duration t=t1+t2, and the modulation frequency of the reflected light wave is 1 / t.

6. A reflected light wave receiving device (3) according to claim 1, characterized in that: The diversity reception includes: using three silicon photodetection diodes equipped with 1550nm band filters, each silicon photodetection diode receives light waves and outputs a signal, through AD conversion, weighted summation is performed in the control processing unit, and PWMI is used to measure the frequency and duty cycle of the signal for feature comparison.

7. The control processing unit (1) according to claim 1, characterized in that: The target automatic tracking function (9) includes: using the fuzzy PID method to control the light wave transmitting device and the reflected light receiving device, and performing target tracking when the target frequency is captured. The tracking device can also be initialized to manually select the tracking target. After the tracking target is determined, the proportional, integral and differential parameters are adjusted in real time by the fuzzy PID method.

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