Target echo simulation device

Abstract

The invention discloses a target echo simulation device which is used for testing a laser radar and simulating target distance, target laser echo energy, target depth information and target space information. Comprising a target distance simulation delayer, an energy simulation unit, a beam splitter, a target depth information simulation unit, a target space information simulation unit, a beam combiner and an optical projection lens. According to the technical scheme, the optical fiber time delay and optical fiber illumination modes are adopted, meanwhile, target and background information of different levels is formed through multiple optical channels, the information is rich, and the defects that an existing single target simulator can only conduct overall target simulation and does not contain multi-level information of the target or background information and the like are overcome.

Description

Technical Field

[0001] The invention relates to the technical field of multi-dimensional target scene simulation for testing laser target tracking imaging recognition equipment, and in particular to a target echo simulation device. Background Art

[0002] In the development process of laser target tracking imaging recognition equipment, there are two serious problems that hinder development: the long development cycle of new technologies and the very limited traditional laboratory testing. In order to solve these two major problems, it is necessary to establish a laser target scene simulation system in order to reliably test the performance of imaging recognition equipment. As the core of the semi-physical simulation system, the accuracy of the laser target scene simulation system is directly related to the reliability of the equipment under test and the accuracy of the results. The laser target scene simulation system currently built can only generate scene simulation information on a single channel, and the scene simulation method used can only control the laser to generate a single scene information and energy information during the target approach process. It includes a power supply unit, a cable, a master control unit, a laser driving circuit, a laser, a laser energy simulation control unit, and an energy attenuator. The power supply unit and the cable are used for power supply. The cable is used to connect the power supply unit with the master control unit, the laser driving circuit, the laser energy simulation control unit, and the power supply circuit of the energy attenuator; the master control unit includes the master control hardware circuit and signal processing software, which is the information processing and exchange center of the entire simulator; the laser energy simulation control unit includes the laser energy simulation control circuit and software, receives and saves the data sent by the master control unit, and controls the energy attenuator to simulate the energy attenuation process of the echo signal according to this data. Patent 202110144577.X "Multi-parameter Simulation Laser Target Simulator" provides an automatic energy calculation module that can automatically calculate the laser echo energy based on the laser radar ranging equation and the set target distance, atmospheric characteristics, irradiation energy and other parameters, and control the laser energy control part to set the simulated echo, thereby outputting the laser echo energy that matches the set parameters for testing laser rangefinders or laser radars. Existing laser target simulators use a single channel to simulate targets, which only contains single delay and energy target information, and cannot simulate the multi-level laser target and background information in a certain scene. Summary of the invention

[0003] To solve the above problems, the present invention only adopts fiber optic delay and fiber optic illumination, and uses multiple optical channels to form different levels of target and background information, which is rich in information and improves the shortcomings of existing single target simulators that can only simulate the overall target but do not include multi-level target information and background information.

[0004] To achieve the above-mentioned purpose, the present invention provides a target echo simulation device, which is used for testing laser radar, simulating target distance, target laser echo energy, target depth information and target space information, and is characterized in that it includes a target distance simulation delay device, an energy simulation unit, a beam splitter, a target depth information simulation unit, a target space information simulation unit, a beam combiner and an optical projection lens;

[0005] The target distance simulation delay device includes a trigger signal unit, which is used to give a trigger signal to the laser radar at a first moment, the first moment is used as the moment when the laser radar starts working, and send a trigger pulse to the energy simulation unit at a second moment, the second moment is delayed by a first preset time relative to the first moment, and the first preset time simulates the target distance;

[0006] The energy simulation unit comprises a pulse laser source, which is used to emit a pulse laser of a first preset energy according to the trigger pulse to simulate the target laser echo energy;

[0007] The beam splitter is used to couple the pulse laser into the optical fiber and then split it into multiple first beams;

[0008] The target depth information simulation unit includes a plurality of target slice information simulation units, each of which includes a first optical fiber delay line and a first attenuator arranged on the first optical fiber delay line, each of which is used to transmit one path of the first sub-beam, and each of which is formed into a second sub-beam after attenuating the second preset energy through the first attenuator on each of the first optical fiber delay lines, so as to simulate the target depth information and the target laser echo energy (the part of the target laser echo energy corresponding to the target slice information);

[0009] The target space information simulation unit includes a plurality of target slice targets, and the plurality of target slice targets correspond to the first optical fiber delay lines of the plurality of target slice information simulation units one by one. After each of the second split light beams irradiates a corresponding target slice target, the image is compounded through the beam combiner to simulate the target space information.

[0010] The optical projection lens is used to match and dock with the laser radar, and the optical signal after image composite is transmitted to the laser radar via the optical projection lens.

[0011] In some possible embodiments, the target depth information simulation unit further includes a background information simulation unit, the background information simulation unit includes a second optical fiber delay line and a second attenuator arranged on the second optical fiber delay line, the second optical fiber delay line is used to transmit one path of the first sub-beam, the first sub-beam in the second optical fiber delay line is subjected to energy attenuation by the second attenuator to form a third sub-beam;

[0012] The target space information simulation unit also includes a background target, and the background target corresponds to the second optical fiber delay line. After the third sub-beam irradiates the background target, image compounding is performed via the beam combiner.

[0013] In some possible embodiments, the energy simulation unit includes a pulse laser source and a third attenuator, the pulse laser source is used to emit a pulse laser with a third preset energy according to the trigger pulse, and the third attenuator is used to attenuate the pulse laser with the third preset energy to obtain a pulse laser with the first preset energy.

[0014] In some possible embodiments, each of the second sub-beams irradiates a corresponding target slice target and then performs image compounding via the beam combiner, including:

[0015] After each of the second sub-beams is resolved, it is set into an illumination array, and after collimation, it illuminates the target slice target, and multiple images are compounded after passing through a splitter prism. The resolution of the second sub-beam includes resolving the target depth information and the target laser echo energy (the part of the target laser echo energy corresponding to the target slice information).

[0016] In some possible embodiments, the delay length of each of the first optical fiber delay lines and the delay length of the second optical fiber delay line are adjustable.

[0017] In some possible embodiments, a laser radar echo model solving module is also included, and the laser radar echo model solving module includes a laser echo energy solving unit, and the laser echo energy solving unit is electrically connected to each of the first attenuator, the second attenuator and the third attenuator. The laser radar echo model solving module is used to calculate the laser echo energy according to the laser radar ranging equation and the input echo parameters, and the first attenuator, the second attenuator and the third attenuator respectively set their respective energy attenuation values ​​according to the laser echo energy.

[0018] In some possible embodiments, a laser collimator is disposed between each of the first optical fiber delay lines and the corresponding target slice target.

[0019] In some possible embodiments, the target distance simulation delay device further includes a target distance calculation module, which is used to calculate the first preset time according to the target distance.

[0020] In some possible embodiments, the laser radar echo model solving module also includes a fiber delay solving unit, which is used to solve and obtain the target depth information and background information corresponding to the delay lengths of each first fiber delay line and second fiber delay line.

[0021] In some possible embodiments, the beam combiner includes a plurality of beam splitters, wherein one beam splitter prism combines two split light beams into one, the two beam splitters combine three split light beams into one, the three beam splitters combine four split light beams into one, and so on.

[0022] Compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:

[0023] Compared with the traditional target simulator device, which has many input parameters and complex linkage between the upper computer and the lower computer, the device of the present invention does not need to be controlled by the upper computer software, is simple to operate, and simply relies on the hardware system to complete the simulation of the target information. At the same time, the superposition of multiple optical channels forms a simulation of multiple targets and background information, and more accurately performs a semi-physical simulation of the laser radar system. On the basis of effectively saving the cost of software and hardware, only the fiber optic delay and fiber optic lighting methods can be used to complete the simulation of the most important target distance and echo energy information in the target simulator. At the same time, multiple optical channels are used to form different levels of target and background information. The information is rich, which improves the shortcomings of the existing target simulator that can only perform a single overall target simulation without including multi-level target information and background information, and can better adapt to the target information in the actual environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0025] Figure 1 is a structural block diagram of a target echo simulation device provided by an embodiment of the present invention;

[0026] Figure 2 It is a structural block diagram of a multi-channel target depth information simulation unit provided by an embodiment of the present invention;

[0027] Figure 3 It is a plurality of target slice targets included in the target space information simulation unit, and the target is sliced ​​in the length direction into slice one, slice two and slice three of the target slice target; corresponding to the target slice model in the target depth information simulation unit.

[0028] 1-slice one (the target slice target corresponding to channel one), 2-slice two (the target slice target corresponding to channel two), 3-slice three (the target slice target corresponding to channel three). DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and implementation methods. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the implementation methods of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] like Figure 1 As shown, the target echo simulation device of the present invention is used for testing laser radar, simulating target distance, target laser echo energy, target depth information and target space information, including a target distance simulation delay device, an energy simulation unit, a beam splitter, a target depth information simulation unit, a target space information simulation unit, a beam combiner and an optical projection lens;

[0031] The target distance simulation delay device includes a trigger signal unit, which is used to give a trigger signal to the laser radar at a first moment, the first moment is used as the moment when the laser radar starts working, and sends a trigger pulse to the energy simulation unit at a second moment, the second moment is delayed by a first preset time relative to the first moment, the first preset time simulates the target distance, and the distance simulated by the first preset time is twice the distance from the laser radar to the target; in another embodiment, the target distance simulation delay device also includes a target distance solution module, which is used to calculate the first preset time according to the target distance.

[0032] The energy simulation unit includes a pulse laser source, which is used to emit a pulse laser with a first preset energy according to the trigger pulse to simulate the target laser echo energy; in another embodiment, the energy simulation unit also includes a third attenuator, the pulse laser source is used to emit a pulse laser with a third preset energy according to the trigger pulse, and the third attenuator is used to attenuate the energy of the pulse laser with the third preset energy to obtain a pulse laser with the first preset energy.

[0033] The beam splitter is used to couple the pulsed laser into the optical fiber and split it into multiple first beams. Figure 2 , multiple first split beams constitute a multiple optical channel target depth information simulation unit (i.e. Figure 2 In the multi-channel target depth simulation unit in the embodiment, the target is segmented and sliced ​​according to its length direction, and the average length can also be used. The length value can also be taken in segments according to the characteristics (head, tail or middle, wing, etc.). In this way, the target depth information simulation unit includes multiple target slice information simulation units (i.e. Figure 2Channel 1, channel 2, ... channel N in the target slice information simulation unit, each target slice information simulation unit simulates the target slice length information and laser energy echo information of each segment of the target slice segmentation along its length direction, each target slice information simulation unit includes a first optical fiber delay line and a first attenuator arranged on the first optical fiber delay line, each first optical fiber delay line is used to transmit one of the first sub-beams, each of the first sub-beams is attenuated by the first attenuator on each first optical fiber delay line to form a second sub-beam, simulates the target depth information, i.e., the information of the length of each target slice segment, and at the same time simulates the target laser echo energy, i.e., the part of the target laser echo energy that specifically corresponds to the target slice information; in this embodiment, the target depth information simulation unit also includes a background information simulation unit (i.e., Figure 2The background channel in the image is used to distinguish the anti-noise, recognition efficiency and other performance of the target. The background information simulation unit includes a second optical fiber delay line and a second attenuator arranged on the second optical fiber delay line. The second optical fiber delay line is used to transmit a first sub-beam. The first sub-beam in the second optical fiber delay line is subjected to energy attenuation by the second attenuator to form a third sub-beam. The target echo simulation device of this embodiment also includes a laser radar echo model solving module. The laser radar echo model solving module includes a laser echo energy solving unit. The laser echo energy solving unit is electrically connected to each of the first attenuator, the second attenuator and the third attenuator. The laser radar echo model solving module is used to calculate the laser echo energy according to the laser radar ranging equation and the input echo parameters. The first attenuator, the second attenuator and the third attenuator respectively set their respective energy attenuation values ​​according to the laser echo energy. The laser echo energy includes the echo energy of the nearest target slice, the echo energy of each target slice, and the background echo energy; the laser radar The echo model solving module also includes a fiber delay solving unit, which is used to solve and obtain the target depth information and background information corresponding to the delay time lengths of each first fiber delay line and the second fiber delay line; specifically, according to the laser radar ranging equation and the input echo parameters, the target slice length information corresponding to the first fiber delay line of the target slice information simulation unit is calculated, and the background length information corresponding to the second fiber delay line of the background information simulation unit is calculated, and the first fiber delay and the second fiber delay lines respectively set their own delay time length values ​​according to the length information, that is, the delay time length of each of the first fiber delay lines and the delay time length of the second fiber delay line are adjustable. The target space information simulation unit includes a plurality of target slice targets, and the target is segmented in the target length direction, specifically segmented according to the average length, or segmented according to the length value of the target characteristics (such as the head, tail or middle, wing, etc.). In this embodiment, the target slice segments of the plurality of target slice information simulation units correspond one-to-one, that is, the plurality of target slice targets correspond one-to-one to the first optical fiber delay lines of the plurality of target slice information simulation units. After each second split light beam irradiates a corresponding target slice target, an image is compounded through a beam combiner to simulate the target space information. Specifically, after each second split light beam is resolved, it is set to form an illumination array (i.e. Figure 2The target slice target is collimated with a fiber collimator and then illuminated. After passing through a beam splitter prism, multiple images are composited. The second beam splitter performs calculations including calculating target depth information and target laser echo energy. In this embodiment, the target space information simulation unit also includes a background target. The background target is set to cover the receiving field of view of the laser radar. In order to simulate the background and increase the richness of the scene, the background target corresponds to the second fiber delay line. After the third beam splitter irradiates the background target, the image is composited through the beam combiner. The beam combiner includes multiple beam splitters. One beam splitter prism combines two beam splitters into one, two beam splitters combine three beam splitters into one, three beam splitters combine four beam splitters into one, and so on.

[0034] The optical projection lens is used to match and dock with the laser radar. The light signal after image composite is transmitted to the laser radar via the optical projection lens for testing the laser radar.

[0035] In summary, the multi-channel laser scene simulation device includes a background channel and multiple target channels, each of which is an independent optical system, and the beam combination of the multi-channel optical paths is achieved through multiple beam splitters. One of the multiple optical channels is a background optical path, and the other channels can be output according to actual needs to form multi-level targets. Multiple optical channels all use optical fiber to complete illumination, synchronously use optical fiber to complete optical path delay, match target distance information, and adjust the output energy through the attenuator equipped on the optical fiber to match the energy information on the channel. The background channel is placed at the end, and the illumination optical system can be adjusted according to needs so that the background can completely cover the receiving field of view of the laser radar. Exemplarily, target channel one is a target with the smallest field of view, target channel two is a ship-shaped target with a slightly larger field of view, and so on. The last target channel is the target with the largest field of view. In addition, the target simulator can be equipped with a variety of different targets according to needs. The target echo information of the laser radar represents the three-dimensional information of the target, including target distance information, target depth information and laser energy scattering information.

[0036] The target distance simulation delay device is used to simulate the target distance information, the energy information simulation unit (including the pulse laser source and the attenuator) is used to simulate the energy dimension information of the echo laser pulse, and the target depth information simulation unit simulates the depth information of the target. Finally, the optical signal is adapted to the laser radar receiver through the optical projection lens, and the optical projection lens is designed according to the receiving field of view of the laser radar. The focal length of the projection lens is calculated according to the size of the circular field of view, and the optical design software is used to optimize the image quality.

[0037] The workflow of each functional module is further decomposed as follows: roughly control the target distance simulation delay time t0 to give the laser radar imaging trigger signal as tstart, and at the same time calculate the target distance delay corresponding time t according to the model, and output TTL trigger pulse to the pulse laser source. After receiving the electrical trigger signal, the pulse laser source outputs a laser pulse, which is attenuated according to the model solution value through the fiber attenuator, and then enters the target depth information simulation unit. The optical signal is transferred from free space to the optical fiber for propagation, and is divided into N optical signals through the beam splitter. The delay of each signal can be achieved through the precise control of the optical fiber delay line, and each signal can simulate the depth information of the target. For example, if the target is a warship, the length of the warship is the depth information of the target. The N optical signals are made into an array, and the target is illuminated after being collimated by the illumination array, and the N images are compounded after passing through the dichroic prism. Finally, the optical projection lens is matched with the optical system of the receiver, and the laser radar receiver receives the optical signal given by the target simulator, that is, the pixel signal of the target image. A laser scene simulator that sets the laser echo energy in multiple channels based on target distance, atmospheric characteristics, irradiation energy, laser beam divergence, background information, etc.

[0038] The target distance simulation delay device calculates the relationship between the target distance and the speed of light, obtains the corresponding distance delay, inputs it into the laser source, and controls the delay of the laser source.

[0039] The energy information simulation unit calculates the laser echo energy according to the laser radar ranging equation and the set parameters such as target distance, atmospheric characteristics, and irradiation energy, and controls the optical fiber attenuator to set the simulated echo, thereby outputting the laser echo energy that matches the set parameters for laser radar testing.

[0040] The target depth information simulation unit obtains the corresponding size information of the target through the target slice model, such as Figure 3 As shown, the target is sliced ​​into slice one, slice one and slice three in the length direction, and then the depth information of the target is simulated by controlling the optical fiber delay. The target spatial information simulation unit includes multiple target slice targets, and the appearance characteristics of the target are characterized by the target slice targets. The target is sliced ​​into slice one, slice two and slice three of the target slice target in the length direction, corresponding to the target slice model in the target depth information simulation unit. The target slice target can be a metal sheet that is scaled according to the size of the target distance and target length, and is placed in the field of view of the lighting array according to the actual position.

[0041] The optical projection lens controls the size of the beam expansion and performs divergence angle matching design to distinguish between background information in a large field of view and target information in a small field of view. Specifically, the divergence angle of the optical projection lens is designed according to the laser radar receiving field of view, and the circular field of view is designed to achieve full coverage of the laser radar field of view by the simulator to ensure signal reception. Optical design software is simultaneously used to optimize the design of the optical projection lens to ensure that no scene distortion occurs.

[0042] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A target echo simulation device for testing laser radar, characterized in that: It includes a target distance simulation delay device, an energy simulation unit, a beam splitter, a target depth information simulation unit, a target space information simulation unit, a beam combiner and an optical projection lens; The target distance simulation delay device includes a trigger signal unit, which is used to send a trigger signal to the laser radar at a first moment, the first moment being the moment when the laser radar starts working, and send a trigger pulse to the energy simulation unit at a second moment, the second moment being delayed by a first preset time relative to the first moment; The energy simulation unit comprises a pulse laser source, which is used to emit a pulse laser with a first preset energy according to the trigger pulse; The beam splitter is used to couple the pulse laser into the optical fiber and then split it into multiple first beams; The target depth information simulation unit includes a plurality of target slice information simulation units, each of the target slice information simulation units includes a first optical fiber delay line and a first attenuator arranged on the first optical fiber delay line, each of the first optical fiber delay lines is used to transmit one path of the first sub-beam, and each of the first sub-beams is formed into a second sub-beam after attenuating the second preset energy through the first attenuator on each of the first optical fiber delay lines; The target space information simulation unit includes a plurality of target slice targets, and the plurality of target slice targets correspond to the first optical fiber delay lines of the plurality of target slice information simulation units one by one. After each of the second split light beams irradiates a corresponding target slice target, the image is compounded through the beam combiner to simulate the target space information. The optical projection lens is used to match and dock with the laser radar, and the optical signal after image composite is transmitted to the laser radar via the optical projection lens.

2. The target echo simulation device according to claim 1, characterized in that: The target depth information simulation unit also includes a background information simulation unit, which includes a second optical fiber delay line and a second attenuator arranged on the second optical fiber delay line, the second optical fiber delay line is used to transmit one path of the first sub-beam, and the first sub-beam in the second optical fiber delay line is subjected to energy attenuation by the second attenuator to form a third sub-beam; The target space information simulation unit also includes a background target, and the background target corresponds to the second optical fiber delay line. After the third sub-beam irradiates the background target, image compounding is performed via the beam combiner.

3. The target echo simulation device according to claim 1 or 2, characterized in that: The energy simulation unit includes a pulse laser source and a third attenuator. The pulse laser source is used to emit a pulse laser with a third preset energy according to the trigger pulse, and the third attenuator is used to attenuate the energy of the pulse laser with the third preset energy to obtain a pulse laser with the first preset energy.

4. The target echo simulation device according to claim 1 or 2, characterized in that: Each of the second split light beams irradiates a corresponding target slice target and then undergoes image compounding via the beam combiner, including: Each of the second sub-beams is resolved and arranged into an illumination array, and illuminates the target slice target after collimation, and multiple images are compounded after passing through a beam splitter prism. The second sub-beam is resolved including the target depth information and the target laser echo energy.

5. The target echo simulation device according to claim 2, characterized in that: The delay length of each of the first optical fiber delay lines and the delay length of the second optical fiber delay line are adjustable.

6. The target echo simulation device according to claim 3, characterized in that: It also includes a laser radar echo model solving module, which includes a laser echo energy solving unit. The laser echo energy solving unit is electrically connected to each of the first attenuator, the second attenuator and the third attenuator. The laser radar echo model solving module is used to calculate the laser echo energy according to the laser radar ranging equation and the input echo parameters. The first attenuator, the second attenuator and the third attenuator respectively set their respective energy attenuation values ​​according to the laser echo energy.

7. The target echo simulation device according to claim 1, characterized in that: A laser collimator is arranged between each of the first optical fiber delay lines and the corresponding target slice target.

8. The target echo simulation device according to claim 1, characterized in that: The target distance simulation delay device also includes a target distance calculation module, which is used to calculate the first preset time according to the target distance.

9. The target echo simulation device according to claim 6, characterized in that: The laser radar echo model solving module also includes a fiber delay solving unit, which is used to solve and obtain the target depth information and background information corresponding to the delay time lengths of each first fiber delay line and second fiber delay line; specifically, according to the laser radar ranging equation and the input echo parameters, the target slice length information corresponding to the first fiber delay line of the target slice information simulation unit is calculated, and the background length information corresponding to the second fiber delay line of the background information simulation unit is calculated, and the first fiber delay and the second fiber delay lines respectively set their own delay time length values ​​according to the length information.

10. The target echo simulation device according to claim 1, characterized in that: The beam combiner includes a plurality of beam splitters, wherein one beam splitter prism combines two split light beams into one, two beam splitters combine three split light beams into one, three beam splitters combine four split light beams into one, and so on.

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