Incoming ammunition simulator and simulation method

Abstract

The invention relates to ammunition simulation, and in particular to an incoming ammunition simulator and a simulation method, wherein a broadband radio frequency module receives a radar transmission signal received by a receiving antenna, converts the received radar transmission signal into a first intermediate frequency signal, and then sends it to a digital processing module; receives a second intermediate frequency signal sent by the digital processing module, converts the second intermediate frequency signal into a simulated target echo signal, and then sends it to a transmitting antenna; the digital processing module receives the first intermediate frequency signal sent by the broadband radio frequency module, stores and forwards it by using a digital radio frequency storage device (DRFM), simulates the target distance by using a time delay method, simulates the target speed by using a phase shift method, performs target simulation feature modulation, and sends the obtained second intermediate frequency signal to the broadband radio frequency module; the technical solution provided by the invention can effectively overcome the defect that it is difficult to accurately simulate the distance and speed of the target in the prior art.

Description

Technical Field

[0001] The invention relates to ammunition simulation, and in particular to an incoming ammunition simulator and a simulation method. Background Art

[0002] The incoming ammunition simulator is a highly specialized simulation training device, which is mainly used to simulate the movement trajectory, explosion effect, etc. of incoming ammunition in a real battlefield environment to provide a training experience close to actual combat.

[0003] At present, most incoming ammunition simulators use frequency shift modulation to simulate the distance and speed of the target. This simulation method produces a large distance error, generally greater than 0.3m, which has a certain degree of impact on the radar's ranging accuracy and cannot be used as a true value device for radar to detect incoming targets. In addition, most simulators can only simulate stationary targets, but not moving targets. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides an incoming ammunition simulator and a simulation method, which can effectively overcome the defect of the prior art that it is difficult to accurately simulate the distance and speed of the target.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] An incoming ammunition simulator includes a transceiver antenna, a broadband radio frequency module, a digital processing module and a host computer;

[0007] The transceiver antenna receives the radar transmission signal when the continuous wave radar is working normally through the receiving antenna, and sends the radar transmission signal to the broadband radio frequency module, and radiates the simulated target echo signal sent by the broadband radio frequency module through the transmitting antenna;

[0008] The broadband radio frequency module receives the radar transmission signal received by the receiving antenna, converts the received radar transmission signal into a first intermediate frequency signal and sends it to the digital processing module; receives the second intermediate frequency signal sent by the digital processing module, converts the second intermediate frequency signal into an analog target echo signal and sends it to the transmitting antenna;

[0009] The digital processing module receives the first intermediate frequency signal sent by the broadband radio frequency module, uses the digital radio frequency storage DRFM to store and forward, uses the time delay method to simulate the target distance, uses the phase shift method to simulate the target speed, performs target simulation feature modulation, and sends the obtained second intermediate frequency signal to the broadband radio frequency module;

[0010] The host computer sets the status information of the RF channel and the digital processing module in the broadband RF module, and edits the target motion situation. The target motion situation information is converted into target motion situation modulation parameters and then sent to the digital processing module for the digital processing module to perform target analog feature modulation.

[0011] Preferably, the transmitting and receiving antenna adopts a transmitting and receiving antenna system, and the receiving antenna and the transmitting antenna adopt a cross-slant polarization mode, and the transmitting and receiving isolation is improved by spatial separation, adding absorbing materials and setting partitions, so as to realize simultaneous operation of transmitting and receiving;

[0012] The receiving antenna and the transmitting antenna are in the form of planar antennas and are integrated with the main chassis.

[0013] Preferably, the broadband radio frequency module includes a power divider, a low-frequency down-conversion channel L, a high-frequency down-conversion channel H, a low-frequency up-conversion channel L, a high-frequency up-conversion channel H and a combiner;

[0014] The power divider receives the radar transmission signal received by the receiving antenna and splits it into two signals and sends them to the low-frequency down-conversion channel L and the high-frequency down-conversion channel H respectively;

[0015] The low-frequency down-conversion channel L and the high-frequency down-conversion channel H respectively cover the low and high operating frequency bands of the continuous wave radar. In each down-conversion channel, the power division signal and the clock local oscillator signal are mixed into the first intermediate frequency signal and sent to the digital processing module;

[0016] The low-frequency up-conversion channel L and the high-frequency up-conversion channel H respectively cover the low and high working frequency bands of the continuous wave radar, respectively receive the second intermediate frequency signal sent by the digital processing module, and filter, up-convert and amplify the second intermediate frequency signal before sending it to the combiner;

[0017] The combiner receives the signals sent by the low-frequency up-conversion channel L and the high-frequency up-conversion channel H, combines the two signals into a simulated target echo signal, and then sends it to the transmitting antenna.

[0018] Preferably, the broadband RF module adopts a dual-channel transceiver system, the instantaneous bandwidth of each transceiver channel is 700 MHz, and the instantaneous bandwidth can be further expanded, and the two transceiver channels respectively cover the low and high operating frequency bands of the continuous wave radar.

[0019] Preferably, the digital processing module includes an analog-to-digital converter ADC, a digital down converter DDC, a target analog unit, a digital up converter DUC and a digital-to-analog converter DAC;

[0020] The analog-to-digital converter ADC receives the first intermediate frequency signal sent by the low-frequency down-conversion channel L and the high-frequency down-conversion channel H, performs AD sampling on the first intermediate frequency signal, and then sends it to the digital down-converter DDC;

[0021] The digital down converter DDC receives the signal sent by the analog-to-digital converter ADC, performs digital down-conversion on the signal, and then sends it to the target analog unit;

[0022] The target simulation unit uses the digital radio frequency memory DRFM for storage and forwarding, uses the time delay method to simulate the target distance, uses the phase shift method to simulate the target speed, performs target simulation characteristic modulation, and sends the obtained target simulation characteristic modulation signal to the digital up converter DUC;

[0023] The digital up converter DUC receives the target analog characteristic modulation signal sent by the target analog unit, performs digital up-conversion on the target analog characteristic modulation signal, and then sends it to the digital-to-analog converter DAC;

[0024] The digital-to-analog converter DAC receives the signal sent by the digital up-converter DUC, performs DA sampling on the digital signal to obtain a second intermediate frequency signal, and then sends it to the low-frequency up-conversion channel L and the high-frequency up-conversion channel H in the broadband RF module respectively.

[0025] Preferably, the target simulation unit includes a digital filtering module, a digital radio frequency storage DRFM, a distance delay modulation module, a speed phase modulation module and an amplitude modulation module;

[0026] A digital filtering module receives the signal sent by the digital down converter DDC, performs digital filtering on the signal, and then sends it to the digital radio frequency storage DRFM;

[0027] Digital radio frequency memory DRFM receives the signal sent by the digital filter module, and stores and forwards the signal;

[0028] The distance delay modulation module receives the signal sent by the digital radio frequency storage DRFM, and based on the delay parameters sent by the host computer, uses a fractional order true delay filter to simulate the target distance of the signal and then sends it to the speed phase modulation module;

[0029] The speed phase modulation module receives the signal sent by the distance delay modulation module, and based on the phase parameters sent by the host computer, uses a variable bandwidth extraction filter and direct digital frequency synthesis DDS to simulate the target speed of the signal and then sends it to the amplitude modulation module;

[0030] The amplitude modulation module receives the signal sent by the speed phase modulation module, performs amplitude modulation on the signal based on the amplitude parameter sent by the host computer to obtain the target analog characteristic modulation signal, and then sends it to the digital up converter DUC.

[0031] Preferably, the distance delay modulation module receives a signal sent by the digital radio frequency memory DRFM, and uses a fractional order true delay filter to simulate the target distance of the signal based on the delay parameter sent by the host computer, including:

[0032] The target distance simulation accuracy depends on the delay accuracy. If the target distance simulation accuracy does not exceed 0.1m, the delay accuracy is required to be less than 0.67ns.

[0033] The integer order + fractional order delay method is used for processing, and the integer order delay accuracy is 1 / 150e6=6.667ns. The fractional order adopts 256-order processing, and the fractional order delay accuracy is 6.667ns / 256=0.026ns, which meets the target distance simulation accuracy requirements.

[0034] Preferably, the speed phase modulation module receives the signal sent by the distance delay modulation module, and uses a variable bandwidth decimation filter and direct digital frequency synthesis DDS to simulate the target speed of the signal based on the phase parameter sent by the host computer, including:

[0035] n Bit phase accumulator exists 2 n possible phase points, the data stored in the phase register represents the number of phase accumulators accumulated in each clock cycle. If the clock frequency is f c , then the output sine wave frequency f 0 is:

[0036] ;

[0037] in, M To store data in the phase register, n The value range is ;

[0038] Direct digital frequency synthesis DDS is used to generate Doppler frequency deviation. The frequency accuracy depends on the phase accuracy. 32-bit phase accuracy is used to control the frequency signal. The system sampling rate is set to 2.4GHz, the instantaneous bandwidth is -1200MHz~1200MHz, and the minimum frequency accuracy is 2400MHz / 2^32=0.56Hz.

[0039] Assume the distance between the target and the CW radar is R , then in the two-way path between the continuous wave radar and the target, the total phase Changes to:

[0040] ;

[0041] in, is the wavelength of continuous wave radar;

[0042] If the target moves relative to the CW radar, the distance between the target and the CW radar is R and total phase will change with time, calculate the total phase About Time t The derivative of for:

[0043] ;

[0044] in, , v r is the radial velocity, f d is the Doppler shift, that is ;

[0045] The modulation of Doppler information is achieved by phase modulation, that is, the target speed is simulated for the signal sent by the range delay modulation module.

[0046] Preferably, the host computer includes a target situation editing module, a target motion situation module and a channel control module;

[0047] The target situation editing module is used by the operator to edit the target movement situation and send the target movement situation information to the target movement situation module;

[0048] The target motion situation module receives the target motion situation information sent by the target situation editing module, interprets the modulation information of the target motion situation information in combination with the continuous wave radar signal characteristics, obtains the delay parameter, phase parameter, and amplitude parameter, and sends them to the distance delay modulation module, the speed phase modulation module, and the amplitude modulation module respectively;

[0049] The channel control module sets the status information of the RF channel and the digital processing module in the broadband RF module, including local oscillator control and gain control.

[0050] An incoming ammunition simulation method controls an incoming ammunition simulator to enter a self-check mode, a calibration mode, and a working mode in sequence to generate a simulated target echo signal modulated by a target simulation feature:

[0051] 1) Self-test mode

[0052] After the simulator is powered on, it will initialize the configuration and perform self-test according to the default status information. After the self-test is normal, it will enter the standby state and wait for calibration instructions.

[0053] 2) Calibration mode

[0054] Connect the transmitting port of the simulator to the receiving port, calculate the system delay of the simulator through the internal calibration mode, and use the laser rangefinder to calculate the distance of the simulator and obtain the corresponding distance delay. Add the system delay and distance delay to obtain the total delay to calibrate the system error of the simulator.

[0055] 3) Working mode

[0056] S1, the host computer sets the status information of the RF channel and the digital processing module in the broadband RF module through the channel control module;

[0057] S2, the operator edits the target motion situation through the target motion situation editing module, and the host computer converts the target motion situation information into target motion situation modulation parameters through the target motion situation module and sends them to the digital processing module for the digital processing module to perform target simulation feature modulation;

[0058] S3, the receiving antenna receives the radar transmission signal when the continuous wave radar is working normally, and sends the radar transmission signal to the broadband radio frequency module;

[0059] S4, the broadband radio frequency module receives the radar transmission signal received by the receiving antenna, converts the received radar transmission signal into a first intermediate frequency signal and sends it to the digital processing module;

[0060] S5, the digital processing module receives the first intermediate frequency signal sent by the broadband radio frequency module, uses the digital radio frequency storage DRFM to store and forward, uses the time delay method to simulate the target distance, uses the phase shift method to simulate the target speed, performs target simulation feature modulation, and sends the obtained second intermediate frequency signal to the broadband radio frequency module;

[0061] S6. The broadband radio frequency module receives the second intermediate frequency signal sent by the digital processing module, converts the second intermediate frequency signal into an analog target echo signal, and then sends it to the transmitting antenna;

[0062] S7. The transmitting antenna radiates the simulated target echo signal sent by the broadband RF module, and cooperates with the continuous wave radar to carry out training tasks.

[0063] Compared with the prior art, the incoming ammunition simulator and simulation method provided by the present invention have the following beneficial effects:

[0064] 1) Fractional-order true delay high-precision delay control technology

[0065] For the target distance simulation of the system, a fractional-order true delay filter designed with fixed-point high-precision delay filter is adopted, which has high target distance simulation accuracy, flexible control and resource optimization;

[0066] 2) Variable bandwidth digital frequency synthesis modulation technology

[0067] For the target speed simulation of the system, variable bandwidth decimation filter and direct digital frequency synthesis DDS are used to improve the quality of the modulation signal and ensure Doppler modulation accuracy better than Hertz level.

[0068] 3) High-quality digital radio frequency storage technology for both transmission and reception

[0069] There is no intermittent period in the continuous wave radar target simulation process. At the same time, in order to achieve a miniaturized structure design, a high-isolation transmit and receive antenna technology is used to transmit and receive simultaneously to achieve high-quality digital RF storage capabilities;

[0070] 4) Target motion control technology based on editable scripts

[0071] Aiming at the complex motion state of the target, combined with high-precision digital modulation technology, it supports the use of editable scripts to edit the target motion situation, which is easy to expand, high-precision and flexible to use;

[0072] 5) Capable of phase calibration of radar receiver

[0073] By receiving the synchronous serial port data and the synchronous clock signal of the radar sent by the radar, the simulator generates a point-frequency continuous wave signal according to the received frequency point and frequency deviation information, which is transmitted to the radar receiver by the transmitting antenna, thereby realizing the phase calibration of the radar receiver. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0075] Figure 1 A schematic diagram of the system framework of the incoming ammunition simulator of the present invention;

[0076] Figure 2 It is a schematic diagram of the working principle of the incoming ammunition simulator of the present invention;

[0077] Figure 3 It is a schematic diagram of the interface relationship of the incoming ammunition simulator in the present invention;

[0078] Figure 4 It is a schematic diagram of the working principle of the digital processing module in the present invention;

[0079] Figure 5 This is a schematic diagram of the working principle of digital radio frequency memory DRFM;

[0080] Figure 6 This is a basic schematic diagram of the digital frequency synthesis DDS;

[0081] Figure 7 It is a schematic diagram of the flow chart of the incoming ammunition simulation method of the present invention. DETAILED DESCRIPTION

[0082] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0083] An incoming ammunition simulator, such as Figure 1 and Figure 2 As shown, it includes a transceiver antenna, a broadband radio frequency module, a digital processing module and a host computer;

[0084] The transceiver antenna receives the radar transmission signal when the continuous wave radar is working normally through the receiving antenna, and sends the radar transmission signal to the broadband radio frequency module, and radiates the simulated target echo signal sent by the broadband radio frequency module through the transmitting antenna;

[0085] The broadband radio frequency module receives the radar transmission signal received by the receiving antenna, converts the received radar transmission signal into a first intermediate frequency signal and sends it to the digital processing module; receives the second intermediate frequency signal sent by the digital processing module, converts the second intermediate frequency signal into an analog target echo signal and sends it to the transmitting antenna;

[0086] The digital processing module receives the first intermediate frequency signal sent by the broadband radio frequency module, uses the digital radio frequency storage DRFM to store and forward, uses the time delay method to simulate the target distance, uses the phase shift method to simulate the target speed, performs target simulation feature modulation, and sends the obtained second intermediate frequency signal to the broadband radio frequency module;

[0087] The host computer sets the status information of the RF channel and the digital processing module in the broadband RF module, and edits the target motion situation. The target motion situation information is converted into target motion situation modulation parameters and then sent to the digital processing module for the digital processing module to perform target analog feature modulation.

[0088] ① The transmitting and receiving antennas adopt a separate transmitting and receiving antenna system. The receiving antenna and the transmitting antenna adopt a cross-slant polarization mode. The isolation between the transmitting and receiving antennas is improved by spatial separation, adding absorbing materials and setting partitions to achieve simultaneous operation of the transmitting and receiving antennas.

[0089] The receiving antenna and the transmitting antenna are in the form of planar antennas and are integrated with the main chassis.

[0090] ② If Figure 2 As shown, the broadband RF module includes a power divider, a low-frequency down-conversion channel L, a high-frequency down-conversion channel H, a low-frequency up-conversion channel L, a high-frequency up-conversion channel H and a combiner;

[0091] The power divider receives the radar transmission signal received by the receiving antenna and splits it into two signals and sends them to the low-frequency down-conversion channel L and the high-frequency down-conversion channel H respectively;

[0092] The low-frequency down-conversion channel L and the high-frequency down-conversion channel H respectively cover the low and high operating frequency bands of the continuous wave radar. In each down-conversion channel, the power division signal and the clock local oscillator signal are mixed into the first intermediate frequency signal and sent to the digital processing module;

[0093] The low-frequency up-conversion channel L and the high-frequency up-conversion channel H respectively cover the low and high working frequency bands of the continuous wave radar, respectively receive the second intermediate frequency signal sent by the digital processing module, and filter, up-convert and amplify the second intermediate frequency signal before sending it to the combiner;

[0094] The combiner receives the signals sent by the low-frequency up-conversion channel L and the high-frequency up-conversion channel H, combines the two signals into a simulated target echo signal, and then sends it to the transmitting antenna.

[0095] In the technical solution of the present application, the broadband RF module adopts a dual-channel transceiver system. The instantaneous bandwidth of each transceiver channel is 700MHz, and the instantaneous bandwidth can be further expanded. The two transceiver channels respectively cover the low and high operating frequency bands of the continuous wave radar.

[0096] ③ Such as Figure 2 As shown, the digital processing module includes an analog-to-digital converter ADC, a digital down converter DDC, a target analog unit, a digital up converter DUC and a digital-to-analog converter DAC;

[0097] The analog-to-digital converter ADC receives the first intermediate frequency signal sent by the low-frequency down-conversion channel L and the high-frequency down-conversion channel H, performs AD sampling on the first intermediate frequency signal, and then sends it to the digital down-converter DDC;

[0098] The digital down converter DDC receives the signal sent by the analog-to-digital converter ADC, performs digital down-conversion on the signal, and then sends it to the target analog unit;

[0099] The target simulation unit uses the digital radio frequency memory DRFM for storage and forwarding, uses the time delay method to simulate the target distance, uses the phase shift method to simulate the target speed, performs target simulation characteristic modulation, and sends the obtained target simulation characteristic modulation signal to the digital up converter DUC;

[0100] The digital up converter DUC receives the target analog characteristic modulation signal sent by the target analog unit, performs digital up-conversion on the target analog characteristic modulation signal, and then sends it to the digital-to-analog converter DAC;

[0101] The digital-to-analog converter DAC receives the signal sent by the digital up-converter DUC, performs DA sampling on the digital signal to obtain a second intermediate frequency signal, and then sends it to the low-frequency up-conversion channel L and the high-frequency up-conversion channel H in the broadband RF module respectively.

[0102] Specifically, Figure 4 As shown, the target simulation unit includes a digital filtering module, a digital radio frequency storage DRFM, a distance delay modulation module, a speed phase modulation module and an amplitude modulation module;

[0103] A digital filtering module receives the signal sent by the digital down converter DDC, performs digital filtering on the signal, and then sends it to the digital radio frequency storage DRFM;

[0104] Digital radio frequency memory DRFM receives the signal sent by the digital filter module, and stores and forwards the signal;

[0105] The distance delay modulation module receives the signal sent by the digital radio frequency storage DRFM, and based on the delay parameters sent by the host computer, uses a fractional order true delay filter to simulate the target distance of the signal and then sends it to the speed phase modulation module;

[0106] The speed phase modulation module receives the signal sent by the distance delay modulation module, and based on the phase parameters sent by the host computer, uses a variable bandwidth extraction filter and direct digital frequency synthesis DDS to simulate the target speed of the signal and then sends it to the amplitude modulation module;

[0107] The amplitude modulation module receives the signal sent by the speed phase modulation module, performs amplitude modulation on the signal based on the amplitude parameter sent by the host computer to obtain the target analog characteristic modulation signal, and then sends it to the digital up converter DUC.

[0108] A. Digital Radio Frequency Memory DRFM is a microwave signal storage system used to implement radio frequency signal storage and forwarding functions. Digital radio frequency memory captures and saves signals by high-speed sampling, storage, transformation processing and reconstruction of received radio frequency signals. It has become a key component of electronic countermeasure systems.

[0109] The working principle of digital radio frequency memory DRFM is as follows Figure 5 As shown in the figure, AD / DA quantization error is the main factor leading to coherence loss, and an AD device with a capacity of no less than 7 bits needs to be selected. The AD quantization depth used in this system is 14 bits, which meets the system application indicators.

[0110] B. The distance delay modulation module receives the signal sent by the digital radio frequency storage DRFM, and uses a fractional order true delay filter to simulate the target distance of the signal based on the delay parameters sent by the host computer, including:

[0111] The target distance simulation accuracy depends on the delay accuracy. If the target distance simulation accuracy does not exceed 0.1m, the delay accuracy is required to be less than 0.67ns.

[0112] The integer order + fractional order delay method is used for processing, and the integer order delay accuracy is 1 / 150e6=6.667ns. The fractional order adopts 256-order processing, and the fractional order delay accuracy is 6.667ns / 256=0.026ns, which meets the target distance simulation accuracy requirements.

[0113] C. The speed phase modulation module receives the signal sent by the distance delay modulation module, and uses a variable bandwidth decimation filter and direct digital frequency synthesis DDS to simulate the target speed of the signal based on the phase parameters sent by the host computer, including:

[0114] n Bit phase accumulator exists 2 n possible phase points, the data stored in the phase register represents the number of phase accumulators accumulated in each clock cycle. If the clock frequency is f c , then the output sine wave frequency f 0 is:

[0115] ;

[0116] in, M To store data in the phase register, n The value range is ;

[0117] Direct digital frequency synthesis DDS is used to generate Doppler frequency deviation. The frequency accuracy depends on the phase accuracy. 32-bit phase accuracy is used to control the frequency signal. The system sampling rate is set to 2.4GHz, the instantaneous bandwidth is -1200MHz~1200MHz, and the minimum frequency accuracy is 2400MHz / 2^32=0.56Hz.

[0118] Assume the distance between the target and the CW radar is R , then in the two-way path between the continuous wave radar and the target, the total phase Changes to:

[0119] ;

[0120] in, is the wavelength of continuous wave radar;

[0121] If the target moves relative to the CW radar, the distance between the target and the CW radar is R and total phase will change with time, calculate the total phase About Time t The derivative of for:

[0122] ;

[0123] in, , v r is the radial velocity, f d is the Doppler shift, that is ;

[0124] The modulation of Doppler information is achieved by phase modulation, that is, the target speed is simulated for the signal sent by the range delay modulation module.

[0125] With the widespread use of digital technology in instrumentation and communication systems, direct digital frequency synthesis (DDS) can be used to generate a digital waveform of a specific frequency and modulate it into a delayed forwarding signal. The basic architecture of digital frequency synthesis DDS is as follows: Figure 6 As shown in Figure 1, this simplified model uses a stable clock to drive a programmable read-only memory (PROM) that stores one or more integer cycles of a sine wave (or other arbitrary waveform). As the address counter steps through each memory location, the corresponding digital amplitude of the signal at each location drives the DAC, which in turn generates the analog output signal. The spectral purity of the final analog output signal depends mainly on the DAC, and the phase noise mainly comes from the reference clock.

[0126] ④The host computer includes a target situation editing module, a target motion situation module and a channel control module;

[0127] The target situation editing module is used by the operator to edit the target movement situation and send the target movement situation information to the target movement situation module;

[0128] The target motion situation module receives the target motion situation information sent by the target situation editing module, interprets the modulation information of the target motion situation information in combination with the continuous wave radar signal characteristics, obtains the delay parameter, phase parameter, and amplitude parameter, and sends them to the distance delay modulation module, the speed phase modulation module, and the amplitude modulation module respectively;

[0129] The channel control module sets the status information of the RF channel and the digital processing module in the broadband RF module, including local oscillator control and gain control.

[0130] In the technical solution of this application, Figure 1 and Figure 3 As shown, the incoming ammunition simulator also includes a power module, a main chassis, a lifting rod, an explosion-proof packaging box and a power adapter, wherein the broadband RF module, the digital processing module and the power module are integrated into the main chassis, and the main chassis is fixedly mounted on the lifting rod, and the host computer uses a reinforced laptop.

[0131] The simulator mainly implements the following four functions:

[0132] 1) Moving target simulation

[0133] The simulator is in a silent state after powering on. After receiving the launch command, it detects the radar launch signal of the continuous wave radar and outputs the simulated target echo signal. After the simulated target moves from the set starting distance to the minimum value of the simulated distance range according to the set Doppler speed, the simulator automatically returns to the silent state to simulate the process of the moving target attacking.

[0134] 2) Stationary target simulation

[0135] The continuous wave radar is in normal working condition. Set the simulator to enter the stationary target simulation mode, set the distance and Doppler speed of the target, and the simulator receives the radar transmission signal of the continuous wave radar, uses the digital radio frequency memory DRFM to store and forward, and outputs the simulated target echo signal in real time. Although the target has a Doppler speed, the target distance does not change;

[0136] 3) External synchronization and external clock input response function

[0137] The simulator can receive the synchronization pulse and 10 MHz clock signal sent by the radar, and output a signal that is synchronized and coherent with the radar timing when the radar is not radiating;

[0138] 4) Point frequency continuous wave output function

[0139] When the simulator is set to the point frequency output mode, it receives the synchronization pulses and 10 MHz clock signal sent by the radar without radiating, generates and outputs a point frequency continuous wave with a certain Doppler frequency superimposed on it, and transmits it to the radar receiver through the transmitting antenna, thereby realizing the phase calibration of the radar receiver.

[0140] The incoming ammunition simulator provided by the present invention has the characteristics of high integration, small size, light weight, portable design, low power consumption, strong functions, etc. It can meet the combat training needs of the troops, adopts digital domain modulation technology to realize continuous wave target simulation function, integrates digital radio frequency storage DRFM, fractional-order true delay high-precision delay control technology, variable bandwidth digital frequency synthesis modulation technology and target motion control technology based on editable scripts, has very high signal fidelity and modulation accuracy, clear module design, and complete functional testing.

[0141] The technical solution of this application, based on the disclosure of the above incoming ammunition simulator, also discloses an incoming ammunition simulation method, such as Figure 7 As shown: the incoming ammunition simulator is controlled to enter the self-check mode, calibration mode, and working mode in sequence to generate a simulated target echo signal modulated by the target simulation characteristics:

[0142] 1) Self-test mode

[0143] After the simulator is powered on, it will initialize the configuration and perform self-test according to the default status information. After the self-test is normal, it will enter the standby state and wait for calibration instructions.

[0144] 2) Calibration mode

[0145] Connect the transmitting port of the simulator to the receiving port, calculate the system delay of the simulator through the internal calibration mode, and use the laser rangefinder to calculate the distance of the simulator and obtain the corresponding distance delay. Add the system delay and distance delay to obtain the total delay to calibrate the system error of the simulator.

[0146] 3) Working mode

[0147] S1, the host computer sets the status information of the RF channel and the digital processing module in the broadband RF module through the channel control module;

[0148] S2, the operator edits the target motion situation through the target motion situation editing module, and the host computer converts the target motion situation information into target motion situation modulation parameters through the target motion situation module and sends them to the digital processing module for the digital processing module to perform target simulation feature modulation;

[0149] S3, the receiving antenna receives the radar transmission signal when the continuous wave radar is working normally, and sends the radar transmission signal to the broadband radio frequency module;

[0150] S4, the broadband radio frequency module receives the radar transmission signal received by the receiving antenna, converts the received radar transmission signal into a first intermediate frequency signal and sends it to the digital processing module;

[0151] S5, the digital processing module receives the first intermediate frequency signal sent by the broadband radio frequency module, uses the digital radio frequency storage DRFM to store and forward, uses the time delay method to simulate the target distance, uses the phase shift method to simulate the target speed, performs target simulation feature modulation, and sends the obtained second intermediate frequency signal to the broadband radio frequency module;

[0152] S6. The broadband radio frequency module receives the second intermediate frequency signal sent by the digital processing module, converts the second intermediate frequency signal into an analog target echo signal, and then sends it to the transmitting antenna;

[0153] S7. The transmitting antenna radiates the simulated target echo signal sent by the broadband RF module, and cooperates with the continuous wave radar to carry out training tasks.

[0154] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An incoming ammunition simulator, characterized in that: Includes transceiver antenna, broadband RF module, digital processing module and host computer; The transceiver antenna receives the radar transmission signal when the continuous wave radar is working normally through the receiving antenna, and sends the radar transmission signal to the broadband radio frequency module, and radiates the simulated target echo signal sent by the broadband radio frequency module through the transmitting antenna; The broadband radio frequency module receives the radar transmission signal received by the receiving antenna, converts the received radar transmission signal into a first intermediate frequency signal and sends it to the digital processing module; Receive the second intermediate frequency signal sent by the digital processing module, convert the second intermediate frequency signal into an analog target echo signal and send it to the transmitting antenna; The digital processing module receives the first intermediate frequency signal sent by the broadband radio frequency module, uses the digital radio frequency storage DRFM to store and forward, uses the time delay method to simulate the target distance, uses the phase shift method to simulate the target speed, performs target simulation feature modulation, and sends the obtained second intermediate frequency signal to the broadband radio frequency module; The host computer sets the status information of the RF channel and the digital processing module in the broadband RF module, and performs target motion situation editing, converts the target motion situation information into target motion situation modulation parameters, and sends them to the digital processing module for the digital processing module to perform target analog feature modulation; The digital processing module includes an analog-to-digital converter ADC, a digital down converter DDC, a target analog unit, a digital up converter DUC and a digital-to-analog converter DAC; The analog-to-digital converter ADC receives the first intermediate frequency signal sent by the low-frequency down-conversion channel L and the high-frequency down-conversion channel H in the broadband RF module, performs AD sampling on the first intermediate frequency signal, and then sends it to the digital down-converter DDC; The digital down converter DDC receives the signal sent by the analog-to-digital converter ADC, performs digital down-conversion on the signal, and then sends it to the target analog unit; The target simulation unit uses the digital radio frequency memory DRFM for storage and forwarding, uses the time delay method to simulate the target distance, uses the phase shift method to simulate the target speed, performs target simulation characteristic modulation, and sends the obtained target simulation characteristic modulation signal to the digital up converter DUC; The digital up converter DUC receives the target analog characteristic modulation signal sent by the target analog unit, performs digital up-conversion on the target analog characteristic modulation signal, and then sends it to the digital-to-analog converter DAC; The digital-to-analog converter DAC receives the signal sent by the digital up-converter DUC, performs DA sampling on the signal to obtain the second intermediate frequency signal, and then sends it to the low-frequency up-conversion channel L and the high-frequency up-conversion channel H in the broadband RF module respectively; The target simulation unit includes a digital filtering module, a digital radio frequency storage DRFM, a distance delay modulation module, a speed phase modulation module and an amplitude modulation module; A digital filtering module receives the signal sent by the digital down converter DDC, performs digital filtering on the signal, and then sends it to the digital radio frequency storage DRFM; Digital radio frequency memory DRFM receives the signal sent by the digital filter module, and stores and forwards the signal; The distance delay modulation module receives the signal sent by the digital radio frequency storage DRFM, and based on the delay parameters sent by the host computer, uses a fractional order true delay filter to simulate the target distance of the signal and then sends it to the speed phase modulation module; The speed phase modulation module receives the signal sent by the distance delay modulation module, and based on the phase parameters sent by the host computer, uses a variable bandwidth extraction filter and direct digital frequency synthesis DDS to simulate the target speed of the signal and then sends it to the amplitude modulation module; The amplitude modulation module receives the signal sent by the speed phase modulation module, performs amplitude modulation on the signal based on the amplitude parameter sent by the host computer to obtain the target analog characteristic modulation signal, and then sends it to the digital up converter DUC; The distance delay modulation module receives the signal sent by the digital radio frequency storage DRFM, and uses a fractional order true delay filter to simulate the target distance of the signal based on the delay parameter sent by the host computer, including: The target distance simulation accuracy depends on the delay accuracy. If the target distance simulation accuracy does not exceed 0.1m, the delay accuracy is required to be less than 0.67ns. The integer order + fractional order delay method is used for processing, and the integer order delay accuracy is 1 / 150e6=6.667ns. The fractional order uses 256-order processing, and the fractional order delay accuracy is 6.667ns / 256=0.026ns, which meets the target distance simulation accuracy requirements; The speed phase modulation module receives the signal sent by the distance delay modulation module, and uses a variable bandwidth extraction filter and a direct digital frequency synthesis DDS to simulate the target speed of the signal based on the phase parameter sent by the host computer, including: n Bit phase accumulator exists 2 n possible phase points, the data stored in the phase register represents the number of phase accumulators accumulated in each clock cycle. If the clock frequency is f c , then the output sine wave frequency f 0 is: ； in, M To store data in the phase register, n The value range is ; Direct digital frequency synthesis DDS is used to generate Doppler frequency deviation. The frequency accuracy depends on the phase accuracy. 32-bit phase accuracy is used to control the frequency signal. The system sampling rate is set to 2.4GHz, the instantaneous bandwidth is -1200MHz~1200MHz, and the minimum frequency accuracy is 2400MHz / 2^32=0.56Hz. Assume the distance between the target and the CW radar is R , then in the two-way path between the continuous wave radar and the target, the total phase Changes to: ； in, is the wavelength of continuous wave radar; If the target moves relative to the CW radar, the distance between the target and the CW radar is R and total phase will change with time, calculate the total phase About Time t The derivative of for: ； in, , v r is the radial velocity, f d is the Doppler shift, that is ; The modulation of Doppler information is achieved by phase modulation, that is, the target speed is simulated for the signal sent by the range delay modulation module.

2. The incoming ammunition simulator according to claim 1, characterized in that: The transmitting and receiving antenna adopts a transmitting and receiving separate antenna system, and the receiving antenna and the transmitting antenna adopt a cross-slant polarization mode. The transmitting and receiving isolation is improved by spatial separation, adding absorbing materials and setting partitions, so as to realize simultaneous operation of transmitting and receiving; The receiving antenna and the transmitting antenna are in the form of planar antennas and are integrated with the main chassis.

3. The incoming ammunition simulator according to claim 1, characterized in that: The broadband radio frequency module includes a power divider, a low-frequency down-conversion channel L, a high-frequency down-conversion channel H, a low-frequency up-conversion channel L, a high-frequency up-conversion channel H and a combiner; The power divider receives the radar transmission signal received by the receiving antenna and splits it into two signals and sends them to the low-frequency down-conversion channel L and the high-frequency down-conversion channel H respectively; The low-frequency down-conversion channel L and the high-frequency down-conversion channel H respectively cover the low and high operating frequency bands of the continuous wave radar. In each down-conversion channel, the power division signal and the clock local oscillator signal are mixed into the first intermediate frequency signal and sent to the digital processing module; The low-frequency up-conversion channel L and the high-frequency up-conversion channel H respectively cover the low and high working frequency bands of the continuous wave radar, respectively receive the second intermediate frequency signal sent by the digital processing module, and filter, up-convert and amplify the second intermediate frequency signal before sending it to the combiner; The combiner receives the signals sent by the low-frequency up-conversion channel L and the high-frequency up-conversion channel H, combines the two signals into a simulated target echo signal, and then sends it to the transmitting antenna.

4. The incoming ammunition simulator according to claim 3, characterized in that: The broadband radio frequency module adopts a dual-channel transceiver system, the instantaneous bandwidth of each transceiver channel is 700MHz, and the instantaneous bandwidth can be further expanded. The two transceiver channels cover the low and high operating frequency bands of the continuous wave radar respectively.

5. The incoming ammunition simulator according to claim 1, characterized in that: The host computer includes a target situation editing module, a target movement situation module and a channel control module; The target situation editing module is used by the operator to edit the target movement situation and send the target movement situation information to the target movement situation module; The target motion situation module receives the target motion situation information sent by the target situation editing module, interprets the modulation information of the target motion situation information in combination with the continuous wave radar signal characteristics, obtains the delay parameter, phase parameter, and amplitude parameter, and sends them to the distance delay modulation module, the speed phase modulation module, and the amplitude modulation module respectively; The channel control module sets the status information of the RF channel and the digital processing module in the broadband RF module, including local oscillator control and gain control.

6. A method for simulating incoming ammunition, applied to the incoming ammunition simulator of claim 1, characterized in that: Control the incoming ammunition simulator to enter the self-check mode, calibration mode, and working mode in sequence to generate a simulated target echo signal modulated by the target simulation characteristics: 1) Self-test mode After the simulator is powered on, it will initialize the configuration and perform self-test according to the default status information. After the self-test is normal, it will enter the standby state and wait for calibration instructions. 2) Calibration mode Connect the transmitting port of the simulator to the receiving port, calculate the system delay of the simulator through the internal calibration mode, and use the laser rangefinder to calculate the distance of the simulator and obtain the corresponding distance delay. Add the system delay and distance delay to obtain the total delay to calibrate the system error of the simulator. 3) Working mode S1, the host computer sets the status information of the RF channel and the digital processing module in the broadband RF module through the channel control module; S2, the operator edits the target motion situation through the target motion situation editing module, and the host computer converts the target motion situation information into target motion situation modulation parameters through the target motion situation module and sends them to the digital processing module for the digital processing module to perform target simulation feature modulation; S3, the receiving antenna receives the radar transmission signal when the continuous wave radar is working normally, and sends the radar transmission signal to the broadband radio frequency module; S4, the broadband radio frequency module receives the radar transmission signal received by the receiving antenna, converts the received radar transmission signal into a first intermediate frequency signal and sends it to the digital processing module; S5, the digital processing module receives the first intermediate frequency signal sent by the broadband radio frequency module, uses the digital radio frequency storage DRFM to store and forward, uses the time delay method to simulate the target distance, uses the phase shift method to simulate the target speed, performs target simulation feature modulation, and sends the obtained second intermediate frequency signal to the broadband radio frequency module; S6. The broadband radio frequency module receives the second intermediate frequency signal sent by the digital processing module, converts the second intermediate frequency signal into an analog target echo signal, and then sends it to the transmitting antenna; S7. The transmitting antenna radiates the simulated target echo signal sent by the broadband RF module, and cooperates with the continuous wave radar to carry out training tasks.

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