Simulator of echo signal of concentrated group of targets

Abstract

This utility model pertains to radio engineering, specifically to devices for generating electrical signals using a microcontroller for timing. The technical result of the utility model is the ability to generate a harmonic signal at the simulator output at one of two selected frequencies. This signal is a sum of eight rectangular radio pulses, modulated at a given Doppler frequency and independently adjustable in amplitude and delay time. The echo signal simulator for a concentrated group of targets includes an additional harmonic oscillation generator with an adjustable signal frequency and a multiplier. The adder input goes to the multiplier, whose second input receives a signal from the harmonic oscillation generator with an adjustable frequency. The output signal from the multiplier is the simulator's output signal. 7 fig.

Description

[0001] The utility model relates to the field of radio engineering, in particular to devices for generating electrical signals using a microcontroller for their timing.

[0002] The purpose of creating a utility model is to enable further development of methods and techniques for detecting, resolving, and recognizing concentrated groups of radar targets through semi-naturalistic simulation modeling, using electrical signals generated by the simulator.

[0003] The technical result of the creation of the utility model is the ability to form at the output of the simulator a harmonic signal at one of two selected frequencies, which is a sum of eight rectangular radio pulses, simulated with a given Doppler frequency, independently adjustable in amplitude and delay time, through the use of a programmable microcontroller.

[0004] One of the promising areas of radar technology development is radar recognition. Implementing this recognition improves the quality of radar information transmitted from the radar to command posts, which in turn improves the quality of decision-making.

[0005] This task is especially relevant in modern conditions, when the purpose of air objects (AO), directly related to their class (type), can vary significantly and choosing the most dangerous of them for destruction will reduce the damage they cause.

[0006] Military object recognition features can include trajectory, tactical, and signal features, or a combination of these. Increasing the number of recognition features and their integration within a given class alphabet leads to an increased probability of military object recognition.

[0007] The most informative recognition feature is the radar range profile (RLP) of the aircraft. Combined with the recognition feature obtained by measuring the aircraft's speed and / or acceleration, it is possible to obtain stable recognition system solutions.

[0008] However, extracting and using signals directly from radars for this purpose is a complex technical task, not to mention collecting sufficient statistics. Therefore, developing a simulator for echo signals from a moving, concentrated group of targets with the ability to specify the number of radars in the group, the signal amplitudes of individual scatterers, and approximating the radar-like projections of these radars and their relative positions is highly relevant.

[0009] The use of several harmonic signal generators and a summing device for the formation of such echo signals, as well as the modulation of the sum signal by the Doppler frequency, is also not always possible, both for financial reasons and due to the technical difficulties associated with the need to synchronize a large number of individual signal generators.

[0010] The closest prototype of the simulator is the simulator of eight reflected echo signals with a programmable delay time, which contains two master oscillators of harmonic oscillations, a microcontroller, eight monostable multivibrators, eight operational amplifiers, eight amplitude regulators, eight delay time regulators, a mixer, an indicator device, control keys, signal connectors (Certificate for Utility Model 227909, H03B 27 / 00, 09 / 08 / 2024). The disadvantage of this device is the inability to simulate an echo signal from a moving concentrated group of targets, as well as the instability of the output total signal, caused by the use of resistors to set the delay time of individual radio pulses.

[0011] Therefore, instead of existing devices and methods for generating simulated echo signals, a simulator of an echo signal of a concentrated group of targets is proposed, the operating principle of which is based on the automated control of peripheral devices by a microcontroller, which ensure the formation of a sum of one to eight rectangular radio pulses with a given Doppler frequency, with a given amplitude and delay time, simulating an echo signal from a moving concentrated group of targets.

[0012] The essence of the invention: in the process of researching methods and techniques for recognizing military objects based on a set of signal and trajectory features, the need arises to generate signals that simulate an echo signal from a moving group concentrated target.

[0013] The simulator of the echo signal of a concentrated group of targets is a device made in a rectangular plastic case with a removable cover, on which are located 9 variable resistors, 2 control keys, a toggle switch, an output connector, a connector for communication with a PC, an indicator device, a connector for connecting a power supply (Figure 1-3).

[0014] The functional diagram of the simulator (Figure 4) includes: a driving part (GEN.1 - a harmonic signal generator with a frequency of ƒ=10000 Hz, GEN.2 - a harmonic signal generator with a frequency of ƒ=107600 Hz, GEN.3 - a harmonic oscillation generator with an adjustable frequency of ƒ=0-3000 Hz), MK - ADUC812BS microcontroller, OdV.1 - OdV.8 - eight single-shot multivibrators, OU.1 - OU.8 - eight operational amplifiers, SUM - adder, MU - multiplier, KL - keyboard, REG.1 - REG.8 - regulators of the amplitude of echo signals of individual scatterers, IND - indicator device).

[0015] An indicator device made on four seven-segment red indicators, designed to display the operating modes of the simulator, the values ​​of the set delay time of each signal (in milliseconds).

[0016] A keyboard designed to select the simulator's operating modes, set the delay time of individual radio pulses, and record specified values ​​in the microcontroller's internal memory.

[0017] Regulators 1-8, located on the top removable cover of the housing and designed to adjust the amplitude of each of the eight radio pulses.

[0018] The toggle switch, installed on the side of the device, is used to switch the master oscillators (GEN.1, GEN.2).

[0019] The upper connector on the side of the case is used to output the summed signal. The lower connector is used to connect the simulator to a PC.

[0020] Structural connections of the echo signal simulator of a concentrated group of targets, allowing to achieve the stated technical result.

[0021] Regulators 1-8 are connected by their outputs to eight inputs of the microcontroller, to the 9th and 10th input of which the control keys are connected, the first output of the microcontroller goes to the indicator device, outputs from the second to the ninth are connected to the inputs of eight monostable multivibrators, the outputs of which are connected to the first input of the adder, in accordance with the position of the toggle switch, a signal from output 1 or 2 of the master oscillator is fed to the inputs of operational amplifiers from 1 to 8, the outputs of the eight operational amplifiers are connected to the second input of the adder, the output of which goes to the first input of the multiplier, to the second input of which a signal from output 3 of the Doppler frequency generator is fed.

[0022] Description of device operation.

[0023] The ADUC812BS microcontroller is the core of the lumped target echo signal simulator. During operation, the microcontroller executes a program and controls both its internal peripherals (two timers, an eight-channel multiplexer, and an analog-to-digital converter) and external peripherals (eight K1006VI1 monostable multivibrators, two keys, and an indicator controller).

[0024] The device starts working after supplying the supply voltages (+15 V, -15 V, +5 V) from the power supply (Figure 5), which is made in a metal case with natural cooling of the stabilizing elements.

[0025] [The power supply unit is based on a step-down transformer TPP-220-127 / 220-50, connected to a 220 V AC circuit via a fuse. Voltages from the transformer output windings (3-4 - 20 V, 8-9 - 20 V, 4-5 - 10 V) are fed through diode rectifiers and filter capacitors to the KR142EN8V and KR142EN5A stabilizer microcircuits, providing a stable output voltage of +15 V, -15 V and +5 V. Voltage from windings 6-7, via a step-down resistor, feeds an indicator LED indicating the on / off state of the power supply. The stabilized output voltages are fed to the simulator via the MGTF-0.35 conductors ligated together and through the MT-System AC connector.]

[0026] The harmonic signal generators (GEN.1 GEN.2 - Figure 5) begin to generate sinusoidal voltage pulses with a frequency of ƒ1 (10000 Hz) or ƒ2 (107600 Hz).

[0027] [The sine wave generators are implemented on a circuit board using point-to-point mounting. These low-distortion sine wave generators are based on a Wien bridge oscillator circuit. The generators are based on feedback amplifiers with a 180° phase shift at the output frequency and loop gain adjustment to produce self-oscillation with a frequency of ƒ=1 / πRC. The AD820AN microcircuit is used as an operational amplifier.]

[0028] At the same time, supply voltages are applied to the microcontroller. After a time of t3 = 0.7RC, determined by the value of the RC circuit elements required to activate the peripheral devices (multiplexer, ADC, DAC, etc.), the program code is loaded from the microcontroller's ROM. The keyboard is polled and the information is displayed on the display.

[0029] Using REG.1-8, the gain values ​​of operational amplifiers OP.1-8 are set, determining the amplitude of the simulated signals. The signal to be adjusted is selected by pressing a key on the keyboard. Each output signal is then fed to the corresponding input of the analog switch. The analog switches are controlled by the microcontroller via eight monostable multivibrators, each of which, when triggered, generates a 400 μs pulse (during which the analog switch is internally commutated). NE555 microcircuits (Russian equivalent: K1006VI1) are used as monostable multivibrators.

[0030] As a result, eight harmonic signals, each with different amplitudes and delay times, each 400 μs long, appear at the output of eight analog switches (based on two K590KH5 four-channel analog switches). The response time of each OB.1-8 monostable multivibrator is set using the keys, sequentially entering the pulse number and delay time value, which are displayed on the indicator.

[0031] All signals from the analog keys are fed to the adder SUM, which is implemented on an operational amplifier.

[0032] The GEN.3 variable frequency sine wave generator generates a low-frequency harmonic signal. This signal modifies the total harmonic oscillation generated at the adder (SUM) output by multiplying the listed signals in the multiplier. The output signal from the multiplier is the simulator's output signal.

[0033] The simulator's operating modes, as well as the delay times of each simulated signal, are displayed on an indicator unit. This unit includes four seven-segment indicators, an SA1064 controller, and add-on components that provide power and interface between the controller and indicators. The display unit's printed circuit board is shown in Figure 6. The display unit controller begins operation when power is supplied. After startup and the program code is loaded into the microcontroller, control words are written to the display unit controller, enabling the subsequent generation of digital and alphanumeric information on the indicators in accordance with the operating algorithm.

[0034] Using the concentrated target group echo signal simulator, it is possible to obtain simulated echo signals from one to eight point sources of secondary reverse radiation, modulated with the Doppler frequency.

[0035] The use of the simulator in a semi-naturalistic experiment to study the effectiveness of methods and techniques for recognizing VOs based on a set of features showed that this device copes with the task of simulating echo signals reflected from moving VOs.

[0036] This device can be further used in other experimental studies related to signal processing. Converting signals obtained by the simulator into digital form using an ADC allows for the addition of noise realizations to the signal to obtain sufficient statistics for studying the detection, resolution, and measurement of signal parameters simulating a signal received by a radar.

[0037] The use of a concentrated target group echo signal simulator provides wide opportunities for scientific and research activities, and the use of the ADUC812BS microcontroller as a control device provides wide opportunities for refinement and further improvement of the device.

[0038] The schematic diagram of the simulator is presented in Appendix 1.

Claims

A simulator of an echo signal of a concentrated group of targets, comprising two master oscillators of harmonic oscillations, a programmable microcontroller, eight single-shot multivibrators, eight operational amplifiers, eight amplitude regulators, an adder, an indicator device, control keys and a signal connector, wherein the amplitude regulators are connected to the programmable microcontroller, to which the control keys are also connected, the outputs of the programmable microcontroller are connected to the indicator device and single-shot multivibrators, which are connected to the adder, a signal from the master oscillators of harmonic oscillations is fed to the operational amplifiers, the outputs of the operational amplifiers are connected by an adder, characterized in that it has in its composition an additional generator of harmonic oscillations with an adjustable signal frequency and a multiplier device, wherein the input of the adder goes to the multiplier device, to the second input of which a signal from the generator of harmonic oscillations with an adjustable frequency is fed,the output signal from the multiplier is the output signal of the simulator.,

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