RU1840909C - Radar antenna movement control system - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: system comprises an aspect angle setter, a threshold unit, an adder, a control signal former, an actuating unit, a frequency divider, a time selector, three pulse formers, a switch, an antenna turning angle setter, an antenna turning angle sensor, a phase detector, an antenna speed setter, an antenna speed sensor, a synchroniser and a sawtooth voltage generator, connected to each other in a certain manner.

EFFECT: short synchronisation time during breakdown.

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Description

The present invention relates to the field of electrical engineering, in particular to automatic control systems, and is intended to provide a sector scanning mode of an antenna of a radar station with a highly stable scanning period. It can also be used in any production mechanisms that perform reciprocating or reciprocating movements, and which are subject to precise requirements for the stability of the period of the technological cycle.

A known system for controlling the movement of the radar antenna in the sector scanning mode. The system comprises, in series, connected with an antenna angle adjuster, an antenna angle sensor, a phase detector, a threshold device, the second input of which is connected to the field of view sensor, an adder, a regulator, an actuator on a linear induction motor, the output of which is connected to the antenna, with one from the inputs of the antenna angle sensor and with one of the inputs of the antenna rotation speed sensor, the other input of which is connected to the output of the scanning speed sensor, and the output to the second input of the adder, The sequence and pulse shaper connected to the switch, whose output is connected to the second input of the actuator, and the input pulse shaper is connected to the first input of the adder.

The disadvantage of the system is the instability of the antenna scanning period.

This disadvantage is eliminated in the second known radar antenna motion control system. The radar antenna motion control system comprises an antenna rotation angle adjuster connected to an input of an antenna rotation angle sensor mechanically connected to the actuator, the output of which is connected through a phase detector to the first input of the threshold unit, the second input of which is connected to the output of the field of view sensor, and the output is connected with the first input of the adder, the second input of which is connected to the output of the antenna speed sensor, and the output is connected to the input of the control command generation unit, the output of which connected to the first input of the actuator, the second input of which is connected through a switch to output the first pulse generator, and an output operatively connected to the first input of the antenna rotation speed sensor, a second input connected to the output of the scan velocity sensor. The system also contains a second pulse shaper, a time selector, a frequency divider and a synchronization unit, the input of which, like the input of the second pulse shaper, is connected to the output of the threshold block, and the output is connected to the input of a frequency divider, the output of which is connected to the first input of the temporary selector, the second the input of which is connected to the output of the second pulse shaper, and the output is connected to the input of the first pulse shaper.

This system is closest in technical essence to the proposed solution and is selected by the authors for the prototype.

It is obvious that the scanning period T _{cc of the} antenna, necessary for calculating the target parameters, can be determined by the formula

T _ck = t _{slave. 1} + t _{rev. 1} + t _{slave. 2} + t _{rev. 2} , where

t _{slave 1} , (t _{slave 2} ) - time of movement of the antenna in the working sector

t _{rev. 1} (t _{rev. 2} ) is the antenna reversal time at the boundaries of the scanning working sector.

As can be seen from the formula, the stability of the antenna scanning period is determined by the stability of its components

T _ck = f (t _{rev 1} , t _{rev 2} , t _{slave 1} , t _{slave 2} )

In order to synchronize the period of scanning of the radar antenna with synchronizing pulses from the radar, it is necessary to fulfill the condition:

$$T_{\mathrm{from}\mathrm{and}nxR.}<\raisebox{1ex}{$T_{\mathrm{from}\mathrm{to}}$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$$

The sequence of synchronizing pulses T _sync. It does not depend on the operating conditions of the radar antenna motion control system and is stable.

The scanning period T _c of the radar antenna depends on many factors, the main of which are, for example, the change in the supply voltage of the system, the change in load over time on the drive (especially for open antennas), etc.

Thus, during the operation of the radar antenna motion control system, the following cases are possible:

a) $$T_{\mathrm{from}\mathrm{and}nxR.}>>\raisebox{1ex}{$T_{\mathrm{from}\mathrm{to}}$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$$

b) $$T_{\mathrm{from}\mathrm{and}nxR.}<\raisebox{1ex}{$T_{\mathrm{from}\mathrm{to}}$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$$

Both of these cases lead to the exit of the radar antenna control system from synchronism.

Re-entry of the system into synchronism in case of random synchronization failures will occur after some time, determined by several tens of scanning periods. If the scanning period is T _ck ≅ 1 ÷ 2 sec, then the time the system re-enters synchronism with random synchronization failures can be several tens of seconds.

Thus, the relatively long time the system re-enters synchronism during synchronization failures is a drawback of the system.

The aim of the present invention is to reduce the time of re-entry of the radar antenna motion control system into synchronism during synchronization failures.

This goal is achieved by the fact that in the radar antenna motion control system comprising an antenna angle adjuster connected to the input of the antenna angle sensor mechanically connected to the actuator, the output of which is connected through a phase detector to the first input of the threshold unit, the second input of which is connected to the output sensor of the magnitude of the viewing sector, and the output is connected to the first input of the adder, the second input of which is connected to the output of the antenna speed sensor, and the output is connected to the input of the block control command generation, the output of which is connected to the first input of the actuator, the second input of which through the switch is connected to the output of the first pulse shaper, and the output is mechanically connected to the first input of the antenna speed sensor, the second input of which is connected to the output of the scanning speed sensor, synchronization unit, the first input of which, like the input of the second pulse shaper, is connected to the output of the threshold block, and the output is connected to the first input of the frequency divider, to the second input of the cat A radar clock pulse generator is connected, the output of the frequency divider is connected to the first input of the temporary selector, the second input of which is connected to the output of the second pulse shaper, the output is connected to the input of the first pulse shaper, the third pulse shaper and the sawtooth voltage generator are connected in series, the output of which is through the third pulse shaper is connected to the second input of the synchronization unit, and the input is connected to the output of the temporary selector.

Since at the synchronization failure the signals at both inputs of the temporary selector do not coincide in time and, therefore, there are no pulses at its output, the signal from the sawtooth generator through the third pulse shaper is fed to the synchronization unit, removing it from self-blocking.

At the first change in the polarity of the output signal from the threshold block, the radar antenna motion control system is automatically pulled into synchronism.

.Thus, the re-entry time of the system into synchronism becomes less than half the scanning period of the antenna $$\raisebox{1ex}{$T_{\mathrm{from}\mathrm{to}}$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$$

.

Figure 1 shows a block diagram of the proposed radar antenna motion control system in sector scanning mode, figure 2 shows voltage plots illustrating the operation of the system.

The block diagram of the system shown in FIG. 1 contains an antenna angle adjuster 1 connected to an input of an antenna angle sensor 2 mechanically connected to the actuator, the output of which through a phase detector 3 is connected to the first input of the threshold unit 4, the second input of which is connected with the sensor output of the magnitude of the field of view 5, and the output is connected to the first input of the adder 6, the second input of which is connected to the output of the rotation speed sensor of the antenna 7, and the output is connected to the input of the control command generation unit 8, the output to otorochno connected to the first input of the actuator 9, the second input of which through the switch 10 is connected to the output of the first pulse shaper 11, and the output is mechanically connected to the first input of the rotation speed sensor of the antenna 7, the second input of which is connected to the output of the scanning speed sensor 12, synchronization unit 13 , the first input of which is the same as the input of the second driver 14, is connected to the output of the threshold unit 4, and the output is connected to the first input of the frequency divider 15, to the second input of which a clock generator is connected x radar pulses, the output of the frequency divider 15 is connected to the first input of the temporary selector 16, the second input of which is connected to the output of the second pulse shaper 14, and the output is connected to the input of the first pulse shaper 11.

In addition, the system further comprises a third pulse shaper 17 and a sawtooth voltage generator 18, the output of which through the third pulse shaper 17 is connected to the second input of the synchronization unit 13, and the input is connected to the output of the temporary selector 16.

The system operates as follows.

At the system input (see Fig. 1), the parameters of the antenna motion are set by the sensors.

By turning the angle of rotation of the antenna 1, which uses a sine-cosine rotary transformer (SCRT), a bearing is set, relative to which the antenna should scan.

The sine and cosine components of a given angle from the windings of the setter of the angle of rotation of the antenna 1 are fed to the stator windings of SKVT - the sensor of the angle of rotation of the antenna 2, from the rotor winding of which a voltage proportional to the difference between the set and true angles of rotation of the antenna is fed to the input of the phase detector 3. Positive, or a negative voltage, depending on the sign of the mismatch between the true and the given values of the angle of rotation of the antenna, is fed to the input of the threshold unit 4, which is set to one of yx possible positions according to the polarity of the signal at the input. The output voltage of the threshold block 4 may be bipolar (see figure 2, 3). It sets the direction of rotation of the antenna in one or the other direction from the specified bearing and is fed to the first input of the adder 6, the inputs of the synchronization unit 13 and the second pulse shaper 14. At the second input of the adder 6, the voltage difference between the voltage proportional to the specified speed in the scanning sector (from the scanning speed sensor 12) and a voltage proportional to the actual antenna speed (from the antenna speed sensor 7). From the output of the adder 6, an error voltage is supplied to the input of the control command unit 3 of the actuator 9 on the linear induction motor to amplify and convert it to a power sufficient to power the main indicators of the linear asynchronous motor. Depending on the sign at the input, the control command generation unit 8 generates a three-phase voltage at the output with direct or reverse phase rotation, due to which the main inductors create a running magnetic field in one or the other direction, which, acting on the moving part of the antenna, rotates it in one or the other way. However, the power of the main inductors of the actuator 9 is not sufficient to provide a quick change in the direction of rotation (reverse) of the antenna. The signals from the output of the threshold unit 4 simultaneously with their supply to the first input of the adder 6 are fed to the input of the second pulse shaper 14, the output of which is formed of pulses of the corresponding polarity (see figure 2, b), allowing through the temporary selector 16 the operation of the boosting inductors of the actuator 9 at the border of the work sector. However, bipolar pulses at the output of the temporary selector 16 (see FIG. 2, c) including forcing the inductor of the actuator 9 for fast reverse of the antenna, appear at the borders of the working sector only at the moments of coincidence of pulses in time at both inputs of the temporary selector 16 of the signals from the second shaper pulses 14 (see Fig. 2, b) and a radar clock pulse generator, arriving at the second input of the temporary selector 16 through a frequency divider 15 (see Fig. 2, d times t ₁ , t ₂ , ...).

A frequency divider 15 converts the signals of a radar clock generator having a high frequency (of the order of several thousand hertz) into a signal with a frequency equal to a given antenna scan frequency.

The repetition period of the synchronizing pulses at the output of the frequency divider 15 slightly exceeds half the scanning period of the antenna (without synchronization). Therefore, the natural occurrence of the system in synchronism takes a long time (of the order of several tens of antenna scanning periods). For quick initial input of the radar antenna motion control system into synchronism, the synchronization unit 13 is intended.

At the first arrival of the antenna to the boundary of the working sector, threshold block 4 is activated and a pulse from its output is fed to the input of synchronization block 13. After a predetermined time t _s necessary for stable operation of the system in synchronization mode, a pulse appears at the output of synchronization block 13 (see figure 2, g), allowing the operation of the frequency divider 15. In this case, the synchronization unit 13 is self-locking. At the output of the frequency divider 15, a first synchronization pulse appears (see Fig. 2, d moment of time t ₁ ) and at regular intervals T _sync. = 0.5 T _ck - the following synchronization pulses (see Fig. 2, d moments of time t ₁ , t ₂ , etc.), including through the time selector 16 forcing the inductor of the actuator 9. In this case, the first pulse shaper 11 when triggered temporary selector 16 generates a pulse, the duration of which is equal to the time of the reverse system, and connects at this time forcing the inductor of the actuator 9 through the switch 10 to a three-phase network.

Depending on the polarity of the pulse arriving at the switch 10, the boosters of the inductor of the actuator 9 are powered by a three-phase voltage with direct or reverse phase rotation, which creates a running magnetic field in one or the other direction and the antenna is reversed in the necessary direction (see Fig. 2, a, time instants t ₁ , t ₂ , etc.).

Since the forcing inductors of the actuator 9 are turned on at strictly defined time points, which are determined by the moment of coincidence at the inputs of the temporary pulse selector 16 pulses from the frequency divider 15 and the second pulse shaper 14, the antenna scanning periods given by the radar clock generator are strictly stabilized.

To quickly re-automatically introduce the radar antenna motion control system into synchronism during random synchronization failures (synchronization failures occur frequently during operation), it is necessary to remove synchronization block 13 from self-locking mode and reset the frequency divider 15, thereby preparing them for the next synchronization cycle.

To accomplish this task, a sawtooth voltage generator 18 and a third pulse shaper 17 are used. In this case, pulses from the output of the temporary selector 16 are fed to the input of a sawtooth voltage generator 18 and break off the saw.

At the end of the pulse from the temporary selector 16, the sawtooth generator 18 again begins to generate a sawtooth voltage (see Fig. 2, e), and according to this law, so that when the next pulse appears from the temporary selector 16, the instantaneous value of the saw voltage does not reach the specified voltage reference U _op (see figure 2, e), the value of which is determined by the size of the scanning sector and the speed of the antenna in the working sector.

When synchronization fails, the pulses from the frequency divider 15 and the second pulse shaper 14 do not coincide in time at both inputs of the temporary selector 16 and, therefore, are absent at its output. In this case, the instantaneous voltage value of the saw continues to increase at time t _obn. ≤0.5T _ck reaches the value of the reference voltage (see Fig.2, e, time t t _obn. ). If the instantaneous value of the saw voltage and the specified reference voltage are equal, the third pulse shaper 17 generates a pulse (see Fig. 2, e), which is supplied to the synchronization unit 13.

The pulse duration is determined by the time required to output the synchronization unit 13 from the self-locking mode and to reset the frequency divider 15. When a pulse arrives from the third pulse shaper 17, the synchronization unit 13 exits the self-locking mode and resets the frequency divider 15, thereby preparing the system for the next synchronization cycle .

Since the moments of withdrawal of the synchronization unit 13 from the self-locking and zeroing of the frequency divider 15 are determined by the moment of equality of the instantaneous value of the saw voltage from the sawtooth voltage generator 18 and the threshold voltage, the time of the re-entry of the radar antenna control system into synchronism with random synchronization failures will be less than T _ck / 2.

Obviously, the invention is not limited to the above-described example of its implementation, on the basis of it, other uses and other embodiments may be envisaged that are not beyond the scope of the subject invention. These include control systems for automatic conveyor lines, automated control systems for ACS and others.

It should be noted that the use of the introduced nodes to reduce the time the system re-enters synchronism during synchronization failures is possible only for systems with a gearless electric drive, because in them, the torque to the moving part of the antenna is transmitted through a traveling electromagnetic field formed by the inductors of the electric drive without mechanical contact between the inductors and the rotor.

Research and testing of a prototype of a radar antenna motion control system operating in the sector scanning mode and synchronizing the scanning period with the introduced nodes confirmed its operability and positive qualities.

Thus, the application of the proposed nodes in the system can significantly (by 1-2 orders of magnitude) reduce the time the system re-enters synchronism during synchronization failures, and this time is one of the main technical parameters of the system that determine its tactical and technical indicators. At the same time, an increase in the mass-dimensional characteristics and a decrease in the reliability of the system as a whole can be ignored, since newly introduced nodes are made on several microcircuits.

Claims (1)

A device for controlling the movement of an antenna of a radar station, which contains a series-connected reference unit for the field of view, a threshold unit, an adder, a driver of control signals and an executive unit, series-connected frequency divider, a time selector, a first pulse shaper and a switch, the output of which is connected to the second input of the executive unit connected in series to an antenna angle adjuster, an antenna angle sensor and a phase detector, the output of which is connected to the second input of the threshold block, the antenna speed controller and the antenna speed sensor, the output of which is connected to the second input of the adder, as well as the synchronizer and the second pulse shaper, the output of the threshold block being connected through the synchronizer to the control input of the divider and through the second pulse shaper with the second input of the temporary selector, the second inputs of the antenna angle sensor and the antenna speed sensor are connected to the corresponding outputs of the o unit, characterized in that, in order to reduce the synchronization time during failures, a sawtooth voltage generator and a third pulse shaper are introduced, and the output of the temporary selector is connected through serially connected sawtooth voltage generator and a third pulse shaper to the second synchronizer input.

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