JPS617482A - Azimuth display apparatus - Google Patents

Abstract

PURPOSE:To simplify a structure and to perform the adjustment of a phase by an electronic means, by reading amplitude data in synchronous relation to the rotation of a goniometer to obtain two equilibrium modulation signals each having amplitude phase. CONSTITUTION:A count output signal is applied to memories 11A, 11B of an azimuth display apparatus 9 from an address counter 12 to repeatedly read addresses from the leading address to the final one. A pulse CK2, which is outputted in the resolving power at every 0.2 deg. obtained from a rotary encoder 4, is applied to the address counter 12 so that the reading cycle is coincided with the rotary cycle of a high frequency goniometer 2 and the count output thereof is applied to the memories 11A, 11B as an address signal and the address counter 12 is reset by a pulse CK1 generated every when the goniometer 2 rotates one time, so that the rotation of the goniometer 2 and the relation of the reading cycles of the memories 11A, 11B are always coincided.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to an orientation display device used in ships and the like.

"Prior Art" A conventional orientation display device connects a low-frequency goniometer to the rotating shaft of a high-frequency goniometer that rotates the pointing direction of the antenna and obtains a high-frequency reception signal modulated by the orientation component. low frequency signal (30KH
z) to create two balanced modulation signals with a phase difference of 90° in amplitude that are synchronized with the rotation of the pointing direction of the antenna, and convert these two balanced modulation signals into a received signal obtained from a high-frequency goniometer. Amplitude modulation is performed either by obtaining a signal amplitude modulated according to the level of the received signal, or by applying a signal obtained by modulating a low frequency signal at the received signal level to a low frequency goniometer to obtain two balanced modulation signals with a phase difference of 90°. The two balanced modulation signals thus obtained are applied to the Y-axis and Y-axis of a cathode ray tube display, and a propeller-shaped image is displayed to indicate the arrival direction of the radio waves.

``Problems to be Solved by the Invention'' According to the conventional structure, a mechanical structure is required to rotate the low frequency goniometer in synchronization with the high frequency goniometer. ■Picture frequency goniometer and low frequency goniometer box 1
It is necessary to perform mechanical phase matching adjustment by mechanical alignment, and this adjustment requires a lot of effort. ■The drawback is that there are restrictions on where the low frequency goniometer can be installed.

``Means for Solving Problems'' This invention has a structure that is relatively small and allows a balanced modulation signal to be underground separately from a high-frequency temporary goniometer by using an electronic one-way structure, and it overcomes restrictions on placement. M? A direction display device is provided.

In this invention, the amplitude data of sine waves and cosine waves are stored in a memory device, and this memory device is read out in synchronization with the rotation of the antenna, that is, the rotation of the goniometer, and two balanced modulations having amplitude phases of sine waves and cosine waves are generated. It is configured to obtain signals.

In particular, the amplitude data to be stored in the memory is amplitude modulation w, 11 pulse data separated by data representing zero voltage, this amplitude modulation pulse data is read out and DA converted, and the DA conversion output is sent to the DC blocking means. The structure is such that a balanced modulation signal can be obtained from this direct current blocking means by applying the following signals. As a result, according to the present invention, the structure is simple, and the phase of the azimuth component and the two-phase balanced modulation signal can be adjusted by electronic means. Display devices can be provided.

"Embodiment" FIG. 1 shows an embodiment of the present invention. In the figure, reference numeral 1 indicates a pair of antennas having directivity, reference numeral 2 indicates a high-frequency goniometer that extracts the azimuth component from the antenna 1, and reference numeral 3 indicates a motor that rotates the moving coil of the goniometer 2. 4 shows the rotary encoder.

This rotary encoder 4 rotates integrally with the high frequency goniometer 2 and outputs one pulse CK+ and 02° per rotation.
It is assumed that one pulse CK2 is output for each pulse. 5 is the antenna for sense determination, 6A and 6B are the sense switches,
7 is a receiver, and 8 is a detector.

Detection by the detector 8 is, for example, negative polarity detection, and the negative polarity detection output is supplied to the direction display device 9.

The direction display device 9 according to the present invention includes a pair of memory devices 11A.
, IIB, this memory 11A, an address counter 12 that provides an address signal to IIB, and the memory 11A.
.

DA converters 13A, ', 13B convert digital data read from 11B to DA=m, and DA converter 13A
, an amplifier 14A that amplifies the DA conversion output of 13B to a predetermined level.

14B, DC blocking means 10A, IOB, DC blocking means 10A, ], resonators 15A, 15B excited by the output signal of OB, resonators 15A,
A cathode ray tube display 16 to which the output signal of 15B is applied to an X-axis input terminal and a Y-axis input terminal, and a sense determination circuit 17 which applies a brightness modulation terminal to a brightness modulation terminal G of the cathode ray tube display 16 and determines the arrival direction of radio waves. It is composed of

In this invention, amplitude-modulated pulse data having sine wave-like amplitude data and cosine-wave-like amplitude data is stored in a pair of memories 11A and IIB. It is characterized by memorized points.

The signal waveforms read from this pair of memories 11A and 11B and subjected to DA conversion are shown in FIGS. 2A and 2H. The amplitude modulated pulses pa and Pb shown in Fig. 2A and B are such that the envelopes of their peak values are sine wave and cosine layered17, and the data for one cycle is stored in the memories IA and IB as a whole. . The amplitude modulation pulses Pa and Pb each have their phases reversed in the first half cycle and the second half cycle in one cycle. These amplitude modulated pulses pa, pb are passed through the DC blocking means 10A,
By removing the DC component contained in the amplitude modulation pulses pa and pb, so-called balanced modulation signals Sa and sb, in which the phase of the carrier wave is reversed every half period, are obtained as shown in C and D of Fig. 2. It will be done.

As the memories 11A and IIB, semicircular memories such as ROMs can be used, for example. As for the resolution of the write data, for example, amplitude data changed by 0.2 degrees is written alternately with zero data for each address.

However, the resolution in the radiation direction is reduced to, for example, 255 steps.

The memories 11A and IIB are supplied with count output signals from the address counter 12, and are repeatedly read from the first address to the last address. The pulse CK2 output from the rotary encoder 4 with a resolution of 0 and 2 degrees is given to the address counter 12 so that this readout period coincides with the rotation period of the high-frequency goniometer 2, and the count output is stored as an address signal in the memory. 11A and 11'B, and the address counter 12 is reset by the pulse CK+ generated every time the goniometer 2 rotates, so that the relationship between the rotation of the goniometer 2 and the read cycle of the memories 11A and IIB always matches. Reference numeral 18 indicates a synchronous circuit, and the counter 12 is controlled by this synchronous circuit 18.
The reset timing of the goniometer 2 and the timing when the goniometer 2 passes the reference point are made to match.

Here, a phase adjustment means 21 is provided between the rotary encoder 4 and the synchronous circuit 18. This phase adjustment means 21
For example, it can be configured by a preset counter 21A and a phase setter 21B that provides a set value to the preset counter 21A. The phase setter 21B can be configured by, for example, a digital switch.

The preset counter 21A can be either an up counter or a down counter. For example, a case will be explained in which a down counter is used.

Set a value corresponding to the delay angle in the phase setter 21B,
The set numerical value may be preset in the preset counter 21A by adding + to the synchronizing pulse C', and the preset numerical value may be down-counted by the pulse CK2. For example, to delay the synchronization pulse CK+ by 1°, 110.2 =
5, that is, set a digital value equivalent to 5 in decimal in the phase setter 21B, preset this set value in the preset counter 21A at the timing of the synchronization pulse CK+, and count down the preset value with the pulse CK2. As a result, when five pulses CK2 are input, the signal CRi is obtained from the preset counter 21A.

Therefore, by supplying this carry down signal CK'+ to the reset terminal R of the address counter 12 through the synchronization circuit J8, the memory 11A,
The phase of the IIB readout start point can be delayed by 1°. Therefore, by setting an arbitrary value in the phase setter 21B, the phase of the azimuth component and the memory 11A,
The phase of the two-phase balanced modulation signal generated from 'IIB can be adjusted to an arbitrary relationship. As a result, even if the azimuth component obtained from the antenna 1 is delayed by the receiver 7, the detector 8, etc., the structure allows electronic adjustment of the phase of the base point two-phase balanced modulation signal of the azimuth component. ing.

Amplitude modulated pulse data having sine amplitude data and amplitude modulated pulse data having cosine amplitude data read from the storage devices 11A and IIB are transferred to DA converters 13A and 13B.
is given to DA conversion. By this DA conversion,
Amplitude modulated pulses pa and Pb shown in and B are obtained.

These amplitude modulated pulses Pa and Pb are amplified to a predetermined level by amplifiers 14A and 14B as necessary,
Supplied to DC blocking means ioA and IOB. The direct current blocking means 10A and IOB can be constructed by capacitors. The DC blocking means 10A provides the amplitude modulation pulses pa and pb to the IOB.
The waveform of the carrier component of Sb shown in D is shaped into a sine wave and is applied to each of the X-axis and Y-axis input terminals of the cathode ray tube display 16.

On the other hand, the reference voltage terminal RE of the DA converters 13A and 13B
A constant DC bias voltage −E8 from the operational amplifier 18 to F
At the same time, the detection output signal of the wave detector 8 is applied to the other input terminal of the operational amplifier 19, and the detection output signal is superimposed on the DC bias voltage, and this superimposed signal is sent to the DA converter 13A,
13B to the reference voltage terminal REF.

Reference numeral 17 indicates a sense determining circuit. This sense determination circuit 17
By turning on the sense decision switches 6A and 6B, the switch gate 17B is controlled to open and becomes operational.

The signal received by the sense antenna 5 is added to the azimuth component extracted by the goniometer 2, and the gate 17B is controlled to open, and the cathode ray tube display 16 is passed through the gate 17B.
A brightness modulation signal is given to the brightness modulation terminal G of. As this brightness modulation signal, for example, the lowest bit signal of the address signal for reading out the memories 11A and IIB can be used. The signal of the least significant bit of the address signal matches the frequency of the carrier component of the balanced modulation signals Sa and Sb, and this brightness modulation signal is transmitted through the amplifier 17C1, the DC blocking means 17D, and the resonator 17E to the shadow 4≠ray tube display 16.
By applying the signal to the brightness modulation terminal GK, the component of one polarity among the signal components received by the antenna 1 is erased, and only the image displayed by the IJy component of one polarity is displayed.

At this time, the image changes from a propeller shape to a cardioid shape, and the direction of the radio wave is determined by the direction of the cardioid. 1.7F is an inertia setting circuit that sets the polarity of the brightness modulation signal for sense determination. This polarity setting circuit 17F
The polarity of the brightness modulation signal is selected by the signal sent to the input terminal 17AKJ. This polarity setting is determined in advance by the arrangement of the receiving antenna 1 and the sense antenna 5, and once it is determined at the time of installation, it cannot be changed thereafter.

"Operation" According to the configuration of the present invention described above, the memory distributors 11A and 11B
Since the amplitude data of sine wave and cosine wave amplitude modulated pulses are sent alternately together with data of zero amplitude value, the DA converters 13A and 13B output amplitude modulation in a sine wave shape as shown in FIGS. 2A and 2B. It is possible to obtain an amplitude modulated pulse pa whose amplitude is modulated in the form of a cosine wave, and an amplitude modulated pulse pb whose amplitude is modulated in the form of a cosine wave.

When there is no received signal, the operational amplifier 19
Since a constant bias voltage -EB is applied to each reference voltage terminal REF of the converters 13A and 13B, D
The amplitude modulated pulses pa to pb output from the A converters 13A and 13B have sine wave and cosine wave amplitudes synchronized with the 220 revolutions of the goniometer. (Third diagram, point F
~T+) By applying these amplitude modulated pulses pa and pb to the DC blocking means 10A and IOB, a balanced modulation signal Sa (FIG. 3E) and a balanced modulation signal sb (FIG. 3G) can be obtained. Therefore, the balanced modulation signals Sa and sb
The cathode ray tube display 1 through the resonators 15A and 15B
Cathode ray tube display 11 by giving Y-axis and Y-axis of 1
As shown in Figure 4, the bias voltage -EI] is applied on the tube surface of the
A circle with a determined radius is drawn. Here, the resonator 15A,
When 15B is not provided, two-phase balanced modulation signal Sa,
Since the Sb carrier signal has a rectangular waveform and is given a Y-axis and a Y-axis signal, the electron beam is deflected from one side to the other at a high speed, so that a circle is drawn in which the inside does not shine at all. When using such a display method, the resonator 15A
, 15B is not required.

On the other hand, for example, if a radio wave arrives from a direction deviated by 90 degrees from the ship's course direction, the detected output signal of the detector 8 will be the third
Figure B shows a pear-shaped stop as shown at time TI-T2. By applying this detection output signal to the operational amplifier 19, a signal obtained by superimposing the detection output signal on the bias voltage -E8 is obtained at the output of the operational amplifier 19, as shown at times T1 to T2 of the 31st IC. This superimposed signal is transferred to the DA converter 13A.
, 13B to the reference voltage terminal REF, the DA converter 13A +' 13B outputs an amplitude modulated q modulated to the amplitude as shown at time TI-T2 in the third diagram and F.
rM pulses Pa' and Pb' are obtained. By supplying these amplitude modulated pulses Pa' and Pb' to the resonators 15A and 15B, the amplitude modulation pulses from the resonators 15A and 15B to FIG.
Equilibrium f-adjusted images -qSa' and Sb' shown in and G are obtained.

These balanced modulation signals S aL and sb' are transmitted to the cathode ray tube display 1.
6), a propeller-shaped image as shown in Fig. 5 appears. As usual, a sense signal is added to this propeller-shaped image to determine the direction of arrival of the N waves.

"Effect" As explained above, according to the present invention, the memory devices 11A and I
The amplitude modulated pulse data in the form of a sine wave and the amplitude modulated pulse data in the form of a cosine wave separated by zero data are read from the IB, and the amplitude modulated pulses pa and pb are obtained by DA converting the pulse data. pa
and pb to the bending flow prevention means 10A.

10B, the balanced modulation signals Sa, Sb
Since this structure is adopted, the rotational phase of the antenna 1 and the phase relationship between the two-phase balanced modulation signals Sa and Sb can be adjusted simply by adjusting the timing of starting reading of the memories 11A and IIB. This adjustment can be performed, for example, by the phase adjustment means 21, and by setting an arbitrary value to the phase setter 21B, the rotational phase of the antenna 1 and the phase of the two-phase balanced modulation signals Sa and Sb can be easily adjusted. .

In other words, even if a phase rotation is applied to the azimuth component signal in the receiver 7, the detector 8, etc., the phase adjustment means 21 can correct a phase shift corresponding to the amount of phase rotation. As a result, there is an advantage that the effort required during installation can be significantly reduced. Furthermore, although multiple azimuth errors may occur depending on the installation condition of the antenna 1, correction of these azimuth errors can also be performed by the phase adjustment means 21, and the structure is such that adjustments can be easily made in this respect as well. .

In addition, since the amplitude modulation pulse data cut off by zero data is stored in the memory devices 11A and IIB, balance can be achieved simply by reading out the amplitude modulation pulse data and applying the DA conversion output to the DC blocking means 10A, IOB. Since the modulation signals Sa and Sb can be obtained, the circuit structure can be simplified.

In other words, the amplitude data of sine waves and cosine waves are stored in IA and IIB, and this amplitude data is read out to generate a balanced modulation signal whose amplitude changes in the form of a sine wave, and a balanced modulation signal whose amplitude changes in the form of a cosine wave. A method of obtaining a modulation signal is conceivable, but such a method requires only two double-balanced liquid devices, which has the drawback of complicating the circuit structure.

On the other hand, in the present invention, since the DC blocking means 10A and IOB can convert the signal into a balanced modulation 7 signal, the circuit structure can be greatly simplified compared to the case where a double balanced modulator is used.

"Modified Embodiment" In the above description, a case has been described in which unipolar amplitude modulated pulse data is stored in the memory devices 11A and IIB, but as shown in FIG. '
Sb itself can also be stored in the storage devices 11A' and IIB. In this case, a balanced modulation signal can be obtained directly from the DA converters 13A and 13B, and the direct current blocking means 1
Does not require 0A or IOB. However, DA converter 13A
, 13B requires a bipolar ODA converter that can convert positive and negative digital signals to DA&.

As another example, as shown in FIG. 7, it may be configured to store amplitude modulated pulse data having, for example, a positive polarity DC component EDC. In the case of FIG. 7, the DA converters 13A and 13B convert the unipolar digital signal I)
It can be anything that has the function of converting A. Furthermore, in this case, by taking out the DA conversion output through the DC blocking means 10A and IOB, the balanced modulation signals Sa shown in Figures C and D of i2 are obtained.
Sb can be obtained.

[Brief explanation of the drawing]

Figure 1 on the side is a system diagram for explaining one embodiment of this invention, Figure 2 is a waveform diagram for explaining the operation of the main parts of this invention, and Figure 3 is an overall azimuth display/device according to this invention. of! 1
Figures 4 and 5 are waveform diagrams to explain fIJ production, and Figures 4 and 5 are waveform diagrams to explain examples of display results on a ten-man display device.
1m1, FIG. 6, and FIG. 7 are waveform diagrams for explaining modified embodiment 111 of the present invention. ]; Receiving antenna, 2: Goniometer, 3: Motor, 4
:1 pivot circuit, 5: sense antenna, 6A. 6B: Sense switch, 7: Reception is weak, 8: Detector, 9
: Direction display device, ], IA, IIB : Memory device, 1
2 Near address counter, 13A, 13B: DA
Converter, 14A, 14B: Amplifier, 15A,
15B: Common camera, 16: Cathode ray tube display, 17: Sense determination circuit, 18 Two synchronization circuit, 19: Operational amplifier, 21
: Phase adjustment means, 21A nib reset counter, 21B
: Phase setter, Pa: Amplitude modulation pulse with sinusoidal amplitude, Pb: Amplitude modulation pulse with cosine wave amplitude, S
a: Balanced modulation signal with a sine wave-like amplitude; sb: Balanced modulation signal with a cosine wave-like amplitude. Patent applicant Koden Seisakusho Co., Ltd. Agent
Takashi Kusano Procedural Amendment (Voluntary) July 24, 1985

Claims (1)

[Claims] (1) A: A first memory storing amplitude modulated pulse data whose amplitude is modulated in a sine wave shape and whose phase is inverted every half cycle; B: Amplitude modulation whose amplitude is modulated in a cosine wave shape and whose phase is inverted every half cycle. a second memory storing pulse data; C. means for reading out the first memory and the second memory in synchronization with the rotation of the pointing direction of the antenna; and D. the first memory and the second memory. a pair of DA converters that convert amplitude modulated pulse data read from the device into amplitude modulated pulse signals, respectively; An azimuth display device comprising: means; F. a display device which is provided with balanced modulation signals obtained from the amplitude modulation means on the X-axis and Y-axis to display the arrival direction of radio waves.