JPS5926083A - Ppi display device - Google Patents

Abstract

PURPOSE:To obtain a polar coordinate deflection type PPI display device of simple constitution which is easy to improve the precision, by processing digitally an antenna angle signal, azimuth line set angle signal, sine and cosine signals for sweep signal generation, and so on. CONSTITUTION:The antenna angle signal from an antenna angle transmitter 10 is converted into a digital value by a digital converter 11. The sine/cosine generator 14 of a PROM is accessed on the basis of the converted digital value or an azimuth line set angle digital value outputted by an electronic azimuth angle digital generator 12. Then, deflecting coils 20a and 20b are controlled through D/A converters 15 and 16, a sweep signal generator 17, sweep current amplifier 18, etc., and a PPI display is performed. The number of bits of a binary digital signal used by the simple constitution for the digital processing is increased to improve display precision easily.

Description

[Detailed Description of the Invention] The present invention provides information on radar, sonar, etc. on a round CRTII!
The present invention relates to a PPi display device that displays images on 11 planes by sweeping an electron beam using a polar coordinate deflection method (PPI method).

Conventionally, PPI is used to display information such as radar and sonar.
As a display device, there is one shown in FIG. 1, for example.

In Fig. 1, 1 is an antenna angle transmitter, which is a sine (s) proportional to the antenna angle e, using a normal resolver or the like.
in#1) and cosine (Co551) signals. 2 is an electronic azimuth transmitter that transmits a azimuth signal to set the azimuth line to be displayed on the CIL T screen.
s, ) and cosine (cosl'2), typically a resolver or a 4-midensiometer for generating sine/cosine functions is used.

The outputs of the antenna angle transmitter 1 and the electronic azimuth transmitter 2 are input to the signal switch 3, and the signal switch 8 is switched according to a switching control signal supplied from the outside to switch between the antenna angle transmitter 1 or the electronic azimuth transmitter. The sine and cosine signals of either one of the generators 2 are selected and supplied to the sweep signal generator 4.

Sweep signal generator 8 Fang 4 integrates each of the sine and cosine signals as the DC voltage signal supplied from the signal switch 8 and converts them into a sweep signal that changes in a sawtooth pattern, and increases the sweep current by 1 m. 5, and the deflection current amplified by the sweep current amplifier 5 is passed through the orthogonal deflection coils 6a and 6b of the CILT, and the image of radar, sonar, etc. or the set azimuth line is displayed as PPI by polar coordinate deflection of the electron beam. There is.

On the other hand, the sweep signal generator 4 receives an external off-center control signal in the X-axis direction (left/right direction) and an off-center control signal in the Y-axis direction (vertical direction).
The off-center control signal υ is provided, and an off-center function is provided in which each sweep starting point of the antenna angle sweep signal or the azimuth line sweep signal can be independently moved to any position on the CLLT screen. That is, in synchronization with the switching control signal externally supplied to the signal switching device 3, an off-center control signal that is weighted against the off-center of the antenna angle deflection (g and azimuth line deflection signals) is supplied in a time-sharing manner. Accordingly, the antenna information and the sweep starting point of the azimuth line can be arbitrarily determined independently.

However, in such a conventional PPI display device, generation of sine and cosine signals corresponding to the antenna angle θ1 and generation of sine and cosine signals corresponding to the set force angle θ of the azimuth line are performed using resorno ( Because the precision of each sine and cosine signal was determined by the mechanical and electrical accuracy of the oscillator such as Resolno (9), increasing the accuracy would require higher cost of the oscillator and Accuracy tends to be limited, and it is difficult to improve the resolution of targets detected by radar, sonar, etc. beyond a certain level.

In addition, since all signal processing is analog processing, it is easily affected by temperature, and of course electrical temperature compensation is applied, but since it is used in relatively harsh environments such as ships, Another problem is that even if temperature compensation is performed, the influence of temperature cannot be completely eliminated, resulting in a lack of stability.

The "Unexploded Tsu" was developed in view of these conventional problems.In PPI display devices that display information by sweeping an electron beam across a round CA'R screen using a polar coordinate deflection method, the antenna angle The signal generation, the generation of the setting azimuth signal for setting the azimuth line, and the generation of the sine and cosine signals corresponding to each antenna angle or azimuth angle signal are all performed digitally. It is an object of the present invention to provide a PPI display device that can significantly improve accuracy and eliminate the influence of temperature to obtain high stability.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 2 is a block diagram showing one embodiment of the present invention.

First, to explain the configuration, 10 is an antenna angle transmitter, for example, a synchro transmitter or a Yaft encoder (
A transmitter such as an angle encoder) is used. Reference numeral 11 denotes a digital converter that converts the angle signal aI digitally output from the antenna angle transmitter 10 according to the antenna angle into a binary digital angle signal. As this digital converter 11, a synchro digital converter is used when the antenna angle transmitter 10 is a synchro transmitter, and a pulse synchronizer is used when the antenna angle transmitter 10 is an incremental one-type shaft encoder. is used.

Here, as a binary digital angle signal converted by the digital converter 11, if the number of bits is set to 12 bits, for example, the binary angle bits and B shown in Table 1 below are used.
It has a correspondence relationship of CD angle.

Table 1 As is clear from Table 1, the most significant bit (MSBa) of the digital angle signal represents 180°, the weight of the second bit a is reduced by half to 90'', and the last 1δ
The lowest bit bit) LSBa, is 0.08789
It corresponds to 0625°.

The antenna angle θ1 converted into the digital angle signal formed by the binary pits shown in Table 1 is supplied to one side of a digital signal switch 18 using a digital multiplexer or the like.

On the other hand, 12 is an electronic azimuth angle digital generator that arbitrarily generates the azimuth angle θ2 of the azimuth line displayed on the CII, T screen according to the setting operation by the operator; for example, a binary addition/subtraction counter is used; Addition of cyclopulse by external addition operation signal or subtraction operation signal by setting operation
1- or any set azimuth by subtracting 0. That is, the digital azimuth θ! having the same number of binary bits as the digital angle signal shown in Table 1 above! Generate a signal. The digital azimuth angle θ signal from the electronic azimuth angle digital generator 12 is supplied to the other input of the digital signal switch 13, and the digital signal switch 18 converts the digital azimuth angle θ according to the switching control signal supplied from the outside. Either one of the digital angle θ and signal from the converter 11 or the digital azimuth angle θ and signal from the electronic azimuth angle digital generator 12 is selected and output. Of course, since the digital signal switch 18 uses a digital multiplexer operated by a switching control signal, the 12-bit binary data from the digital converter 11 or the electronic azimuth angle digital generator 12 can be switched in parallel. Output.

Digital angle 0. selected by digital signal switch 1B. The signal or digital azimuth angle θ signal is provided to a sine/cosine generator 14 . As this sine/cosine generator 14, for example, a P-ILOM (programmable read-only memory) is used, and the 12-bit binary digital signal shown in Table 1 is used as an address signal to generate a sweep angle of 360° for each address. The sine and cosine values of the angle divided into predetermined unit angles are stored in advance as digital data, and the digital angle σ1 signal or digital azimuth angle θ2 signal given by the digital signal switch 13 is Sine digital data and cosine digital data are read out by addressing. The sine and cosine digital data generated by the sine/cosine generator 14 are transferred to the digital/analog converter 15.
16, and is converted into an analog voltage corresponding to each digital data.

For analog conversion in the digital/analog converters 15 and 16, the output voltage of a constant voltage source with BCD angle weighting corresponding to the binary bits shown in Table 1 above is converted into a binary digital signal of sine and cosine. By selecting and adding data according to the bit position of the data, it is possible to generate an analog voltage with an accuracy determined by the weighting of the last bit of the binary digital data.

The sine and cosine signal voltages from the digital/analog converters 15 and 16 are supplied to a sweep signal generator 18, which integrates the sine and cosine signal voltages to convert the sawtooth-varying sweep signal into a sweep current amplifier. 18, and the direct deflection coil 20a of the CRT with current amplification by the sweep current amplifier 18.

20b is configured to supply a sweep current.

On the other hand, an external off-center control signal in the X-axis direction (horizontal direction) and an off-center signal in the Y-axis direction (vertical direction) are supplied to the sweep signal generator 17, and an antenna angle sweep signal and an azimuth line Each of the sweep starting points of the sweep signal can be independently moved to any position on the CILT screen.

Next, the present invention will be explained in detail.

First, an antenna angle signal #1 corresponding to the rotation of the antenna of a radar, sonar, etc. is output from the antenna angle transmitter 1°, and is sent to the digital converter 11 as shown in Table 1 above.
For example, it is converted into a 12-bit binary digital angle-1 signal and supplied to one input of the digital signal switch 18.

Also, the set azimuth θ of the azimuth line displayed on the ctt'r screen!
is supplied as a digital azimuth angle σ by the shimiko azimuth angle digital generator 12 to the other input of the digital signal switch 13 as a signal according to a setting operation by an operator. This digital azimuth angle signal is generated by giving an addition operation signal or a subtraction operation signal to the electronic azimuth angle digital generator 12 using an addition/subtraction counter in accordance with the setting operation by the operator. An addition count or a subtraction count is performed, and a digital azimuth angle I2 signal is generated as a count value of an addition/subtraction counter corresponding to an arbitrary azimuth angle θ.

Either the digital angle aI signal or the digital azimuth angle signal supplied to the digital signal switch 18 is switched and outputted to the sine/cosine generator 14 according to a switching control signal supplied from the outside, and this digital angle I, pH, OM which configures the sine/cosine generator 14 using the digital azimuth angle θ2 signal as an address signal
The sine and cosine digital data stored in advance at the designated address is read out, converted into a sia-analog signal voltage by the digital-to-analog converters 15 and 16, and supplied to the sweep signal generator 17. Ru. The sweep signal generator 17 integrates the sine and cosine conversion voltages of the digital-to-analog converters 15 and 16 to generate sine and cosine sweep signals that vary in a sawtooth pattern, and the sweep current amplifier 18 converts them into sweep signals. CILT by performing proportional current amplification
supplying a sweep current to the orthogonal deflection coils 20a and 20b;
Information on radar, sonar, etc. is displayed by sweeping the electron beam using the polar coordinate deflection method.

On the other hand, if the operator performs an off-center operation to perform an off-center PPI display, an X-axis off-center control signal and a Y-axis off-center control signal corresponding to the off-center position are supplied to the sweep signal opening device 17, and the sweep signal The sweep starting points of the sine and cosine sweep signals in the generator 17 are moved to arbitrary off-center positions, and the electron beam is swept off-center.

FIG. 8 is a block diagram showing another embodiment of the dud. The only differences between this embodiment and the embodiment of FIG. 2 are 28 digital sweep signal generators and 24 and 25 digital-to-analog converters.

In FIG. 3, a digital sweep signal generator 23 digitally converts sine digital data and cosine digital data corresponding to the digital data of the antenna angle σ1 or the digital data of the digital azimuth output from the sine/cosine generator 14. It has the function of integrating.

That is, the input sine digital data and cosine digital data are cumulatively added at regular intervals and outputted. As a concrete explanation, first T
If we input the sine gauge digital data XI at the timing of
v = XI) and the previous stored value X, X2+X, = 2X.

(X!=XI) and output this value.

At the next timing T, the data X input this time,
(However, Xs ""' Xt = XI) and the previous memory value sum X, 10X, 10X, = 8X.

and output this value. I will explain this behavior below.

The same applies to the cosine digital data Y.

Furthermore, this digital sweep signal generator 23 has x qq
Since the u and Y 1111 off-center control signals are externally applied, in the case of off-center display, the digital data values corresponding to the X-axis and Y-axis off-center are algebraically added to the cumulative addition values of the sine and cosine digital data described above. Basically, the force is [1], and this total value is output.

The next digital-to-analog converters 24 and 25 convert the cumulative addition values of the sine and cosine digital data, which are the two outputs of the digital sweep signal generator 23, into analog voltages, respectively. A sawtooth voltage with an offset value added is obtained.

These two outputs are each applied to a sweep current amplifier 18.

The output signals of the sine/cosine generator 14 are first each converted to an analog signal and then integrated in an analog manner to create a sawtooth signal, whereas in the embodiment of FIG. The purpose is to first digitally integrate the output signal of the generator 14 and then convert it into an analog signal.

The advantage of the embodiment of FIG. 3 is that it can eliminate factors that degrade accuracy, such as nonlinear distortion and temperature drift, which normally occur in the analog integrator of the embodiment of FIG.

That is, in digital integral calculation, if the number of bits of digital data required for calculation accuracy is provided, nonlinear distortion, temperature drift, etc. cannot theoretically occur.

In the embodiment shown in FIG. 3, even if the same operation is performed, the second
As shown in the example in the figure, υ also has high precision and high stability (the generation of sine and cosine digital data corresponding to the set angle of the temperature line is
In other embodiments, the sine and cosine can be calculated directly from the digital signal representing the υ angle using a program calculation by a microprocessor or a digital calculator that digitally performs the sine and cosine calculations. It is also possible to calculate digital data, and in particular, in program calculation control by a microprocessor, not only sine and cosine digital data generation, but also sine data generated by υ executed by similar program control calculations can be used for other digital processing. To generate digital data of sine and cosine, store the sine and cosine data in P-ROM in advance, and use the input digital angle signal as an address signal to immediately generate highly accurate sine data by simply calling P-[LOM. and cosine data, and the processing time is only the time required to read the P-ROM, which is desirable in that high processing speed can be achieved. In the present invention, the generation of sine and cosine signals based on the angle signals for generating the antenna angle signal, azimuth line setting angle signal and sweep signal, and even the generation of the sweep signal are all digitally processed. Therefore, by increasing the number of bits of the binary digital signal, the precision of signal processing can be made extremely high, and the variation of the analog signal within the angular range determined by the weighting of the final bit of the binary digital signal can be increased. It is possible to ignore the errors due to this, and the effect of temperature is small, resulting in stable performance.Furthermore, each digital processing section can use commercially available digital circuit elements, so compared to the conventional analog method, The cost can also be reduced.

As explained above, according to the present invention, information is displayed by sweeping an electron beam over a round 081 screen using a polar coordinate deflection method.1) In a PI display device, generation of an antenna angle signal and direction line are performed. The generation of the setting azimuth angle signal for setting, and the generation of sine and cosine signals corresponding to each signal of the antenna angle or azimuth line angle are all done digitally, so the binary digital signal used is Accuracy can be easily increased by increasing the number of bits in Since commercially available digital circuit elements can be used as they are, the cost of the PI display device can be significantly reduced compared to the conventional analog processing method.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a conventional device, FIG. 2 is a block diagram showing one embodiment of the present invention, and FIG. 3 is a block diagram showing another embodiment of the present invention. 10...Antenna angle transmitter 11...-Digital converter 12...Electronic azimuth angle digital generator 18...Digital signal switch 14...Sine/cosine generator 15.16, 24.25. ...Digital/analog converter 17...Sweep signal generator 18...Sweep? District current amplifiers 20a, 20b...Deflection coil 28...Digital sweep signal generator Patent applicant: Tokyo Keiki Co., Ltd. Agent Patent attorney: Susumu Takeuchi (Volunteer) Commissioner of the Special γF Agency Kazuo Wakasugi Tono 1 , Indication of the case 1982 Patent Application No. 135010 2, Name of the invention PPI display device 3, Person making the amendment Relationship to the case Patent applicant address 2-16-46 Minami Kamata, Ota-ku, Tokyo Name (
338) Tokyo Keiki Co., Ltd. 4, Agent No. 105 Address: 4th floor, Nishi-Shinbashi Chuo Building, 3-15-8 Nishi-Shinbashi, Minato-ku, Tokyo Details Column 6: Detailed explanation of the explanation of the paste, Contents of the amendment (1) Details Book 8th line 12th rBcD angle 1 Ai' is changed to '
``weight angle''. (2) ``R 13 CD approx. (3) Correct page 12, line 12 rBcDfθ) good j for the specification as "weight angle".

Claims (2)

[Claims] (1) In a PPI display device that displays information by sweeping an electron beam across a round Cl (T screen) using a polar coordinate deflection method, the CB '1'' screen can be moved in any direction according to the azimuth setting operation. A digital azimuth transmitter that digitally generates the set azimuth of the azimuth line to be displayed on the screen, an antenna angle transmitter that generates an antenna angle signal, and a converter that converts the antenna angle signal from the antenna angle transmitter into a digital angle signal. a digital angle converter that selects the output of the digital azimuth transmitter and the output of the digital angle converter according to a set timing; sine/cosine that generates each digit data of cosine and cosine
a cosine generator; a digital/analog converter that converts the sine and cosine digit data output from the sine/cosine generator into analog voltage; and an antenna angle converter proportional to the output signal of the digital/analog converter. 1 for sweep signal or direction line? ! a sweep signal generator that generates a pull signal and varies the origin position of each sweep signal by an external signal; A PPI display device characterized by comprising: a current amplifier that supplies current. (2) Using the polar coordinate deflection method, the electron beam is swept across the round C'1' screen to display convergence. In the 5PPI display device u, the CR'I' ill is displayed according to the azimuth setting operation. ! I
A digital azimuth angle transmitter that digitally generates the set azimuth of the azimuth line to be displayed in any direction on the i-plane, an antenna angle transmitter that generates an antenna angle signal, and the antenna angle light (the antenna from the i-plane). a digital angle converter that converts the angle 11i into a digital angle signal; a signal switch that selects the output of the digital azimuth transmitter and the output of the digital angle converter according to a set timing; A sine/cosine generator that generates sine and cosine digital data corresponding to the selected digital angle signal.
A cosine generator and a digital A/integral operation based on the sine and cosine digital data of the sine/cosine generator generate an antenna angle sweep signal or an azimuth line sweep signal, and determine the origin position of each sweep signal. The present invention is characterized by comprising a digital sweep signal generator that is variable according to an external signal, and a current amplifier that supplies a deflection current to the orthogonal deflection coil of the CRT by amplifying a current proportional to the output signal of the digital sweep signal generator. PPI display device.