JPH0157749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that uses a rotary encoder to rotate an electronic azimuth marker displayed on a display screen of a radar device that employs the PPI method.

Relatively new radar equipment replaces the traditional angularly graduated cursor board with an electronic orientation marker displayed on the display screen to measure the orientation of the signal present on the display screen. The turning of the azimuth marker to a desired azimuth is performed using a rotary encoder due to mechanical and cost considerations. That is, the rotary encoder is configured to add or subtract rotational pulses sent out every fixed angular rotation by rotation of the rotary encoder based on the rotational direction, and display the azimuth marker at an angular position corresponding to the counted value. In observing signals in radar equipment,
It is desirable that the rotary encoder has a azimuth resolution of about 0.1° per rotation pulse on the screen. By the way, rotary encoders, which are currently popular, send out about 50 rotational pulses per rotation, so for example, if you want to turn the orientation marker half a circle on the screen, you have to rotate the rotary encoder 36 times. This makes it difficult to set up quickly, and also poses problems in practical terms. Therefore, as a method to achieve both the above-mentioned resolution and quick setting, (1) attaching a gear mechanism for increasing speed, or (2) using a high-resolution rotary encoder that sends out about 1000 rotational pulses per rotation, for example. It is possible to use

However, regarding (1), the addition of mechanical parts leads to an increase in the size of the device, and regarding (2), it is difficult to make fine adjustments due to the cost and conversely, so it cannot be said to be a fundamental solution.

The present invention has been made in view of the above, and uses a commonly used rotary encoder, and when the rotational speed is increased to a certain level or higher, the turning movement speed of the orientation marker is made faster than usual. The present invention provides an orientation marker turning device using a rotary encoder that corresponds to the rotational speed during rotation.

The following description will be made based on the embodiments shown in the drawings.

In Fig. 1, 1 sends out, for example, 50 rotation pulses per rotation, and at the same time outputs a high (hereinafter referred to as H) level output when the rotation direction is clockwise, and a low (hereinafter referred to as H) level output when the rotation direction is counterclockwise. This is a rotary encoder that can detect the amount and direction of rotation by sending out a level output (referred to as L).
2 and 3 are operated by rotation pulses sent from the rotary encoder 1, and have fixed time widths t ₁ and t ₂
It is a monostable multi-pulse that sends out each pulse (<t ₁ ). The monostable multi ₂ and ₃
When the next rotational pulse is sent within, the operation continues for a certain period of time from that point onwards. 4 and 5 are D-types that determine whether the sending speed (period) of the rotation pulse is small, intermediate, or large compared to the times t ₁ and t ₂ and sends out 2 bits of information, 1 bit for each. It is a flip-flop (hereinafter referred to as FF). FF4 and 5 above are CK
When a rotation pulse is sent to the terminal, if the D terminal is at the H level, the Q output is maintained at the H level, and conversely, if the D terminal is at the L level, the L level is sent out. Reference numeral 6 denotes an original oscillation circuit that sends out pulses with a period of t ₀ , and the sent out pulses are frequency-divided by 1/4 and 1/2 by frequency dividing circuits 7 and 8, respectively. 9 is the above FF4,
This is a selection gate that allows either the rotating pulse or the frequency-divided pulses from the frequency dividing circuits 6 and 7 to pass based on the information sent from the frequency dividing circuits 6 and 7.

10 to 13 are reversible counters, the output count value of the reversible counter 10 is the value in the first digit after the decimal point, the output count value of the reversible counter 11 is the value in the first digit, and the output count value of the reversible counter 12 is 2. The output count value of the reversible counter 13 indicates the third digit value, and thereby an azimuth value of 0.0° to 359.9° can be obtained. Although the range from 0.0° to 359.9° is not shown in the drawing, it is assumed that the range is continuous in terms of operation. The reversible counter 10 is
The CI (carry-in) terminal is set at L level so that a counting operation is performed by sending a pulse passing through the selection gate 9 to the CK terminal. On the other hand, the CI terminals of the reversible counters 11, 12, and 13 are normally set at H level so that counting operations are prohibited except when carrying up or down. And reversible counter 1
For carry up and down by 1, 12, and 13, send an L level signal from each CO (carry out) terminal.
Reversible counter 11, 12 or 13 one digit higher
This is done by performing the counting operation only once. Further, each U/D (up-down) terminal is configured to perform addition counting when an H level is applied, and subtractive counting when an L level is applied. The count values of the reversible counters 10 to 13 are sent out, for example, in binary code and guided to the orientation display 14 and the orientation marker generation circuit 15.

Although the azimuth marker generating circuit 15 is not shown in detail in the figure, this circuit varies depending on the display method of the detection signal of the radar main body (not shown) including the display 16. In other words, (1) record the detection signal in one screen's worth of memory;
In the case of a system in which this is repeatedly read out and displayed using X-Y raster scanning or spiral scanning. In this case, the orientation θ is stored in the above memory together with the detection signal, or is stored in a separate memory with X, Y coordinate conversion, or as it is (spiral (for scanning)
is written at regular intervals. This certain period of time is related to the follow-up ability when changing direction, but it is conceivable to write to a predetermined location for each transmission (within a pause period from the end of writing the received signal to the next transmission), for example.
In addition, if a dedicated memory for the orientation θ is provided, it may be associated with the transmission, and an independent period (for example,
Writing may also be performed at the read/display cycle.

(2) In the case of a display method using radial scanning that rotates sequentially In this case, it is not necessary to memo the direction θ, but it is sufficient to import and display it at regular intervals. This fixed period of time is related to the tracking ability as described above, but may also be made to coincide with the transmission cycle, for example (scanning is performed at least once in the azimuth θ direction during the pause period from the end of displaying the received signal to the next transmission). , or about one integer fraction thereof.

In this way, the azimuth marker generation circuit 15 has a primary relationship with the display method, and although the outline of its operation has been explained in (1) and (2) above, such technology is well known.

In the above circuit configuration, the second
This will be explained with reference to the waveform diagram in the figure.

In Figure 2, (a) is rotary encoder 1
is the normal speed (the rotational pulse sending period T is T>t ₁
(b) is a waveform diagram when the period T is in the range of t ₂ < T ≦ t ₁ ; (c)
is a waveform diagram when the period T is in the range of T≦t ₂ . For convenience of explanation, in each case, the current direction θ is
150.0°, and the rotation direction of rotary encoder 1 is clockwise.

Regarding the case (a), the rotational pulse A ₁ sent from the rotary encoder 1 is guided to the monostable multis 2 and 3 and the FFs 4 and 5. By sending the rotation pulse A ₁ mentioned above, the monostable multi 2 sends out an H level pulse B ₁ at time t ₁ ,
The monostable multi 3 sends out an H level pulse C ₁ at time t ₂ . The above H level pulses B ₁ and C ₁ are each FF
It is sent to D terminals 4 and 5. By the way, since the rotation pulse _A2 is sent out after the pulse _B1 is returned to the L level due to the relationship T> _t1 , the Q output terminals of FFs 4 and 5 both maintain the L level (the signal d , e). For this reason, the selection gate 9 directly passes only the rotation pulse and guides the rotation pulse to each CK terminal of the reversible counters 10 to 13. In this way, the reversible counter counts the rotation pulses, so the count value is as shown in the signal f.
The orientation is changed by 0.1° per rotation pulse like 150.0, 150.1, 150.2... In this case, although the rotation pulses are normally counted by the reversible counter 10, the reason why they are also led to the reversible counters 11 to 13 is to ensure counting operations during carry up and down.

Regarding case (b), in this case, as shown in signal a', the rotation pulse is in the range of period t ₂ to _{t 1} , so the time at which rotation pulse A ₂ ' is sent out after the rotation pulse A ₁ ' is sent out. In , the H level pulse C ₁ of the monostable multi 3 has already been returned to the L level, and conversely, the monostable multi 2 is still in the sending period of the H level pulse B ₁ . At this time,
As described above, the monostable multi-pulse 2 operates so as to send out an H level pulse for an additional time t ₁ from the point in time when the rotational pulse A ₂ ' is sent. As a result, FF4 maintains the H level state (signal d'), while FF5 maintains the L level state (signal e'). Based on the above-mentioned H level and L level output states, the selection gate 9 passes the divided pulse g' obtained by dividing the pulse with period _t0 from the original oscillation circuit 6 by 1/4 in the frequency dividing circuit 7,
to 13 CK terminals. In this way,
Since the reversible counter counts frequency-divided pulses, the count value is independent of the rotation pulse, as shown in signal f′.
The direction is changed like 150.0, 150.1, 150.2...

Regarding case (c), in this case, as shown in the signal a'', the rotation pulse is within the period t ₂ , so it is monostable at the time when the rotation pulse A ₂ '' is sent after the rotation pulse A ₁ '' is sent. Both multis 2 and 3 are in the period of sending out the H level pulses B ₁ and C _1. At this time, as mentioned above, monostable multis 2 and 3 are further away from the time of sending out the rotation pulse A ₂ ″.
It operates to send out H level pulses for hours _t1 and _t2 . As a result, both FFs 4 and 5 maintain the H level state (signals d″, e″), and this level signal is guided to the selection gate 9. Therefore, the selection gate 9 divides the pulse of period _t0 from the original oscillation circuit 6 into 1/1 by the frequency dividing circuit 8.
The frequency-divided pulse g'' whose frequency has been divided by 2 is passed through and guided to each CK terminal of the reversible counters 10 to 13. In this way, the reversible counter counts the frequency-divided pulse g'', and as shown in the signal f'', the frequency is 150.0. , 150.1, 150.2...

By the way, in the cases (b) and (c) above, the reversible counter counts the frequency-divided pulses g' and g'' that are unrelated to the rotation pulse, but the period of these frequency-divided pulses g' and g'' (main In the embodiment, 4t ₀ , 2t ₀ ) are set as follows.

When rotating a rotary encoder quickly, a high speed of count change is required.
If rotational pulses are sent out within a certain period, pulses shorter than the sending period must be sent out and guided to the reversible counter. From this point of view, it is required that at least the period 4t ₀ is smaller than t ₁ .
In addition, if you want to always satisfy the above requirements within the range of rotation pulse sending period t ₂ to _{t 1} , the period 4t ₀
must be less than t ₂ . After all, the cycle
Although 4t ₀ may be t ₂ <4t ₀ <t ₁ , it is preferable from an experimental standpoint to set it so that 4t ₀ <t ₂ and the speed of change in the count does not change drastically.

As explained above, in this embodiment, the azimuth counting speed, that is, the turning speed of the azimuth marker, can be switched and changed in stages according to the rotational speed of the rotary encoder, so that quick setting is possible.

In this embodiment, there are three stages, and the pulse period has a 2:1 relationship of 4t ₀ and 2t ₀ , but the pulse period is not limited to this, and in general, it can be set to m stages (m≧3). It is possible.

Furthermore, in the above, the FFs 4 and 5 are a type of logic circuit that exhibits an inverted state according to the period of the rotation pulse based on the presence or absence of the rotation pulse within the output sending time of each of the monostable circuits 2 and 3. Therefore, this type of logic circuit is not limited to FFs 4 and 5 in FIG. 1, and can be modified in various ways.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.
FIG. 2 is a waveform diagram thereof.

Claims (1)

[Scope of Claims] 1. A radar device comprising: a rotary encoder that sends out a rotational pulse every time the rotational pulse is rotated at a fixed angle; a reversible azimuth counter that counts the rotational pulse; time t ₁ , t ₂ ...t _o (however, n≧2, t _k >
tk _-1 , 1≦k≦n- ₁ ), and _τ1 , _τ2 ... _τo ( _τk >) satisfying at least _τk < _tk .
n pulse generating means for transmitting periodic pulses of τ _k+1 ), and based on the outputs of the n signal generating means, the transmission period of the rotational pulses is set from t ₂ to _{t 1} , t ₃ to _{t 2} . . . t _o ~ t _o-1 ,
A periodic pulse of τ ₁ corresponding to 0 to t _o ,
A means for guiding either the periodic pulse of τ ₂ or the periodic pulse of τ _o to the reversible azimuth counter in place of the rotation pulse; an azimuth indicator that displays the azimuth value indicated by the reversible azimuth counter; and a radar signal. An azimuth marker turning device in a radar device, comprising azimuth marker display means for displaying an azimuth marker in the above-mentioned azimuth direction on a display.