JPH03295484A - Radar device - Google Patents

Abstract

PURPOSE:To prevent an error due to a change in azimuth with the frequency of continuation of input echo information by adding echo information of the same information, which is obtained every time an energy wave pulse is sent out, as many times as properly set. CONSTITUTION:Storage elements 1a, 1b, 1c, and 1d of a storage circuit 1 delay the input echo information for times corresponding to transmission intervals of the energy pulse wave. The output (g) of the storage element 1a is therefore echo information obtained by last transmission, the output (h) of the storage element 1b is echo information obtained by transmission right before the last transmission, and the outputs (i) and (j) are pieces of echo information obtained previously in order. Those pieces of echo information are added by an adder 2, whose addition result is outputted as an output signal (b) through a switch 3.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention transmits a pulsed energy wave, receives echo information of this energy wave from a target object with a receiver,
Radar devices and radar-like devices that can increase the S/N ratio and prevent interference from other similar devices without sacrificing azimuth resolution, and are related to radar devices that display the position of targets. The present invention relates to a device (hereinafter simply referred to as a radar device) having a function of transmitting energy waves and making it possible to observe the position of a target based on echo information from the target.

[Prior Art] Conventionally, as a method for increasing the S/N ratio in a radar device, a <weighting is an averaging circuit> as shown in Japanese Patent Application Laid-Open No. 52-10094 is known. FIG. 5 is a block diagram showing a weighting and averaging circuit.

In FIG. 5, input echo information a is fed to an adder. The input echo information a is delayed by a delay circuit with a time corresponding to the sending interval of the pulsed energy waves, and is multiplied by a number smaller than 1 in a multiplier to attenuate the input echo information, and is then combined with the echo information obtained by the previous transmission. , are added by an adder, and an output signal is output.

With this configuration, echo information from the same distance obtained each time a pulsed energy wave is sent out is added with a smaller weight as the time goes by, and is automatically discarded eventually. Due to this integral action, information that is not continuous at the same distance, such as noise, is suppressed, and information that is continuous at the same distance, such as echo information from the target object, is emphasized.

[Problems to be Solved by the Invention] However, such conventional weighting and averaging circuits have two problems as shown in (1) and (2) below.

(1) One problem is that the maximum point of the output signal changes depending on the number of consecutive input echo information of the same distance. As an example, as shown in FIG. 6(A), when the input echo information is repeated two times in a row (C) and when the input echo information is received four times in a row (d), as shown in FIG.
), the output signals are e and f, respectively,
The maximum points of each are shifted. This means that the direction changes depending on the number of consecutive input echo information, which is a serious problem for radar equipment.

■Another problem is that if you try to obtain a sufficient integral effect, the azimuth resolution will deteriorate.

In other words, it is clear that in order to obtain a sufficient integral effect, it is necessary to bring the multiplier of the multiplier shown in Figure 5 closer to 1, but the closer the multiplier is to 1, the more output shown in Figure 6 (B). It is also evident that the attenuation band of the signal C or d becomes longer and the lateral resolution deteriorates.

[Means for Solving the Problems] In order to solve the above problems (1) and (2), the radar device of the present invention includes: (a) a plurality of pieces of echo information obtained by sending out a plurality of consecutive pulsed energy waves; (c) an adder that simultaneously reads and adds the plurality of echo information stored respectively; and (C) continuity that determines the continuity of the plurality of echo information read simultaneously. and (d) a switch for controlling the output of the adder by the continuity determiner, or an output adjustment means for applying a predetermined weight to the output of the continuity determiner. It is.

In addition, in the radar device of claim 2, as a continuity determiner for determining the continuity of a plurality of echo information, (e) one or more of the plurality of echo information read out at the same time is It was equipped with an echo detector that outputs a signal that, if not present, turns off the switch that controls the output of the adder.

Furthermore, in the radar device of claim 3, together with the echo detector, (f) echo information of a predetermined level or higher exists among the plurality of simultaneously read echo information; If at least one set of echo information does not exist next to each other,
The configuration includes a high-level echo determiner that outputs a signal to turn off the switch that controls the output of the adder.

[Effect 1] With this configuration, a plurality of pieces of echo information obtained by sending out a plurality of continuous pulsed energy waves are stored, and the stored pieces of echo information are simultaneously read out, and the pieces of echo information obtained by sending out a plurality of continuous pulsed energy waves are read out at the same time. echo information is added.

Also, a plurality of pieces of stored echo information are checked, and if one or more pieces of echo information near the center do not exist at the same time, the output is turned off.

In addition, each stored plural pieces of echo information are checked, and if there is a signal above a predetermined level, such as interference from other similar devices, and the signals are not continuous, the output is turned off.

C Embodiment One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, memory elements 1a, 1b, I
c and ld are for delaying the input echo information by a time corresponding to the transmission interval of the pulsed energy waves, respectively. Therefore, the output g of the memory element 1a is the eco information obtained by the previous transmission, the output of the memory element 1b is the eco information obtained two times ago, and similarly, i and j are the eco information obtained three times ago and four times ago, respectively. This is the echo information. These pieces of echo information are added by an adder 2, and the addition result is outputted as an output signal through a switch 3.

On the other hand, the echo information of g-j is sent to the continuity determiner 4,
The switch 3 is turned on or off by this determination output signal k.

Next, one embodiment of the continuity determiner 4 is shown in FIG. Second
The figure shows an echo detector 5 that outputs OFF as an output signal m if echo information i does not exist at the same time, and an echo detector 5 that outputs off as an output signal m if echo information g to j do not exist at the same time. If they are not consecutive, a signal k is output by the high level echo judger 6 which outputs an OFF signal as the output signal n, and the OFF logical adder 7 which performs the logical sum of the two judgment outputs m and n regarding OFF. do.

Further, as an example, the echo detector 5 when the input echo information is a 2-pin binary signal and is configured with a positive logic circuit.
An example of the circuit is shown in FIG. 3, and an example of the circuit of the high-level echo determiner 6 is shown in FIG.

The echo detector 5 in Fig. 3 has an OR circuit 8 and a NAN i)
It is composed of a circuit 9, and when echo information and l do not exist at the same time, it outputs an off signal of logic level 1 as an output signal m.

In addition, in the high level echo determination device 6 of FIG.
The bit echo information is input into an AND circuit 10 and 1 for every 2 bits, that is, the highest level echo information p-s is extracted. This information is processed by an AND circuit 11 and a NOR circuit 12, and if any of the adjacent echo signals is not at the highest level, the signal t is output as a logic level 1. On the other hand, O
The R circuit 13 outputs the signal U as logic level 1 when any echo information is at the highest level.

These two signals t and U pass through an AND circuit 14 and become a high-level echo determiner output n. That is, echo information g
=j is at the highest level, but only when any adjacent information is not at the highest level, an off signal of logic level 1 is output as the signal n.

As shown in FIG. 2, the signals m and n are logically summed by the OFF logical adder 7 and become the output signal of the continuity determiner 4. That is, only when there is no information in the echo information and i at the same time, or only when the highest level information exists independently in the echo information g-j, the output signal of the continuity determiner 4 contains the third
Turn off the switch 3 shown in the figure.

In this embodiment, the switch for controlling the output is attached after the integrator, but it may be controlled before the integrator or the integrator itself. Furthermore, it goes without saying that various modifications to the systems and circuits can be made within the scope of the spirit of the present invention.

[Effects of the Invention] First, the present invention has a configuration in which echo information of the same distance obtained each time a pulsed energy wave is sent out is added by an appropriately set number. Therefore, an ideal integral effect without any weighting etc. can be obtained. Note that the number to be integrated may be determined based on the directivity characteristics of the transducer, its rotation speed, the sending interval of the pulsed energy waves, and the like.

Second, the present invention is equipped with an echo information continuity determiner that checks multiple pieces of continuous echo information and operates only on the true echo information from the target object. can be avoided.

In the second aspect of the present invention, the continuity determiner is configured such that if the integral output is controlled by detecting echoes near the center before integration, no output is output when there is no echo information near the center. Therefore, the azimuth resolution is not deteriorated.

Note that if the output is not output unless there is echo information from a plurality of echoes near the center, for example, two at the same time, uncorrelated signals such as fiber sounds can be removed, and the S/N ratio can be improved in addition to the integration effect.

Furthermore, in claim 3, a high level signal is provided to prevent the output from being output when relatively high level information exists in an independent state with no correlation, such as an interference signal directly coming in from another similar device. The configuration is such that echo judgment H is also used. Therefore, interference can be prevented without impairing the integral effect.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram of an embodiment of a continuity determiner, Fig. 3 is a circuit diagram of an echo detector, and Fig. 4 is a high-level echo judgment. FIG. 5 is a block diagram of a conventional weighting and averaging circuit, and FIG. 6 is a waveform diagram illustrating the operation of FIG. Engineering: Memory circuit, 2: Adder, 3: Output adjustment means (switch), 4: Continuity determiner, 5: Echo detector, 6: High level echo determination vessel.

Claims (3)

[Claims] (1) In a radar device that transmits pulsed energy waves, receives echo information from the target object by a receiver, and displays the position of the target object, a plurality of consecutive pulsed energy waves are used. A memory circuit (which stores each of the multiple pieces of echo information obtained by sending out the
1), an adder (2) that simultaneously reads and adds a plurality of stored echo information, and a continuity determiner (4) that determines the continuity of the plurality of echo information read simultaneously; The continuity determiner (4) causes the adder (
A radar device characterized by comprising: output adjustment means (3) for controlling the output of step 2). (2) The output adjustment means (3) is a switch that is turned on or off, and the continuity determiner (4) that determines the continuity of echo information is a switch that is turned on or off. An echo detector (5) that outputs a signal that turns off a switch (3) that controls the output of the adder (2) if one or more of the echo information does not exist at the same time.
The radar device according to claim 1, further comprising: (3) The output adjustment means (3) is a switch that is turned on or off, and the continuity determiner (4) that determines continuity of echo information is a switch that is turned on or off. An echo detector (5) that outputs a signal that turns off a switch (3) that controls the output of the adder (2) if one or more of the echo information does not exist at the same time.
If there is echo information of a predetermined level or higher among the plural pieces of echo information read out at the same time, and at least one set of echo information does not exist adjacent to each other, the adder (2) The radar device according to claim 1, further comprising a high-level echo determiner (6) that outputs a signal for turning off the switch (3) that controls the output.