JP3208213B2 - Radar sweep correlation circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar sweep correlation circuit used for removing interference in a radar apparatus.

[0002]

2. Description of the Related Art A radar device is a device that detects the presence of a target present in the vicinity by transmitting and receiving radio waves. That is, a radio wave is transmitted to the surroundings at a predetermined repetition cycle, and a reflected wave from the target is received. The distance to the target is detected as the time required from the transmission of the radio wave to the reception of the reflected wave, and the direction of the target is detected as the direction of the antenna during transmission and reception.
One transmission / reception is usually called a sweep, and data obtained by one sweep is called a sweep data.

FIG. 3 shows a configuration of a radar sweep correlation circuit according to a conventional example. The sweep correlation circuit is
This is a circuit that determines a correlation between sweep data related to a plurality of continuous sweeps, and removes data determined to have no correlation as noise such as radar interference. Radar interference refers to noise caused by reception of radio waves emitted from other radar devices existing in the vicinity.

The circuit shown in FIG. 3 includes N buffer memories 10-1 and 10- for storing sweep data.
2,... 10-N. Buffer memory 10-
, 10-N are, for example, 2 kby
It has a configuration of te × 8 bits / 1 word. N
Is usually about 5 to 6. The sweep write control circuit 12 includes N buffer memories 10-1, 10-2,.
10-N, and writes the sweep data input from the radar receiver (not shown) to the selected buffer memory. The buffer memory control circuit 14 generates write addresses for the buffer memories 10-1, 10-2,..., 10-N. The selector 16 is a buffer memory 1
Of the 0-1, 10-2,..., 10-N, the output of the buffer memory storing the data related to the current sweep is
The selection is made according to a signal from the sweep write control circuit 12. The data selected by the selector 16 is AND
The signal is output to a circuit at a subsequent stage via 18. In a subsequent circuit (not shown), predetermined processing such as coordinate conversion is performed and the obtained processing is performed.
A radar image is displayed on a CRT or the like.

[0005] The correlation determination circuit 20 includes a buffer memory 10
-1, 10-2,... 10-N. That is, if the data obtained in consecutive N sweeps have a correlation with each other,
The data related to the current sweep can be regarded as data indicating the target that actually exists. Conversely, if there is no correlation, it is considered to be data related to radar interference etc. Can be. When determining that there is no correlation, the correlation determination circuit 20 sets the gate signal to the L value. This gate signal is ANDed together with the output of the selector 16 described above.
18 is input. Therefore, the data output from the AND 18 is data from which data relating to the determination that there is no correlation is removed.

[0006]

However, when a sweep correlation process is to be executed by such a circuit, N storage means for storing data for one sweep are required. Normally, N is set to 5 or 6, and as a result, a large number of buffer memories are required for correlation determination, and the storage capacity required for the circuit becomes large.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and has as its object to reduce the number and capacity of storage means for storing sweep data.

[0008]

In order to achieve the above object, a first aspect of the present invention is to provide a temporary storage means for inputting sweep data from a data receiving unit and storing the data for one sweep period, When the input sweep data has a correlation with the sweep data relating to the previous sweep, the correlation number on the correlation number storage means is added and updated. A counter means for resetting, a gate signal generating means for generating a gate signal indicating that there is a correlation when the correlation number on the correlation number storage means is not reset, and a gate signal indicating that there is a correlation is generated. In the state in which the data is stored, the data on the temporary storage means is regarded as valid data and supplied to a subsequent circuit.
It is characterized by having.

According to a second aspect of the present invention, a storage means for storing the number of correlations for one sweep period, and a case where the sweep data input from the radar receiving section has a correlation with the sweep data relating to the previous sweep. In addition, a counting means for adding and updating the correlation number in the storage means and resetting when the correlation number is not provided, and a gate signal indicating that there is a correlation when the correlation number obtained by the counting means is not reset are generated. In the state where the gate signal generating means and the gate signal indicating that there is a correlation are generated, the sweep data input from the radar receiving unit is regarded as valid data and supplied to the subsequent circuit, and is not generated. And a gate means for preventing the supply.

[0010]

According to the first aspect of the present invention, the sweep data input from the radar receiver is stored in the temporary storage means for one sweep period. When the input sweep data has a correlation with the sweep data relating to the previous sweep, the counting means adds and updates (increments) the sweep data and stores it in the correlation number storage means. Conversely, if not, the sweep data is reset. As described above, the gate signal generation unit has a correlation when the correlation number on the correlation number storage unit is not reset, that is, the sweep data on the temporary storage unit has a correlation with the sweep data on the previous sweep. In this case, a gate signal indicating that there is a correlation is generated. The gate unit receives the gate signal and gates the sweep data stored in the temporary storage unit. Therefore, in the present invention, the number of storage means for storing sweep data is reduced, and the storage capacity required for the circuit is reduced. Further, since the correlation number in the correlation number storage means is used in generating the gate signal, the gate processing can be executed by the gate signal corresponding to one sweep delay of the sweep data by the temporary storage means.

Also, in the second aspect of the present invention, the same correlation processing as in the first aspect is performed. However, in this claim, the sweep correlation processing is executed in real time. That is, first, the sweep data input from the radar receiving section is supplied to the counting means in the same manner as in the first aspect, and the update / reset of the correlation number is executed. The correlation number is stored in the storage means, but the correlation number on this storage means is only to be subjected to the next addition / update / reset, and does not form the basis of gate signal generation. The gate signal generation means generates a gate signal based on the correlation number obtained by the counting means, that is, the correlation number added / updated / reset based on the currently input sweep data. The gate unit receives the supply of the gate signal, and gates the sweep data input from the radar receiving unit . Therefore, in the present invention, in addition to the same operation as that of the first embodiment, there is an effect that it is not necessary to temporarily store the sweep data input from the radar receiving unit at a stage before the gate means. In other words, the sweep correlation processing is executed in real time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the same components as those in the conventional example shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 shows a configuration of a radar sweep correlation circuit according to a first embodiment of the present invention. The circuit shown in FIG. 1 includes a buffer memory 10 for storing sweep data input from a radar receiving unit, and further gates data on the buffer memory 10 and outputs the data.
ND18 is provided. In addition, the circuit of the present embodiment includes an interference rejection (IR) buffer memory 22, a correlation counter 24, and a gate signal generation circuit 26. Buffer memory control circuit 14
Are the buffer memory 10 and the IR buffer memory 22
And the write timing and the address, and the read timing and the address.

In this embodiment, the sweep data input from the radar receiver is stored in the buffer memory 10 while being input to the correlation counter 24. The correlation number counter 24 determines whether or not the input sweep data has a correlation with the sweep data relating to the previous sweep, and if it has a correlation, increments the correlation number by one. If not, 0 is set for the correlation number. The IR buffer memory 22 stores the correlation number counter 2
The correlation number obtained by 4 is stored and held until the next sweep. When the correlation number on the IR buffer memory 22 is not 0, the gate signal generation circuit 26 generates a gate signal having an H value and supplies the gate signal to the AND 18.
As a result, of the sweep data in the buffer memory 10, only data having a correlation with the sweep data relating to the previous sweep is output to the subsequent circuit.

When determining the presence or absence of a correlation in the correlation counter 24, sweep data relating to the previous sweep is used in addition to the sweep data input from the radar receiving unit. The latter, that is, the previous data, may be read from the buffer memory 10 and input to the correlation counter 24 as shown by a broken line in the figure. When the sweep data input from the radar receiver is stored in the IR buffer memory 22 together with the correlation number, the previous data may be read from the IR buffer memory 22 and input to the correlation number counter 24.

Since the sweep data input from the radar receiving unit is delayed by one sweep by the buffer memory 10, in this embodiment, the IR buffer memory 22 is used.
Is used, the correlation number delayed by one sweep. That is, the correlation number is read from the IR buffer memory 22 when the gate signal is generated. Thereby, the gate processing according to the delay can be executed.

As described above, according to this embodiment, for example,
The number of buffer memories 10 having a capacity of kbytes × 8 bits / 1 word is reduced from N to 1 (2 even including the IR buffer memory 22). Therefore,
The storage capacity required of the circuit is clearly reduced.

Further, according to the present embodiment, it is possible to execute the sweep correlation processing over a large number of sweeps without increasing the number of buffer memories 10. That is, in the conventional example shown in FIG. 3, the number N of the buffer memories 10 has to be increased when the sweep correlation processing is to be performed for a larger number of sweeps. On the other hand, in the case of the present embodiment, the number of sweeps to be subjected to the sweep correlation process is defined only by the number of bits per word of the IR buffer memory 22. Therefore, it is not necessary to increase the number of buffer memories 10. . For example, as the IR buffer memory 22, 8 bi
When the correlation counter 24 executes correlation processing using sweep data on the buffer memory 10 using a memory of t / 1 word, it is possible to execute sweep correlation processing over a maximum of 2 ⁸ = 256 sweeps. In the case where the sweep data is also stored in the IR buffer memory 22 having the same configuration and the correlation number counter 24 performs the correlation process using the sweep data on the IR buffer memory 22, 1wo
3 bits in rd are used for data storage, and the remaining 5 bits
If it is used for storing the correlation number, it is possible to execute the sweep correlation processing over a maximum of 2 ⁵ = 32 sweeps.

The buffer memory 1 according to the present embodiment
It is also possible to configure the 0 and IR buffer memory 22 on an integrated memory.

FIG. 2 shows the configuration of a radar sweep correlation circuit according to a second embodiment of the present invention.

In this embodiment, the sweep data input from the radar receiving unit is input to the AND 18 without passing through the buffer memory. Therefore, the sweep data input to the AND 18 is not delayed by one sweep. In response to this, the gate signal generation circuit uses not the correlation number in the IR buffer memory 22, that is, the delayed correlation number obtained by the correlation number counter 24, instead of the delayed correlation number. With such a configuration, the sweep correlation processing can be executed in real time.

In each of the above embodiments, the presence or absence of the correlation is determined based on the previous sweep data and the current sweep data, but the present invention is not limited to such a configuration. That is, the correlation determination can also be performed by providing a determination reference circuit for determining whether the current sweep data is valid or invalid based on continuity. In this case, the previous sweep data is not necessary for determining whether or not there is a correlation between the current sweep data and the previous sweep data.

[0023]

As described above, according to the present invention,
A means for storing the correlation number is provided, and the sweep correlation processing is performed by adding / updating / resetting the correlation number and generating a gate signal based on the result, so that it is not necessary to store sweep data relating to a large number of sweeps.
The storage capacity of the circuit can be significantly reduced. Further, the present invention can be realized as either a configuration for executing the sweep correlation processing in real time (Claim 2) or a configuration for executing the sweep correlation processing with delay (Claim 1).

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a radar sweep correlation circuit according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a radar sweep correlation circuit according to a second embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a radar sweep correlation circuit according to a conventional example.

[Explanation of symbols]

 Reference Signs List 10 buffer memory 14 buffer memory control circuit 18 AND 22 IR buffer memory 24 correlation number counter 26 gate signal generation circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01S ⁷ /00-7/42 G01S 13/00-13/95

Claims (2)

(57) [Claims] 1. A temporary storage means for inputting sweep data, which is data obtained per transmission / reception of radio waves, from a radar receiving unit and storing the data for one sweep period; a correlation number storage means for storing a correlation number; Counting means for adding and updating the correlation number on the correlation number storage means when the sweep data to be processed has a correlation with the sweep data relating to the previous sweep, and resetting when not having the correlation, storing the correlation number A gate signal generating means for generating a gate signal indicating that there is a correlation when the correlation number on the means is not reset; and a data on a temporary storage means when a gate signal indicating that there is a correlation is generated. And gate means for supplying the data to a subsequent circuit assuming that the data is valid data, and blocking the supply when the data is not generated. Seki circuit. 2. A storage means for storing a correlation number for one sweep period, and a correlation number on the storage means when sweep data inputted from a radar receiving section has a correlation with sweep data relating to a previous sweep. Counting means for adding and updating, and resetting when not having, and gate signal generating means for generating a gate signal indicating that there is a correlation when the correlation number obtained by the counting means is not reset, In the state where a gate signal indicating that there is a signal is generated, the sweep data input from the radar receiving unit is regarded as valid data and supplied to a subsequent circuit, and in the state where it is not generated, the gate means for preventing the supply is provided. And a radar sweep correlation circuit comprising: