JP2544892Y2 - Radar equipment - 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 device, and more particularly to a radar device in which a receiving sensitivity level and an STC level can be automatically set according to a detection distance range.

[0002]

2. Description of the Related Art In a radar apparatus, a detection distance range can be switched according to a use situation of an operator. For example, the maximum detection distance of the device itself is 24
Even with NM (Nautical Mile) radar equipment,
The detection distance range (corresponding to the maximum detectable distance) can be switched in several steps, such as 1.5, 3, 6, 12, and 24 NM. 5NM range, 24N while sailing in the open sea
It can be appropriately selected such as the M range.

At this time, the transmission output of the pulse (peak output × pulse width), the transmission pulse width, and the reception intermediate frequency signal (I
The value of the pass band of F) is an optimum value every time the detection distance range is different, that is, if the detection distance range is short, the output is small, the pulse width is short, the IF pass band width is wide, and vice versa. The values having the relationship shown in Table 1 below were selected and used.

[0004]

[Table 1]

[0005] Each of these values is stored in a storage means such as a ROM in correspondence with the detection distance range, and the respective values for the detection distance range are not limited to the combinations in the above table. However, the transmission pulse width and the IF pass bandwidth are basically unchanged. For example, if the transmission pulse width is changed to 300 nSec in the 1.5 NM range, I
The F pass bandwidth is set to 3 MHz.

However, as the set value of the ROM, for example, a value that can be used as needed in the RAM is set separately from the ROM, and for example, the pulse repetition period is set to a value other than 500 Hz in the 24 NM range. Is possible.

[0007] The pulse generated under the above conditions is emitted from the antenna, reflected on the target, and again input to the receiver via the antenna. Since this input signal is attenuated according to the distance (time), it is necessary to increase the gain (with time) according to the distance when always trying to obtain a constant output with the amplifier of the receiver.

For this reason, conventionally, in a radar apparatus, an STC (Sensitive) for generating a gain control signal for changing the gain of an amplifier of a receiver over time.
(TimeTime Control) circuit is used.

This gain control signal is generated based on a predetermined theoretical value which is a function of the distance between the target and the antenna (for example, proportional to the −4 power), and is used to set the gain control signal set in the STC circuit. Adjusted by parameters.

The gain control parameter includes a reception sensitivity level for determining a reference value of the gain to be controlled, and an STC level for relatively adjusting the predetermined theoretical value.
This gain control parameter is manually adjusted and
Set to C circuit.

The STC circuit has been digitized in recent years for the purpose of improving the accuracy and the like. For example, JP-A-60-190881 and JP-A-60-19081
Japanese Patent Application Laid-Open No. 195470 discloses that a discrete value of an STC waveform (corresponding to the above-described predetermined theoretical value) corresponding to a detection distance (time) is set to RO
There is disclosed an STC circuit which stores a value in M and reads out a value corresponding to the time after the pulse emission to control the receiver level. According to such a configuration, various STC waveforms adapted to the surrounding environment can be used.

[0012]

By the way, in order to obtain a clear received image, if the transmission parameters such as the transmission output, pulse width and IF pass bandwidth are changed as described above, the reception sensitivity level and the STC level become lower. It is necessary to readjust the gain control parameter, and in the above-described conventional apparatus, the operation is manually performed, which is very troublesome.

The present invention has been proposed in view of the above-mentioned conventional circumstances, and has as its object to provide a radar apparatus capable of automatically setting the gain control parameter according to a transmission parameter. It is.

[0014]

This invention employs the following means to achieve the above object. That is, the transmitting unit that emits the transmission pulse generated by the pulse generation circuit via the antenna, and the signal that receives the transmission pulse reflected by the target via the antenna is a function of the distance to the target. An amplifier that amplifies with a gain controlled by a gain control signal that changes with time based on a predetermined theoretical value, and a reception sensitivity level that determines a reference value of the gain of the amplifier and the predetermined theoretical value are relatively adjusted And a STC circuit for generating the gain control signal according to a gain control parameter consisting of an STC level for performing the detection and the transmission pulse. Storage means for storing the transmission parameter including the width and the gain control parameter in association with the detection distance range,
Control means for reading out the transmission parameters and setting them in the pulse generation circuit or the transmission section based on the detection distance range inputted from the detection distance range input means, and reading out the gain control parameters and setting them in the STC circuit. The configuration is as follows.

Thus, when the detection distance range is input from the detection distance range input means 31, the gain control parameter is read out from the storage means 35 together with the transmission parameter for the same previous detection distance range, and the STC is read.
Set in the circuit. In the STC circuit, a gain control signal Gc corresponding to the gain control parameter is generated and input to the IF amplifier 25. Thereby, the gain control parameter, that is, the reception sensitivity level and the STC level are changed according to the transmission parameter changed according to the detection distance range.

[0016]

FIG. 1 is a block diagram showing an embodiment of the present invention. A microwave is formed in the transmission unit 12 by the pulse generated by the pulse generation circuit 11, and the antenna 41
Transmission pulses are fired at more predetermined intervals. Thereafter, the antenna 41 receives the signal reflected by the target.

On the other hand, when the transmission pulse is formed, the transmission pulse is also input to the delay circuit 37, and the STC circuit 38 in the next stage is operated after being delayed by the width of the transmission pulse.
The STC circuit 38 includes a keyboard and a volume, and is used in accordance with the reception sensitivity level and the STC level set by the input device 31 as the detection distance range input means for setting operation parameters of the radar device such as the detection distance range. The gain control signal Gc is generated and the IF amplifier 25
To enter. That is, the reflected signal is a value that attenuates with respect to time (distance of the target) in order to keep the output of the IF amplifier 25 constant.
The gain of the F amplifier 25 is increased with time.

The IF amplifier 25 includes an RF amplifier 21,
The intermediate frequency signal generated from the received signal by the mixer 22 is input, and the gain control signal Gc determines the gain of the IF amplifier 25 by subtracting the gain of the IF amplifier 25 from the distance R between the target and the antenna 41 based on the reception sensitivity level. The theoretical value proportional to the fourth power is controlled by a value relatively adjusted by the STC level (actually, the distance R is represented by time). The output of the IF amplifier 25 is detected by a detection circuit 26, then subjected to image processing and A / D conversion by a signal processing circuit 27, and displayed on a display unit 28. As a result, the intensity of the reflected wave from the target of the radar device becomes constant, and the contrast of the displayed image becomes constant irrespective of the distance from the target, resulting in an image that is easy for the operator to see.

The above theoretical value, which is a function of the distance R between the target and the antenna 41, is not limited to a value proportional to the −4 power,
Various functions adapted to the surrounding environment can be used. Prior to transmission, the operator inputs a detection distance range from the input device 31 as a detection distance range input unit.
The input detection distance range is input to the CPU 33 serving as control means via the A / D converter 32, and the CPU 33 corresponds to the input detection distance range from a table such as Table 1 stored in the ROM 34. A transmission parameter, that is, a peak value output, a pulse width, an IF pass bandwidth, and a pulse period are read out, a signal designating the peak value output is sent to the transmission unit 12, and a signal designating the pulse width and the pulse period is sent to a pulse generation circuit. 11 and a signal designating an IF pass bandwidth is input to a filter group 29 including a plurality of filters provided at a stage preceding the IF amplifier 25. As a result, the transmission condition according to the detection distance range is set, and the pass band is set by a filter having an appropriate pass band width selected from the filter group 29.

When the transmission conditions are determined in this manner, a parameter for determining the gain of the IF amplifier 25, that is, a gain control parameter including the reception sensitivity level and the STC level, is manually input by the input device 31 in order to obtain a clear image. , And is set in the STC circuit 38. STC
The circuit 38 generates a gain control signal Gc based on the gain control parameter set as described above and inputs the signal to the IF amplifier.

At first, the gain control parameters are manually adjusted as described above, but the adjusted values are input to the RAM 35 as storage means. If the detection distance range input from the base station 31 is the same as the previous one, the CPU 33 accesses the ROM 34 to read the transmission parameters corresponding to the input detection distance range,
M35 is accessed, and a gain control parameter consisting of a reception sensitivity level and an STC level corresponding to the input detection distance range is read. Thereafter, the gain control parameter is set in the STC circuit 38 and the corresponding gain control signal Gc is set.
Is input to the IF amplifier. This eliminates the need to manually set the reception sensitivity level and STC level.

[0022]

As described above, in the present invention, the transmission parameter and the gain control parameter corresponding to the detection distance range are stored in the storage means, and when the specific detection distance range is designated, the specific The transmission parameters corresponding to the detection distance range are read and set in the transmission unit, and the gain control parameters are read and set in the IF amplifier. Therefore, the transmission parameters and the gain control parameters are set in accordance with the detection distance range. There is an advantage that can be set automatically. Therefore, complicated work such as STC level adjustment when the detection distance range is changed becomes unnecessary, which is effective in improving the operability of the radar device.

[Brief description of the drawings]

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

[Explanation of symbols]

 25 IF amplifier 31 Detecting distance range input means 33 Control means 35 Storage means

Claims (1)

(57) [Scope of request for utility model registration] A transmitting unit that emits a transmission pulse generated by a pulse generation circuit via an antenna, and a signal that receives the transmission pulse reflected by the target via the antenna and transmits the signal to an object at a distance from the target. An amplifier that amplifies with a gain controlled by a gain control signal that changes with time based on a predetermined theoretical value that is a function, and a reception sensitivity level that determines a reference value of the gain of the amplifier and the predetermined theoretical value are relative to each other. For generating the gain control signal according to a gain control parameter consisting of an STC level for dynamic adjustment
A radar circuit comprising: a C circuit; a detection distance range input means capable of selecting a maximum detectable distance; and a transmission parameter including at least a transmission pulse width and the gain control parameter are stored in association with the detection distance range. Based on the detection distance range input from the detection distance range input means, the transmission parameter is read and set in the pulse generation circuit or the transmission unit, and the gain control parameter is read and set in the STC circuit based on the detection distance range input from the detection distance range input means. A radar device comprising a control unit.