JP2014224787A - Azimuth pulse signal converter - Google Patents

Abstract

An azimuth pulse signal conversion apparatus capable of generating an azimuth pulse signal corresponding to an azimuth and displaying a high-precision radar image with high azimuth accuracy. A first pulse time generator for generating a first pulse time of a first azimuth pulse signal, a second pulse time setting unit for setting a second pulse time of a second azimuth pulse signal, An input counter 40 that outputs the input count number of the azimuth pulse signal, a control signal output unit 52 that outputs the count control signal, an output counter 44 that outputs the output count number of the second azimuth pulse signal based on the count control signal, The control signal output unit 52 includes a comparison result between the output count number and the first reference value of the output count number set based on the ratio between the resolution and the pulse number and the input count number, or the input count number A count control signal is output to the output counter based on the input. [Selection] Figure 2

Description

  The present invention relates to an azimuth pulse signal conversion device that converts a first azimuth pulse signal generated by an azimuth signal generation unit into a second azimuth pulse signal and supplies the converted signal to a radar processing unit that processes a radar echo received by an antenna.

  The radar device transmits radar signals (detection signals), receives radar echoes reflected by targets such as ships and aircraft, displays radar images, and monitors the direction of the target and the distance to the target. It is a device to do. The azimuth of the target is calculated based on an azimuth pulse signal generated by an azimuth signal generation unit such as a rotary encoder provided in the rotation drive unit of the antenna. The distance to the target is calculated based on the time from when the radar signal is transmitted until the radar echo is received.

  The number of azimuth pulse signals per rotation of the antenna generated by the azimuth signal generator is usually less than the resolution necessary for radar echo processing. Patent Document 1 discloses a conversion device that converts an azimuth pulse signal into an azimuth pulse signal having a necessary resolution. In this conversion device, time Tb × N / D is set in a timer, and radar echoes are processed based on this time Tb × N / D. Here, Tb is the time of one cycle of the azimuth pulse signal generated every time the antenna rotates by a certain angle. N is the number of azimuth pulse signals generated per one rotation of the antenna. D is the resolution of the azimuth pulse signal necessary for signal processing such as display.

Japanese Patent No. 2927985

  However, the conversion device of Patent Document 1 has a problem when the rotational speed of the antenna fluctuates. For example, if the rotation speed of the antenna is reduced to 1 / a times while the radar echo is being processed according to time Tb × N / D, the time of one cycle of the direction pulse signal generated by the direction signal generation unit Is a × Tb. In this case, the radar echo is processed based on the time Tb × N / D before deceleration until the time a × Tb × N / D corresponding to the reduced rotational speed of the antenna is calculated. For this reason, the orientation of the radar echo precedes the actual orientation of the radar echo corresponding to the orientation pulse signal whose time in one cycle is a × Tb, and the orientation is deviated. Similarly, when the rotation speed of the antenna is accelerated by b times, the direction of the radar echo is delayed from the actual direction of the radar echo corresponding to the direction pulse signal whose time in one cycle is 1 / b × Tb, Deviation occurs in azimuth. Such a deviation in azimuth increases as the variation in the rotation speed of the antenna increases, and thus the azimuth of the target cannot be accurately displayed.

  With respect to such a problem, Patent Document 1 determines that a failure occurs when the rotation speed of the antenna greatly fluctuates, and issues a warning, or the time of one cycle of the azimuth pulse signal in the section where the rotation speed fluctuates. I try not to update it. However, such a countermeasure cannot avoid inappropriate display of the radar image.

  The present invention has been made to solve the above-described problems, and when converting an azimuth pulse signal to an azimuth pulse signal having a necessary resolution, the azimuth corresponding to the azimuth is not affected by fluctuations in the rotation speed of the antenna. An object of the present invention is to provide an azimuth pulse signal conversion device capable of generating a pulse signal and displaying a highly accurate radar image with high azimuth accuracy.

  An azimuth pulse signal conversion device according to the present invention converts a first azimuth pulse signal generated by an azimuth signal generation unit into a second azimuth pulse signal, and supplies it to a radar processing unit that processes a radar echo received by an antenna. In the pulse signal conversion device, a first pulse time generation unit that generates a first pulse time based on a pulse width or a pulse period of the first azimuth pulse signal, the first pulse time, and per rotation of the antenna Based on the number of pulses of the first azimuth pulse signal and the resolution of the second azimuth pulse signal necessary for processing of the radar echo, the second pulse time is determined based on the pulse width or pulse period of the second azimuth pulse signal. A second pulse time setting unit for setting, an input counter for outputting an input count number of the first azimuth pulse signal, and a control for outputting a count control signal And an output counter that outputs an output count number of the second azimuth pulse signal based on the count control signal, and the control signal output unit has a higher resolution than the pulse number, The time interval of the second pulse time based on a comparison result between the output count number and the first reference value of the output count number set based on the ratio between the resolution and the pulse number and the input count number A first processing function for outputting the count control signal to the output counter, and when the resolution is greater than the number of pulses, the output count based on the first reference value when the input count number is input. A second processing function for outputting the count control signal for forcibly changing the number to the output counter, and when the resolution is greater than the number of pulses, The count control signal is output at a time interval of a third pulse time set to a time shorter than the second pulse time until the output count number reaches the first reference value. The third processing function to be output to the counter, and the input count number set based on the input count number, the ratio of the pulse number and the resolution, and the output count number when the resolution is smaller than the pulse number And a fourth processing function for outputting the count control signal to the output counter at a time interval of the second pulse time based on a comparison result with the second reference value. Features.

In the azimuth pulse signal conversion device, when the resolution is greater than the number of pulses, the control signal output unit, the first reference value,
Coutmax = INT [(Cin + 1) × D / N]
Coutmax: the first reference value INT [(Cin + 1) × D / N]: an integer part of (Cin + 1) × D / N Cin: the input count number D: the resolution N: set as the number of pulses To do.

In the azimuth pulse signal converter, when the resolution is greater than the number of pulses, the control signal output unit, the output count number,
Cout = Coutmax + 1
Cout: the output count number Coutmax: the count control signal to be forcibly changed as the first reference value is output to the output counter.

In the azimuth pulse signal conversion device, when the resolution is less than the number of pulses, the control signal output unit, the second reference value,
Cinmax = INT [(Cout + 1) × N / D]
Cinmax: the second reference value INT [(Cout + 1) × N / D]: an integer part of (Cout + 1) × N / D Cout: the output count number N: the pulse number D: set as the resolution To do.

  In the azimuth pulse signal conversion device of the present invention, when the first azimuth pulse signal is converted into the second azimuth pulse signal, it is set based on the output count number, the ratio between the resolution and the pulse number, and the input count number. A comparison result of the output count number with a first reference value, or a second reference of the input count number set based on the input count number, a ratio of the pulse number and the resolution, and the output count number Based on the comparison result with the value, the count control signal is output to the output counter at the time interval of the second pulse time, and the second azimuth pulse signal is generated, so that the rotation speed of the antenna is changed. In addition, a highly accurate radar image with high azimuth accuracy can be displayed.

  In the azimuth pulse signal converter according to the present invention, when the input count number based on the first azimuth pulse signal is input, the output count number is forcibly changed based on the first reference value, thereby Even when the rotation speed of the vehicle is accelerated, a highly accurate radar image with high azimuth accuracy can be displayed.

  In the azimuth pulse signal converter according to the present invention, when the input count number based on the first azimuth pulse signal is input, the second pulse time is used until the output count number reaches the first reference value. Even when the rotation speed of the antenna is accelerated by outputting the count control signal to the output counter at the time interval of the third pulse time set to a short time, the azimuth accuracy is high. Radar image can be displayed.

1 is a configuration block diagram of a radar apparatus including an azimuth pulse signal conversion apparatus according to a first embodiment. It is a block diagram of the configuration of the azimuth pulse signal converter of the first embodiment. It is a flowchart of the radar apparatus of 1st Embodiment. It is a flowchart of the azimuth | direction pulse signal converter of 1st Embodiment. It is a timing chart in the case of converting and outputting the 1st azimuth | direction pulse signal supplied from the azimuth | direction signal generation part of 1st Embodiment to the 2nd azimuth | direction pulse signal of high resolution. It is a timing chart in the case of converting and outputting the 1st azimuth | direction pulse signal supplied from the azimuth | direction signal generation part of 1st Embodiment to the 2nd azimuth | direction pulse signal of a low resolution. It is a timing chart in the case of converting and outputting the 1st azimuth | direction pulse signal supplied from the azimuth | direction signal generation part of 1st Embodiment to the 2nd azimuth | direction pulse signal of a low resolution. It is a block diagram of the configuration of the azimuth pulse signal converter of the second embodiment. It is a timing chart in the case of converting and outputting the 1st azimuth | direction pulse signal supplied from the azimuth | direction signal generation part of 2nd Embodiment to the 2nd azimuth | direction pulse signal of high resolution.

  Embodiments of the present invention will be described below with reference to the drawings.

<Configuration of First Embodiment>
FIG. 1 is a configuration block diagram of a radar apparatus 10 including an azimuth pulse signal conversion apparatus 34 according to the first embodiment.

  The radar apparatus 10 includes an antenna unit 12 and a radar processing unit 14 that displays and displays a radar image. For example, in the case of the radar device 10 mounted on a ship, the antenna unit 12 is usually provided outside the ship and the radar processing unit 14 is provided on the ship, and these are connected by a cable.

  The antenna unit 12 includes an antenna 16, a rotation driving unit 18 that rotationally drives the antenna 16, a direction signal generation unit 20 that generates a direction signal corresponding to the rotation angle of the antenna 16, and a transmission / reception unit 22. The azimuth signal generator 20 is a signal generator that generates the first azimuth pulse signal BPin and the azimuth reference signal BZ. The first azimuth pulse signal BPin is generated with N (number of pulses) pulses per rotation of the antenna 16 according to the rotation angle of the antenna 16. Further, the azimuth reference signal BZ is generated by one pulse every time the antenna 16 makes one rotation. The azimuth signal generation unit 20 can be configured by a rotary encoder, for example. The transmission / reception unit 22 is a transmission / reception unit that transmits a radar signal via the antenna 16 and receives a radar echo.

  The radar processing unit 14 includes an A / D conversion unit 24, a signal processing unit 26, a radar echo storage unit 28, a display control unit 30, a display unit 32, and an azimuth pulse signal conversion device 34. The radar processing unit 14 processes the radar echo based on the second azimuth pulse signal BPout generated by the azimuth pulse signal conversion device 34.

  The A / D converter 24 is a converter that converts the radar echo of the analog signal received by the transmitter / receiver 22 into a digital signal. The signal processing unit 26 is a processing unit that performs processing such as noise removal of radar echoes converted into digital signals and conversion of polarities of radar echoes into orthogonal coordinates. The radar echo storage unit 28 is a storage unit that stores the radar echo processed by the signal processing unit 26. The display control unit 30 is a control unit that controls display of radar echoes stored in the radar echo storage unit 28. The display unit 32 is a display unit that displays radar echoes as a raster scan image on the screen. The azimuth pulse signal converter 34 is a converter that converts the first azimuth pulse signal BPin into the second azimuth pulse signal BPout. The second azimuth pulse signal BPout is a pulse signal having a resolution D required for signal processing such as radar echo display.

  FIG. 2 is a block diagram showing the configuration of the azimuth pulse signal converter 34 according to the first embodiment. The azimuth pulse signal converter 34 includes a first pulse time generation unit 36, a second pulse time setting unit 38, an input counter 40, a count control unit 42, an output counter 44, a pulse conversion unit 46, and a failure determination. Part 48. The pulse number N of the first azimuth pulse signal BPin and the resolution D of the second azimuth pulse signal BPout are set in the second pulse time setting unit 38 and the control signal output unit 52 of the count control unit 42.

  The first pulse time generator 36 measures the pulse width from the rise of the first azimuth pulse signal BPin to the next fall, and the time from the fall of the first azimuth pulse signal BPin to the next rise, Is a pulse time generation unit that generates the time as the first pulse time T. The second pulse time setting unit 38 is a pulse time setting unit that calculates the pulse width of the second azimuth pulse signal BPout and sets it as the second pulse time t. The input counter 40 is a counter that detects and counts the rising and falling edges of the first azimuth pulse signal BPin and outputs it as an input count number Cin.

  The count control unit 42 includes a timer 50 and a control signal output unit 52. The timer 50 is a timer that counts the second pulse time t as a time count and outputs a timer pulse signal TP when the time count ends. The control signal output unit 52 is a control unit that outputs a count control signal CS that controls the output count number Cout of the second azimuth pulse signal BPout. The output counter 44 is a counter that outputs the output count number Cout of the second azimuth pulse signal BPout based on the count control signal CS. The pulse converter 46 is a converter that outputs the second azimuth pulse signal BPout when the output count number Cout is input. The failure determination unit 48 is a determination unit that determines whether or not there is a failure in the azimuth signal generation unit 20 based on the input count number Cin.

<Operation of First Embodiment>
[Overall Operation of Radar Device 10]
FIG. 3 is a flowchart of the radar apparatus 10 shown in FIG.

  The transmission / reception unit 22 generates a radar signal by driving the magnetron, and transmits the radar signal from the antenna 16 (step S1). Next, the transmission / reception unit 22 receives the radar echo reflected by the target via the antenna 16 (step S2), and outputs it to the A / D conversion unit 24 of the radar processing unit 14. The A / D converter 24 converts the radar echo, which is an analog signal, into a digital signal (step S3) and supplies the digital signal to the signal processor 26. The signal processing unit 26 performs signal processing including noise removal of radar echo based on the second azimuth pulse signal BPout supplied from the azimuth pulse signal converter 34 (step S4). The processed radar echo is stored in the radar echo storage unit 28. Next, the display control unit 30 processes the radar echo stored in the radar echo storage unit 28 based on the second azimuth pulse signal BPout, and displays the radar image on the display unit 32 (step S5).

[Processing of Directional Pulse Signal Converter 34]
Next, regarding the conversion process from the first azimuth pulse signal BPin to the second azimuth pulse signal BPout by the azimuth pulse signal converter 34, (1) the first azimuth pulse signal BPin is converted into the second azimuth pulse signal BPout with high resolution. This will be described in detail separately for the case of (2) converting the first azimuth pulse signal BPin into the second azimuth pulse signal BPout having a low resolution.

(1) When converting the first azimuth pulse signal BPin into the second azimuth pulse signal BPout with high resolution FIG. 4 is a flowchart of the azimuth pulse signal conversion device 34 of the first embodiment. FIG. 5 is a timing chart when the first azimuth pulse signal BPin supplied from the azimuth signal generation unit 20 of the first embodiment is converted into a high-resolution second azimuth pulse signal BPout and output. Here, FIG. 5A shows a case where the rotational speed of the antenna 16 is constant, FIG. 5B shows a case where the rotational speed of the antenna 16 is reduced, and FIG. It is a timing chart in case speed is accelerated. In the following description, the pulse number N of the first azimuth pulse signal BPin is 360, and the resolution D of the converted second azimuth pulse signal BPout is 2048.

  When the antenna 16 is rotationally driven by the rotation driving unit 18, the azimuth signal generation unit 20 generates the first azimuth pulse signal BPin and the azimuth reference signal BZ. In this case, the azimuth signal generation unit 20 sequentially generates the first azimuth pulse signals BPin from 0 to 359th while the antenna 16 rotates once. In addition, the azimuth signal generation unit 20 generates the azimuth reference signal BZ every time the antenna 16 rotates once.

  The bearing signal generator 20 outputs the first bearing pulse signal BPin to the first pulse time generator 36 (step S11). The first pulse time generation unit 36 generates a first pulse time T (step S12). Here, the first pulse time T is the time (pulse width) from the rise of the first azimuth pulse signal BPin measured by the first pulse time generator 36 to the next fall, and the rise of the first azimuth pulse signal BPin. It is each measured value of the time from the fall to the next rise. The first pulse time generation unit 36 outputs the generated first pulse time T to the second pulse time setting unit 38.

The second pulse time setting unit 38 calculates the pulse width of the second azimuth pulse signal BPout from the first pulse time T, the pulse number N of the first azimuth pulse signal BPin, and the resolution D of the second azimuth pulse signal BPout. The second pulse time t
t = T × N / D (1)

(Step S13). The second pulse time setting unit 38 outputs the second pulse time t calculated from the first pulse time T to the timer 50. In the following description, the second pulse times t = t0 to t9 and ta to te are time measured by the timer 50 corresponding to the first pulse times T = T0 to T9 and Ta to Te.

  Next, the azimuth signal generator 20 outputs the first azimuth pulse signal BPin to the input counter 40. The input counter 40 detects and counts the rising and falling edges of the first azimuth pulse signal BPin, and outputs the input count number Cin to the control signal output unit 52 and the failure determination unit 48 (step S14).

The control signal output unit 52 sets the first reference value Coutmax of the output count number Cout output from the output counter 44. The first reference value Coutmax is set based on the ratio between the required resolution D of the second azimuth pulse signal BPout and the pulse number N of the first azimuth pulse signal BPin, and the input count number Cin input. For example, the control signal output unit 52 calculates the first reference value Coutmax by the equation (2).
Coutmax = INT [(Cin + 1) × D / N] (2)
Note that INT [(Cin + 1) × D / N] is an integer part obtained by rounding down the decimal part of (Cin + 1) × D / N.

For example, when the input count number Cin = 0 is input to the control signal output unit 52, the first reference value Coutmax is obtained from the equation (2):
Coutmax = INT [(0 + 1) × 2048/360]
= 5
It becomes. The first reference value Coutmax is calculated and updated every time a new input count number Cin is input to the control signal output unit 52.

  The control signal output unit 52 resets the timer 50 when the output count number Cout is input. The timer 50 sets the second pulse time t input from the second pulse time setting unit 38 as a time measurement time. The timer 50 starts measuring time, and outputs the timer pulse signal TP to the control signal output unit 52 when the time has elapsed. The timer 50 repeats the process of measuring the time and outputting the timer pulse signal TP.

  When the timer pulse signal TP is input, the control signal output unit 52 outputs the count control signal CS to the output counter 44 as an increment command (step S15). The output counter 44 to which the increment command (CS) has been input increments the output count number Cout by +1 and outputs it (step S16). The output count number Cout output from the output counter 44 is input to the control signal output unit 52.

  The control signal output unit 52 compares the output count number Cout with the first reference value Coutmax every time the output count number Cout is input from the output counter 44.

  When the output count number Cout is less than the first reference value Coutmax, that is, when the relationship Cout <Coutmax is established, the control signal output unit 52 is output from the timer 50 until the next input count number Cin is input. Based on the timer pulse signal TP, the increment command (CS) is output to the output counter 44 at the time interval of the second pulse time t (step S15). In this case, for example, since the first reference value Coutmax with respect to the input count number Cin = 0 is 5, the output counter 44 is incremented at the time interval of the second pulse time t0 according to the increment command (CS). Is output (step S16, FIGS. 5A and 5B).

  When the output count number Cout is equal to the first reference value Coutmax, that is, when the relationship Cout = Coutmax is established, the control signal output unit 52 outputs the first reference value until the next input count number Cin is input. A count control signal CS for holding Coutmax as the output count number Cout is output to the output counter 44 as a hold command (step S15). In this case, the output counter 44 holds and continuously outputs the output count number Cout in accordance with the holding instruction (CS) (step S16, FIGS. 5A and 5B).

  When the input count number Cin is input to the control signal output unit 52 before the time set in the timer 50 elapses, the timer 50 receives the second second time input from the second pulse time setting unit 38. The pulse time t is reset as the time measurement time. The timer 50 continues timing according to the new timing. When the time is elapsed and the timer pulse signal TP is input from the timer 50, the control signal output unit 52 outputs an increment command (CS) to the output counter 44 (step S15). The output counter 44 increments the output count number Cout (FIG. 5A).

  The control signal output unit 52 latches the timer pulse signal TP when the timer time signal TP is input after a lapse of time before the input count number Cin is input. Then, when the input count number Cin is input, the control signal output unit 52 outputs an increment command (CS) to the output counter 44 (step S15). The output counter 44 increments the output count number Cout (FIG. 5B).

When the output count number Cout is less than the first reference value Coutmax, that is, when the relationship of Cout <Coutmax is established, the control signal output unit 52 determines that the next input count number Cin is input (3) Accordingly, the count control signal CS for forcibly changing the output count number Cout is output to the output counter 44 as a forcible change command (step S15).
Cout = Coutmax + 1 (3)
In this case, the output counter 44 forcibly changes the output count number Cout to Coutmax + 1 according to the forcible change command (CS) and outputs the result (step S16, FIG. 5C). Further, the control signal output unit 52 resets the timer 50 in accordance with the output count number Cout. The timer 50 sets the next second pulse time t input from the second pulse time setting unit 38 as a time measurement time. The timer 50 starts counting time.

  The output count number Cout output from the output counter 44 is supplied to the pulse converter 46 and the signal processor 26. Each time the pulse conversion unit 46 receives the output count number Cout, the pulse conversion unit 46 generates the second azimuth pulse signal BPout in the order of L level and H level, and outputs the second azimuth pulse signal BPout to the signal processing unit 26 (step S17). The signal processing unit 26 uses the second azimuth pulse signal BPout as a timing signal and processes the radar echo according to the azimuth corresponding to the output count number Cout. The display unit 32 displays a radar image with high azimuth accuracy according to the second azimuth pulse signal BPout and the output count number Cout.

  Next, it demonstrates concretely based on FIG.

  When the rotation speed of the antenna 16 is constant (FIG. 5A), since the pulse period of the first azimuth pulse signal BPin is also constant, each first pulse time T becomes equal, and the first pulse time T0 = T1 = T2. The control signal output unit 52 outputs an increment command (CS) for sequentially incrementing the output count number Cout to 1 to 5 to the output counter 44 at the time interval of the second pulse time t0 calculated from the first pulse time T0. . Next, when the input count number Cin = 1 is input, the control signal output unit 52 updates the first reference value Coutmax from 5 to 11. The timer 50 updates the set second pulse time t0 to the second pulse time t1. When the timer 50 counts the second pulse time t1 and the timer pulse signal TP is input from the timer 50, the control signal output unit 52 outputs an increment command (CS) for incrementing the output count number Cout to 6 by the output counter 44. Output to. The output counter 44 outputs the output count number Cout = 6. The control signal output unit 52 resets the timer 50 when the output count number Cout = 6 is output. The timer 50 sets the second pulse time t1 input from the second pulse time setting unit 38 as a time measurement time. The timer 50 starts counting time. The output counter 44 outputs the output count number Cout to the pulse conversion unit 46 and the signal processing unit 26. In this case, the output counter 44 can output the output count number Cout corresponding to the direction at the time interval of the second pulse time t corresponding to the constant rotation speed of the antenna 16.

  When the rotation speed of the antenna 16 is decelerated, the pulse period of the first azimuth pulse signal BPin becomes longer. Therefore, for example, the first pulse times T2 and T3 of the 0th first azimuth pulse signal BPin are longer than the first pulse times T0 and T1 of the 359th first azimuth pulse signal BPin (FIG. 5B). ).

  The control signal output unit 52 outputs the increment command (CS) to the output counter 44 at the time interval of the second pulse time t0 based on the timer pulse signal TP while the output count number Cout is less than the first reference value Coutmax = 5. . The output counter 44 outputs the output count number Cout of 1 to 5 that is sequentially incremented at the time interval of the second pulse time t0 according to the increment command (CS). Next, when the timer pulse signal TP is input after the output count number Cout becomes equal to the first reference value Coutmax = 5, the control signal output unit 52 outputs the timer pulse signal until the input count number Cin = 1 is input. While latching TP, a holding instruction (CS) for holding the output count number Cout = 5 is output to the output counter 44. Accordingly, the output counter 44 has a time until the input count number Cin = 1 is input to the control signal output unit 52 (time t0 + α of the second azimuth pulse signal BPout in FIG. 5B), and the output count number Cout = 5. Is output continuously.

  Next, when the input count number Cin = 1 is input, the control signal output unit 52 updates the first reference value Coutmax from 5 to 11. The control signal output unit 52 outputs an increment command (CS) to the output counter 44 in accordance with the timer pulse signal TP from the timer 50. The output counter 44 increments the output count number Cout to 6. The control signal output unit 52 resets the timer 50 when the output count number Cout is input. The timer 50 sets the second pulse time t1 input from the second pulse time setting unit 38 as a time measurement time. The timer 50 starts counting time. The output counter 44 outputs the output count number Cout = 6 to the pulse conversion unit 46 and the signal processing unit 26. In this case, even when the rotation speed of the antenna 16 is decelerated, the output counter 44 delays the time α corresponding to the decelerated rotation speed and outputs the output count number Cout = 6 corresponding to the actual direction. Can output.

  When the rotation speed of the antenna 16 is accelerated, the pulse period of the first azimuth pulse signal BPin is shortened. Therefore, for example, the first pulse times T2, T3, T4, and T5 of the 0th first azimuth pulse signal BPin are shorter than the first pulse times T0 and T1 of the 359th first azimuth pulse signal BPin (FIG. 5 (c)).

  The control signal output unit 52 outputs an increment command (CS) to the output counter 44 at the time interval of the second pulse time t0 while the output count number Cout is less than the first reference value Coutmax. The output counter 44 sequentially outputs the output count number Cout of 1 to 3 that is incremented at the time interval of the second pulse time t0 according to the increment command. Next, since the input count number Cin = 1 is input before the output count number Cout becomes equal to the first reference value Coutmax, the control signal output unit 52 updates the first reference value Coutmax from 5 to 11. The control signal output unit 52 outputs a forced change command (CS) to the output counter 44 in accordance with the input of the input count number Cin. The control signal output unit 52 resets the timer 50 in accordance with the forced change command (CS). The timer 50 sets the second pulse time t1 input from the second pulse time setting unit 38 as a time measurement time. The timer 50 starts counting time. The output counter 44 changes the output count number Cout from 3 to 6 according to the equation (3). Therefore, the output counter 44 has a time until the input count number Cin is input to the control signal output unit 52 (time t0-β of the second azimuth pulse signal BPout in FIG. 5C), and the output count number Cout = 3. Is output, and the output count number Cout = 6 is output according to the forced change command (CS). The output counter 44 outputs the output count number Cout = 6 to the pulse conversion unit 46 and the signal processing unit 26. In this case, even when the rotational speed of the antenna 16 is accelerated, the output counter 44 advances the time β corresponding to the accelerated rotational speed, and outputs the output count number Cout corresponding to the actual direction with high accuracy. Can output.

  As described above, the azimuth pulse signal conversion device 34 is configured so that the second azimuth pulse signal BPout and the output count number Cout corresponding to the actual azimuth based on the first azimuth pulse signal BPin, regardless of whether or not the rotation speed of the antenna 16 varies. Is supplied to the signal processing unit 26. And the signal processing part 26 can display the highly accurate radar image | video with high azimuth | direction precision according to the output count number Cout by using the 2nd azimuth | direction pulse signal BPout as a timing signal.

  The failure determination unit 48 compares the input count number Cin with the failure determination value, and determines whether or not the azimuth signal generation unit 20 is operating normally according to the comparison result. The failure determination value is a determination value that is set to determine whether the number of pulses of the first azimuth pulse signal BPin output from the azimuth signal generator 20 is an allowable number of pulses. In this case, the failure determination value is set based on the pulse number N of the first azimuth pulse signal BPin that the azimuth signal generation unit 20 generates per rotation of the antenna 16. For example, when the number N of pulses generated by the azimuth signal generation unit 20 is 360, the maximum value of the input count number Cin obtained when the azimuth signal generation unit 20 is operating normally is 719. Therefore, the maximum value 719 is set in the failure determination unit 48 as a failure determination value. Further, the failure determination value may be set to a value in consideration of a predetermined allowable range with respect to the maximum value 719. The input counter 40 counts the input count number Cin from when the azimuth reference signal BZ is input until the next azimuth reference signal BZ is input. The input counter 40 outputs the input count number Cin immediately before the next azimuth reference signal BZ is input to the failure determination unit 48. The failure determination unit 48 compares the previous input count number Cin with the failure determination value, and when the maximum value of the input count number Cin is not equal to the failure determination value, or the maximum value is within the allowable range of the failure determination value. If it does not enter, it can be determined that the azimuth signal generator 20 is defective, and a warning or the like can be taken.

(2) Case where First Azimuth Pulse Signal BPin is Converted to Low Resolution Second Azimuth Pulse Signal BPout FIGS. 6 and 7 show the first azimuth pulse signal BPin supplied from the azimuth signal generator 20 of the first embodiment. Is a timing chart in the case of converting to a second resolution pulse signal BPout with a low resolution and outputting it. 6A is a timing chart according to two modes when the rotational speed of the antenna 16 is constant, and FIGS. 6B and 6C are timing charts according to two modes when the rotational speed of the antenna 16 is decelerated. It is. 7A shows the case where the rotation speed of the antenna 16 is the same as that in FIG. 6A, and FIGS. 7D and 7E show the case where the rotation speed of the antenna 16 is accelerated. It is a timing chart concerning one mode. In the following description, it is assumed that the pulse number N of the first azimuth pulse signal BPin is 2048 and the resolution D of the converted second azimuth pulse signal BPout is 360.

  The first pulse time generation unit 36 generates a first pulse time T from the first azimuth pulse signal BPin and outputs the first pulse time T to the second pulse time setting unit 38. The second pulse time setting unit 38 calculates and sets the second pulse time t that is the pulse width of the second azimuth pulse signal BPout according to the equation (1), and outputs the second pulse time t to the timer 50. The input counter 40 detects and counts the first azimuth pulse signal BPin, and outputs the input count number Cin to the control signal output unit 52 of the count control unit 42.

The control signal output unit 52 is based on the ratio between the pulse number N of the first azimuth pulse signal BPin and the required resolution D of the second azimuth pulse signal BPout and the output count number Cout output from the output counter 44. A second reference value Cinmax for the input count number Cin output from the input counter 40 is set. For example, the control signal output unit 52 calculates the second reference value Cinmax by Expression (4).
Cinmax = INT [(Cout + 1) × N / D] (4)

For example, when the output count number Cout = 0 is input to the control signal output unit 52, the second reference value Cinmax is obtained from the equation (4):
Cinmax = INT [(0 + 1) × 2048/360]
= 5
It becomes. The second reference value Cinmax is calculated and updated every time a new output count number Cout is input to the control signal output unit 52.

  The control signal output unit 52 resets the timer 50 when the output count number Cout is input. The timer 50 sets the second pulse time t input from the second pulse time setting unit 38 as a time measurement time. The timer 50 starts counting time. When the next second pulse time t is input from the second pulse time setting unit 38 before the elapsed time has elapsed, the timer 50 updates the measured time to a new second pulse time t. The timer 50 continues to count the time measured from the reset time. The timer 50 outputs a timer pulse signal TP to the control signal output unit 52 when the time measured has elapsed.

  The control signal output unit 52 compares the input count number Cin with the second reference value Cinmax every time the input count number Cin is input from the input counter 40.

  When the input count number Cin is less than the second reference value Cinmax, that is, when the relationship of Cin <Cinmax is established, the control signal output unit 52 sends a holding instruction (CS) for holding the output count number Cout to the output counter 44. Output. In this case, for example, when Cinmax = 5, the output counter 44 holds Cout = 0 during Cin = 0-5.

  When the input count number Cin is equal to the second reference value Cinmax, that is, the control signal output unit 52 is Cin = Cinmax, and until the timer pulse signal TP is input from the timer 50 after the time has elapsed. During this time, a holding instruction (CS) for holding the output count number Cout is output to the output counter 44 (FIGS. 6A and 6B).

  The control signal output unit 52 outputs an increment command (CS) for incrementing the output count number Cout when the relationship of Cin = Cinmax is satisfied after the timer has elapsed and the timer pulse signal TP is input from the timer 50. Output to the counter 44. In this case, the control signal output unit 52 latches the timer pulse signal TP from the timer 50 until the relationship of Cin = Cinmax is established (FIGS. 6C and 7D). Further, when the output count number Cout is incremented, the control signal output unit 52 updates the second reference value Cinmax and resets the timer 50. The timer 50 sets the second pulse time t input from the second pulse time setting unit 38 as a time measurement time. The timer 50 starts counting time.

  The control signal output unit 52 establishes the relationship of Cin> Cinmax when the time is elapsed and the input count number Cin exceeds the second reference value Cinmax before the timer pulse signal TP is input from the timer 50. In this case, an increment instruction (CS) for incrementing the output count number Cout is output to the output counter 44 (FIG. 7 (e)).

  The output count number Cout output from the output counter 44 is supplied to the pulse converter 46 and the signal processor 26. Then, similarly to the case of converting the second azimuth pulse signal BPout to a high resolution, the display unit 32 displays a radar image with high azimuth accuracy according to the second azimuth pulse signal BPout and the output count number Cout.

  Next, it demonstrates concretely based on FIG.6 and FIG.7.

  When the rotation speed of the antenna 16 is constant (FIGS. 6A and 7A), since the pulse period of the first azimuth pulse signal BPin is also constant, the first pulse times T are equal to each other. Pulse time T0 = T1 = T2... When the timer pulse signal TP is input from the timer 50, the control signal output unit 52 increments the output count number Cout to 0 and resets the timer 50. The timer 50 sets the second pulse time t0 input from the second pulse time setting unit 38 as a time measurement time. The timer 50 starts counting time. The second pulse time t1 to t3 is sequentially input from the second pulse time setting unit 38 to the timer 50 according to the input count number Cin = 3 to 5 before the second pulse time t0 elapses. Accordingly, the timer 50 sequentially updates the time measurement time from the second pulse time t1 to the second pulse time t3 and continues the time measurement. When the input count number Cin = 5 is input, the control signal output unit 52 updates the second reference value Cinmax from 5 to 11.

  On the other hand, the timer 50 outputs a timer pulse signal TP to the control signal output unit 52 when the second pulse time t3 that is a time measurement time has elapsed. If the input count number Cin = 5, the control signal output unit 52 outputs an increment command (CS) to the output counter 44. The output counter 44 outputs the output count number Cout = 1. The control signal output unit 52 resets the timer 50 when the output count number Cout is input. The timer 50 sets the next second pulse time t4 input from the second pulse time setting unit 38 as a time measurement time. The timer 50 starts counting time. The output counter 44 outputs the incremented output count number Cout = 1 to the pulse converter 46 and the signal processor 26. In this case, the output counter 44 can output the output count number Cout corresponding to the actual azimuth at the time interval of the second pulse time t corresponding to the constant rotation speed of the antenna 16.

  If the rotational speed of the antenna 16 is decelerated at the time of Cin = Cinmax (= 5), the pulse period of the first azimuth pulse signal BPin becomes longer (FIG. 6B). Therefore, for example, the first pulse time T5 is longer than the previous first pulse time T4. When the timer pulse signal TP is output from the timer 50 after the elapse of the second pulse time t3 that is the time measurement time, the control signal output unit 52 increments the output count number Cout to 1 and resets the timer 50. In addition, the control signal output unit 52 updates the second reference value Cinmax from 5 to 11. The timer 50 sets the second pulse time t4 calculated from the first pulse time T4 before deceleration as the time measurement time. Next, the timer 50 sequentially sets the second pulse time t5 to t9 after deceleration as the timed time before the timed time elapses. Accordingly, the timer 50 sequentially updates the time measured after being reset to the second pulse times t5 to t9 and continues the time measurement. Then, the timer 50 outputs a timer pulse signal TP to the control signal output unit 52 when a second pulse time t9 that is a time measured after deceleration elapses. The control signal output unit 52 outputs an increment command (CS) to the output counter 44 when Cin = Cinmax = 11. The output counter 44 outputs the output count number Cout = 2 in accordance with the increment command (CS). In this case, even when the rotational speed of the antenna 16 is decelerated, the output counter 44 can output the output count number Cout corresponding to the actual azimuth with a delay corresponding to the decelerated rotational speed.

  Further, when the rotational speed of the antenna 16 is reduced at the time of Cin <Cinmax (= 5), the pulse period of the first azimuth pulse signal BPin becomes longer (FIG. 6C). Therefore, for example, the first pulse time T3 is longer than the previous first pulse time T2. The control signal output unit 52 latches the timer pulse signal TP when the second pulse time t2, which is a time measurement, has elapsed, and the timer pulse signal TP is output from the timer 50, and holds a hold command (CS) in the output counter 44. Is output. The output counter 44 holds the output count number Cout = 0. When Cin = Cinmax = 5, since the second pulse time t2 has already passed, the control signal output unit 52 outputs an increment command (CS) to the output counter 44. In addition, the control signal output unit 52 updates the second reference value Cinmax from 5 to 11. The timer 50 updates the measured time to the second pulse time t3 calculated from the first pulse time T3 after deceleration. Next, the timer 50 sequentially sets the second pulse times t4 to t9 after deceleration as a time count before the second pulse time t3 elapses. Therefore, the timer 50 sequentially updates the time measurement time to the second pulse times t4 to t9 and continues the time measurement. Then, the timer 50 outputs a timer pulse signal TP to the control signal output unit 52 when a second pulse time t9 that is a time measured after deceleration elapses. The control signal output unit 52 outputs an increment command (CS) to the output counter 44 when Cin = Cinmax = 11. The output counter 44 updates the output count number Cout to 2 and outputs it in accordance with the increment command (CS). In this case, even when the rotational speed of the antenna 16 is decelerated, the output counter 44 can output the output count number Cout corresponding to the actual azimuth with a delay corresponding to the decelerated rotational speed.

  Next, when the rotational speed of the antenna 16 is accelerated at the time of Cin <Cinmax (= 5), the pulse period of the first azimuth pulse signal BPin is shortened (FIG. 7 (d)). Therefore, for example, the first pulse time T2 is shorter than the previous first pulse time T1. When the second pulse time t2 calculated from the first pulse time T2 after acceleration elapses and the timer pulse signal TP is output from the timer 50, the control signal output unit 52 latches and outputs the timer pulse signal TP. A holding instruction (CS) is output to the counter 44. The output counter 44 holds the output count number Cout = 0. When Cin = Cinmax = 5, since the second pulse time t2 has already passed, the control signal output unit 52 outputs an increment command (CS) to the output counter 44. In addition, the control signal output unit 52 updates the second reference value Cinmax from 5 to 11. The timer 50 updates the time measured to the next second pulse time t3 calculated from the first pulse time T3 after acceleration. Next, the timer 50 sequentially sets the second pulse times t4 to t8 after the acceleration as timed times before the second pulse time t3 elapses. Accordingly, the timer 50 sequentially updates the time measurement time to the second pulse times t4 to t8 and continues the time measurement. Then, the timer 50 outputs a timer pulse signal TP to the control signal output unit 52 when the second pulse time t8, which is the time measured after acceleration, elapses. The control signal output unit 52 outputs an increment command (CS) to the output counter 44 when Cin = Cinmax = 11. The output counter 44 increments the output count number Cout to 2 according to the increment command (CS) and outputs the result. In this case, even when the rotational speed of the antenna 16 is accelerated, the output counter 44 can output the output count number Cout corresponding to the actual azimuth earlier by the time corresponding to the accelerated rotational speed.

  Further, when the rotational speed of the antenna 16 is accelerated at the time of Cin = Cinmax (= 5), the pulse period of the first azimuth pulse signal BPin becomes longer (FIG. 7 (e)). Therefore, for example, the first pulse time T5 is shorter than the previous first pulse time T4. In this case, the input count number Cin becomes Cin> Cinmax (= 5) before the timer pulse signal TP is output from the timer 50 after the second pulse time t4 has elapsed. The control signal output unit 52 outputs an increment command (CS) to the output counter 44. In addition, the control signal output unit 52 updates the second reference value Cinmax from 5 to 11. The output counter 44 outputs the incremented output count number Cout = 1. The control signal output unit 52 resets the timer 50 when the output count number Cout = 1 is input. The timer 50 sets the second pulse time t4 calculated from the first pulse time T4 before acceleration as the time measurement time. Next, the timer 50 sequentially sets the second pulse times t5 to t9 after acceleration as the timed time before the timed time elapses. Accordingly, the timer 50 sequentially updates the timekeeping time to the second pulse times t5 to t9 and continues the timekeeping. Then, the timer 50 outputs a timer pulse signal TP to the control signal output unit 52 when a second pulse time t9 that is a time measured after acceleration elapses. The control signal output unit 52 outputs an increment command (CS) to the output counter 44 when Cin = Cinmax = 11. The output counter 44 increments the output count number Cout to 2 according to the increment command (CS) and outputs the result. In this case, even when the rotational speed of the antenna 16 is decelerated, the output counter 44 can output the output count number Cout corresponding to the actual azimuth with a delay corresponding to the decelerated rotational speed.

<Configuration of Second Embodiment>
FIG. 8 is a configuration block diagram of the azimuth pulse signal converter 54 of the second embodiment. The same components as those in the azimuth pulse signal converter 34 shown in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The second pulse time setting unit 56 constituting the azimuth pulse signal converter 54 is a pulse time setting unit that calculates the pulse width of the second azimuth pulse signal BPout and sets it as the second pulse time t. The second pulse time setting unit 56 outputs a preset third pulse time ts to the timer 50 in addition to outputting the second pulse time t to the timer 50. The third pulse time ts is set as a sufficiently short time with respect to the change in the rotation speed of the antenna 16.

<Operation of Second Embodiment>
FIG. 9 is a timing chart when the first azimuth pulse signal BPin supplied from the azimuth signal generation unit 20 according to the second embodiment is converted into a high-resolution second azimuth pulse signal BPout and output. The second embodiment is a modification of the process when the rotational speed of the antenna 16 shown in FIG. 5C is accelerated.

  When the rotation speed of the antenna 16 is accelerated, the pulse period of the first azimuth pulse signal BPin is shortened. Therefore, for example, the first pulse times T2 and T3 of the 0th first azimuth pulse signal BPin are shorter than the first pulse times T0 and T1 of the 359th first azimuth pulse signal BPin.

  The control signal output unit 52 outputs an increment command (CS) to the output counter 44 at the time interval of the second pulse time t0 while the output count number Cout is less than the first reference value Coutmax. The output counter 44 sequentially outputs the output count number Cout of 1 to 3 that is incremented at the time interval of the second pulse time t0 according to the increment command. Next, the input count number Cin = 1 is input to the control signal output unit 52 before the output count number Cout becomes equal to the first reference value Coutmax = 5. Therefore, the control signal output unit 52 outputs a forced change command (CS) to the output counter 44. In this case, the forced change instruction (CS) is an instruction for incrementing the output count number Cout by +1 instead of changing the output count number Cout from 3 to 6 according to the expression (3) as in the first embodiment. . The output counter 44 increments the output count number Cout to 4 in accordance with the forced change command (CS). The control signal output unit 52 resets the timer 50 when the output count number Cout is incremented.

On the other hand, the second pulse time setting unit 56 determines the condition of the following expression (5) based on the output count number Cout, the input count number Cin, the resolution D, and the pulse number N.
Cout <(INT [Cin × D / N] +1) (5)
When the condition of Expression (5) is satisfied, the second pulse time setting unit 56 outputs the third pulse time ts set to a time sufficiently shorter than the second pulse time t0 to the timer 50. For example, when Cin = 1, the right side of Equation (5) is
INT [1 × 2048/360] + 1 = 6
Therefore, when the output count number Cout = 3, the condition of Expression (5) is satisfied, and the second pulse time setting unit 56 outputs the third pulse time ts to the timer 50.

The third pulse time ts can be set as follows. For example, assuming that the minimum expected value of the first pulse time T is Tmin, the third pulse time ts is
tmin = Tmin × N / D (6)
Can be set as a value smaller than the minimum expected value tmin. In this case, the minimum expected value Tmin is
Tmin = Tmax / (2 × N) (7)
Can be obtained as Tmax is the minimum time required for one rotation of the applied antenna 16, and N is the number of pulses output from the azimuth signal generation unit 20 per one rotation of the antenna 16.

The second pulse time setting unit 56 outputs the third pulse time ts to the timer 50 until the output count number Cout reaches the first reference value Coutmax according to the following equation (8).
Coutmax = INT [Cin × D / N] +1 (8)
Specifically, when Cin = 1, the second pulse time setting unit 56 outputs the third pulse time ts to the timer 50 until Cout = 6. The timer 50 sets the third pulse time ts as a time measurement time. The timer 50 starts counting time.

  When the input count number Cin = 1 is input, the control signal output unit 52 follows the timer pulse signal TP that is input from the timer 50 at the time interval of the time until the output count number Cout reaches the first reference value Coutmax. Then, a forced change command (CS) which is a count control signal is output to the output counter 44. The output counter 44 sequentially outputs the output count number Cout = 4 to 6 at the time interval of the third pulse time ts. The control signal output unit 52 resets the timer 50 when the output count number Cout is incremented. On the other hand, when the output count number Cout becomes 6, the condition of the expression (5) is not satisfied, so the second pulse time setting unit 56 switches the third pulse time ts to the second pulse time t1 and outputs it to the timer 50. To do. The timer 50 sets the second pulse time t1 as a time measurement time. The timer 50 starts counting time. In this case, the control signal output unit 52 outputs an increment command (CS) to the output counter 44 in accordance with the timer pulse signal TP input again at the time interval of the second pulse time t1.

  As described above, even when the rotation speed of the antenna 16 is accelerated, the output counter 44 converts the output count number Cout composed of the number of pulses corresponding to the number of pulses of the first azimuth pulse signal BPin to the pulse conversion unit 46 and The signal is output to the signal processing unit 26. Therefore, the signal processing unit 26 can display a radar image with high azimuth accuracy on the display unit 32.

  The present invention is not limited to the embodiment described above, and can be modified without departing from the gist of the present invention.

The azimuth pulse signal converter 34 has a first pulse time T, which is a pulse width from the rising edge of the first azimuth pulse signal BPin to the next falling edge, and from the falling edge of the first azimuth pulse signal BPin to the next rising edge. The second pulse time t of the second azimuth pulse signal BPout is obtained based on the first pulse time T which is time, and the radar echo is processed according to the output count number Cout generated at the time interval of the second pulse time t. However, the present invention is not limited to this as long as radar echoes can be processed at desired time intervals. For example, the azimuth pulse signal converter 34 obtains the pulse period of the second azimuth pulse signal BPout based on the pulse period of the first azimuth pulse signal BPin, and the radar according to the output count number Cout generated at the time interval of this pulse period. The echo may be processed. In such a case, the input counter 40 detects and counts either the rising edge or the falling edge of the first azimuth pulse signal BPin, and outputs it to the control signal output unit 52 as the input count number Cin. The first reference value Coutmax is
Coutmax = INT [(Cin × 2 + 1) × D / N] (9)
Will be calculated as

  Further, the first pulse time generation unit 36 measures the pulse width of the first azimuth pulse signal BPin and the time from the falling edge of the first azimuth pulse signal BPin to the next rising edge. The present invention is not limited to this as long as the time from the fall of the pulse signal BPin to the next rise can be generated. For example, the first pulse time generation unit 36 measures the pulse width and the period of the first azimuth pulse signal BPin, and calculates the time from the fall of the first azimuth pulse signal BPin to the next rise of these times. It may be generated as a difference.

  The second pulse time setting unit 38 sets the second pulse time t from the pulse width of the first azimuth pulse signal BPin and the time from the falling edge to the next rising edge of the first azimuth pulse signal BPin. However, the present invention is not limited to this as long as the second pulse time t can be set. For example, the second pulse time setting unit 38 determines the second pulse time t from only one of the pulse width of the first azimuth pulse signal BPin or the time from the fall of the first azimuth pulse signal BPin to the next rise. May be set.

  In addition, when the output count number Cout becomes equal to the first reference value Coutmax, the control signal output unit 52 sets the output count number Cout output from the output counter 44 based on the count control signal CS that is a holding command. However, the present invention is not limited to this as long as the output count number Cout can be held. In such a case, when the output count number Cout is equal to the first reference value Coutmax, the control signal output unit 52 temporarily stops outputting the count control signal CS to the output counter 44. The output counter 44 holds the output count number Cout until the next count control signal CS is input. For example, the output counter 44 includes a latch circuit.

Further, the control signal output unit 52 sets the first reference value Coutmax based on the equation (2). However, the present invention is not limited as long as the output count number Cout that improves the accuracy of the azimuth angle can be output. It is not limited to this. For example, the control signal output unit 52 may set the first reference value Coutmax by rounding off based on the following equation (10). In such a case, the output counter 44 can output an output count number Cout that further improves the accuracy of the azimuth angle.
Coutmax = INT [(Cin + 1) × D / N + 0.5] (10)
Note that when the first reference value Coutmax is set according to the equation (10), for example, in the above-described embodiment, when the input count number Cin = 719,
Coutmax = INT [720 × 2048/360 + 0.5]
= 4096
It becomes. Therefore, when the first reference value Coutmax based on Equation (10) is 4096, the control signal output unit 52 sets the first reference value Coutmax to 0 so that 0 ≦ Coutmax ≦ 4095.

DESCRIPTION OF SYMBOLS 10 ... Radar apparatus 12 ... Antenna part 14 ... Radar processing part 16 ... Antenna 18 ... Rotation drive part 20 ... Direction signal generation part 22 ... Transmission / reception part 24 ... A / D conversion part 26 ... Signal processing part 28 ... Radar echo storage part 30 Display control unit 32 Display units 34 and 54 Direction pulse signal converter 36 First pulse time generation unit 38 and 56 Second pulse time setting unit 40 Input counter 42 Count control unit 44 Output counter 46 Pulse conversion unit 48 ... failure determination unit 50 ... timer 52 ... control signal output unit

Claims (4)

In the azimuth pulse signal conversion device that converts the first azimuth pulse signal generated by the azimuth signal generation unit into the second azimuth pulse signal and supplies the radar processing unit that processes the radar echo received by the antenna,
A first pulse time generation unit that generates a first pulse time based on a pulse width or a pulse period of the first azimuth pulse signal;
From the first pulse time, the number of pulses of the first azimuth pulse signal per rotation of the antenna, and the resolution of the second azimuth pulse signal necessary for processing the radar echo, the second azimuth pulse signal A second pulse time setting unit for setting the second pulse time based on the pulse width or pulse period of
An input counter that outputs an input count number of the first azimuth pulse signal;
A control signal output unit for outputting a count control signal;
An output counter that outputs an output count of the second azimuth pulse signal based on the count control signal;
With
The control signal output unit is
When the resolution is greater than the pulse number, the output count number is compared with a first reference value of the output count number set based on the ratio of the resolution and the pulse number and the input count number. Based on a first processing function for outputting the count control signal to the output counter at a time interval of the second pulse time;
When the resolution is greater than the pulse number, when the input count number is input, the count control signal for forcibly changing the output count number based on the first reference value is output to the output counter. Processing functions,
When the resolution is greater than the number of pulses, a third time set to be shorter than the second pulse time until the output count reaches the first reference value when the input count is input. A third processing function for outputting the count control signal to the output counter at time intervals of a pulse time;
When the resolution is less than the number of pulses, the input count number is compared with the second reference value of the input count number set based on the ratio of the pulse number and the resolution and the output count number. Based on the fourth processing function of outputting the count control signal to the output counter at the time interval of the second pulse time, an azimuth pulse signal conversion device comprising at least one processing function. In the azimuth pulse signal converter according to claim 1,
When the resolution is greater than the number of pulses, the control signal output unit, the first reference value,
Coutmax = INT [(Cin + 1) × D / N]
Coutmax: the first reference value INT [(Cin + 1) × D / N]: an integer part of (Cin + 1) × D / N Cin: the input count number D: the resolution N: set as the number of pulses Direction pulse signal conversion device. In the azimuth pulse signal converter according to claim 1 or 2,
When the resolution is greater than the number of pulses, the control signal output unit, the output count number,
Cout = Coutmax + 1
Cout: the output count number Coutmax: an azimuth pulse signal conversion device that outputs the count control signal to be forcibly changed as the first reference value to the output counter. In the azimuth pulse signal converter according to claim 1,
If the resolution is less than the number of pulses, the control signal output unit, the second reference value,
Cinmax = INT [(Cout + 1) × N / D]
Cinmax: the second reference value INT [(Cout + 1) × N / D]: an integer part of (Cout + 1) × N / D Cout: the output count number N: the pulse number D: set as the resolution Direction pulse signal conversion device.

Images