JPS6337320B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for predicting the trajectory of the next bullet that occurs when shooting an anti-aircraft target under the influence of a tracking error of a fire control radar that occurs due to a deviation between the target and the bullet at the time of scheduled meeting. The present invention relates to a trajectory prediction device for predicting a meeting when a meeting is scheduled in order to eliminate deterioration in accuracy.

As shown in Figure 1, a bullet B fired from a gun G aiming at a flying object T that is being tracked using a fire control radar A deviates from the target T when it is scheduled to meet the target, and the bullet If B enters within the same radar antenna beam and range tracking gate R _G , it will receive reflected waves from both target T and bullet B, and due to the difference in the reflected signal level of target T and bullet B, the antenna The antenna axis is _T compared to when the tracking center axis and center of tracking distance were tracking only target T.
_B OL _T (=ε ₎ is generated. Furthermore, the center of the tracking distance moves from point P to Q.

When the bullet B passes through the antenna beam and then leaves the beam, it returns to tracking only the target T.

If an error occurs in instantaneous target tracking in the fire control radar when a meeting is scheduled, there will naturally be an error in the target speed calculated by inputting the radar information with that error, and the target speed will be calculated based on that target speed. There is also an error in the calculated firing angle, resulting in a deterioration in accuracy.

In order to eliminate these drawbacks, this invention calculates the firing angle by holding the target velocity immediately before the tracking error occurs at the time of scheduled meeting after the flight time of the bullet when firing the first bullet has elapsed, and calculates the firing angle of the next bullet. This is to improve accuracy. FIG. 2 shows a main configuration diagram of a method for predicting the trajectory of the next bullet according to the present invention.

In FIG. 2, A is a fire control radar device, G is a gun, 1 is a first prediction filter that calculates a target position prediction vector and a velocity smoothing vector, and 2 is a control signal MS that is the output of a filter switching circuit 7, which will be described later. At the time when the input control signal MS switches to the ``SET'' state, the second prediction filter 1 inputs the target velocity smoothed vector which is the output of the first prediction filter 1, holds the value, and calculates the target position prediction vector. The predictive filter 3 switches the first,
A switch 4 switches between the predicted target position vector and velocity smoothed vector which are the outputs of the second predictive filters 1 and 2. 4 is a switch that inputs the predicted target position vector and the smoothed velocity vector to vector the predicted hit point of the bullet. This is a trajectory calculation device that calculates the firing angle.
In equation (1) above, X _f(o) is the predicted hit point vector, X^
(n) is the predicted target position vector, X〓(n) is the smoothed target velocity vector, and T _f(o) is the bullet's flight time. 5 is a launch control circuit that controls launch start/end based on the operator's instruction OS; 6 is a launch control circuit 5;
Input the firing _start signal GS, which is _the output of 7 is the first shot meeting scheduled time detection signal CS which is the output of the first shot meeting scheduled time detection circuit 6 and the output of the launch control circuit 5. Input firing end signal GE and first bullet meeting scheduled time detection signal CS
a filter switching circuit 8 having a function of switching to the second predictive filter 2 from the input point of time to a time point of inputting the firing end signal GE, and a function of switching to the first predictive filter 1 after the input of the firing end signal; is a gun controller which inputs the firing angle which is the output of the trajectory calculation device 4 and controls the direction of the gun (not shown).

Note that the characteristics of the first and second prediction filters 1 and 2 will be explained below. Both filters 1 and 2 are first-order predictors.

The first filter 1 is a digital filter constructed using the following formula.

Further, the second filter 2 is a digital filter configured by the following formula and holds the velocity vector.

However, X(n): target observation position vector X〓 ₁ (n), X〓 ₂ (n): target position smoothed vector of prediction filters ₁ and ₂ at time n ): Prediction filter at time n Target position prediction vector X〓 ₁ (n), X〓 ₂ (n): Prediction filter at time n Target speed smooth vector α ₁ (n), α ₂ (n): Prediction at time n Filter Position vector smoothing gain β ₁ (n): Velocity vector smoothing gain Δt of prediction filter 1 at time n: Sampling time n: 0, 1, 2, 3,... m: Filter switching from prediction filter 1 to prediction filter 2 Show time.

Next, the operation of the device for predicting the trajectory of the next bullet according to the present invention will be explained with reference to the block diagram shown in FIG.

First, the radar information (target distance, elevation angle, azimuth angle) is sent to the first prediction filter 1 by the fire control radar A.
is given as the target position prediction vector X ₁ (n),
_Velocity vector Ru. At the same time, the flight time required for the bullet to hit the target
T _f is calculated by the trajectory calculation device 4, and the flight time T _f is sent to the first bullet scheduled time detection circuit 6 in synchronization with the first bullet firing start signal output from the launch control circuit 5 according to the operator's command. Given this, the first bullet encounter time detection circuit 6 calculates the flight time T _f of the first bullet calculated by the trajectory calculation device 4 based on the atmospheric conditions on that day, the initial velocity of the bullet, etc., as the actual trajectory outside the gun, and the actual trajectory. There will be some difference between the first bullet's flight time T _fp and the first bullet's flight time.
In addition, actually the target T and bullet B as shown in Fig.
In order to avoid the influence of the tracking disturbance caused by the bullet as described above, when the meeting is scheduled, the duration of target tracking should be as long as possible, and the expected bullet flight time just before target T and bullet B will enter the same antenna beam. When the time (T _f −a) seconds is calculated and the value (T _f −a) seconds is subtracted for each millisecond time, and the time when the value becomes zero or negative is detected, the detection circuit 6 detects a bullet. It outputs a set signal that generates the expected timing just before entering the same antenna beam when it is scheduled to meet the target, and when it is given to the filter switching circuit 6, the filter switching circuit 6 outputs a set signal that switches to the second predictive filter 2. The switch 3 is switched to the second predictive filter 2 side by the set signal.
At the same time, the second prediction filter 2 inputs the target speed smoothing vector from the first prediction filter 1,
The value is held and radar information is input from the fire control radar A to calculate a target position prediction vector. When the target position prediction vector and velocity vector, which are the output of the second prediction filter 2 as a result of the calculation, are given to the trajectory calculation device 4 via the switch 3, the firing angle is calculated by the trajectory calculation device 4 in the same manner as above. The direction of the gun is controlled by a gun controller 8.
Further, in accordance with the operator's command, the firing control circuit 5 outputs a firing end signal and the signal is applied to the filter switching circuit 7, and the filter switching circuit 7 outputs a reset signal for switching to the first predictive filter. is switched to the first prediction filter side, and the output of the filter to be given to the trajectory calculation device 4 is selected.

As explained above, in the trajectory prediction method of the next bullet according to the present invention, the first bullet encounter time detection circuit 6 and the filter switching circuit 7 are added to the conventional trajectory prediction device, and the tracking error caused by the bullet on the radar at the time of the scheduled encounter is added. It is possible to remove the influence of the above, provide stable trajectory prediction accuracy, and increase hit accuracy.

[Brief explanation of drawings]

Figure 1 shows a situation where a target tracking error occurs when a bullet approaches the target and both enter the same antenna beam and tracking gate, and the bullet passes with a certain deviation from the target. The figure is a block diagram showing an embodiment of the invention. In the figure, A is a fire control radar device, C is a trajectory calculator, G is a gun, 1 and 2 are prediction filters, 3 is a switch, 4 is a trajectory calculation device, 5 is a launch control circuit,
Reference numeral 6 is a first bullet encounter time detection circuit, 7 is a filter switching circuit, and 8 is a gun controller.

Claims (1)

[Claims] 1 Input the radar information from the fire control radar and the fire control radar above, and calculate the target position prediction vector,
A first prediction filter that calculates a target velocity smoothing vector, radar information from the fire control radar, and a target velocity smoothing vector output from the first prediction filter are input, and the value of the target velocity smoothing vector is held. a second prediction filter that calculates a target position prediction vector;
and a switch that switches and connects the output end of the second prediction filter, and a trajectory calculation that inputs the outputs of the first and second prediction filters through the switch to calculate the firing angle and bullet flight time T _f . a gun controller that controls the direction of the gun based on the output of the trajectory calculation device; a firing control circuit that generates firing start/end signals under instructions from an operator; and a firing start from the firing control circuit. Input the signal and the bullet flight time T _f calculated by the above-mentioned trajectory calculation device, and set the set signal when the expected bullet flight time T _f -a (a is a small positive value) has elapsed from the time when the above-mentioned firing start signal was input. The switch is connected to the output terminal of the second predictive filter based on the set signal from the first bullet meeting scheduled time detection circuit that generates the first bullet meeting scheduled time detection circuit and the first bullet meeting scheduled time detecting circuit, and the second predictive filter is operated. and a filter switching circuit that generates a signal to switch and connect the switch to the output terminal of the first prediction filter in response to the firing end signal, and the filter switching circuit generates a signal to switch and connect the switch to the output terminal of the first prediction filter in response to the firing end signal, and the filter switching circuit generates a signal to switch and connect the switch to the output terminal of the first predictive filter. After detecting the scheduled meeting time of the first bullet, the target velocity vector is held until the firing of the next bullet is completed, and the trajectory of the next bullet is predicted by calculating the scheduled meeting time of the next bullet. Features a trajectory prediction device for the next bullet.