JPS58135965A - Measuring device for initial speed - Google Patents

Abstract

PURPOSE:To sharply reduce the probability of the generation of erroneous operation, by providing a plurality of actual-speed measuring positions near to and remote from an artillery piece for one shelling, by applying operational processing to actual speed measured at said positions in plural for evaluation, and by calculating an intial speed by using only the actual speed judged to be normal. CONSTITUTION:A microwave, which is a continuous wave, is emitted to a shell, and a reflected wave therefrom is received by an antenna and transduced into a Doppler pulse, which is sent to a measuring gate generator 8. The measuring gate generator 8 generates a measuring gate pulse for measuring a plurality of actual speed values and opens a measuring gate 9 to give a Doppler pulse to a Doppler frequency measuring circuit 11. By using a clock pulse, the period of the Doppler pulse is measured, and the value thereof is given to a microcomputer 12. The microcomputer 12 performs evaluation for the actual speed values in plural and selects normal values theefrom. Thereafter, a speed at the position of a start pulse is calculted from the relations of the selected actual speed values with the positions from the start pulse whereat each of the actual values is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an initial velocity measuring device for measuring the initial velocity of a moving object such as a cannonball fired from a gun or the like. The following explanation will be given using a cannonball as an example of a moving object.

Conventionally, there is a device that measures the initial velocity of a shell based on a Doppler frequency signal that corresponds to the velocity of the shell.

The velocity of the shell after a certain period of time has elapsed after firing the shell (
A method was used to calculate the initial velocity of the shell based on the measured velocity.

However, there are problems with this method.

In other words, it is very difficult to determine where to measure the current speed.

If the velocity measurement position is set near the gun, the blast wave during firing,
There is a greater possibility that the device will not operate properly due to the effects of shock, etc. On the other hand, if the velocity measurement position is set far away, the amount of reflected signals from the shells will be very small.
Similarly, there is a large possibility that the device will not operate properly.

This invention aims to improve these problems, and its feature is that the current speed measurement position for one shot is determined from the vicinity of the gun where the amount of reflected signals from the shell is large, and from the influence of blast waves, impact, etc. The idea is to set up multiple points far away where it is difficult to be affected, perform arithmetic processing on the measured speed at the multiple points, evaluate it, calculate the initial speed using only the speed determined to be normal, and display it as one.

FIG. 1 is an embodiment for explaining the present invention.

In the configuration shown in Fig. 1, the continuous wave microwave radiated from the antenna (3) via the microwave oscillator (11) and the chelator (2) is irradiated onto the shell.
The reflected wave is received by an antenna (3). This received signal differs from the transmitting frequency by a Doppler frequency corresponding to the velocity of the shell.

The above received signal is passed through the circulator (2) to the mixer (
4) is given.

Since a part of the transmission signal is supplied to the mixer (4) using the leakage result of the circulator (2), the mixer (4) performs homodyne detection of both signals and directly detects the Doppler frequency. It will be detected.

This signal is amplified to the required level by an amplifier (5).

Note that since the approximate value of the velocity of the shell is known in advance, a bandpass filter (6) is provided at the next stage of the amplifier (5) in order to pass the corresponding Doppler frequency.

This filter (6) not only passes the above-mentioned Doppler frequency, but also has the function of suppressing unnecessary noise.

The amplified continuous wave Doppler signal Fi shown in FIG. 2(-) is converted into the Doppler pulse shown in FIG. ).

The measurement gate generator (8) is a microcomputer (2)
It generates measurement gate pulses to measure multiple speed values. This situation is shown in Figure 2 (C1).

Further, when the microcomputer α2 generates the measurement gate pulse, the measurement gate pulse generation position (speed measurement position) is controlled using the start pulse shown in FIG. 2(C) as a reference.

The measurement gate pulse opens the measurement gate (9) and provides the Doppler pulse to the Doppler frequency measurement circuit αυ.

The Doppler frequency measurement circuit (11) uses the clock pulse generator α for Doppler frequency measurement generated by the clock pulse generator α shown in FIG.
The period (frequency) of the Doppler pulse is measured using the clock pulse indicated by dl, and the value is given to the microcomputer a.

The microcomputer a-yu calculates, for multiple speed values,
6 Whether or not the values are moving with uniform acceleration.

After evaluating whether or not there is a significant variation in the values before and after, and selecting a normal speed value, the selected multiple speed values and the start pulse that measured each speed value. The velocity at the position of the start pulse is calculated using a linear approximation formula or a quadratic curve approximation formula from the relationship with the position from .

Here, if the position of the start pulse is the muzzle, the calculated speed is the initial speed.

The display (13 displays the initial speed.

As described in detail above, the present invention provides multiple speed measurement positions for one shot, from near the gun, where the amount of reflected signals from the shell is large, to far away, where it is less likely to be affected by blast waves, impact, etc. As a result, large shells with a large blast and impact are automatically measured at a distance because they have a large amount of reflected signals, and small shells with small reflected signals are automatically measured at a distance because their blast and impact are small. Since it will be measured near the gun,
The probability of occurrence of malfunction of the device is significant. Figure 1 is a block diagram showing an embodiment of the initial velocity measuring device invented by Jin, and Figure 2 is a waveform diagram showing an embodiment of this invention. Oscillator, (2) is a circulator, (3) is an antenna, (4) is a mixer, (5) is an amplifier, (6) is a bandpass filter, (7) is a waveform conversion circuit, (8) is a measurement gate generator, (9) is a measurement device), Ql is a clock pulse generator for 12-frequency foot measurement, and the unit is a Doppler frequency measurement circuit.

The ring is a microcomputer, al is a display, (a) is a Doppler signal, (b) is a top 2 pulse tle; jx
Terthals and measurement gate pulses, (d) is the clock pulse for Doppler frequency measurement, and (.) is the Doppler frequency measurement situation.

Agent Nobu Kuzuno - Figure 1

Claims (1)

[Claims] In an initial velocity measuring device that measures the initial velocity of a moving object such as a cannonball based on a Doppler frequency signal corresponding to the speed of the moving object such as a cannonball, Means for measuring the speed a plurality of times, and evaluating whether each of the plurality of measured speeds of the object to be measured is normal. An apparatus for measuring the initial velocity of a moving object such as a cannonball, comprising means for calculating the initial velocity using only the velocity of an object to be measured that has been determined to be normal, and means for displaying the calculated result.