JPS5819229B2 - Misdistance measuring device - Google Patents

Description

Detailed Description of the Invention The present invention provides a target object that utilizes the Doppler effect in waves such as radio waves, and a cannonball, flying object, or moving object (hereinafter referred to as a moving object) that is fired toward the target object.
The present invention relates to a miss distance measuring device that measures the closest distance to a.

Conventionally, misdistance measuring devices using the Doppler effect include a pulsed Doppler method, a multi-wave Doppler method, and a CW single-wave Doppler method.

In the pulse Doppler method, a carrier wave is amplitude-modulated using pulses with a precise pulse width and then radiated.

If a reflected wave returns while the pulse wave is being transmitted, the reflected wave is received and a Doppler signal is detected.

If the reflected wave cannot be received while the pulse wave is being transmitted because the distance between the target object and the moving object is long, the Doppler signal cannot be detected.

When the target object and the moving object reach a predetermined distance, Doppler signals begin to be detected.

The predetermined distance is a device-specific value related to the pulse width and is known in advance.

When the moving object passes the closest point to the target object, the Doppler frequency becomes O.

Furthermore, when the Doppler signal is generated for one period, the distance between the target object λ and the moving object becomes shorter (or longer) by − (λ is the carrier wave, which is approximately known by the wavelength).

The pulsed Doppler method depends on the distance at which the Doppler signal begins to be detected and the wave number (
or the number of cycles), and the distance between the target object and the moving object at the closest point is measured from the following equation (1) K.

MD: Miss distance D: Distance at which the Doppler signal begins to be detected n: Wave number of the Doppler signal λ: Wavelength of the carrier wave The multi-wave Doppler system simultaneously emits two carrier waves f1 and f2 whose frequency and phase are precisely controlled. , separately detect two Doppler signals generated between the target object and the moving object, perform phase detection on the other Doppler signal using one of these two Doppler signals as a reference, and measure the misdistance using the following equation (2). It is something.

MD=K・φ MD: Miss distance φ: Phase detector output: Unique constant of the device CW In the single wave Doppler system, the wave number n of the Doppler signal generated between two objects and the wave number n of the Doppler signal generated between the two objects are generated. Sets (nl, 11), (n2, t2), (with required time t)
na, t3)......(nm, tm) (where m is an integer of 4 or more) as measurement data, solve the equation for the miss distance MD (thereby finding the miss distance) .

The definition of the symbols in the above equation is ■: Relative velocity between both chest bodies at time 1 = 0 L: Time 1
Distance X between both chest bodies at time 1 = 0: Component a in the moving direction of the distance between both chest bodies at time 1 = 0: Acceleration.

In the CW single-wave Doppler method, since it is necessary to measure the wave number of the Doppler signal, the measurement must be performed continuously without interruption. There is a drawback that if the Doppler signal cannot be received during the process, the MD cannot be determined.

The present invention has an equation that falls within the range of the CW single wave Doppler method, but instead of measuring the wave number of the Doppler signal, it measures the instantaneous value of the frequency of the Doppler signal.
As a result, it is not necessary to measure the Doppler signal continuously; measurement at instantaneous intervals is sufficient.

Since continuous measurement is unnecessary, the influence of noise that enters during measurement can be reduced, and MD can be determined even if there is a period when Doppler signals cannot be received due to obstacles.

Moreover, it is a particularly effective means when measurement is carried out over a long period of time.

That is, according to the present invention, in the device for side-distorting the misdistance between two objects moving linearly at a relatively constant velocity,
A Doppler detection means that detects the Doppler phenomenon occurring between the two objects due to wavelength-type waves and outputs a Doppler signal, and the Doppler signal from the Doppler detection means is input, and the Doppler frequency f2 at time t=0, the time −△
Doppler frequency f at time t; means for measuring Doppler frequency f3 at time Δt;
, Δt and the wavelength formula used by the Doppler detection means as constants, the relative velocity between the two chest bodies as V, and the distance when the two chest bodies are closest to each other as MD, the time 1=0.
The relative velocity between both chest bodies at is V, and the above time 1=
A mis-distance measuring device characterized in that it is equipped with a calculation means having a function of solving an equation established as X, which is the component of the distance between the two chest bodies at 0 in the direction along the movement path, for MD, ■, and X. It will be done.

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

A diagram of the principle of the present invention is shown in FIG. Target object 2 is at point T,
Moving object 1 is point P.

Relative velocity V (m/s) more directly on LN in the direction of point Q
ee) performs uniform linear motion.

Point T does not have to be stationary.

Point Q is the intersection of the perpendicular line drawn to straight line LN, and Qp2=
x, QT=MD, Tpl=L1, Tp2=L2, TP
3=L3.

Assuming that the time at which the moving object passes point p2 is 1=0, let Δ be the position of the moving object seconds ago as pl, and Δ be the position of the moving object seconds later as p3.

Point p1. Measure the Doppler frequency at p2p3 and find f
When l, f2, and f3, the following equation holds true from the properties of the Doppler frequency.

By applying the Pythagorean theorem to FIG. 1, it is easy to see that the following equation holds true.

(x + △tV) 2+MD2= Lp
(2)x +MD-L2(3) (X-△tV)2+MD2=LX (4)(
2), (3) Differentiating equation (4) with respect to time t and substituting , the following equation holds true.

(X+△tv) V=L1i, 1(5)xV=L
2L2 (6) (X-△tv
) v=L3i, 3 (force (5), (6),
(Squaring both sides of the force equation, (L), (2), (3), (
4) The following equation is obtained by substituting the equation.

In equations (8), (9), αO), △t, fl, f
2 and f3 are constants obtained from Doppler signal count data, and x, -V, and MD are unknown quantities.

By solving equations (8), (9), and (10) for these unknowns, we can calculate the misdistance MD and relative velocity V.
can be requested.

The solution of MD and V can be calculated as follows, for example.

First, constants such as 0υ~(20) are replaced.

01) to (20) to find V, x, and MD.

Fig. 2 shows a block diagram of an embodiment of the present invention, and Fig. 3 shows a block diagram of an embodiment of the present invention.
A detailed block diagram of the Doppler detector 3 shown in the figure is shown.

Various types of Doppler detectors can be used as the Doppler detector 3, but in this embodiment, the simplest one is shown as an example.

In FIG. 3, a sine wave signal generated by an oscillator 13 is amplified by a power amplifier 12 and supplied to an antenna 10 via a circulator 11.

By manufacturing the circulator 11 so that two parts of the output of the power amplifier 12 leak into the detection circuit 14 as shown by the arrow 1γ, the transmitted wave and the received reflected wave are mixed in the detection circuit 14, and a beat signal is generated. is generated and detected by autodyne.

The output of the detection circuit 14 is amplified by an amplifier 15, and the S/N
In order to improve the frequency of the Doppler signal, the signal is output as a Doppler signal through a low-pass filter 16 suitable for the frequency of the Doppler signal.

The Doppler signal is input to a frequency meter 4, converted to a digital frequency, and output.

During measurement, the computer 7 uses the sample/hold circuit 5 to take in the frequency value as sample data and stores it in the computer's memory.

The sample/hold circuit is controlled as follows.

A measurement time interval tb is set in advance in the timer 6, and a signal is sent from the timer 6 to the computer 7 at each set time to start the computer 7.

The activated computer 7 gives a hold timing signal to the sample/hold circuit 5, and during this hold, the frequency and time information from the timer 6 are taken in.

Instead of the timer 6, it is also possible for a human to give the measurement time.

When the input of the Doppler signal is completed, the input of the above information to the computer 7 is stopped, and the input frequency and time information sets (fbl, tb), (fb2.2tb), (f
b3.3 tb)... is read from the memory and printed using the printing device 8.

A human judges the quality of the data and determines the reference time ktb, Δt=ltb (ktb is time information within the measured time information, a positive integer satisfying 1<k) at which 1=0, and kt
The frequency of time b is f 2 , and ktb-△ is the frequency of time f
1. Input ktb+Δ using the keyboard input device 9 with the time frequency as f3.

The computer 7 inputs fl, f2, f3, △t
Calculate the formula αυ~(24) based on the misdistance M
D. The relative velocity V is determined and printed out using the printing device 8.

In this embodiment, it is also possible for a human to specify data automatically using a computer program, and in this case, the calculation results of MD and V can be obtained relatively quickly.

In this embodiment, only the printing device 8 is considered as the output device of the computer 7, but it is also possible to output MD, V, and x information as control signals to other output devices or other devices. It is.

Furthermore, in this embodiment, a Doppler detector that uses radio waves as shown in FIG. 3 and utilizes reflected waves from a moving object is used. However, the present invention is not limited to the one shown in FIG.

That is, Doppler detectors that can be used in the present invention can be categorized by the waves used: (1) those that use radio waves, (2) those that use light, and (3) those that use sound waves. (4) Those that use radiation 1 Also classified based on the type of transmission and reception, (1) As shown in Figure 3, a Doppler detector transmits a transmitted wave and receives a reflected wave from a moving object. , which detects Doppler signals.

(2) The moving object has a receiver that receives the signal transmitted from the Doppler detector, gives it a certain frequency shift, and transmits it toward the Doppler detector, thereby generating a Doppler signal. (3) A moving object emits waves that are known in advance, and Doppler detectors detect Doppler signals by simply receiving those waves.

Also, the formats of the transmitted and received waveforms are (1) C, W, (2)
It can be divided into modulated waves.

As a Doppler detector as a component of the present invention, any type or type of Doppler detector is effective as long as it is capable of obtaining a Doppler signal.

As explained above, the mis-distance measuring device according to the present invention does not require continuous measurement, which is a disadvantage of conventional mis-distance measuring devices, and can perform sample measurements alone, and is free from noise and interruption during the measurement period. It has the effect of reducing the influence of

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the present invention in detail, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a detailed block diagram of the Doppler detector 3 shown in FIG. 2. 1...Moving object, 2...Dyemstone object, 3.
...Doppler detector, 4...Frequency meter,
5...Sample/hold circuit, 6...
・Timer, 7...Computer, 8...
・Printing device, 9...Keyboard input device, 10
...Antenna, 11... Circulator, 12... Power amplifier, 13... Oscillator, 14... Detection circuit, 15... ...Amplifier, 16...Low pass filter, 1T...
...Transmission wave leakage signal.

Claims (1)

[Claims] 1. In a device for measuring a misdistance between two objects moving in a relatively uniform linear motion, a Doppler detection means detects a Doppler phenomenon occurring between the two objects due to wavelength human waves and outputs a Doppler signal; Means for inputting the Doppler signal from the Doppler detection means and measuring Doppler frequency f2 at time 1=0, Doppler frequency at time -Δt, Doppler frequency f3 at time Δt, and the f1. Let f2, f3, Δt and the wavelength used by the Doppler detection means be constants, V be the relative velocity between the two chest bodies, MD be the distance when the two chest bodies are closest to each other, and the time be A function that solves an equation for MD, V, and x, where V is the relative velocity between the two chest bodies at 10, and X is the component of the distance between the two chest bodies in the direction along the movement path at time 1=0. What is claimed is: 1. A misdistance measuring device comprising: calculation means having the following functions.