JP3000145B1 - Self-position detection circuit - Google Patents

Abstract

An object of the present invention is to provide a self-position detection circuit that can be reduced in size by eliminating a mechanical drive system and an electronic scanning antenna, and can be built in an object. SOLUTION: A control circuit unit 2 for outputting a control signal for frequency modulation, a microwave capable of transmitting and receiving a radio wave frequency-modulated by a signal of the control circuit unit 2, and outputting a beat signal based on a transmission signal and a reception signal A first circuit which outputs a relative velocity component, a distance component, and a relative angle component by digital signal processing from a beat signal of the microwave circuit unit 1; and a first object and a second object which move relatively. Is built in the first object so as to detect the relative positional relationship of the object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a first relative moving device.
Angle component between the first object (self) and the second object (partner)
And then emit radio waves from the first object is reflected by the second object, by receiving the reflected wave and in the first object, is detected by utilizing the frequency difference of the received radio wave transmission waves And a self-position detecting circuit.

[0002]

2. Description of the Related Art A position detecting method using an absolute coordinate system is generally used for detecting a position between relatively moving objects.
FIG. 8 shows an example of a position detection method using an absolute coordinate system.
In this figure, object A (speed Vo) and object B (speed V
t) is monitored by the ground radar station 30. The terrestrial radar station 30 can clarify the exact absolute positional relationship. Further, in an aircraft or a ship equipped with radar, it is possible to detect a position between objects that move relatively without specifying a place or an area.

[0003]

However, in the above-mentioned conventional method, a large-scale system, a mechanical drive system, and an electronic scanning antenna are required to detect the position between objects that move relatively.

[0004] In view of the above, the present invention can reduce the size by eliminating the need for a mechanical drive system and an electronic scanning antenna.
An object of the present invention is to provide a self-position detection circuit that can be built in an object.

[0005] Other objects and novel features of the present invention will be clarified in embodiments described later.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for moving a first object and a second object which move relative to each other.
A self-position detection circuit built in the first object so as to detect a relative angle , a control circuit unit for outputting a control signal for frequency modulation, and a radio wave frequency-modulated by a signal of the control circuit unit. A microwave circuit unit capable of transmitting and receiving and outputting a beat signal based on a transmission signal and a reception signal, and obtaining a change in Doppler frequency with respect to a time change by digital signal processing from the beat signal of the microwave circuit unit
And an arithmetic circuit for outputting a relative angle component .

In the arithmetic circuit section, the beat signal from the microwave circuit section may be converted from analog to digital, and the digital signal processing may be performed by a program operation using a DSP (Digital Signal Processor).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a self-position detecting circuit according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of a self-position detecting circuit according to the present invention. In this figure, object A
The microwave circuit unit 1, the control circuit unit 2, and the arithmetic circuit unit 3 are built in (self), and a control signal for frequency modulation generated by the control circuit unit 2 is input to the microwave circuit unit 1, A frequency-modulated radio wave can be radiated into space via an antenna (antenna) of the circuit unit 1.
In addition, as described later with reference to FIG.
If (the other party) is present, a part of the radiated radio wave is input to the microwave circuit unit 1 as a reflected radio wave. At this time, the microwave circuit unit 1 transmits a desired beat signal based on the transmitted radio wave and the received radio wave. Output to the arithmetic circuit unit 3. The arithmetic circuit unit 3 outputs a relative speed component (output 1), a distance component (output 2), and a relative angle component (output 3) by a circuit including a DSP or the like.

FIG. 2 is a specific block diagram of the microwave circuit unit 1. In this figure, a frequency modulation control signal (for example, a triangular wave having a constant period) from the control circuit unit 2 is supplied to a voltage control oscillator 6 (VCO; Voltage Control Oscillato).
The voltage-frequency conversion is performed by r). The frequency-converted signal is distributed to the LO signal and the RE signal by the coupler 5, and the LO signal is radiated to the space via the circulator 4 by the transmitting / receiving antenna (antenna) 15 as a radio wave (a carrier whose frequency is modulated). You. The RE signal is
The data is directly input to the mixer 7. Further, the transmitting / receiving antenna 15 receives a reflected signal from the target (object B), and the reflected signal is input to the mixer 7 again via the circulator 4. The mixer 7 receives the input of the RE signal and the LO signal and outputs an IF signal. The IF signal is superimposed on the sum of the frequencies of the RE signal and the LO signal, which is a received signal (reflected signal), a frequency difference, and a modulated wave (including harmonic components). The modulated wave component is removed by limiting, and a desired beat signal is output.

FIG. 3 is a specific block diagram of the arithmetic circuit unit 3. In the figure, the beat signal output from the microwave circuit unit 1 is converted from analog to digital by an A / D converter 9 and is converted into a DSP (Digital Signal Process).
r) Output to 11 In DSP11, an arithmetic program programmed in advance (for example, equations (1) to
(5) The ROM 10 (Read Only Me)
mory), and performs an operation according to the program to calculate the relative velocity component, the distance component, and the relative angle component into D.
The digital-to-analog converter 12 converts the digital-to-analog data and outputs it.

As a result, self-position detection becomes possible without constructing the conventional large-scale position detection system shown in FIG. Further, by configuring the arithmetic circuit unit 3 using a DSP, the size of the arithmetic circuit unit 3 can be reduced.

FIG. 4 shows a self-position detecting circuit 20 according to the embodiment.
FIG. 9 is a schematic diagram illustrating a self-position detecting operation using the. In this figure, the relative speed V between the object A (self) and the target object B (partner) is represented by V = Vt + Vo (1) (where Vt: speed of the object B, Vo: speed of the object A). Is done. At this time, it is clear that the amount corresponding to the relative velocity V is detected by the Doppler effect from the transmission wave and the reception wave of the radio wave radiated from the self-position detection circuit 20 built in the object A. Is represented by the following relationship: fd = α · V (2) Here, α is a proportionality constant.

The distance R in FIG. 4 is determined from the radar equation as follows: fr = 4 ・ Δf ・ fm ・ R / c (3) where beat frequency fr is used because a frequency-modulated radar is used. be able to. Here, Δf is the modulation repetition frequency (repetition frequency of the triangular wave in FIG. 5), fm is the modulation frequency (frequency changed by the modulation of the VCO), and c is the speed of light.

FIG. 5 schematically shows the above relationship (fr, fd). In this figure, the use of a triangular wave as a modulating wave has the effect of minimizing the frequency dispersion of the beat frequency by using the straight line portion of the triangular wave. In addition, the beat signal is repeated in density in synchronization with the repetition period of the modulated wave. When this is subjected to FFT (Fast Fourier Transform) processing, fr-fd and fr + fd are obtained.
d and the distance component fr are obtained.

FIG. 6 schematically shows a method of detecting the relative angle Δθ. In this figure, object A and object B
Performs relative motion, the velocity component of the object A is set to 0, and the velocity component can be schematically added to the object B. Then, the vertical angle θ when the object A first detects the object B
1 is represented by the following equation by Doppler equation: θ1 = sin ⁻¹ (λ · fdl / 2V) (4) Here, λ is the wavelength of the radio wave. Further, the vertical angle θ2 after the time t seconds is represented by θ2 = sin ⁻¹ (λ · fd2 / 2V) (5) as described above. Therefore, if the difference between θ1 and θ2 is obtained, the relative angle can be theoretically obtained. Actually, since the change in the above equation is fdl when the object B is detected and fd2 after t seconds, Δθ is obtained by detecting a change in the Doppler frequency fd with respect to a change in time t. FIG. 8 shows time t and f
The relationship of r + fd is shown, in which the Doppler frequency fd decreases with time. When the objects A and B are moving on a straight line connecting the objects A and B, the rate of change of the Doppler frequency fd is zero, and the smaller the rate of change, the closer the objects A and B are to the direct opposition. It can be determined that it is moving relatively.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and that various modifications and changes can be made within the scope of the claims. There will be.

[0018]

As described above, according to the self-position detecting circuit according to the present invention, the first object and the second object can be detected without constructing a large-scale system for measuring accurate absolute coordinates. There is an effect that the relative angle component can be independently determined on the first object side.

[Brief description of the drawings]

FIG. 1 is a basic block diagram showing an embodiment of a self-position detection circuit according to the present invention.

FIG. 2 is a block diagram of a microwave circuit unit in the self-position detection circuit.

FIG. 3 is a block diagram of an arithmetic circuit unit in the self-position detection circuit.

FIG. 4 is an explanatory diagram of a position detection method using a self-position detection circuit.

FIG. 5 is a schematic diagram of a method of detecting a relative speed component fd and a distance component fr.

FIG. 6 is an explanatory diagram of a relative angle detection method.

FIG. 7 is an explanatory diagram of a calculation method of Δθ.

FIG. 8 is an explanatory diagram of a conventional position detection method using an absolute coordinate system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 microwave circuit section 2 control circuit section 3 arithmetic circuit section 4 circulator 5 coupler 6 VCO 7 mixer 8 BPF 9 A / D converter 10 ROM 11 DSP 12 D / A converter 15 transmitting / receiving antenna 20 self-position detecting circuit 30 ground radar Station

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-9-222474 (JP, A) JP-A-9-15477 (JP, A) JP-A-9-311186 (JP, A) JP-A-9-222 101361 (JP, A) JP-A-9-43344 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01S ⁷ /00-7/42 G01S 13/00-13/95

Claims (2)

(57) [Claims] A first object and a second object which move relative to each other;
A self-position detecting circuit built in the first object so as to detect a relative angle , wherein the control circuit outputs a control signal for frequency modulation;
該制can send and receive radio wave frequency-modulated by a signal control circuit portion, Doppler microwave circuit section for outputting a beat signal by the transmitted and received signals, with respect to time changed by the digital signal processing from the beat signal of the microwave circuit section
A self-position detection circuit, comprising: a calculation circuit section that outputs a relative angle component by calculating a change in the frequency . 2. The arithmetic circuit unit according to claim 1, wherein the beat signal from the microwave circuit unit is converted from analog to digital, and the digital signal processing is performed by a program operation using a DSP (Digital Signal Processor). Self-position detection circuit.