JPS6336471B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mobile body position detection method using guided radio.

It has long been known to use guided radio to detect the position of moving objects running along a fixed track, such as railway vehicles and various industrial transport engines, and various methods have been proposed to date. has been done.

On the other hand, there are cases in which it is essential for automatic driving systems for mobile objects to divide the traveling section of a moving object into certain small sections and constantly detect on the moving object which section the moving object is in. This is a particularly important problem in systems in which a computer is mounted on a moving object and the moving object automatically moves according to its built-in program.

FIG. 1 shows an example of a conventionally known moving object position detection method to meet this demand.

Reference numerals 21, 22, 23, 24, and 25 are paired conductors laid along the traveling path of the moving object, and 26 is an antenna (frame-shaped coil) mounted on the moving object.
The paired conductors 21 to 25 constitute an inductive radio line, and the paired conductors 21 are laid in parallel over the entire length of the line so that there are no intersections. The pair conductor 22 has an intersection C ₂ at the point where the total line length is divided into two, the pair conductor 23 has an intersection C ₃ at the point where the total line length is divided into four, and similarly the pair conductors 24 and 25
will be laid with intersections _C4 and _C5 at the points where the line is divided into 8 and 16 sections, respectively.

Here, a high frequency current (50~
When a current (200 kHz) is applied, a voltage is induced in each of the pair conductors 21 to 25 due to electromagnetic induction.

Now, the voltage induced in the pair conductor 21 and the pair conductor 2
Considering the voltage induced in C 2, the phase difference between the two voltages changes by 180° with the crossing point C ₂ as the border, and the phase difference between the voltage on the pair conductor 21 and the voltage on the pair conductor 22 is By measuring, it is possible to know whether the moving object is on the left or right side of the intersection _C2 .
Similarly, by comparing the phase of the voltage induced in each of the paired conductors 23, 24, and 25 with the phase of the voltage induced in the paired conductor 21, segmented position information of the moving body can be obtained.

However, the above method has the following problems.

(1) Each pair conductor 22, 23, 24, 25 has only 1 bit of position information, and
Since the pair of conductors 21 for setting the reference phase is required, in order to obtain a large amount of position information, the number of conductors composing the guided radio line inevitably increases, leading to an increase in cost.

(2) The pair conductor 21 has no intersection, and the pair conductor 2
2 and 23, which are in charge of upper address information, have larger intervals between intersections, which lacks the ability to cancel out ambient noise, and also increases the crosstalk voltage between each pair of conductors, resulting in unstable operation. This may cause measurement errors.

The present invention solves the problems of the prior art described above, and provides a moving object position detection method that can increase the amount of position information given per conductor and is less susceptible to the effects of ambient noise and crosstalk. This is the purpose.

The moving object position detection method of the present invention is characterized in that three conductors are arranged to form a periodic structure in which a sinusoidal inter-conductor voltage is induced between each conductor as the position of the moving object changes, and A guided radio track in which the above-mentioned periodic structure is different for each small section obtained by dividing the running section of the body into a plurality of sections is laid along the moving body running path, and on the other hand, a predetermined line is placed on the moving body in the longitudinal direction of the track. By arranging two antennas at a distance and exciting the two antennas with signals of different frequencies f _a and f _b , a voltage is induced between the conductors of the guided radio line, and the voltage induced between each conductor is Selectively receive the voltage at the terminal of the inductive radio line, find the square value of the envelope amplitude of each conductor voltage for each frequency fa _and f _b , and calculate the difference between these square values. By modulating a new carrier wave with the thus obtained voltage, the voltage V ^(a) _u at the frequency f _a ,
Voltage V ^(b) _u for V ^(a) _v , V ^(a) _w and frequency f _b ,
Obtain V ^(b) _v and V ^(b) _w , and define the positive sequence voltage V _pa and negative sequence voltage _{V oa for V (a) u , V (a) v , and V (a) w} ^using _the ^{following equations} _. , V _pa =V ^(a) _u +e ^-j2 〓 ^/3 V ^(a) _v +e ^j2 〓 ^/3 V ^(a) _w V _oa =V ^(a) _u +e ^j2 〓 ^/3 V ^(a) _v +e ^{- j2} 〓 ^/3 V ^(a) _wAlso , the positive sequence voltage V _pb for V ^(b) _u , V ^(b) _v , V ^(b) _w
When the negative-sequence voltage V _ob is defined by the following formula, V _pb = V ^(b) _u +e ^-j2 〓 ^/3 V ^(b) _v +e ^j2 〓 ^/3 V ^(b) _wTwo positive-sequence voltages V _pa This feature is characterized in that the small section in which the moving object is present can be determined by determining the phase difference between V _pb and V pb or the phase difference between two opposite phase voltages V _oa and V _ob .

Hereinafter, the present invention will be explained in detail with reference to FIGS. 2 to 4.

In Fig. 2, 1, 2, 3 are guided radio lines 4.
, and 5 _a and 5 _b are mobile body-mounted antennas arranged at intervals of Δz in the longitudinal direction of the line 4 .

Each of the conductors 1, 2, and 3 is bent into a waveform shape with a period P on a plane, and is laid out with a shift of P/3 from each other, so that the line 4 has a repeating structure with a period P. Therefore, when a high frequency current (50 to 200kHz) is applied to the antennas _5a and _5b , a sinusoidal voltage is induced between each conductor 1, 2, and 3 as the moving object moves. Become.

Now, the antennas 5 _a and 5 _b are excited with signals of different frequencies fa and f _{b ,} respectively, and the starting end of the line 4 (z=
Consider the case where signals of frequencies f _a and f _b are selectively received at 0).

The voltages induced between conductors 1 and 2, between 2 and 3, and between ₃ and ₁ are expressed as V ^(a) ₁₂ and
Assuming V ^(a) ₂₃ , V ^(a) ₃₁ and V ^(b) ₁₂ , V ^(b) ₂₃ , V ^(b) ₃₁ , these can be expressed as in the following equation.

V ^(a) ₁₂ =k _1a cos(2π/P)z V ^(a) ₂₃ =k _1a cos(2π/P){z+(1/3)P} =k _1a cos{(2π/P)z+( 2π/3)} V ^(a) ₃₁ =k _1a cos(2π/P){z+(2/3)P} =k _1a cos{(2π/P)z−(2π/3)} …(1) V ^(b) ₁₂ = k _1b cos (2π/P) (z + Δz) V ^(b) ₂₃ = k _1b cos (2π/P) {(z + Δz) + (2π/3
)} V ^(b) ₃₁ =k _1b cos(2π/P) {(z+Δz)−(2π/3
)} ...(2) Note that k _1a and k _1b are constants determined by the shapes, dimensions, frequencies, etc. of the antennas 5 _a and 5 _b and the line 4.

Now, if we linearly detect each voltage V ^(a) ₁₂ , V ^(a) ₂₃ , and V ^(a) ₃₁ to find the absolute value of its envelope, and then find its square value, we get the following.

|V ^(a) ₁₂ | ² =k ² _1a cos ² (2π/P)z = (1/2)k ² _1a [1+cos(4π/P)z] |V ^(a) ₂₃ | ² =k ² _1a cos ² {(2π/P)z + (2π/3)} (1/2)k ² _1a [1+cos{(4π/P)z −(2π/3}] |V ^(a) ₃₁ | ² = k ² _1a cos ² {(2π/P)z−(2π/3)
} = (1/2) k ² _1a [1 + cos {(4π/P)z + (2π/3}] …(3) Then, V ^(a) _eu = k _2a (|V ^(a) ₁₂ | ² − ｜V ^(a) ₂₃ ｜ ² ) V ^(a) _ev = k _2a (｜V ^(a) ₂₃ ｜ ² −｜V ^(a) ₃₁ ｜ ² ) V ^(a) _ew = k _2a (｜V ^(a) ₃₁ | ² − | V ^(a) ₁₃ | ² )…Define V ^(a) _eu , V ^(a) _ev , and V ^(a) _ew respectively by (4), and (3
By substituting the equation ) into the equation (4), the following equation is obtained.
Note that k _2a is a constant.

V ^(a) _eu = (√3/2)k ² _1a k _2a・cos {(4π/P)z + (π/6)} V ^(a) _ev = (√3/2)k ² _1a k _2a・cos{(4π/P)z +(π/6)−(2π/3)} V ^(a) _ew = (√3/2)k ² _1a k _2a・cos{(4π/P)z +( π/6) + (2π/3)} …(5) Here, a new carrier wave is created by V ^(a) _eu , V ^(a) _ev , and V ^(a) _ew
e ^j 〓′ ^t and transform them into V ^(a) _u , V ^(a) _v , V ^(a
) _w
Then, the following formula is obtained.

(√3/2)k ² _1a k _2a・cos {(4π/P)z + (π/6)}・e ^j 〓′ ^t V ^(a) _v = (√3/2)k ² _1a k _2a・cos {(4π/P)z + (π/6) − (2π/3)}・e ^j 〓′ ^t V ^(a) _w = (√3/2)k ² _1a k _2a・cos {(4π /P)z + (π/6) + (2π/3)}・e ^j 〓′ ^t …(6) Here, the positive values for V ^(a) _u , V ^(a) _v , V ^(a) _w phase voltage
V _pa and negative phase voltage V _oa are defined by the following equations.

V _pa =V ^(a) _u +e ^-j2 〓 ^/3 V ^(a) _v +e ^j2 〓 ^/3 V ^(a) _w V _oa =V ^(a) _u +e ^j2 〓 ^/3 V ^(a) _v +e ^-j2 〓 ^/3 V ^(a) _w …(7) By substituting equation (6) into equation (7), the following equation is obtained.

V _pa = (3√3/4)k ² _1a k _2a・e ^-j(4 〓 ^/P) [ ^z+( 〓 ^/6) ]・e ^j
〓′ ^t V _oa = (3√3/4)k ² _1a k _2a・e ^j(4 〓 ^/P) [ ^z+( 〓 ^/6) ]・e ^j 〓
′ ^t
…(8) Perform signal processing similar to equations (3) to (7) for V ^(b) ₁₂ , V ^(b) ₂₃ , and V ^(b) ₃₁ to calculate the positive sequence voltage V _pb and negative sequence voltage
Calculating V _ob is as follows.

V _pb = (3√3/4)k ² _1b k _2b・e ^-j(4 〓 ^/P) [ ^z+ 〓 ^z+( 〓 ^/6) ]
・
e ^j 〓′ ^t V _ob = (3√3/4)k ² _1b k _2b・e ^j(4 〓 ^/P) [ ^z+ 〓 ^z+( 〓 ^/6) ]・
e ^j 〓′ ^t
...(9) If the phase difference between V _oa and V _ob is φ _o , the following relationship is obtained.

φ _o =∠V _ob −V _oa = (4π/P)Δz (10) The same result can be obtained from the phase difference between V _pa and V _pb as shown in the following equation.

φ _p =∠V _pb −V _pa = (4π/P)Δz …(11) Here, as shown in Fig. 3, the entire traveling section of the moving body is divided into n small sections, and each small section is _D1 ……,
Let D _i , . . . _Do , and the period of the line 4 in each small section _be P _{1 ,} .

The phase difference φ _oi when the moving object is in the small section D _i is φ _oi = (4π/P _i )Δz (12). Since Δz is constant, P _i can be known through the measurement of φ _oi , and thereby it can be detected that the moving object is within the small section D _i .

FIG. 4 shows an example of a signal processing circuit connected to the terminal of the guided radio line.

6 ₁ , 6 ₂ , 6 ₃ are transformers, 7 ₁ , 7 ₂ , 7 ₃ are branching filters, 8 _a1 , 8 _a2 , 8 _a3 , 8 _b1 , 8 _b2 , 8 _b3 are square law detection circuits, 9 _a1 , 9 _a2 , 9 _a3 , 9 _b1 , 9 _b2 , 9 _b3 are subtraction circuits, 10 _a1 , 10 _a2 , 10 _a3 , 10 _b1 , 10 _b
2 , 10 _b3 are amplitude modulation circuits, 11 _a2 , 11 _b2 are -
120° phase shift circuit, 11 _a3 and 11 _b3 are +120° phase shift circuit,
12 _a and 12 _b are adder circuits, 13 is a carrier wave power supply, 1
4 is a phase meter.

The voltage at frequency f _a is detected by square law detection circuits 8 _a1 , 8 _a2 ,
8 At _a3 |V ^(a) ₁₂ | ² , |V ^(a) ₂₃ | ² , |V ^(a) ₃₁ | ²
is _converted into a voltage proportional _to
2 , 9 processed by _a3 , |V ^(a) ₁₂ | ² − |V ^(a) ₂₃ | ² , |V ^(
a) ₂₃ |
A voltage proportional to ² −|V ^(a) ₃₁ | ² , |V ^(a) ₃₁ | ² −|V ^(a) ₁₂ | ² is output. Amplitude modulation circuit 10 _a1 , 10 _a2 , 1
Carrier wave guided from carrier wave power source 13 at 0 _a3
e ^j 〓' ^t is modulated by 100%, the output from the amplitude modulation circuit _10a1 is inputted as is to the addition circuit _12a , and the outputs from the amplitude modulation circuits _10a2 and _10a3 are input to the phase shift circuits _11a2 and _11b2 , respectively. After undergoing phase deformation of −120° and +120°, the voltage is led to the adder circuit _12a , and the adder circuit _12a outputs the voltage V _oa .

The voltage of frequency f _b is similarly led to the adder circuit 12 _b , and the adder circuit 12 _b outputs the voltage V _ob .

Then, the phase difference between the voltages V _oa and V _ob is displayed on the phase meter 14, and from this it is possible to know in which subsection the moving object is present.

The structure of the guided radio line used in the present invention is not limited to the shape shown in FIG. 2, but may have a rectangular or triangular wave shape as long as it uses an odd number of conductors of three or more. Well, again.
Not only a flat conductor structure but also a spiral conductor structure may be used.

As explained above, according to the present invention, it is possible to obtain a large amount of position information with a small number of conductors, and the influence of external noise and crosstalk is greatly reduced. Furthermore, even when two or more lines as shown in FIG. 2 are laid in order to obtain positional information regarding upper addresses, the influence of crosstalk can be greatly reduced.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional example, Fig. 2 is an explanatory diagram of a configuration example of a guided radio line in the present invention, Fig. 3 is an explanatory diagram of a state where the position detection section is divided into small sections, and Fig. 4 is an explanatory diagram of the present invention. FIG. 2 is an explanatory diagram of an example of a signal processing circuit used in the invention. 1, 2, 3: conductor, 4: guided radio line, 5 _a ,
5 _b : Mobile-mounted antenna, 6 ₁ , 6 ₂ , 6 ₃ : Transformer, 7 ₁ , 7 ₂ , 7 ₃ : Duplexer, 8 _a1 , 8 _a2 , 8 _a3 ,
8 _b1 , 8 _b2 , 8 _b3 : square law detection circuit, 9 _a1 , 9 _a2 , 9
_a3 , 9 _b1 , 9 _b2 , 9 _b3 : subtraction circuit, 10 _a1 , 10 _a
2 , 10 _a3 , 10 _b1 , 10 _b2 , 10 _b3 : amplitude modulation circuit, 11 _a2 , 11 _b2 : -120° phase shift circuit, 11 _a3 ,
11 _b3 : +120° phase shift circuit, 12 _a , 12 _b : addition circuit, 13: carrier wave power supply, 14: phase meter.

Claims (1)

[Scope of Claims] 1. Three conductors are arranged so as to form a periodic structure in which a sinusoidal inter-conductor voltage is induced between each conductor as the position of the moving body changes, and when the moving body moves. The guided radio track is formed by dividing the section into a plurality of sections, and each section has a different periodic structure, and is laid along the moving object running path, while the moving object is provided with a predetermined interval in the longitudinal direction of the track. By arranging two antennas and exciting the two antennas with signals of different frequencies f _a and f _b , a voltage is induced between the conductors of the inductive radio line, and the voltage induced between each conductor is is selectively received at the terminal of the guided radio line, and the square value of the envelope amplitude of each conductor voltage for each frequency f _a and f _b is determined, and the difference between these square values is obtained. _{By modulating} ^{a new} _carrier ^wave _with ^a _{voltage that} ^(b) _v , V ^(b) _w , V ^(a) _u , V ^(a) _v , V ^(a
) Define the positive sequence voltage V _pa and negative sequence voltage V _oa for _w using the following formula, V _pa = V ^(a) _u +e ^-j2 〓 ^/3 V ^(a) _v +e ^j2 〓 ^/3 V ^(a) _w V _oa =V ^(a) _u +e ^j2 〓 ^/3 V ^(a) _v +e ^-j2 〓 ^/3 V ^(a) _wAlso , regarding V ^(b) _u , V ^(b) _v , V ^(b) _w Positive sequence voltage V _pb
When the negative sequence voltage V _ob is defined by the following formula, V _pb = V ^(b) _u +e ^-j2 〓 ^/3 V ^(b) _v +e ^j2 〓 ^/3 V ^(b) _w V _ob = V ^(b) _u +e ^j2 〓 ^/3 V ^(b) _v +e ^-j2 〓 ^/3 V ^(b) _wThe phase difference between two positive sequence voltages V _pa and V _pb or the phase difference between two negative sequence voltages V _oa and V _ob A moving body position detection method characterized in that a small section in which a moving body exists is determined by determining a phase difference.