JPH02236186A - Method for sensing position of moving body - Google Patents

Abstract

PURPOSE:To excite two car-borne antennas with different high frequency waves, detect and calculate line voltage of an induction line with a signal processing circuit provided at the terminal of the induction line and obtain two pieces of information regarding the position of a vehicle by a method wherein a three- line induction line is placed along a moving body running path and the two antennas are mounted on different positions of the moving body. CONSTITUTION:Three-line induction lines 123 of a moving body position detecting system are crossed each other with constant intervals P and placed along a moving body running path while two car-borne antennas 4a,4b are fixed on different positions on the moving body, each of which is excited by high frequency current having different frequency and voltages having different frequencies are induced to the induction lines 123. A signal processing circuit 6 located at a terminal of the induction lines 123 detect voltages having different frequencies induced between conductors 1,2 with linear detectors 63a,63b and converts them into absolute values respectively to input them to an arithmetic unit 64. Then based on the absolute induction voltage value and lines to the moving body, the position of the moving body is periodically detected within a frequency interval of P/2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting the position of a moving object traveling on a fixed travel route on the ground using three-wire intersecting guidance lines, and in particular, In the mobile object positioning method using wires, even if a disconnection accident occurs in one of the conductors that make up the guide wire, the function of detecting the position of the mobile object can be maintained using the remaining two conductors. The present invention relates to a mobile body position detection method in which there are two antennas on a mobile body (hereinafter referred to as "vehicle antennas"), and each antenna is excited by a high-frequency current having a different frequency.

[Prior art]

In autonomous driving of linear motor vehicles, the position of the vehicle is continuously and periodically measured within the range of the array spacing of ground propulsion coils arranged at regular intervals along the running route. Based on this, it is necessary to control the frequency, amplitude, phase, etc. of the current supplied to the ground propulsion coil.

Figure 5 shows the configuration of a guided radio system that has already been proposed to meet this demand. In the same figure, 12, 3
are line conductors (hereinafter abbreviated as "conductors") constituting the three-wire guide wire 123, each formed in a trapezoidal waveform with a constant period P, and located at positions shifted by P/3 from each other in the longitudinal direction. will be placed in P is set to twice the spacing between adjacent ground propulsion coils (belonging to the same phase). Reference numeral 4 denotes an on-vehicle antenna, which is composed of a rectangular loop coil, and is supplied with a high-frequency current from an on-vehicle transmitter 5. The on-vehicle antenna 4 maintains a constant height directly above the guide line 123 and moves along its center line together with a moving object (in this case, a near-motor vehicle). Z is the distance from the start of the line to the onboard antenna 4, and 6 is a signal processing circuit located at the start of the line, which calculates the voltage induced between adjacent conductors 1-2, 2-3, and 3-1 of the line 123. It functions to take in VIE, VZ3, and V''I1 and derive the value of antenna position (vehicle position) Z.

Here are the dimensions of the on-board antenna 4 and the guide wire? By appropriately selecting the separation distance (height) from 23, the induced voltages v1, VZ3, and V31 between the conductors can be made into sinusoidal functions with respect to Z, respectively. In other words, k is a constant determined by the configuration of the entire system, r=αZ+j
βZ, where α and β mean the attenuation constant and phase constant of the line, respectively. Next, in the signal processing circuit 6, calculations corresponding to the following equations are performed to derive the positive phase voltage V and the negative phase voltage v7.

From equations (1) and (2), here, V,,V. If the phase angles of are expressed by /■2 and Zvn, respectively, and the difference between the two is φ, then from equation (3), φ= l V r l V − = 4 z Z
/P The relationship (4) is derived. That is, Z
φ shows a linear increase of 2π every time φ increases up to Z+P/2.

Since 0 and 2π are indistinguishable, the relationship between Z and φ becomes a sawtooth wave as shown in FIG. Therefore, if P/2 is set equal to the spacing between the ground propulsion coils and the guide wire 123 is laid along the running path so that the position where φ becomes 0 or 2π coincides with the position of each ground propulsion coil, the Through this value, the vehicle position Z can be detected continuously and periodically within the range of the arrangement interval P/2 of the ground propulsion coils. The above-mentioned functions are performed by the signal processing circuit 6.

[Problem to be solved by the invention]

However, the following problem has been pointed out in the configuration shown in FIG. That is, any one of the line conductors l, 2, and 3
If a wire breakage accident occurs in the conductor 3, for example, VZZ and V31 disappear at the starting end of the guide wire, and the signal processing circuit 6 loses its function. Apart from the system shown in Figure 5, a system for detecting the position of a moving object using two guiding wires and two antennas was published in Japanese Patent Publication No. 62-46828.
As shown in the issue, this system also becomes unable to detect if one guide wire is disconnected.

[Means to solve the problem]

The present invention has been made in view of the above, and takes the following measures to solve the above problems.

That is, a three-wire guide wire is laid along the traveling path of the moving object, and two on-vehicle antennas are mounted at different positions on the moving object.

This on-board antenna has a 3-wire guide wire and a predetermined interval,
It is excited by two different high frequency currents. A signal processing circuit is provided at the terminal of the three-wire guide wire to detect the line voltage of the guide wire induced by the high-frequency current of the on-board antenna and perform predetermined calculations.

[Effect]

On-board antennas placed at different positions are each excited with high-frequency currents of different frequencies, and the corresponding line induced voltages are selectively received at the starting end of the line. That is,
Even if two of the three line induced voltages disappear, the remaining one
Two pieces of information regarding the vehicle position Z can be derived from the two line induced voltages. These two induced voltages are both Z
is a sinusoidal function that varies with period P with respect to
Since there is a certain phase shift between the two, it is possible to determine the value of Z based on this.

〔Example〕

1 to 3 show one embodiment of the present invention, FIG. 1 is a plan view showing the positional relationship between the guide wire and the on-board antenna, and FIG.
The figure is a cross-sectional view. Of these figures, 1, 2, 3
, 123, 6, and Z are the same as in the case of FIG. 5, so their explanation will be omitted. 4a and 4b are two on-board antennas fixed to the vehicle, with P in the longitudinal direction of the track.
They are arranged at intervals of an odd multiple of /8 (3 P/8 in the case of FIG. 1) and are excited by high frequency power sources 5a and 5b with different frequencies fa and fbO, respectively.

In the configuration described above, the high frequency magnetic field formed by the on-vehicle antennas 4a and 4b is transmitted to the starting end of the guide wire 123, and is selectively received by the signal processing circuit 6. It will be done. Received voltage of signal processing circuit 6 1■, VZ3, V,, (7) [a
The components are V lta , Vt3a , Vfflm , f
If the b component is expressed as "lRh % Vzx'b s v3lb," then r.=α, Z+jβ & Zs rb ""α-
(Z+3P/8)+jβb (Z+3P/8), and the meanings of k, α, β, and P are the same as in equation (1), and the subscripts written at the bottom right of these quantities are each frequency fa.
, fb.

When all the conductors of the induction wire 123 are sound, the signal processing circuit 6 has a voltage V I Z m ”' V 3 1 II
, V I R h −V 3 1 b or both, the vehicle position Z is detected using the same procedure as in FIG. 5 and equations (1) to (4). be able to.

Here, it is assumed that a disconnection accident occurs in the conductor 3. At this time, as shown in FIG. 3, the number of induced lines becomes substantially two, and all induced voltages other than V+za and Vl■ disappear. This two-wire guide line will be indicated by 12.

The signal processing circuit 6 performs linear detection on Vlla and vrtb, and then squares them to obtain I Vital z=kaJcos(2zZ/P) l
"e-2"2=(k."/2) e-"2(1+co
s(tyrZ/P)) (8)V+zb I ””k
b”l cos (2i (Z+3P/8)/P)
I ”X e-2 6 (l bow F/I) == (k1/2) e-tab (2*3F/#)
X (1+cosc4xZ/P-π/2)) (9)
obtain. In the case of a linear motor vehicle, in addition to the cycle and vehicle position detection method that is the object of the present invention, there is also a means for detecting the absolute position of the vehicle (distance N from the starting point of the running path) using an approximate value (in units of tens of meters). has been done. This uses point-sensing loops placed along the route to provide vehicle position information to the ground propulsion coil's power supply system. The signal processing circuit 6 can constantly receive information about the approximate value of 2 from the means. Since the value of α,, α, is small in many cases, (ka”/2) e−!aa!, (1(1/2)
e-! a (Z+3P/a) numerical value can be calculated with sufficient accuracy if the approximate value of Z is known, and furthermore, these values hardly change even if Z fluctuates by about ±ΔP/2, therefore, In the following discussion, it can be regarded as a constant.

Therefore, by multiplying both or one of equations (8) and (9) by a correction coefficient, each is expressed as I V+za I ”= k” < 1 + cos(4
rZ/P)l (10) I VIxb I ”=
k" (1 +cos(4gZ/P-π/2))=
k” (1 + sin(4 7K Z/P))
It can be transformed into the form (II). Here, k2 is a known quantity. 2〇〇), 01) can be obtained. Immediately from this formula or as mentioned above, the right-hand side of formula 04 is IVI! -1, IV+z
It is a quantity that can be calculated based on b, and therefore it is possible to derive the value of Z using the formula side.

FIG. 4 is a block diagram showing an example of a specific configuration of the signal processing circuit 6 in the embodiment shown in FIGS. 1 and 3.
Transformers 62a and 62b for converting balanced to unbalanced voltage are band-pass filters whose center frequencies are fa and fb, respectively;
3a and 63b are linear detectors; 64 is an arithmetic unit that performs digital signal processing on input signals; an input interface 64e that takes in input signals; ROM64 that stores RAM
b. A CPU 64a that performs the digital calculation itself;
It is composed of a RAM 64C that temporarily stores the intermediate data, and an output interface 64d that outputs the signal processing results to the outside.

Voltage induced between conductors 1 and 2 at the terminal of the induction wire ■1
■ is converted into an unbalanced voltage by a transformer 61, decomposed into faX fb components by filters 62a and 62b, linearly detected by linear detectors 63a and 63b, respectively, and converted into lV+z- and lv+■,1. Ru. In the calculation unit 64, the input interface 64e is the above-mentioned IVI! -1, lv+■, 1, as well as the power system control system (controls the power supply to the ground propulsion coil; not shown)
The CPU 64a, ROM 64b, and SRAM 64c work together to calculate the precise value of Z by performing the calculations in equations (7) to 04), and output the power through the output interface 64d. Output to the control system.

In addition, the system shown in FIG. 3 has induced voltages Vt3, V3
1 also holds true. With this, the guidance of Article 3? 1, 2
, 3, the vehicle position detection function can be maintained even if a disconnection accident occurs in any of the above. Also, if conductors 1, 2, and 3 are all healthy, v. ! 1, V22m -. The vehicle position Z is detected based on at least one of V31m or ■1■b, V23h, and Verb based on FIG. You can switch.

As shown in formula (8) to 0/0, the method of the present invention is IVI!
．． 1"V+zbl", the influence of spatial harmonic components included in the line-to-line induced voltages VIZII and VIZk is emphasized, and the three-wire induction method (Fig. 5 and equations (1) to (4) ) The vehicle position detection error tends to increase slightly. Therefore, it is preferable to use the method of the present invention only for disconnection accidents.

As mentioned above, in the configurations shown in FIGS. 1 and 3, the spacing between the on-board antennas 4a and 4b is 3P/8, but this can be changed to (2m+1)P/8 (m=0, 1, 2, 3・－・－
・−・1) is acceptable. However, in this case, the relationship of the expression 0 must be modified as follows. Furthermore, if the distance between the on-vehicle antennas 4a and 4b is expressed as d, the value of d does not necessarily have to be exactly (2m+1)P/8. As can be seen from the calculation process of Equations (5) to Q4], in this case, Vtza/kl" l=cos(4iZ/P)
OωI V+gb/k l ” − 1 = cos
(4πZ/P+δ)07) δ=4πd/P
It becomes a Q mark. 206) ~ From a? Z 3 ■ tan - 1 4 π, and it is possible to derive the value of Z from this relationship. However, this relationship holds true when δ is close to an integer multiple of π (d
is an integer multiple of P/4), which causes an extremely large error, and this must be kept in mind. In addition, data processing is also slightly more complicated than in the case of 2〇 and yen.

In the signal processing circuit 6 of FIG. 4, the position signal is processed digitally, but this may be replaced by an analog calculation circuit having an equivalent function.

Although the conductors 1 and 2 of the line in FIG. 3 have trapezoidal waveforms, they may have other waveforms, such as triangular or rectangular waves. Furthermore, although these conductors are arranged at a distance of P/3 in the longitudinal direction, this spacing is not necessarily limited to P/3. Further, the structure of the guide wire is not limited to a planar structure, but may be a spiral structure. Although the embodiments shown in FIGS. 1 to 4 have been mainly explained with reference to their application to linear motor vehicles, the method of the present invention can also be applied to other moving objects (transportation vehicles, cranes, railway vehicles, etc.) that move along a fixed travel path. Of course, it is also applicable to

〔Effect of the invention〕

As explained above, according to the moving object position detection method of the present invention, the guide wire is composed of three intersecting conductors, which are fixed at different positions on the moving object, and each has a different frequency. An induced voltage is generated by two antennas supplied with a high-frequency current, and a signal processing circuit selectively receives the line-to-line induced voltage between at least the same two lines for each frequency component, and detects the position of a moving object based on these. As a result, the mobile object position detection function can be maintained even in the event of a disconnection accident in one of the line conductors of the three-wire guide line.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG.
3 is an explanatory diagram showing only the part that will actually function if a disconnection accident occurs in one of the guide wires in the configuration shown in FIG. 1, and FIG. FIG. 5 is an explanatory diagram showing the configuration of a conventional moving body position detection system using a three-wire guide wire, and FIG. is the phase difference φ between the positive and negative phase voltages and the moving body position Z in the configuration shown in FIG.
An explanatory diagram showing the relationship. Explanation of symbols 3 - - - Conductor constituting one lead wire -
----------1. Guide wire 4 b -----------1. On-board antenna 5 b
=・・・1・1・・1 On-board transmitter signal processing circuit・Balanced-to-unbalanced conversion transformer・11111・−・1 Bandpass filter・−−−−
---・1 Linear detector calculation section ----1...-CPU 64 b-
--------・---ROM...- RAM ・Output interface...--Single driver interface 1, 2, l2, 123 4, 4a, 5, 5a, 6-... -・-・ 6l...1...- 62a, 62b 63a, 63b 64-・64a 64C1... 64d 64e

Claims (1)

[Claims] Three-wire guide wires that intersect at a constant period P and are laid along the moving path of the moving object, and high-frequency currents that are fixed at different positions on the moving object and have different frequencies. two on-board antennas that are excited by and induce voltages of different frequencies in the three-wire induction wire; Periodically detecting the position of the moving object within a periodic interval of P/2 based on the absolute values of two induced voltages with different frequencies and the approximate value of the distance from the terminal of the guiding wire to the moving object. A mobile object position detection method comprising a signal processing means that performs a signal processing.