JPH05274030A - Deflection detecting sensor and electromagnetic induction type unmanned vehicle using the same - Google Patents

Abstract

PURPOSE:To output a quantity which is not affected by the relative position change in the vertical direction to the guide base line of a deflecting coil and is proportional to only the extent of deflection. CONSTITUTION:A follow-up coil 11 and deflecting coils 13a and 13b which are arranged on both sides of this coil 11 in parallel with the surface of a guide road constitute a sensing part 10. This sensing part 10 detects the change of the magnetic field generated by the AC current supplied to an electromagnetic induction line 5 and outputs it to a processing part. The processing part performs the arithmetic processing of input signals from coils 11, 13a, and 13b and outputs a quantity proportional to only the extent of deflection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bias detecting sensor for detecting a magnetic field formed by an electromagnetic induction wire installed on a traveling road surface or under the traveling road surface and for detecting a deviation from the electromagnetic induction wire, and the deviation detecting sensor. The present invention relates to an electromagnetic induction type unmanned vehicle that uses an electromagnetic induction sensor.

[0002]

2. Description of the Related Art Conventionally, a bias detection sensor for detecting a concentric magnetic field formed by an alternating current applied to an electromagnetic induction wire installed on a traveling road surface or below the traveling road surface is used as an electromagnetic induction wire. There is known an electromagnetic induction type unmanned vehicle that steers the vehicle so that it is directly below the center of the sensor and travels on a traveling road surface. The bias sensor used for this purpose is of a type consisting of a pair of bias coils that detect the bias from the electromagnetic induction wire and a tracking coil that follows the electromagnetic induction wire and detects the presence or absence of derailment. It has been known.

[0003]

However, in such a bias detection sensor used in the conventional electromagnetic induction type unmanned vehicle, since the magnetic field strength formed by the electromagnetic induction wire is inversely proportional to the distance from the electromagnetic induction wire, the bias coil is used. The detected value of is attenuated as the distance from the electromagnetic induction wire increases.

For this reason, when the distance (usually the height) between the electromagnetic induction wire and the bias coil changes, the signal value of each bias coil changes, and the difference between the signal values of the bias coils, that is, from the electromagnetic induction wire. The amount of bias could not be detected accurately. Further, since the signal value from the bias coil changes in intensity depending on the distance from the electromagnetic induction wire, for example, the same 10 m
Even with a deviation of m, the signal value is “large” when the distance to the electromagnetic induction wire is small (low), and the signal value is “small” when the distance is large (high). The steering of an electromagnetic induction type unmanned vehicle depending on the value may not be constant.

In the case of an electromagnetic induction type unmanned vehicle in which a sensor is installed on a spring, the influence of such a change in the height of the bias coil is caused by the displacement of the spring and the traveling road surface (that is, the electromagnetic induction wire). And the height of the bias coil is large, so that the change in height of the bias coil has a large effect, which is a problem.

Therefore, the present invention has an object to solve the above-mentioned problems, and a bias capable of outputting an amount proportional to only the amount of bias is not affected by a change in the relative position of the bias coil in the height direction with respect to the electromagnetic induction wire. An object is to provide a detection sensor and an electromagnetic induction type unmanned vehicle using the sensor.

[0007]

In order to achieve such an object, the present invention has the following constitution as a means for solving the problem. That is, the bias detection sensor according to claim 1 is a bias detection sensor that detects a magnetic field formed by an electromagnetic induction wire and detects a deviation with the electromagnetic induction wire, in which the axes are parallel and the central cross section is on the same plane. A pair of bias coils arranged in a certain manner, obtaining an output of the pair of bias coils, a processing unit that calculates and outputs a value proportional to the bias of the electromagnetic induction wire and the pair of coils from the output. An electromagnetic induction type unmanned vehicle according to claim 2 is characterized in that the bias detection sensor according to claim 1 is used as an electromagnetic induction sensor.

[0008]

In the bias detection sensor having the above-described structure, the axes of the bias coils are substantially orthogonal to the road surface, and the central cross sections of both bias coils are substantially parallel to the road surface. It will be installed almost directly above the guide wire.

The bias coil generates an induced current in itself by an electromotive force according to the strength of the magnetic field formed by the electromagnetic induction wire, and also outputs according to the electromotive force. The output is
Input to the processing unit. Since the pair of bias coils are arranged symmetrically on the same plane with their axes parallel to each other, the distance from the electromagnetic induction wire is determined by the height and the amount of bias. Therefore, the difference in the magnetic flux density intersecting with both the bias coils also depends on the height bias amount. Therefore, the electromotive force generated by the electromagnetic induction in both the bias coils is a quantity that correlates with the height from the electromagnetic induction wire and the amount of deviation.

If the outputs of both bias coils are regarded as simultaneous equations in which the height from the electromagnetic induction wire and the amount of bias are unknowns,
It is possible to eliminate the height component and obtain a value that correlates only with the deviation amount. Therefore, when the output values of both the bias coils are input to the processing unit and the processing unit performs arithmetic processing, a value proportional to only the bias amount is calculated. Then, the processing unit outputs this value.

The output value from this processing section is a value proportional to only the amount of deviation, and is not affected by the height change of the deviation coil from the electromagnetic induction wire. In the electromagnetic induction type unmanned vehicle characterized by using this bias detection sensor as an electromagnetic induction sensor, the processing unit is provided in accordance with the output from the processing unit of the bias detection sensor mounted at an appropriate position of the unmanned vehicle. The steering wheel is steered so that the output value from is 0. As a result, the electromagnetic induction type unmanned vehicle is steered so that the axis of symmetry of the bias detection sensor is located almost directly above the electromagnetic induction wire,
It runs along the electromagnetic induction line.

Since the output value of the deviation detecting sensor is not affected by the height change from the electromagnetic induction wire as described above,
Even if the heights of the electromagnetic induction sensor and the traveling road surface (that is, the electromagnetic induction wire) fluctuate, they are not affected by the change. Therefore, the instability of steering of the electromagnetic induction type unmanned vehicle, which is performed according to the output value, is eliminated. In particular, the steering is stabilized in an electromagnetic induction type unmanned vehicle in which a sensor is installed on a spring.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. (Embodiment 1) As shown in FIG. 1, in a sensing portion 10 of a displacement detection sensor 1 according to an embodiment of the present invention, a follow-up coil 11 located at the center, and predetermined left and right sides of the follow-up coil 11 in the figure. Bias coils 13a, 1 symmetrically arranged at the positions
3b is stored. Each coil 11, 13a, 13b
Will be described as a one-turn ring coil, which is so small that the magnetic flux density distribution in the coil can be regarded as substantially uniform. In this embodiment, each coil 11, 13a, 13
Both b have the same shape with an outer diameter of about 30 mm.

Both bias coils 13a and 13b are in relative positions which can be regarded as being placed on a plane parallel to the road surface, and the axes of both bias coils 13a and 13b are parallel to each other.
It is at the same distance from the tracking coil 11. Tracking coil 11
The axis of is on the central cross section of the left and right bias coils 13a, 13b.

Further, below the sensing unit 10 in the drawing,
An electromagnetic induction wire 5 is buried under the road surface 3. An alternating current from a power source (not shown) is passed through the electromagnetic induction wire 5, and a magnetic field centering on the electromagnetic induction wire 5 is formed by the action of the alternating current.

As shown in FIG. 2, each coil 11, 13
The outputs from a and 13b are configured to be input to the processing unit 20. As shown in FIG. 3, the processing unit 20 is
Amplifies the input signal from each coil 11, 13a, 13b,
A drive circuit 21 for rectifying, A for receiving a signal corresponding to the input signal from the drive circuit 21 and performing analog / digital conversion
The A / D conversion circuit 23 and the microcomputer 25 which reads the digital signal converted by the A / D conversion circuit 23, processes the digital signal, and outputs the digital signal. The microcomputer 25 includes a well-known CPU 25a and ROM 25
b, the RAM 25c, the input port 25d, and the output port 25e are connected by a bidirectional bus 25f to constitute an arithmetic logic operation circuit. Programs for performing various processes according to a predetermined procedure are stored in the ROM 25b in advance.

Next, the arithmetic processing in the processing section 20 will be described. FIG. 4 shows the routine. Data proportional to each output of the follow-up coil 11 and the bias coils 13a and 13b is input through the drive circuit 21, the A / D conversion circuit 23 and the input port 25d and read by the CPU 25a (step 100). Then, a value proportional to only the deviation amount is calculated and output based on each of the data (step 200).

In step 200, the following calculation is performed. First, as illustrated in FIG. 5, a description will be given of the case where the relative position between the electromagnetic induction wire 5 and each of the coils 11, 13a, 13b is deviated, that is, is deviated. For convenience of explanation, each physical quantity and constant are expressed as follows.
All distances or intervals are core-core. a: Distance between the follow-up coil 11 and both the bias coils 13a and 13b (m) B: Magnetic flux density (Wb / m ² ) due to the current being applied to the electromagnetic induction wire 5 h: Follow-up coil 11 and the two bias coils 13a, 13b height from the electromagnetic induction line 5 (m) H: intensity of the magnetic field due to current being energized electromagnetic induction line _{5 (a / m) H a} : amount proportional to the output of the bias coil 13a H _B: Amount proportional to the output of the biasing coil 13b H _O : An amount proportional to the output of the follow-up coil 11 I: Current being supplied to the electromagnetic induction wire 5 (A) r: Distance from the electromagnetic induction wire 5 (m) x: Deflection amount (m) μ _o : Permeability of vacuum (4π × 10 ^-7 ) At the distance r, the strength of the magnetic field due to the current of the electromagnetic induction wire 5 is

[0019]

[Equation 1]

And the magnetic flux density is

[0021]

[Equation 2]

It is The induced voltage of the ring coil at the point of the distance r is proportional to the magnetic flux density at that point, and is proportional to I and inversely proportional to r if the magnetic flux density in the ring coil is substantially constant. Further, in the follow-up coil 11 whose axis is horizontal, the magnetic flux intersecting with the coil is proportional to sin θ, where θ is the crossing angle between the coil and the magnetic field. Therefore, the electromotive force generated in the tracking coil 11 is proportional to sin θ / r. sin θ =
Since it is h / r, the induced voltage of the following coil 11 is

[0023]

[Equation 3]

Proportional to Where r = √ (x ² + h ² )
Therefore, if 1 / 2π is regarded as a proportionality constant, H _O is an amount proportional to I,

[0025]

[Equation 4]

[0026] Also, the bias coils 13a, 13b
Since the axis is vertical, the magnetic flux crossing the coil is proportional to cos θ, where θ is the crossing angle between the coil and the magnetic field. Therefore, the electromotive force generated in the bias coils 13a and 13b is proportional to cos θ / r.

Since cos θ = x / r, H _A , H
_B , is

[0028]

[Equation 5]

Proportional to The horizontal distance of the bias coil 13a is (x + a), and the horizontal distance of the bias coil 13b is (x−a).
Since it is a), instead of x in the equation (5), (x + a),
Substituting (x−a), H _A becomes

[0030]

[Equation 6]

H _B is

[0032]

[Equation 7]

It becomes If h is eliminated from equations (6) and (7),

[0034]

[Equation 8]

It becomes As a result, both bias coils 13
The quantities H _A and H _B proportional to the outputs of a and 13b are stored in the CPU 25.
A value proportional to only the deviation amount x can be calculated by inputting it to a. Incidentally, when the bias amount x = 0, the amount H _A, which is proportional to the output of the bias coil 13a, 13b, H _B is, the absolute value is equal positive, the negative is reversed, (H _A in equation (8) The term of + H _B ) becomes 0. Therefore, the calculated value in this case is 0.

Since the equation (8) does not use the height h of both the bias coils 13a and 13b from the electromagnetic induction wire 5, the influence of the relative position change of the bias coils 13a and 13b with respect to the electromagnetic induction wire 5 in the height direction. Without it, it is possible to output an amount proportional to only the amount of deviation. Next, the operation of the deviation detection sensor 1 of this embodiment will be described.

The coils 11 and 1 of the bias detecting sensor 1 arranged at relative positions so as to be almost directly above the electromagnetic induction wire 5.
3a and 13b are in the magnetic field formed by the alternating current applied to the electromagnetic induction wire 5. Since the strength of the magnetic field formed by the change in the phase of the alternating current applied to the electromagnetic induction wire 5 also changes, the coils 11, 13a, 1
The magnetic flux density interlinking with 3b changes. As a result, an induced voltage is generated in each coil 11, 13a, 13b. An electric signal corresponding to the induced voltage is applied to each coil 11, 13a, 13
Input from b to the processing unit 20.

In the processing section 20, first, each coil 11,
The electric signals from 13a and 13b are subjected to processing such as amplification, noise signal removal, and rectification in the drive circuit 21, and A / D
It is sent to the conversion circuit 23. The signal input to the A / D conversion circuit 23 is converted into a digital signal here and input to the microcomputer 25 as data proportional to the output of each coil 11, 13a, 13b.

When data is input to the input port 25d, the CPU 25a starts the routine process shown in FIG. That is, data proportional to each output of the bias coils 13a and 13b is read (step 100), and a value proportional to only the amount of bias is calculated and output based on each data (step 200). This value is x shown in the equation (8).

The output of the follow-up coil 11 is mainly used to detect the presence or absence of a magnetic field formed by the electromagnetic induction wire 5. For example, it has a role of detecting disconnection of the electromagnetic induction wire 5. Therefore, the output from the follow-up coil 11 is processed separately from the outputs from the bias coils 13a and 13b. Therefore, description of the output processing of the follow-up coil 11 is omitted.

The output from the processing unit 20 is proportional to the outputs of the bias coils 13a and 13b at the relative position where the bias detection sensor 1 is almost directly above the electromagnetic induction wire 5 as shown in FIG. Since the absolute values of the quantities H _A and H _B to be applied are equal and the signs are opposite, the output of the deviation detection sensor 1 is also 0.

However, the relative position of the deviation detection sensor 1 and the electromagnetic induction wire 5 is as shown in FIG. 5, for example.
If it deviates to the left or right from the axial direction of | H _A | ≠ |
H _B | and a value proportional to the deviation amount x is output. Therefore, the output value makes it possible to detect whether the deviation is on the left or right side of the electromagnetic induction wire 5 and the deviation amount.

In this case, depending on whether it is biased to the right or the left, by setting the value of equation (8) to either positive or negative,
The output value also becomes positive and negative values accordingly. The coils 11, 13a, and 13b in this embodiment have been described as one-turn ring coils, but the shape of each coil is not limited to this. However, it is desirable that the magnetic flux density distribution in the coil is small enough to be regarded as substantially uniform.
Although it is not necessary to provide the follow-up coil 11, the provision of the follow-up coil 11 facilitates detection of disconnection of the electromagnetic induction wire 5.

Further, in the present embodiment, the arithmetic processing in the processing section 20 is performed by the microcomputer 25, but instead of this, an analog circuit in which an adding circuit and a multiplying circuit are combined can be used. In this case, A /
The D conversion circuit 23 becomes unnecessary. The description of the first embodiment is completed above, and then, an embodiment of an electromagnetic induction type unmanned vehicle using the deviation detection sensor 1 described in the first embodiment as an electromagnetic induction sensor will be described. (Embodiment 2) FIG. 6 is an explanatory view showing a device configuration of an electromagnetic induction type unmanned vehicle 50 of the present embodiment, and FIG. 8 is a block diagram illustrating a basic configuration of the electromagnetic induction type unmanned vehicle.

First, the structure of the electromagnetic induction type unmanned vehicle 50 will be described. As shown in FIG. 6, an electromagnetic induction type unmanned vehicle 50
Includes four wheels, a front guide wheel 53 and a rear guide wheel 55 attached to the center of the longitudinal end of the carriage 51, and drive wheels 57a and 57b installed in the center of the side portions.

FIG. 7 shows an electromagnetic induction type unmanned vehicle 50 on a traveling road surface 7.
It is explanatory drawing of the state mounted in 0. The front guide wheel 53 and the rear guide wheel 55 are not shown. An electromagnetic induction wire 80 of a conductive cable is buried under the traveling road surface 70, and an alternating current from a power supply device (not shown) is supplied to the electromagnetic induction wire 80. The electromagnetic induction type unmanned vehicle 50 has a traveling road surface 7
It is possible to move forward and backward along the axis 0 of the electromagnetic induction wire 80.

The drive wheels 57a and 57b are respectively the motor 5
Motors 59a and 59b are connected to 9a and 59b.
It is driven by and rotates. A traveling control device 61 including a microcomputer 63 is electrically connected to the motors 59a and 59b. Further, the traveling control device 61 includes a power control unit 62 having a built-in battery. The power control unit 62 supplies the current from the battery to the motors 59a and 59b according to the instruction from the microcomputer 63, and
It is possible to control operating states such as rotation and stop of 9a and 59b.

The traveling control device 61 is electrically connected to an electromagnetic induction sensor 65 which is installed at an end portion of the electromagnetic induction type unmanned vehicle 50 so as to be bilaterally symmetrical with respect to a central longitudinal section. As a result, the output signal of the electromagnetic induction sensor 65 can be input to the traveling control device 61, more precisely, to the microcomputer 63. This electromagnetic induction sensor 65
Is a position crossing a vertical extension plane of the axis of the electromagnetic induction wire 80.

The microcomputer 63 is a well-known CP.
The U63a, the ROM 63b, the RAM 63c, and the input / output circuit 63d are connected by a bidirectional bus 63f to form an arithmetic logic operation circuit. In addition, in the ROM 63b,
Programs for performing various processes according to a predetermined procedure are stored in advance.

In the steering amount calculation routine shown in FIG. 9, the microcomputer 63 reads the output from the electromagnetic induction sensor 65, calculates the steering amount based on the signal, and gives an instruction to the power control unit 62. , The traveling speed and traveling direction are also instructed by a separately set subroutine.

In the steering amount calculation routine, the microcomputer 63 reads a value proportional to the deviation amount output from the electromagnetic induction sensor 65 as data (step 10).
00). Then, the steering amount is calculated based on the read data (step 2000). Next, the calculated steering amount is instructed to the power control unit 62 (step 300).
0).

Next, the operation of the electromagnetic induction type unmanned vehicle 50 of this embodiment will be described. When an instruction to start traveling is given to the electromagnetic induction type unmanned vehicle 50 mounted on the traveling road surface 70, the microcomputer 63 outputs an instruction signal regarding traveling speed and traveling direction. The traveling control device 61 supplies electric power to the motors 59a and 59b so that the traveling speed and the traveling direction correspond to the instruction signal of the microcomputer 63.

The drive wheels 5 are driven by the motors 59a and 59b operating.
When 7a and 57b are rotated, the electromagnetic induction type unmanned vehicle 50 travels in a direction corresponding to the rotation direction of the drive wheels 57a and 57b. During traveling, the relative position of the electromagnetic induction wire 80 and the horizontal direction intersecting the axial direction of the electromagnetic induction wire 80 of the electromagnetic induction type unmanned vehicle 50 is changed, and the axis line along the traveling direction of the electromagnetic induction sensor 65 becomes electromagnetic induction. When the line 80 is biased to the left or right from the vertical extension plane of the axis, the electromagnetic induction sensor 65 outputs a signal proportional to the bias amount, and the microcomputer 63
Entered in.

For example, assuming that the electromagnetic induction type unmanned vehicle 50 is deviated by x (m) in the direction of arrow A in FIG. 7 (deviation amount x), kx (k is a proportional constant) from the electromagnetic induction sensor 65.
Is output. When kx is input, the microcomputer 63 first reads a value proportional to the deviation amount as data according to the routine shown in FIG. 9 (step 1
000). Then, the steering amount is calculated based on the read data (step 2000). Next, the calculated steering amount is output (step 3000).

The power control unit 62 controls the motors 59a, 5a depending on the steering amount calculated and output by the microcomputer 63.
The rotation speed of 9b is changed so that the drive wheels 57a,
The rotation speed of 57b is changed. In the above example, the rotational speeds of the motors 59a and 59b are controlled so that the rotational speed of the drive wheel 57b is higher than the rotational speed of the drive wheel 57a. Then, the electromagnetic induction type unmanned vehicle 50 curves in the direction opposite to the arrow A, and the deviation is corrected. When the steering process according to the steering amount input from the microcomputer 63 is completed, the rotational speeds of the motors 59a and 59b are set to the same speed again, and the electromagnetic induction type unmanned vehicle 50 goes straight.

When the electromagnetic induction sensor 65 detects a deviation from the electromagnetic induction wire 80 in the electromagnetic induction type unmanned vehicle 50 in the straight traveling state, the electromagnetic induction type unmanned vehicle 50 repeats the same process as described above. It becomes a state. The electromagnetic induction type unmanned vehicle 50 travels along the electromagnetic induction wire 80 while repeating this, and stops at a position set separately.

Even if the electromagnetic induction type unmanned vehicle 50 moves up and down due to a change in the state of the traveling road surface 70 and the relative height to the traveling road surface 70, that is, the electromagnetic induction wire 80 changes, the electromagnetic induction sensor 6
5 is not affected by the height change, and outputs an output signal proportional to only the amount of deviation. Therefore, the steering amount calculated according to the signal is not affected by the height change, and stable steering is possible.

In this embodiment, the motors 59a and 59b are driven by the battery built in the traveling control device 61, but electric power is supplied from the trolley installed on the traveling road surface 70 instead of the battery. May be An analog circuit may be used instead of the microcomputer 63 of the travel control device 61.

Further, the steering system of the electromagnetic induction type unmanned vehicle is not limited to the above, depending on the rotational speeds of the left and right drive wheels, for example, the system of changing the direction of the guide wheels. Drive wheel,
The number and arrangement of the guide wheels are not limited to those in the second embodiment, and various numbers and arrangements such as two front wheels-two rear wheels and one front wheel-two rear wheels can be used.

The present invention is not limited to the embodiments as described above, and can be carried out in various modes without departing from the gist of the present invention.

[0061]

As described in detail above, the deviation detecting sensor of the present invention is not affected by the change in the relative position of the deviation coil in the height direction with respect to the electromagnetic induction wire, and is capable of outputting an amount proportional to only the deviation amount. Become. In addition, the electromagnetic induction type unmanned vehicle that uses this deviation detection sensor as an electromagnetic induction sensor can be stably steered without being affected by changes in the height of the electromagnetic induction sensor and the electromagnetic induction wire.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a sensing unit of a deviation detection sensor according to a first embodiment.

FIG. 2 is a block diagram of the deviation detection sensor according to the first embodiment.

FIG. 3 is a block diagram illustrating a configuration of a processing unit of the deviation detection sensor according to the first exemplary embodiment.

FIG. 4 is a flowchart of a deviation amount calculation routine in the first embodiment.

FIG. 5 is an explanatory diagram of a relative position of each coil of the electromagnetic induction wire and the deviation detection sensor in the first embodiment.

FIG. 6 is an explanatory diagram showing a configuration of an electromagnetic induction type unmanned vehicle of a second embodiment.

FIG. 7 is an explanatory diagram of relative positions of an electromagnetic induction type unmanned vehicle and an electromagnetic induction wire according to a second embodiment.

FIG. 8 is a block diagram of an electromagnetic induction type unmanned vehicle according to a second embodiment.

FIG. 9 is a flowchart of a steering amount calculation routine for an electromagnetic induction type unmanned vehicle according to a second embodiment.

FIG. 10 is a block diagram of a travel control device for an electromagnetic induction type unmanned vehicle according to a second embodiment.

[Explanation of symbols]

1 ... bias detection sensor, 3, 70 ... running road surface,
5, 80 ... Electromagnetic induction wire, 10 ... Sensing part,
11 ... Follow-up coil, 13a, 13b ... Biasing coil, 15 ... Height coil, 20 ... Processing part, 21 ...
..Drive circuits, 23 ... A / D conversion circuits, 25 ...
Microcomputer, 50 ... Electromagnetic induction type unmanned vehicle,
57a, 57b ... Drive wheels, 59a, 59b ... Motor, 61 ... Travel control device, 63 ... Microcomputer, 65 ... Electromagnetic induction sensor,

Claims (2)

[Claims] 1. A deviation detection sensor for detecting a magnetic field formed by an electromagnetic induction wire to detect a deviation from the electromagnetic induction wire, the pair being arranged such that axes thereof are parallel and central cross sections thereof are on the same plane. A bias coil, and an output of the pair of bias coils is obtained, and a processing unit for calculating and outputting a value proportional to the bias of the electromagnetic induction wire and the pair of coils from the output is provided. Bias detection sensor. 2. An electromagnetic induction type unmanned vehicle, wherein the deviation detection sensor according to claim 1 is used as an electromagnetic induction sensor.