JPH061249A - Position sensor and electromagnetic induction type automated guided vehicle using the same - Google Patents

Abstract

PURPOSE:To cope with the fore and aft motion and traverse motion of an electromagnetic induction type automated guide vehicle by one position sensor by disposing upper and lower declination coils at the center of a sensing block, and disposing offset coils on two straight lines intersecting at the center. CONSTITUTION:A sensing block 10 is provided at its center with a lower declination coil pair 12 and an upper declination coil pair 14 formed of mutually orthogonal declination coils, and four offset coils 16a, 16b, 18a, 18b are disposed around the lower declination coil pair 12. With this constitution, longitudinal and lateral travel can be coped with by one sensing block 10. A position sensor obtains the output of the respective coils 12, 14, 16a, 16b, 18a, 18b and generates an induced current to itself by electromotive force corresponding to the intensity of a magnetic field formed by an electromagnetic induction line 30 and sends output corresponding to the electromotive force. With the use of this position sensor as an electromagnetic induction sensor, the fore and aft motion and traverse motion of an electromagnetic induction type automated guided vehicle can be coped with by one electromagnetic induction sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position sensor which detects a magnetic field formed by an electromagnetic induction wire installed on a road surface and detects a relative position to the electromagnetic induction wire, and the position sensor as an electromagnetic induction sensor. The present invention relates to an electromagnetic induction type unmanned vehicle used.

[0002]

2. Description of the Related Art Conventionally, an electromagnetic sensor for detecting a concentric magnetic field formed by an alternating current applied to an electromagnetic induction wire installed on a road surface has been used as an electromagnetic induction sensor, and the electromagnetic induction wire is at the center of the sensor. There is known an electromagnetic induction type unmanned vehicle that steers the vehicle directly below and travels on a traveling road surface. As the electromagnetic sensor used for this purpose, a pair of bias coils having a common axis in a direction orthogonal to the axial direction of the electromagnetic induction wire, and a follow-up coil that follows the electromagnetic induction wire and detects the presence or absence of derailment. It is known that the format is composed of.

[0003]

Such a conventional electromagnetic induction sensor is usually used by being attached to the end of an electromagnetic induction type unmanned vehicle. Therefore, when the vehicle moves forward or backward only in one direction, one electromagnetic induction sensor can be used, but in order to respond to the vehicle moving forward or backward, a plurality of electromagnetic induction sensors can be used, for example. I had to prepare for the edge. Further, in order to cope with the lateral movement of the vehicle in addition to the forward / backward movement, the number of electromagnetic induction sensors to be mounted is further increased, which complicates the mounting work of the electromagnetic induction sensors and complicates the output processing thereof. There was such a problem.

On the other hand, in the conventional electromagnetic induction sensor, the relative displacement of the sensor in the direction orthogonal to the axial direction of the electromagnetic induction wire,
That is, although the deviation amount can be detected, it is insufficient for detecting the angle of the axis line of the sensor with respect to the axial direction of the electromagnetic induction wire, that is, the deviation angle. Therefore, since the steering amount is determined according to the sensor signal value of only the deviation amount regardless of the deviation angle, steering of the electromagnetic induction type unmanned vehicle may not be stable, which is a problem. Alternatively, an electromagnetic induction sensor is installed at the front and rear ends of the electromagnetic induction type unmanned vehicle to correct the declination.

Therefore, the present invention has an object to solve the above-mentioned problems, and can cope with the forward and backward movement and the lateral movement of an electromagnetic induction type unmanned vehicle with one sensor, and further, the deviation from the electromagnetic induction wire and the electromagnetic induction wire can be used. It is an object of the present invention to provide a position sensor capable of outputting an amount correlating with the declination angle and an electromagnetic induction type unmanned vehicle using the sensor.

[0006]

The present invention adopts the following constitution as means for solving the above problems. That is, the position sensor according to claim 1 is a position sensor that detects a magnetic field formed by an electromagnetic induction wire to detect a relative position to the electromagnetic induction wire, and two straight lines that are substantially on the same plane and intersect each other. As an axis, each of the axes has one bias coil disposed on each side of the intersection of the axes, and an axis substantially parallel to the plane and not parallel to each other, and the plane at the intersection. A pair of lower deflection angle coils arranged with the coil center on a vertical line orthogonal to
A pair of upper deflection angles that have axes that are substantially parallel to the plane and are non-parallel to each other, the coil center is located on the vertical line, and the upper deflection angle is arranged above the lower deflection angle coil with a gap therebetween. A process of obtaining a sensing block having a coil, outputs of the bias coil and upper and lower deflection coils, and calculating and outputting a value correlating with the relative position of the electromagnetic induction wire and the sensing block from the output. And a section are provided.

An electromagnetic induction type unmanned vehicle according to a second aspect uses the position sensor according to the first aspect as an electromagnetic induction sensor.

[0008]

In the position sensor having the above structure, the sensing block makes the surfaces formed by the axes of the two sets of bias coils substantially parallel to the traveling road surface so that the intersections of the axes are located almost directly above the electromagnetic induction wires. Is installed. Each coil forming the sensing block 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.

The electromotive force due to electromagnetic induction generated in the coil placed at a point in the magnetic field formed by the current flowing through the electromagnetic induction wire is proportional to the magnetic flux intersecting the coil. The strength of the magnetic field at that point is inversely proportional to the distance from the electromagnetic induction line, and the magnetic flux crossing the coil is proportional to the sine of the crossing angle between the coil and the magnetic field. Therefore, the electromotive force generated in the coil correlates with the distance between the coil and the electromagnetic induction wire and the crossing angle between the coil and the magnetic field, that is, the relative position between each coil and the electromagnetic induction wire.

When a value proportional to the output of each coil is input to the processing unit and processed, a value correlating with the deviation amount and the deviation angle between the sensing block and the electromagnetic induction wire is calculated. The processing unit outputs the calculated value. In an electromagnetic induction type unmanned vehicle characterized by using this position sensor as an electromagnetic induction sensor, in accordance with the output from the position sensor attached to the unmanned vehicle at an appropriate position, the unmanned vehicle is moved along the traveling direction. The axis is steered so that it is located directly above the electromagnetic induction wire.

Since the output value from this position sensor is a value proportional to the deviation amount and the deviation angle, the electromagnetic induction type unmanned vehicle is adapted to the vehicle body motion characteristics not only according to the deviation amount but also the deviation angle. Therefore, the steering angle can be controlled. Therefore, the course of the electromagnetic induction type unmanned vehicle is smoothly corrected, the electromagnetic induction line following ability of the electromagnetic induction type unmanned vehicle is improved, and the steering is stabilized.

Moreover, since the deflection coil is arranged at the center of the sensing block and the deflection coils are arranged on the two straight lines intersecting at the center, the deflection of the electromagnetic induction type unmanned vehicle in the front-rear direction and the left-right direction is unbalanced. Absent. Therefore, the position sensor can be used for any of forward movement, backward movement, leftward movement and rightward movement of the electromagnetic induction type unmanned vehicle. Therefore, since one position sensor can cope with the forward and backward movement and the lateral movement of the electromagnetic induction type unmanned vehicle, it is not necessary to provide a plurality of sensors according to the traveling direction of the electromagnetic induction type unmanned vehicle.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. (Example 1) The position sensor 1 is installed in an electromagnetic induction type unmanned vehicle (not shown). As shown in FIGS. 1 and 2, a lower deflection angle coil pair 12 including deflection angle coils 12a and 12b orthogonal to each other is arranged at the center of a sensing block 10 of the position sensor 1. The axes of the declination coils 12a and 12b are orthogonal to each other, and the intersections thereof coincide with the coil centers of the declination coils 12a and 12b.

Above the lower deflection angle coil pair 12, there is disposed an upper deflection angle coil pair 14 which is also composed of deflection angle coils 14a and 14b which are also orthogonal to each other. Declination coil 1
The axes of 4a and 14b are orthogonal to each other, and the intersecting point coincides with the coil centers of the deflection coils 14a and 14b. Further, a straight line connecting the coil centers of the deflection coils 12a and 12b and the coil centers of the deflection coils 14a and 14b is orthogonal to the axes of the deflection coils 12a to 14b.

Each of the deflection coils 12a to 14b is a one-turn ring coil, and the description will be made assuming that the magnetic flux density distribution in the coils is small enough to be considered substantially uniform. In this embodiment, each of the deflection coils 12a to 14b has an outer diameter of about 6
0 mm, one of the deflection coils 12a, 14a at the intersection
There is only a slight recess in the shape, which is almost the same shape.

Around the lower deflection coil pair 12, the deflection coils 16a, 16 having an axis on a plane (common plane in this embodiment) parallel to the axes of the deflection coils 12a, 12b.
b, 18a, 18b are arranged. Bias coil 16
The axes of a and 16b are common, and the bias coils 16a and 1b are
The first bias coil pair 16 is formed by 6b. Also,
The bias coils 18a and 18b have the same axis, and the bias coils 18a and 18b form a second bias coil pair 18.

The axes of the bias coils 16a and 16b and the axes of the bias coils 18a and 18b are 2α (rad) relative to each other.
Intersect at the angle. In this embodiment, 2α = π / 2
And both axes are orthogonal. The intersection is the declination coil 12
It coincides with the intersection of the axes of a and 12b. The distance from the intersection of the axes to the bias coils 16a-18b is a
In (m), the influence of mutual induction is negligible, and in this example, a = 0.1 (m). The distance 2a between the pair of bias coils 16a and 16b and the distance between the bias coils 18a and 18b is not particularly limited, but the sensing block 10 or the position sensor 1 becomes larger as the distance becomes larger. It is preferable to make it appropriate.

The bias coils 16a to 18b are ring coils having one turn, and the description will be made assuming that the magnetic flux density distribution in the coils is small enough to be regarded as substantially uniform. In this embodiment, each of the bias coils 16a to 18b has an outer diameter of about 30.
The shape is mm and can be regarded as the same shape.

Further, as shown in FIG. 2, below the sensing block 10 in the drawing, the electromagnetic induction wire 3 is provided below the traveling road surface 20.
0 is buried. An alternating current from a power source (not shown) is passed through the electromagnetic induction wire 30, and a magnetic field centered on the axis of the electromagnetic induction wire 30 is formed by the action of the alternating current.

The axes of the deflection coils 12a-14b and the deflection coils 16a-18b and the traveling road surface 20 are substantially parallel to each other. As shown in FIG. 3, the deflection angles and the outputs from the deflection coils 12 a to 18 b are configured to be input to the processing unit 40.

As shown in FIG. 4, the processing unit 40 includes the deflection coils 12a-14b and the deflection coils 16a-18b.
A drive circuit 42 for amplifying and rectifying the input signal from the drive circuit 42, an A / D conversion circuit 44 for analog / digital conversion of a signal corresponding to the input signal from the drive circuit 42, and an A / D conversion circuit 44 for conversion. It is composed of a microcomputer 46 which reads a digital signal, performs arithmetic processing, and outputs it. The microcomputer 46 is a well-known CP.
U46a, ROM46b, RAM46c, input port 4
6d and the output port 46e are connected by a bidirectional bus 46f, which is configured as an arithmetic logic operation circuit. ROM
A program for performing various processes according to a predetermined procedure is stored in advance in 46b.

Next, the arithmetic processing in the processing section 40 will be described. FIG. 5 shows the routine. Data proportional to the outputs of the deflection coils 12a-14b and the deflection coils 16a-18b are input via the drive circuit 42, the A / D conversion circuit 44, and the input port 46d, and the CPU 4
6a is read (step 100). Then, a value that correlates with the relative position of the sensing block 10 with respect to the electromagnetic induction wire 30 is calculated based on each of the above-mentioned data and is output (step 200).

In step 200, the following calculation is performed. First, a case will be described in which the electromagnetic induction type unmanned vehicle on which the position sensor 1 is installed is to be moved along the electromagnetic induction wire 30 in the arrow F direction in FIG. As illustrated in FIG. 1, the sensing block 10 of the position sensor 1
The horizontal position of the sensing block 10 from the electromagnetic induction wire 30 (hereinafter referred to as the amount of deviation) is x (m), and the relative position between the electromagnetic induction wire 30 and the electromagnetic induction wire 30 is Form an angle of θ (rad) (hereinafter referred to as a declination angle).

For convenience of explanation, each physical quantity and constant are expressed as follows. All distances or intervals are core-core. a: 1/2 (m) of the gap between the bias coil pairs B: Magnetic flux density (Wb / m ² ) due to the current being applied to the electromagnetic induction wire 30 h: From the electromagnetic induction wire 30 of the bias coil and the lower deflection coil Height (m) h _c : Distance between upper deflection coil and lower deflection coil (m) H: Magnetic field strength (A / m) due to current being applied to electromagnetic induction wire 30 H _AL : Deflection the amount proportional to the output of the coil 16a H _BL: amount proportional to the output of the bias coil 16b H _AR: amount proportional to the output of the bias coil 18a H _BR: amount proportional to the output of the bias coil 18b H _oF: declination coil Amount proportional to the output of the eccentric coil 12b H _OT : An amount proportional to the output of the eccentric coil 12b H _CF : An amount proportional to the output of the eccentric coil 14a H _CT : An amount proportional to the output of the eccentric coil 14b I: Electromagnetic induction The electric current (A) r being applied to the wire 30 : Distance from electromagnetic induction wire 30 (m) x: Deflection amount (m) α: 1/2 of crossing angle of axis of bias coil pair (ra
d) η: angle formed by the horizontal plane of r (rad) θ: declination (rad) μ _o : permeability of vacuum (4π × 10 ^-7 ), the strength of the magnetic field due to the current of the electromagnetic induction wire 30 at a distance r

[0025]

[Equation 1]

And the magnetic flux density is

[0027]

[Equation 2]

[0028] The electromotive force due to electromagnetic induction generated in the coil placed at a certain point in the magnetic field formed by the current flowing through the electromagnetic induction wire 30 is proportional to the magnetic flux intersecting the coil. The strength of the magnetic field at that point is inversely proportional to the distance r from the electromagnetic induction line. The magnetic flux that intersects the coil is
If the coil axis is horizontal and there is an angle of r and η, it is proportional to sin η. Therefore, the electromotive force generated in the coil is sin η
Proportional to / r.

Considering the point x in the horizontal direction and h in the height direction from the electromagnetic induction line,

[0030]

[Equation 3]

In addition,

[0032]

[Equation 4]

It becomes Therefore, if 1 / 2π is regarded as a proportional constant and the argument of the sensing block 10 is θ,
The amount H _OF proportional to the output of the deflection coil 12a is

[0034]

[Equation 5]

Therefore, in the same direction as the deflection coil 12a,
The amount H _CF proportional to the output of the deflection coil 14a located above it is _calculated by substituting h + h _c for h in equation (5).

[0036]

[Equation 6]

[0037] Similarly, the quantity H _OT proportional to the output of the deflection coil 12b and the quantity H _CT proportional to the output of the deflection coil 14b are

[0038]

[Equation 7]

[0039]

[Equation 8]

It becomes Furthermore, from equations (5) and (6)

[0041]

[Equation 9]

Is obtained. Also, from equations (5) and (7)

[0043]

[Equation 10]

Since the value corresponding to tan θ is obtained, the deviation angle θ can be calculated from this.

[0045]

[Equation 11]

Since θ can be obtained from the equation (11), h can be calculated by substituting this into the equation (9) and calculating the output values of the deflection coils 12a to 14b. Next, the quantities H _AL , H _BL , H _AR proportional to the outputs of the respective bias coils 16a-18b.
And H _BR will be described.

In FIG. 1, P and Q are respectively

[0048]

[Equation 12]

[0049]

[Equation 13]

It is Therefore, H _AL , H _BL , H _AR and H _BR are

[0051]

[Equation 14]

[0052]

[Equation 15]

[0053]

[Equation 16]

[0054]

[Equation 17]

Since α = π / 4 in this embodiment, in the above equations (14) to (17),

[0056]

[Equation 18]

It becomes Above H _AL , H _BL , H _AR and H _BR
A value proportional to the displacement amount x is calculated by the following equation, and combined with the deflection angle θ obtained by the equation (11) and h obtained by the equation (9), the relative position of the sensing block 10 to the electromagnetic induction wire 30 is calculated. Can be shown.

In order to calculate a value which is accurately proportional to the displacement amount x from the above equations (14) to (17), the calculation becomes complicated and the accuracy required for the position sensor 1 is taken into consideration. In the example, as the relative deviation amount that is approximately proportional to the deviation amount x,

[0059]

[Formula 19]

The obtained D was used. The result of the simulation based on the equation (19) is shown in FIG.
The specific deviation amount D obtained by the equation (9) is proportional to the deviation amount x without being influenced by the height h, and the deviation increases as the deviation angle increases, but it is sufficiently practical. Note that the approximation formula that can be adopted is not limited to the formula (19), and an appropriate approximation formula may be used in consideration of accuracy required by the purpose of use of the position sensor 1 and the like. Of course, deviation x
It is also possible to calculate a value that is exactly proportional to and output it.

As the output of the position sensor 1, the deviation angle θ obtained by the equation (11), h obtained by the equation (9), and the specific deviation amount D obtained by the equation (19) are individually output.
It is also possible to combine these and output. In the present embodiment, the sensor output S is an amount proportional to the steering angle corresponding to the relative position with respect to the electromagnetic induction wire 30 of the electromagnetic induction type unmanned vehicle,

[0062]

[Equation 20]

It is output in the form of. k ₁ and k ₂ are proportional constants and are set according to the motion characteristics of the electromagnetic induction type unmanned vehicle in which the position sensor 1 is installed. As described above, each coil 12a
The quantities H _OF , H _CF , H _OT and H _{CT which} are proportional to the output of
H _AL , H _BL , H _AR, and H _BR can be input to the CPU 46a to calculate and output a value that correlates to the relative position of the sensing block 10 with respect to the electromagnetic induction wire 30.

When the angle of deviation θ = 0, sin θ = 0
Therefore, H in equation (7)_OT= 0. Also,
Tan θ = 0 according to the equation (10). Therefore output
S = k ₁It is D. When the deviation amount x = 0, H_AR
= H_BR, H_AL= H_BLTherefore, D = 0 in equation (19)
Become. Therefore the output S = k₂θ.

Next, the operation of the position sensor 1 of this embodiment will be described. The deflection angle and the deflection coil 12 of the position sensor 1 arranged at a relative position almost directly above the electromagnetic induction wire 30.
a to 18b are in the magnetic field formed by the alternating current passing through the electromagnetic induction wire 30. Since the strength of the magnetic field formed by the change in the phase of the alternating current applied to the electromagnetic induction wire 30 changes, the deflection angle and the deflection coil 1
The magnetic flux density interlinking with 2a to 18b changes. As a result, an induced voltage is generated in the deflection angle and deflection coils 12a-18b. An electric signal corresponding to this induced voltage is input to the processing unit 40 from the deflection angle and deflection coils 12a to 18b.

In the processing section 40, first, the electric signals from the deflection angle and deflection coils 12a to 18b are subjected to processing such as amplification, noise signal removal and rectification in the drive circuit 42,
It is sent to the A / D conversion circuit 44. The signal input to the A / D conversion circuit 44 is converted into a digital signal here, and input to the microcomputer 46 as data proportional to the deflection angle and the outputs of the deflection coils 12a to 18b.

When data is input to the input port 46d, the CPU 46a starts the routine process shown in FIG. That is, the data proportional to the output of each coil 12a-18b is read (step 100), and the value proportional to the steering angle corresponding to the relative position of the sensing block 10 with respect to the electromagnetic induction wire 30 is calculated based on the data. , Is output (step 200). This value is the value shown in the equation (20).

D in the output S from the processing unit 40 is set to be positive or negative depending on the direction of the bias, that is, the right bias or the left bias. Similarly, θ is set to be either positive or negative depending on the right or left declination. Further, by adjusting the set values of k ₁ and k _{2 in} the equation (20), the proportion of the displacement amount element or the deflection angle element in the output S can be adjusted according to the motion characteristics of the electromagnetic induction type unmanned vehicle. You can

When the electromagnetic induction type unmanned vehicle is moved along the electromagnetic induction wire 30 in the direction of arrow R in FIG. 1, that is, the position sensor 1 is moved along the electromagnetic induction wire 30 in the direction of arrow R in FIG. In this case, the outputs of the bias coil 16a and the bias coil 16b are exchanged with each other.
If the outputs of 8a and the bias coil 18b are interchanged and processed, the same output as above can be obtained.

Further, since the electromagnetic induction wire 30 is at a position rotated by about 90 degrees from the case shown in FIG. 1, the electromagnetic induction type unmanned vehicle,
That is, when the position sensor 1 is traversed in the leftward direction along the position sensor 1, the deflection angle coil 12a and the deflection angle coil 12b.
And the outputs of the deflection coil 14a and the deflection coil 14b are exchanged with each other, and the outputs of the deflection coil 16a → the deflection coil 18b → the deflection coil 16b → the deflection coil 18a → the deflection coil 16a are exchanged. Just process it. Similarly, in the case of traversing to the right in the drawing, the coil outputs may be exchanged and processed in the reverse direction to the case of traversing to the left.

Such an electromagnetic induction type unmanned vehicle, that is, the process of changing the coil output depending on the relative moving direction of the position sensor 1 can be realized by storing a program therefor in the ROM 46b in advance. is there. Although each of the coils 12a to 18b in this embodiment has been described as a one-turn ring coil, 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. When the windings of the upper and lower deflection coils are crossed a plurality of times, the windings of one coil are passed inside and outside by alternately passing the winding inside and outside the other coil at the intersection, for example. Good output characteristics are obtained by balancing the windings as a whole.

Further, in the present embodiment, the arithmetic processing in the processing section 40 is performed by the microcomputer 46, 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 44 becomes unnecessary. The description of the first embodiment is completed above, and then, an example of an electromagnetic induction type unmanned vehicle using the position sensor described in the first embodiment as an electromagnetic induction sensor will be described. (Embodiment 2) FIG. 7 is a block diagram illustrating the basic configuration of an electromagnetic induction type unmanned vehicle, and FIG. 8 is an explanatory diagram showing the device configuration of an electromagnetic induction type unmanned vehicle 50 of this example.

First, the structure of the electromagnetic induction type unmanned vehicle 50 will be described. 9 and 10 show an electromagnetic induction type unmanned vehicle 50.
FIG. 3 is an explanatory diagram showing a state in which is mounted on a traveling road surface 52. An electromagnetic induction wire 54 of a conductive cable is embedded under the traveling road surface 52, and an alternating current from a power supply device (not shown) is supplied to the electromagnetic induction wire 54. The electromagnetic induction type unmanned vehicle 50 is movable on the traveling road surface 52 along the axial direction of the electromagnetic induction wire 54.

The electromagnetic induction type unmanned vehicle 50 is a rectangular carriage 5.
Four driving wheels 58a, 58b, 58 arranged at the four corners of 6
c, 58d. The driving wheels 58a to 58d are provided with motors 60a, 60b, 60c, respectively.
It is driven by 60d to rotate.

Further, the moving wheels 58a to 58d are respectively provided with the carriage 5 via the supporting members 62a, 62b, 62c and 62d.
It is attached to 6. These support members 62a-6
2d has 36 axes with the axis perpendicular to the floor of the truck 56 as the axis of rotation.
It is possible to steer 0 degrees. The support members 62a to 62
Depending on the rotation of d, the relative orientations of the rotating surfaces of the moving wheels 58a to 58d can be changed over 360 degrees.

A traveling controller 68 having a microcomputer 64 and a power controller 66 is electrically connected to the motors 60a-60d. The power control unit 66 has a built-in battery, and the microcomputer 64
In response to the instruction from the
0a to 60d and the motors 60a to 60d
It is possible to control the operating state such as rotation and stop of d. In addition, the driving wheels 58a to
The direction of the rotating surface of 58d can be controlled.

An electromagnetic induction sensor 70 installed substantially in the lower center of the carriage 56 is electrically connected to the travel control device 68, and an output signal of the electromagnetic induction sensor 70 is accurately transmitted to the travel control device 68. Input to the microcomputer 64 is possible. The electromagnetic induction sensor 70 is the position sensor shown in the first embodiment.

The microcomputer 64 is a well-known CP.
The U64a, the ROM 64b, the RAM 64c, and the input / output circuit 64d are connected by a bidirectional bus 64f to constitute an arithmetic logic operation circuit. In addition, in the ROM 64b,
Programs for performing various processes according to a predetermined procedure are stored in advance.

In the steering amount calculation routine shown in FIG. 11, the microcomputer 64 reads the output from the electromagnetic induction sensor 70, calculates the steering amount based on the signal, and gives an instruction to the power control unit 66. The traveling speed and traveling direction are also instructed by a subroutine set separately.

In the steering amount calculation routine, the microcomputer 64 reads the value output from the electromagnetic induction sensor 70 as data (step 1000). Then, the steering amount is calculated according to the traveling speed based on the data read in step 1000 (step 2000).
Next, the calculated steering amount is instructed to the power control unit 66 (step 3000).

The electromagnetic induction type unmanned vehicle 50 is equipped with a direction switching sensor for detecting a traveling direction switching point such as a branch point of the electromagnetic induction wire 54. When the direction switching sensor detects the traveling direction switching point, the data is input to the microcomputer 64. Microcomputer 64
Indicates a traveling speed and a traveling direction according to the input by a subroutine set separately.

In addition, when the traveling direction is switched,
The direction data is input from the microcomputer 64 to the electromagnetic induction sensor 70. Then, in the processing unit of the electromagnetic induction sensor 70, the outputs from the coils forming the sensing block are switched according to the traveling direction.
Accordingly, the output S from the electromagnetic induction sensor 70 becomes an appropriate output according to the traveling direction of the electromagnetic induction type unmanned vehicle 50.

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 placed on the traveling road surface 52, the microcomputer 64 outputs an instruction signal regarding a traveling speed and a traveling direction. The traveling control device 68 supplies electric power to the motors 60a to 60d so that the traveling speed and traveling direction correspond to the instruction signal from the microcomputer 64.

The motors 60a-60d are operated to drive the moving wheel 58.
When a to 58d are rotated, the electromagnetic induction type unmanned vehicle 50 travels in a direction corresponding to the rotating direction of the moving wheels 58a to 58d.
If the horizontal relative positions of the electromagnetic induction wire 54 and the electromagnetic induction type unmanned vehicle 50 change during traveling, a deviation angle and / or a deviation occurs.

The axis line of the electromagnetic induction sensor 70 along the traveling direction of the electromagnetic induction type unmanned vehicle 50 yaws to the left or right from the vertical extension plane of the axis line of the electromagnetic induction line 54, and at the same time from the electromagnetic induction line 54. When there is a deviation, a signal proportional to the deviation angle and the steering angle corresponding to the deviation amount is output from the electromagnetic induction sensor 70 and input to the microcomputer 64.

For example, the electromagnetic induction type unmanned vehicle 50 moving in the direction of arrow A in FIG. 13 causes a deviation angle of θ (rad) with respect to the electromagnetic induction wire 54 (deviation angle θ), and a deviation of x (m). Suppose that (the deviation amount x), S from the electromagnetic induction sensor 70
= K ₁ D + k ₂ θ (k ₁ and k ₂ are proportional constants) is output.

The microcomputer 64 follows the routine shown in FIG. 11 and outputs the output S of the electromagnetic induction sensor 70.
Is read as data (step 1000). next,
A steering amount suitable for the traveling speed is calculated based on the read data (step 2000). Then, the calculated steering amount is output (step 3000).

The power control unit 66 controls the moving wheels 58a to 58 according to the steering amount calculated and output by the microcomputer 64.
Steer d. This steering is performed by changing the azimuths of the rotation surfaces of the two front wheels, the two rear wheels, or the four wheels in the traveling direction.
In response to the steering, the electromagnetic induction type unmanned vehicle 50 turns in the direction of the arrow B, and the deviation and the deviation angle are corrected.

In the present embodiment, the steering of the electromagnetic induction type unmanned vehicle 50 is carried out according to the amount of deviation and the angle of deviation.
The steering is smoother than the steering based only on the deviation amount. When the steering process according to the steering amount input from the microcomputer 64 is completed, the steering is returned to neutral and the electromagnetic induction type unmanned vehicle 50 goes straight.

In the electromagnetic induction type unmanned vehicle 50 in the straight traveling state, when the electromagnetic induction sensor 70 detects the deviation angle and the deviation from the electromagnetic induction wire 54, the electromagnetic induction type unmanned vehicle is again subjected to the same process as described above. 50 goes straight. Even when the horizontal relative position change between the electromagnetic induction wire 54 and the electromagnetic induction type unmanned vehicle 50 is only the declination or only the deviation,
Similarly to the above, the microcomputer 64 reads the output of the electromagnetic induction sensor 70 as data (step 10
00), the steering amount is calculated based on the read data (step 2000), and the calculated steering amount is output (step 3000).

Subsequently, as in the above, the power control unit 66.
Operates the moving wheels 58a to 58d in accordance with the steering amount calculated and output by the microcomputer 64 and brings the electromagnetic induction type unmanned vehicle 50 into a straight traveling state. Further, for example, as shown in FIG. 14, the electromagnetic induction type unmanned vehicle 50 traveling in the direction of the arrow Y along the electromagnetic induction line 54 is branched by the electromagnetic induction line 54.
The traveling direction may be switched in the arrow X direction along a.

Even in such a case, as described above, by exchanging the inputs of the respective coil outputs constituting the sensing block of the electromagnetic induction sensor 70 to the processing section, the values equivalent to those obtained by rotating the sensing block by 90 degrees are obtained. It becomes a state. Further, when switching from the forward direction to the reverse direction or from the rightward direction to the leftward direction, the directivity of the sensing block can be similarly changed. Therefore, one electromagnetic induction sensor 70 can handle forward and backward movement of the electromagnetic induction type unmanned vehicle 50 along the electromagnetic induction wire 54 and traverse along the electromagnetic induction wire 54a.

When using the prior art position sensor, FIG.
It was difficult to switch the traveling direction as shown in FIG. For this reason, loading and unloading and the opposing electromagnetic induction type unmanned vehicle 5
A side-line system as shown in FIG. 15 has been adopted when passing 0a each other.

However, the electromagnetic induction type unmanned vehicle 5 of the present embodiment.
As 0 can deal with forward and backward movement and left and right movement as described above, only the length of itself plus the section of alpha is sufficient for loading, unloading and evacuating. Since the side line is not necessary, the work area can be reduced. Further, it is possible to work in a narrow area.

Further, even when the electromagnetic induction type unmanned vehicle 50 is mounted on an elevator or the like, it is sufficient to provide a branch guide wire extending from the traveling electromagnetic induction wire parallel to the elevator entrance / exit to the elevator entrance / exit. Yes, no special equipment is required. Therefore, the application range of the electromagnetic induction type unmanned vehicle 50 in the cargo handling work is expanded.

The electromagnetic induction type unmanned vehicle 50 travels along the electromagnetic induction line 54 while repeating the change of the relative position with respect to the electromagnetic induction line 54 and the steering according to the change as described above, and is set separately. Stop at the position. Although the deflection angle component and the displacement amount component of the electromagnetic induction sensor 70 are combined and output in the present embodiment, each component may be independently input to the microcomputer 64.

Although the motors 60a to 60d are driven by the battery built in the traveling control device 68, electric power may be supplied from a trolley wire installed on the traveling road surface 52 or the like instead of the battery. . Further, the steering method of the electromagnetic induction type unmanned vehicle is not particularly limited, for example, a method based on the rotation difference between the left and right moving wheels and a method of changing the direction of the moving wheels. The number and arrangement of the wheels are not particularly limited, 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.

[0099]

As described above in detail, the position sensor according to the present invention is capable of supporting the forward and backward movement and the lateral movement of the electromagnetic induction type unmanned vehicle with one sensor. For this reason, side lines are unnecessary,
Since the passage area is reduced, it is possible to effectively use the site of the factory, for example. Further, the range of use of the electromagnetic induction type unmanned vehicle is expanded.

Moreover, since the position sensor of the present invention can output an amount correlating with the deviation from the electromagnetic induction wire and the deviation angle with the electromagnetic induction wire, steering of the electromagnetic induction type unmanned vehicle using the sensor is possible. It is smooth and has excellent followability to electromagnetic induction wires.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a sensing block of a position sensor according to a first exemplary embodiment.

FIG. 2 is an explanatory diagram of a sensing block of the position sensor according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a position sensor according to the first embodiment.

FIG. 4 is a block diagram illustrating a configuration of a processing unit of the position sensor according to the first exemplary embodiment. 6 is a flowchart of a declination calculation routine in the first embodiment.

FIG. 5 is a flowchart of a value calculation routine that correlates with the relative position of the sensing block with respect to the electromagnetic induction wire in the first embodiment.

FIG. 6 is a graph showing the result of simulation based on equation (19).

FIG. 7 is a block diagram of an electromagnetic induction type unmanned vehicle according to a second embodiment.

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

FIG. 9 is a front view of an electromagnetic induction type unmanned vehicle according to a second embodiment.

FIG. 10 is a plan view of an electromagnetic induction type unmanned vehicle according to a second embodiment.

FIG. 11 is a flowchart of steering amount calculation in the second embodiment.

FIG. 12 is a block diagram of a travel control device according to a second embodiment.

FIG. 13 is an explanatory diagram of a relative position between an electromagnetic induction type unmanned vehicle and an electromagnetic induction wire according to a second embodiment.

FIG. 14 is an explanatory diagram of traveling direction switching in the electromagnetic induction type unmanned vehicle of the second embodiment.

FIG. 15 is an explanatory diagram of lateral lines in a conventional electromagnetic induction type unmanned vehicle.

[Explanation of symbols]

1 ... Position sensor, 10 ... Sensing block,
12 ... Lower deflection coil pair, 12a, 12b ... Deflection coil, 14 ... Upper deflection coil pair, 14a, 14
b ... Declination coil, 16 ... First bias coil pair, 1
6a, 16b ... bias coil, 18 ... 2nd bias coil pair, 18a, 18b ... bias coil, 20 ...
Road surface, 30 ... Electromagnetic induction wire, 40 ... Processing unit,
50: electromagnetic induction type unmanned vehicle, 52: traveling road surface, 5
4, 54a ... Electromagnetic induction wire, 68 ... Travel control device, 70 ... Electromagnetic induction sensor.

Claims (2)

[Claims] 1. A position sensor which detects a magnetic field formed by an electromagnetic induction wire and detects a relative position to the electromagnetic induction wire, wherein the axis line is two straight lines which are substantially on the same plane and intersect each other. A bias coil disposed on each side of the intersection of the axes with respect to each of the above, and having axes that are substantially parallel to the plane and non-parallel to each other, on a vertical line orthogonal to the plane at the intersection. A pair of lower declination coils arranged with their coil centers positioned, and axes that are substantially parallel to the plane and non-parallel to each other, and the coil centers are located on the vertical lines, and the lower declination angles are set. A sensing block including a coil and a pair of upper deflection coils arranged with a space above the coil, and outputs of the deflection coil and the upper and lower deflection coils, and the electromagnetic induction wire from the outputs. Position sensor is characterized by providing a processing unit that calculates and outputs a value correlated to the relative positions of the sensing block. 2. An electromagnetic induction type unmanned vehicle, wherein the position sensor according to claim 1 is used as an electromagnetic induction sensor.