JPS62245406A - Guiding system for unmanned traveling vehicle - Google Patents

Abstract

PURPOSE:To perform a simplified and low cost guide control with high accuracy, by traveling an unmanned traveling vehicle based on a posture against the guide line of the unmanned traveling vehicle detected from the coil voltage of respective axis of a three-dimensional pickup coil. CONSTITUTION:When coil voltage Vx, Vy, and V2 in respective direction of an (x), a (y), and a (z), are inputted, a CPU60 calculates a distance l1 from the center of an unmanned traveling vehicle 1 to a guide line A, and the angle of deviation theta of the unmanned traveling vehicle 1 against the guide line A, respectively. Following that, the CPU60 calculates a steering angle delta to guide and travel the unmanned traveling vehicle 1 with an appropriate posture along the guide line A, based on calculated distance l1, and the angle of deviation theta, and supplies a steering angle command based on the steering angle delta to a steering control part 61. After that, the steering control part 61 steers a steering corresponding to the steering angle, and guides and runs the unmanned traveling vehicle 1 with the appropriate posture along the guide line A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for guiding an unmanned vehicle such as an unmanned guided vehicle or an unmanned forklift.

[Conventional technology]

For example, an unmanned vehicle 1 used in a conventional unmanned vehicle guidance system using an electromagnetic guidance system has a configuration as shown in FIG. Two pickup coils 2 and 3 are provided.

When the unmanned vehicle 1 is actually guided along the guide line A, the pickup coils 2 and 3 can each obtain a predetermined voltage corresponding to the distance from the guide line A. .

Therefore, by monitoring the voltage difference between the two pickup coils 2 and 3, it is possible to recognize how far the unmanned vehicle 1 has moved from the guide line A in either the left or right direction.

Generally, in a guidance system having the above-described configuration, the relationship between the voltage difference between the pickup coils 2 and 3 and the distance of the unmanned vehicle 1 from the guidance line A has characteristics as shown in FIG.

Among these characteristics, in particular, the unmanned vehicle 1 can be adjusted by utilizing the area of linear relationship shown by the dotted line frame in the same figure, for example, by operating the steering so that the voltage difference between the pickup coils 2 and 3 becomes zero. The vehicle is guided so that it does not deviate from the guide line A.

In addition, in a guidance system having a guide line network in which guide lines having the same configuration as guide line A are laid out so that they intersect at multiple locations, the unmanned vehicle 1 is A special control sequence was set up to guide the turn when the vehicle was transferred to the guide line.

For example, in FIG. 14, the conventional control sequence for transferring the unmanned vehicle 1 from the guide line A to the guide line B is as follows.

First, on the guide line A, the unmanned vehicle 1 is traveling in the direction of the arrow a under the guidance control as described above.

When this unmanned vehicle 1 passes through the station line S,
When the station line S is detected by a separately provided station coil, for example, a control section (not shown) immediately causes the unmanned vehicle 1 to travel at a reduced speed.

At the same time, the control unit starts calculating the travel distance of the unmanned vehicle 1 after passing the station line S based on measurement data from, for example, a wheel rotation speed sensor.

Furthermore, when the traveling distance reaches a preset distance g with respect to the turning point, the control section controls a preset fifteenth point.
The unmanned vehicle 1 is guided to turn based on a certain turning pattern as shown in the figure.

When the unmanned vehicle 1 finishes transferring from the guide line A to the guide line B by this turning guidance, the control section again moves the unmanned vehicle 1 in the direction indicated by the arrow along the guide line B by the method described above. I was trying to make it run guided.

[Problem that the invention seeks to solve]

In this way, conventionally, when guiding the unmanned vehicle 1, characteristics (linear region) as shown in FIG. 13 regarding the voltage difference between the pickup coils 2 and 3 and the distance from the guiding wire A are used Was.

However, in this method, the above-mentioned characteristics also change as the level of the current flowing through the guide wire A changes, and the following problems may occur.

For example, suppose that the control section is now storing the characteristic of Q shown in FIG. 16 and is controlling the guidance of the unmanned vehicle 1.

When the current flowing through the guide wire A increases in this state, the characteristic Q changes to the characteristic P.

At this time, if vl is detected as the voltage difference between the pickup coils 2 and 3, the unmanned vehicle 1 is actually at a distance MDoL from the guide line A.

Even though there is no deviation, it is erroneously recognized as having deviated by a distance Ro'.

In order to minimize this (l o -fl o' error) and achieve high-precision guidance control based on accurate position recognition, a high-performance device that can adjust the current flowing through the guidance wire A to a constant level is required. This requires a constant current circuit, which poses a problem of complicating the configuration and increasing costs.

In addition, conventionally, when guiding the unmanned vehicle 1 to turn,
After passing the station line S, the vehicle is caused to perform a turning operation in a predetermined turning pattern from a position where the vehicle has traveled a distance g.

For this reason, when the system was introduced, a huge amount of effort was required to set the above-mentioned distance g at all turning points at the site.

Furthermore, when measuring the distance g using the method described above, if a detection error occurs due to tire wear, etc., accurate turning guidance cannot be achieved, such as going off course due to variations in the turning starting point. There were also problems.

The present invention has been made in view of these circumstances, and it is possible to improve the performance of a constant current circuit for adjusting the current flowing through the induction wire, and to reduce the effort required to set the turning start position. , has a simple configuration and is advantageous in terms of cost.
The purpose of the present invention is to provide a guidance method for an unmanned vehicle that can perform highly accurate guidance control.

[Failure to solve the problem]

In the present invention, a pickup coil is provided which has a coil that separately detects voltages corresponding to components in three mutually orthogonal directions of a magnetic field acting from a guide wire, and the guide wire is detected based on each coil voltage detected by the pickup coil. The attitude of the unmanned vehicle is recognized, and based on the recognized attitude, the unmanned vehicle is driven so as not to deviate from the guide line.

Further, in guiding the turning of the unmanned vehicle, a second pickup coil having the same configuration as the pickup coil for detecting the attitude of the unmanned vehicle with respect to a second guide line that intersects the guide line is provided; When the distance between the unmanned vehicle and the second guide line reaches a set distance, the attitude of the unmanned vehicle with respect to the second guide line detected by the second pickup coil Accordingly, a turning pattern is set one by one, and the unmanned vehicle is caused to turn from the guide line to the second guide line based on the set turning pattern.

[Effect]

In the method for guiding an unmanned vehicle of the present invention, since the attitude of the unmanned vehicle with respect to each guide line is detected based on the ratio of the voltages of the respective pickup coils, the unmanned vehicle is guided based on the detected attitude. In doing so, it is not affected by variations in the strength of the magnetic field due to variations in the current flowing through the guide wire, and there is no need to adjust the current flowing through the guide wire with high precision.

In addition, when guiding the unmanned vehicle to turn, the turning pattern is automatically set according to the attitude of the unmanned vehicle at that time, so there is no need to set the turning start position at each turning position. This not only greatly reduces time and effort, but also enables accurate turning with the best possible turning pattern.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 conceptually shows the configuration of a guidance system for an unmanned vehicle according to the present invention.

In FIG. 1, a three-dimensional pickup coil 10 is disposed at the rear left end of an unmanned vehicle 1 that is guided along a guide line A in the direction of an arrow C.

As shown in FIG. 2, this three-dimensional pickup coil 10 is formed by patterning a ferromagnetic thin film 12 on each surface of, for example, a cubic base material 11. Due to the magnetoresistive effect, it has a function of separately detecting each direction component of the magnetic field x, y, and z acting on the three-dimensional pickup coil 10.

For example, in FIG. 3, if the three-dimensional pickup coil 1G is placed at a certain distance from the guide wire 14 through which a constant current is flowing from the constant current source 13, then from the guide wire 14 to point P. X* of the acting magnetic field B >'+
The Z components are each B.

Detected as B,,B.

The following can be said from this detection result.

That is, the angle α between the y-axis of the three-dimensional pickup coil 10 and the guiding wire 14 can be derived from FIG. obtain.

Further, the distance e between the guide wire 14 and the pickup coil 1° (point P) can be derived from FIG. 4(b), and tanβ IBH1/lB21 is obtained.

However, B: the composite component of Bx and By h: the mounting height of the three-dimensional pickup coil 1o, β: the angle of the line segment connecting the three-dimensional pickup coil 1° (point P) and the guide wire 14 with respect to the horizontal plane In the figure, the arrangement of the three-dimensional pickup coil 1o with respect to the unmanned vehicle 1 is as follows (■): The X-axis of the three-dimensional pickup coil 1o is parallel to the longitudinal centerline of the unmanned vehicle 1.

(■) The two axes of the three-dimensional pickup coil 1o are perpendicular to the horizontal plane.

The voltages detected by the three-dimensional pickup coil 10 corresponding to the x, y, and z components of the magnetic field acting from the guiding wire A in the attitude shown in FIG. ,V,,
It is V.

x z It is assumed that the following conditions are also satisfied.

From the above, the attitude of the unmanned vehicle 1 with respect to the guide line A in FIG. 1 can be recognized as described later.

First, the declination angle θ of the unmanned vehicle 1 with respect to the guide line A is determined by the above (
From equation 1), θ-jan-1(V/V), X...(3) Also, the distance g1 from the center of the unmanned vehicle 1 to the guide line A
From the above formula (2), l111IIIe+e' ■, 7 +wcos θ+D1sin θ ・(4) However, h: The mounting height of the three-dimensional pickup coil 10 W: The height between the center of the unmanned vehicle 1 and the three-dimensional pickup coil 1
Length Dl in the y-axis direction between the center of the unmanned vehicle 1 and the center of the three-dimensional pickup coil 10 Next, FIG. 1 is a block diagram showing the configuration of a control section in a vehicle guidance system.

When the unmanned vehicle 1 is guided in the state shown in FIG. A voltage corresponding to the Xr'l*Z component of the magnetic field is obtained.

Here, the voltages corresponding to the x, y, and z components of the magnetic field are the voltages V and V shown in the above-mentioned condition (nI), respectively.
, V.

x y z These X-axis coil 20, Y-axis coil 30%, Z-axis coil 4
The detection voltages V , V , V of 0 are x
y z A through band pass filters 21, 31, 41, full wave rectifier circuits 22, 32, 42, integrators 23, 33° 43, respectively
/D converter 50, and after being individually A/D converted,
It is input to the CPU 60.

Thereafter, this CPU 60 executes processing operations as shown in the flowchart of FIG.

That is, after the processing by the preceding stage circuit described above, x, y
, z, the coil voltages V , V in each direction.

When y V is input (step 100), the CF'U
60 is each of these coil voltages V 1 and V .

Based on y V , the distance g1 from the center of the unmanned vehicle 1 to the guide line A and the declination angle θ of the unmanned vehicle 1 with respect to the guide line A are calculated using equations (4) and (3), respectively (step 101 ).

Next, the CPU 60 guides the unmanned vehicle 1 along the guide line A in an appropriate attitude based on the distance g1 and the deflection angle θ calculated as described above (step 102 to calculate the steering angle δ), and performs a steering operation. A steering angle command based on the steering angle δ is given to the control unit 61 (step 103).

Thereafter, the steering control unit 61 steers the steering wheel according to the steering angle command, and guides the unmanned vehicle 1 along the guide line A in the appropriate attitude as described above.

In addition, when guiding a reach type forklift, two guide wires are normally required, but by using the guidance method of the present invention, the number of guide wires can be reduced to one, reducing the cost of burying the guide wire. It becomes possible to reduce the amount by approximately 1/2.

The above describes the guidance method for guiding the unmanned vehicle 1 along the guidance line A. However, in the present invention,
For example, as shown in FIG.
By additionally configuring a three-dimensional pickup coil 10' having the same configuration as the dimensional pickup coil 10, turning guidance to the guide line B intersecting the guide line A can also be performed.

In this case, the entire control section has a configuration as shown in FIG. For 90,
Bandpass filters 71, 81, 91, full wave rectifier circuit 72°82.92, integrator 73, 83, 93, A
A pre-stage circuit consisting of a /D converter 51 is provided.

A guiding wire B is connected to this three-dimensional pickup coil 10'.
Voltages v', v,' detected by the X-axis coil 70, the y-axis coil 80S, and the Z-axis coil 90 of the three-dimensional pickup coil 10', respectively, corresponding to the x, y, and z components of the magnetic field acting from the three-dimensional pickup coil 10'.

2' is input to the CPU 60 after being processed by the preceding circuit.

Now, in FIG. 7, assuming that the wiring manner of the three-dimensional pickup coil 10' for the unmanned vehicle 1 satisfies the same conditions (I) and (n) as the wiring manner of the three-dimensional pickup coil 10 described above. , the CPU 60 receives the input voltage Vx'.

Unmanned driving z from v', v' to guide line B The attitude of the car 1 can be recognized as follows.

First, the deflection angle φ of the unmanned vehicle 1 with respect to the guide line B is determined by the above (
1) From equation φ-jan (V'/V') -C5
)y Also, the distance g2 from the center of the unmanned vehicle 1 to the guide line B
From the above formula (2), 12-61+ei' +Wsinφ+D2eO8φ - (6) However, h: 3
The mounting height of the dimensional pickup coil 10' is W: between the center of the unmanned vehicle 1 and the 3-dimensional pickup coil 1.
0' in the y-axis direction D2: Length in the X-axis direction between the center of the unmanned vehicle 1 and the center of the three-dimensional pickup coil 10' The processing operation of the CPU 60 in turning guidance from guide line A to B will be described in detail with reference to FIG.

First, the unmanned vehicle 1 is guided along the guide line A by the method described above and passes through the station line S.

At this time, the CPU 60 detects the station line S based on the output of the three-dimensional pickup coil 10' when the station line S passes, which is input from the A/D converter 51 (step 200).

When the station line S is detected in this way, a signal indicating the turning direction from the guide line A to B is immediately input to the CPU 60 (step 201). Next, based on this input, the CPU 6 starts decelerating the unmanned vehicle 1 in order to perform turning guidance in the turning direction (step 202).
.

The CPU 60 continues to operate the three-dimensional pickup coil 10.
Coil voltages v', v' in each direction of x, y, and z detected by ' and processed through the above-mentioned front-stage circuit
, v' from the A/D converter 51 x y
z acquisition (step 203), each of these coil voltages v
Based on ', v', v', x
From yz and equation (5), the distance g2 from the center of the unmanned vehicle 1 to the guide line B and the deflection angle φ of the unmanned vehicle 1 with respect to the guide line B are calculated, respectively (step 204).

Then, the CPU 6G calculates the distance fI calculated as described above.
2 determines whether the set turning start distance g3 has been reached (step 205).

In such a judgment, is the distance Ω2 the turning start distance j? While it is determined that the number has not reached 3, the CPU 60
Coil voltages V in each of the x, t, and z directions detected by the dimensional pickup coil 10 and processed through the pre-stage circuit,
A/DX V,,V
Z taken from the converter 50 and these coil voltages V.

While referring to the attitude z of the unmanned vehicle 1 calculated based on v and (corresponds to steps 100 to 1θ3 in the flowchart shown in FIG. 6).

In addition, in the above judgment, the distance g2 is the turning start distance II3
When it is determined that the state has been reached, the CPU 60 performs step 204 regarding the attitude of the unmanned vehicle 1 at this time.
The deflection angle φ of the unmanned vehicle 1 with respect to the guide line B detected by and the unmanned vehicle 1 detected in step 207
Based on the distance p1 from the center of the guide line A to the guide line A
Determine the turning pattern from to B (step 210)
.

In this way, the turning pattern of the unmanned vehicle 1 of the present invention is determined according to the attitude of the unmanned vehicle 1 when it reaches the turning start position, and for example, as shown by Pl in FIG. When the vehicle 1 is already tilted in the turning direction, a turning pattern that requires a relatively short travel distance is set, as shown by Pl in FIG.

On the other hand, when the unmanned vehicle 1 is not tilted in the turning direction as shown at P2 and P3 in FIG. 10, or when it is tilted in the opposite direction, the traveling distance is A long turning pattern is set.

Note that the turning pattern set by this method includes a turning end set distance p4 and a turning end setting angle η, which will be described later, for determining the turning end position of the unmanned vehicle 1.

After completing the setting of the turning pattern in this way, the CPU 60
immediately takes in the output from a distance measuring means (not shown) and detects the distance traveled by the unmanned vehicle 1 thereafter (step 211).

Subsequently, the CPU 60 reads the steering angle corresponding to the travel distance of the unmanned vehicle 1 detected in step 211 from the turning pattern determined by the method described above (
Step 212), a steering angle command corresponding to the steering angle is given to the steering control section 61 (step 213).

Here, the steering control unit 61 guides the unmanned vehicle 1 to turn along the turning pattern based on the steering angle command.

During this time, the CPU 60 detects the x,
Coil voltages vx', v', v in each direction of y and z
' is fetched from the A/D converter 51 (step 214), and these coil voltages Vx/
, V / , V L Based on the above (6) and y
The distance f12 from the center of the unmanned vehicle 1 to the guide line B and the deflection angle φ of the unmanned vehicle 1 with respect to the guide line B are calculated using equation (5) (step 215).

Next, the CPU 60 calculates the distance calculated in step 215, l! ll12, the deflection angle φ and the set turning end distance g4 of the turning pattern set in step 210 above,
In relation to the turning end setting angle η, distance 12 is the turning end setting distance! ! 4 and the deflection angle φ reaches the turning end set angle η
A determination is made as to whether this has been reached (step 216).

While this condition is not satisfied, the CPU 60 repeatedly performs the processing operations of steps 211 to 216.

Then, when the above conditions are met, the turning guidance control of the unmanned vehicle 1 is immediately ended (step 217).

Note that the guided travel of the unmanned vehicle 1 along the guide line B after the completion of the turn can be performed in the same manner as the guided travel along the guide line A.

〔Effect of the invention〕

As explained above, according to the unmanned vehicle guidance method of the present invention, three-dimensional pickup coils x, y.

Since the unmanned vehicle is guided to travel along the guide line based on the attitude of the unmanned vehicle with respect to the guide line detected from the coil voltage of each axis in step 2, it is possible to move the unmanned vehicle along the guide line when checking the attitude of the unmanned vehicle. It is not affected by time fluctuations in current, eliminates the need for a high-precision constant current circuit to keep the current constant, and allows extremely high-precision induction control to be performed with a simple and low-cost configuration. .

In addition, for turning guidance, a turning pattern is set one by one at an appropriate turning start position during guided driving based on the distance between the unmanned vehicle and the guide line to transfer to, detected by a three-dimensional pickup coil, and the attitude of the unmanned vehicle at this time. However, since the unmanned vehicle is guided to turn according to the turning pattern, there is no need to set a turning start position at each turning point, and the effort required when installing the system can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing a first embodiment of the guidance system for an unmanned vehicle according to the present invention, FIG. 2 is a conceptual diagram showing an example of a three-dimensional pickup coil used in the present invention, and FIG.
The figure is a conceptual diagram showing how the three-dimensional pickup coil is arranged with respect to the guide wire in the present invention, and FIG. 4 shows how the attitude of the three-dimensional pick-up coil arranged in the manner shown in FIG. 3 with respect to the guide wire is detected. 5 is a block diagram showing the configuration of the guidance control section in the first embodiment, FIG. 6 is a flowchart showing the processing operation of the CPU in the guidance control section shown in FIG. 5, FIG. 7 shows an unmanned vehicle according to the present invention. A conceptual diagram showing the second embodiment of the guidance system, FIG.
A block diagram showing the configuration of the guidance control section in the second embodiment, FIG. 9 shows the CP in the guidance control section shown in FIG.
FIG. 10 is a conceptual diagram showing the attitude of the unmanned vehicle at the turning start position; FIG. 11 is a flowchart showing the processing operation of U; FIG. 11 is a conceptual diagram showing the attitude of the unmanned vehicle at the turning start position; Figure 12 showing each side of the turning pattern
The figure is a conceptual diagram showing a configuration example of a conventional guidance system for an unmanned vehicle, and FIG. 13 shows the voltage difference detected by two pickup coils in the conventional guidance system and the distance from the guidance line of the unmanned vehicle. Characteristic diagram showing the relationship between
FIG. 4 is a conceptual diagram for explaining a turning guidance method in a conventional guidance system, FIG. 15 is a diagram showing a turning pattern of an unmanned vehicle used in the turning guidance method shown in FIG. 14, and FIG. 16 is a characteristic diagram similar to the characteristic shown in FIG. 13 for explaining the disadvantages of the conventional guidance system. 1...Unmanned vehicle, 2.3...Pickup coil, 10.10'...Three-dimensional pickup coil, 1
DESCRIPTION OF SYMBOLS 1... Base material, 12... Ferromagnetic thin film, 13... Constant current source, 20.70... X-axis coil, 30.80...
・Y-axis coil, 40.90...2-axis coil, 21,3
1,41゜71.81.91...Band pass filter, 22゜32.42,72,82.92...Full wave rectifier circuit, 23.33.43.73.83.93...Integrator equipment, 50.51...A/D converter, 60...CPU
, 61... Steering control section, A, B, 149.・Guiding wire. Figure 1 Figure 2 Figure 3 (Q) (b) Figure 4 Figure 12 Figure 13 Figure 16 Figure 14 Rudder/row distance Figure 15

Claims (2)

[Claims] (1) A pickup coil that is placed on an unmanned vehicle and has coils that separately detect voltages corresponding to components in three mutually orthogonal directions of a magnetic field acting from a guide wire, and each coil detected by the pickup coil. attitude detection means for detecting the distance between the center of the unmanned vehicle and the guide line and the inclination of the unmanned vehicle with respect to the guide line based on voltage; A method for guiding an unmanned vehicle, comprising causing the unmanned vehicle to travel without deviating from the guide line based on the distance and the inclination. (2) first pickup coils each mounted on the unmanned vehicle and each having a coil that separately detects voltages corresponding to components in three mutually orthogonal directions of the magnetic field acting from the first guiding wire; a second pickup coil having a coil that separately detects voltages corresponding to components in three mutually orthogonal directions of a magnetic field acting from a second guide wire that intersects with the first guide wire; A first distance between the center of the unmanned vehicle and the first guide line based on each coil voltage detected by the pickup coil, a first inclination of the unmanned vehicle with respect to the first guide line, and Attitude detection means for detecting a second distance between the center of the unmanned vehicle and the second guide line, and a second inclination of the unmanned vehicle with respect to the second guide line; When the second distance detected by the means reaches a preset third distance, the second guide line is moved from the first guide line based on the second distance and the second slope. a turning pattern setting means for setting a turning pattern of the unmanned vehicle toward a line, the first direction detected by the attitude detecting means;
and the first inclination, the unmanned vehicle is caused to travel without deviating from the first guide line, and when the second distance reaches the third distance during the travel, A method for guiding an unmanned vehicle, comprising causing the unmanned vehicle to turn from the first guide line to the second guide line based on the turning pattern set by the turning pattern setting means.