JPH0477907A - Stop method for unmanned vehicle - Google Patents

Abstract

PURPOSE:To stop an unmanned vehicle when it travels a setting distance from the center of a marker by setting a place where the magnetic flux of a marker is started detecting to be a marker leading end and a place where in cannot be detected to be a trailing end and stopping the vehicle at a place travelling from the marker trailing end by a distance obtained by subtracting the half of a distance between the marker leading end and the trailing end from the previously set distance. CONSTITUTION:The place where the marker detection sensor 10 starts detecting the magnetic flux of a marker 30 is approved as the marker leading end and the place where the marker detection sensor 10 cannot detect magnetic flux to be the marker trailing end, and the marker distance being the distance between the marker leading end and the marker trailing end is detected. Then, the unmanned vehicle 1 is stopped at the place where it travels from the place approving the marker trailing end by the distance obtained by subtracting half the distance of the marker distance from the previously set setting distance. Thus, a stop position can be set to the place where the vehicle travels by the setting distance from the center of the marker even if it travels any place on the marker 30.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for stopping an unmanned vehicle, and is intended to improve stopping accuracy.

B. Summary of the Invention In the present invention, the center position of a marker is determined and the marker is stopped at a point that has traveled a predetermined distance from the center of the marker.

C1 Conventional technology Automatic guided vehicles (hereinafter referred to as "unmanned vehicles") are used in various factories and
This is a device that transports parts, products, small items, etc. in warehouses, offices, etc. Electromagnetic induction and optical guidance are generally used to guide unmanned vehicles along a route.

In the electromagnetic induction method, electric wires are laid along the route and alternating current is passed through them, and the position of the electric wires is determined by detecting the magnetic field caused by the electric wire current with a magnetic sensor (pickup coil, etc.) installed in the unmanned vehicle. The magnetic sensor is steered so that there is no discrepancy between the sensor position and the wire position, that is, the magnetic sensor is positioned directly above the wire.In addition, for the number of light guides, light reflective tape is laid along the running path, The position of the light-reflecting tape is determined by detecting the reflected light emitted from the unmanned vehicle and reflected by the light-reflecting tape with an optical sensor provided in the unmanned vehicle. Then, the steering is performed so that there is no misalignment between the sensor position and the electric wire position, that is, so that the optical sensor is located directly above the light reflective tape.

Here, the unmanned vehicle 1 will be specifically explained with reference to FIG.

In this unmanned vehicle 1, one front wheel 2 performs steering and rotational drive, and two rear wheels 3 are driven wheels. The front wheels 2 are rotated by a drive motor 4, and the distance traveled is detected by an encoder 5. In other words, pulses are output from the encoder 5 in accordance with the amount of rotation of the front wheel 2, and by counting the number of pulses with a software counter provided in the control device 9, the distance traveled can be determined. Further, the front wheels 2 are steered by driving a steering motor 6, and the steering angle is detected by a potentiometer 7. The position of the guidance line (electric wire or light reflective tape) is
It is detected by a course detection sensor (magnet sensor or optical sensor) 8. Furthermore, a marker detection sensor 10 is provided on the bottom of the unmanned vehicle 1, and markers are attached at required positions on the ¥ line course.

The marker detection sensor 10 detects a marker by a beam passing over the marker.

The control device 9 includes an encoder 5.in which a driving program is incorporated. Voltage warning meter 7, course detection sensor 8
．． It receives detection signals from the marker detection sensor 10 and the like, and also controls the driving of the travel motor 4 and the steering motor 6 and the braking of the brake (not shown). Then, the number of markers detected by the marker detection sensor 10 is compared with the entrainment program, and an operation (for example, deceleration, stop, spin turn, restart, etc.) is performed according to the number of detected markers.

Here, with reference to FIG. 5, when the marker 20 is a magnet, the state from when the marker detection sensor 10 detects the marker 20 until it stops will be described. Magnetic flux is emitted from the marker 20, as shown by the two-dot chain line in the figure.

As the unmanned vehicle 1 moves to the left in the figure, the marker detection sensor 10 detects magnetic flux. The marker detection sensor 10 detects the presence of a marker when it receives a magnetic flux φ having a predetermined strength among the magnetic fluxes and a stronger magnetic flux. Therefore, point P,
The starting end of the marker is recognized at point P2, and the ending end of the marker is recognized at point P2. Then, after traveling a certain distance from the point P2 where the end of the marker is recognized, the vehicle applies the brakes and stops. The above-mentioned fixed distance is measured by counting the pulses of the encoder 5. In addition, in FIG. 5, 21 is a resin for marker protection.

D Problems to be Solved by the Invention When the marker is a magnet, the magnetic flux distribution becomes circular, so the point at which the end of the marker is recognized is shifted depending on the passage route of the marker detection sensor 10. This will be explained based on FIG. 6, which shows the marker 20 in a plan view (view from the V (-VI arrow) in FIG. 5. As shown in the figure, the marker detection sensor 10 passes through) R, When the marker detection sensor 10 moves along the passing route R2, the point P2 is recognized as the end point of the marker, and when the marker detection sensor 10 moves along the route R2, the point Pat is recognized as the end point of the marker. Therefore, the authorized position of the marker end is Δ
It will be "off" by l. Since this deviation Δl occurs when the passing route is different, the stopping position of the unmanned vehicle 1 also differs from the deviation Δj
t'! It gets messy. In the end, the stopping position differs little by little depending on which position on the marker 20 is passed, and the stopping accuracy deteriorates.

In order to make the above deviation Δ as small as possible, it is necessary to align the end face fluxes of the markers 20 in the vertical direction and to align the end recognition positions on a straight line. For this purpose, the marker shape must be square, thin, and wide. Therefore, considering the trajectory deviation of the unmanned vehicle 1, the marker 2° is 100+nm.
A square plate-shaped magnet of about X100+am was required.

However, even if such a magnet is used as a marker, the deviation △t
could not be completely eliminated. Furthermore, since the marker 2° is rectangular and wide, the marker embedding groove becomes large, which is one of the factors that increases the number of man-hours, and increases the system cost in a system where a large number of markers are installed. Furthermore, since the resin 21 is applied over a wide area, it takes a long time (about one day) for the resin 21 to harden, which increases the number of man-hours.

In view of the above-mentioned prior art, an object of the present invention is to provide a method for stopping an unmanned vehicle that can accurately keep the stopping position of the unmanned vehicle constant even if the marker is a magnet.

E. @Means for Solving the Problem The method of the present invention that achieves the above object detects the magnetic flux of a marker formed of a magnet and buried in the driving route with a marker detection sensor installed in an unmanned vehicle, and then A method of stopping an unmanned vehicle after traveling a distance, in which the point where the marker detection sensor begins to detect the magnetic flux of the marker is recognized as the marker starting point, and the marker detection sensor that was detecting the magnetic flux of the marker The point where magnetic flux can no longer be detected is recognized as the marker end, and the marker distance, which is the distance between the marker start and marker end, is detected, and the distance is calculated by subtracting half the marker distance from the preset distance. However, the feature is that the unmanned vehicle is stopped after proceeding from the point where the marker end point is recognized.

F, Marker distance lit between the working marker start end and marker end end
, and stop the unmanned vehicle after moving L-1 from the end of the marker. In this way, the stop position will be a point that has traveled the set distance jIil from the center of the marker.

G example Embodiments of the present invention will be described in detail below based on the drawings.

As shown in FIG. 1, in this embodiment, the marker 30 is a cylindrical magnet, and the upper surface of the marker 30 is covered with resin 31.
is applied, so that the road surface of the running path 32 and the surface of the resin 31 are flush with each other. The marker detection sensor 10 provided in the unmanned vehicle 1 detects the marker 30 by receiving the magnetic flux φ having a certain strength or more output from the marker 3o.

Then, the unmanned vehicle 1 moves to the left in the figure, and the point where the marker detection sensor 10 detects the magnetic flux φ is recognized as the marker starting point, and the marker detection sensor 10 that had been detecting the magnetic flux φ1 detects the magnetic flux φ1. The point where it is no longer possible is recognized as the marker end. This authorization is performed by the control device 9. Of course, the pulse signal output from the encoder 5 in response to wheel rotation and the marker detection signal from the marker detection sensor 10 are sent to the control device 9.

Here, Fig. 2 shows the marker 30 in plan (■ in Fig. 1).
The manner in which the unmanned vehicle 1 stops will be described with reference to (-■ arrow view). As shown in FIG. 2, the marker detection sensor 10
As it progresses along route R1, point P
Point PI3 is recognized as the marker starting point, and point PI3 is recognized as the marker ending point. Further, when the marker detection sensor 1o moves along the route R12, the point P2.
is recognized as the starting point of the marker, and point P23 is recognized as the ending point of the marker.

Note that the set distance is preset in the controller equipment w9.

When the marker detection sensor 10 moves along the route R,1, the control device 9 determines (a) the marker distance J1!1. which is the distance between the marker start end P12 and the marker end P13; is detected, and at that point, a command to apply the brakes is issued to stop the unmanned vehicle 1.

Similarly, when the marker detection sensor 0 moves along the route R, the control device 9 (a) detects the marker distance l, which is the distance between the marker start end P21 and the marker end P23, and (b) Next, L 2 is calculated, and then a brake application command is issued to stop the unmanned vehicle 1.

Since the unmanned vehicle 1 is stopped in this manner, even if the traveling route () deviates, the unmanned vehicle 1 will stop after traveling the set distance I from the center of the marker 30. Further, in this embodiment, since a cylindrical magnet can be used as the marker, the hole for embedding the marker 30 may be a round hole, which simplifies the marker installation work. Further, the surface to which the resin 31 is applied may be small.

FIG. 3 shows functional blocks of the control device 9. In the same figure, the first count function section 9i detects the marker distance l by counting the pulses of the encoder 5 from the time when the marker detection sensor 10 detects the start end of the marker 30 until the end thereof. do.

do. Furthermore, the second counting function section 9C starts counting up the encoder 5 from the time when the marker detection sensor 10 detects the end of the marker. When the second count function 9c counts up, the command unit 9d issues a braking command to the brake 11 to stop the unmanned vehicle 1. In this way, even if the progress route is slightly off, you can press the setting button all L t! from the center of the marker. After advancing, the unmanned vehicle 1 stops accurately.

H Effects of the Invention As specifically explained above in conjunction with the embodiments, according to the present invention, even if the traveling route is slightly deviated, the unmanned vehicle will always stop accurately after traveling a set distance from the center of the marker. .

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing the state of a marker and an unmanned vehicle according to the present invention, FIG. 2 is a plan view showing the marker according to the present invention, and FIG.
Figure 4 is a block diagram showing the functional blocks of the control device, Figure 4 is a transparent perspective view showing an unmanned vehicle, Figure 5 is a configuration diagram showing the state of a marker and an unmanned vehicle in the prior art, and Figure 6 is a conventional marker. FIG. In the drawing, 1 is an unmanned vehicle, 5 is an encoder, 9 is a control device, 10 is a marker detection sensor, 11 is a brake, and 20.30 is a marker.

Claims (1)

[Claims] The magnetic flux of a marker formed by a magnet and embedded in a running route,
A method of stopping an unmanned vehicle in which the unmanned vehicle is detected by a marker detection sensor installed in the unmanned vehicle and then stopped after traveling a predetermined distance, and the point where the marker detection sensor begins to detect the magnetic flux of the marker is defined as the starting point of the marker. At the same time, the point where the marker detection sensor that was detecting the magnetic flux of the marker can no longer detect the magnetic flux is recognized as the marker end, and the marker distance, which is the distance between the marker start and marker end, is detected and set in advance. A method for stopping an unmanned vehicle, characterized in that the unmanned vehicle is stopped at a point where the unmanned vehicle has proceeded from a point where the end of the marker is recognized by a distance obtained by subtracting half the distance of the marker distance from the set distance.