JPH0283710A - Traveling controller for unmanned carrier - Google Patents

Abstract

PURPOSE:To avoid the unnecessary low-speed traveling cases and to improve the traveling efficiency of an unmanned carrier by activating and inactivating repetitively the obstacle sensors of two unmanned carriers in the different cycles from each other in case both carriers are travelling in the countersections to each other and changing the carriers to low speed traveling only when the presence of obstacles are recognized. CONSTITUTION:The counter section entry markers 23A and 23B and the counter section escape markers 24A and 24B are set on a traveling route of an unmanned carrier 10A. At the same time, the counter section entry markers 25A and 25B and the counter section esxcape markers 26A and 26B are set on a traveling route of an unmanned carrier 10B. When the point sensors 14A and 14B detects the markers 23A and 23B while the carrier 10A is traveling, a route comparator 13 detects the entry of the carrier 10A into its counter section. Then the front and back obstacle sensors 20A and 20B connected to an obstacle recognizer 16 have the flickering actions. While the carrier 10B also perform the same action. Then both carriers 10A and 10B are change to low speed traveling respectively as long as the flickering actions of both carriers are coincident with each other.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to an automatic guided vehicle travel control device.

(Prior Art) Conventionally, automatic guided vehicle control devices used for transporting goods in factories are equipped with obstacle detection sensors (for example, ultrasonic sensors or photoelectric sensors) at the front and rear of the guided vehicle as a safety measure. If there is an obstacle on the road, the obstacle detection sensor detects this and switches the vehicle from normal speed to a low speed that will not cause property damage in the event of a collision.

FIG. 5 shows an example of such a conventional automatic guided vehicle control device, in which the left and right drive wheels 2A, 2B of the automatic guided vehicle 1 generate a signal from the guide line 4 generated from the front and rear guidance detectors 3A, 3B. The automatic guided vehicle 1 is steered by the shift signal, and is accelerated or decelerated as appropriate in order to quickly and safely travel to the target position.

The automatic guided vehicle 1 is provided with obstacle detection sensors 5A, 5B; 6A, 6B at the front and rear thereof.

When moving forward, the front obstacle detection sensors 5A and 5B
detects obstacles on the path, and when reversing, the rear obstacle detection sensors 6A and 6B detect obstacles on the path, automatically switching from normal speed to low speed driving. become.

Note that 7A and 7B are point detectors, and 8A and 8B are driven wheels.

(Problem to be Solved by the Invention) However, in such a conventional automatic guided vehicle control device, the detection areas of the obstacle detection sensors 5A, 5B: 6A, 6B located before and after the automatic guided vehicle 1 are As shown in Figure 6, the sensor is adjusted in the direction of travel to a detection distance that is sufficient for deceleration to a low speed after detecting an obstacle, and a detection width that is equal to the width of the vehicle body. This caused the following problems.

Usually, such obstacle detection sensors 5A, 5B.

6A and 6B, the level of the transmitted signal is quite high in order to capture the reflected wave from any object, as shown in Figure 6.
As shown by the dotted and broken lines, the signal reaches a distance farther than the shaded detection area DZ, and the transmission width is also adjusted so that it is transmitted over a wider range than the detection area DZ.

Therefore, as shown in Fig. 6, two automatic guided vehicles LA, 1
．． When 8 cars run opposite each other, they will receive the transmitted signal from the other automatic guided vehicle even if they are far away.If the detection method is simply based on the reception level, the reflected wave will be directly transmitted It is not possible to distinguish whether it is an arriving wave or not, and it recognizes that there is an obstacle and automatically switches to low-speed operation.

And, such low-speed driving is performed by each automatic guided vehicle 1, A,
Since the process continues until the IB is out of alignment, a considerable amount of time is wasted, resulting in a decrease in the operating rate.

This invention was made to solve these conventional problems, and even when automatic guided vehicles pass each other, they will not receive the transmitted waves from the other party and misidentify them as obstacles. An object of the present invention is to provide an automatic guided vehicle control device that can reliably detect only actual obstacles.

[Structure of the Invention] (Means for Solving the Problem) The automatic guided vehicle control device of the present invention includes obstacle detection sensors that are attached to the front and rear of the automatic guided vehicle and detect obstacles that obstruct the travel of the automatic guided vehicle. , an oncoming section detection means for detecting a traveling section in which automatic guided vehicles face each other and pass each other, and when this oncoming section detection means detects an oncoming section, the obstacle detection sensor is activated at a cycle different from that of other automated guided vehicles. motion·
Obstacle recognition means for repeating non-operation and outputting an obstacle detection signal only when the obstacle detection sensor receives a signal corresponding to the operation period, and the obstacle recognition means outputs an obstacle detection signal. The vehicle is equipped with travel control means for switching the unmanned transport width from normal travel to low speed travel when outputting.

(Function) In the automatic guided vehicle control device of the present invention, when the obstacle detection sensor detects an obstacle ahead in the normal section, the obstacle recognition means outputs an obstacle detection signal, and the travel control means controls the automatic guided vehicle. Automatically switches from normal driving to low speed driving.

Then, when the oncoming section detection means detects that there is an oncoming section where automatic guided vehicles pass each other, the obstacle recognition means repeatedly sends a signal to the obstacle detection sensor at a different cycle from that of other automatic guided vehicles. The obstacle detection signal is output only when the obstacle detection signal is received in accordance with this signal sending period, and the traveling speed of the automatic guided vehicle is switched to low speed.

However, even if the obstacle detection sensor receives an obstacle detection signal out of the signal transmission period in the oncoming section, it determines that it must have received a signal from an oncoming vehicle and does not output the obstacle detection signal. The vehicle is shifted at normal speed without switching to low speed driving.

In this way, the vehicle travels at low speed only when there is definitely an obstacle in front of it to prevent damage due to collision with the obstacle.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 shows an embodiment of the present invention. Reference numeral 11 denotes an address setting device, which is composed of operation keys, a transmission device, etc. The location information is sent to the route calculator 12.
pass it on to

The route calculator 12 outputs route information to be traveled and travel information to the route comparator 13 based on the information on the entire route stored in advance based on the current position and target position information described above.

Here, the route information includes the count number of detection markers up to the target position, the count number of detection markers up to the opposing section, and the count number of the detection markers until the end of the opposing section. The traveling information includes the traveling speed between each marker,
These include the obstacle detection sensor transmission cycle within each opposing section.

The route comparator 13 confirms the current position based on the route information calculated by the route calculator 12 and the signals from the point detection sensors 14A and 14B. Then, the target speed command for that section is output to the travel control circuit 15. In addition, in the opposing section, the operation command and operation cycle of the sensor transmitter are sent to the obstacle recognition device 16 in that section.

The marker count number is incremented by 1 only when two signals from the point detection sensors 14A and 14B are input at the same time.

The travel control circuit 15 determines the traveling direction of the route calculator 12;
Speed command from route comparator 13, obstacle recognition device 16
The drive motors 17A and 17B are controlled by low speed commands from the automatic guided vehicle to travel to the target position.

Further, this traveling control circuit 15 includes a pulse generator 18A,
18B also has the function of keeping the speed constant. Note that 19A and 19B are electromagnetic brakes.

The obstacle recognition device 16 is an obstacle detection sensor 2OA.

20B: Compares the operation signal of the transmitter of 21A and 21B with the received signal to determine the presence or absence of a true obstacle, and outputs a low-speed travel command to the travel control circuit 15 if there is an obstacle.

Note that these obstacle detection sensors 2OA and 20B.

The transmission units 21A and 21B can repeat operation and non-operation at a predetermined cycle based on commands from the obstacle recognition device 16. In addition, obstacle detection sensors 20A, 20B, 21
The receiving units A and 21B are always in operation and output received signals to the obstacle recognition device 16.

The drive motors 17A, 17B are rotationally controlled by the travel control circuit 15, and the electromagnetic brakes 18A, 18B are also controlled by the travel control circuit 15 so as to be open when the automatic guided vehicle is traveling and closed when the automatic guided vehicle is stopped.

The pulse generators 18A and 18B are the motor 17A.

17B generates a pulse according to the rotation of the travel control circuit 1.
Output to 5.

Note that 22 is a departure command signal, which is input by a start button on the operation panel or a data transmission start command.

The operation of the automatic guided vehicle control device having the above configuration will be described next.

FIG. 2 shows the automatic guided vehicles 10A and 10B in the opposing section, and there are opposing section entry markers 23A and 23B on the travel path of one automated guided vehicle 10A.

Opposing section escape markers 24A and 24B are provided.

Also, on the traveling path of the other automatic guided vehicle 10B, there are opposing section entry markers 25A, 25B and opposing section exit markers 26A.
, 26B are provided, respectively.

To explain one automatic guided vehicle 10A, when its point detection sensors 14A and 14B detect markers 23A and 23B, the route comparator 13 recognizes that it has entered the oncoming section, and sends the obstacle recognition device 16 to the obstacle recognition device 16 at regular intervals. A command is given to operate/inoperate, that is, flicker, and in response to this, the obstacle recognition device 16 activates the front obstacle detection sensor 2.
O.A.

20B is flickered.

The other automatic guided vehicle 10B has already entered the oncoming section, and is flickering the obstacle detection sensors 2OA and 20B at a cycle different from that of the other automatic guided vehicle OA.

The state of the signals at this time is shown in FIG.
B starts flickering at a predetermined period T1 from timing t2 ((b) in the same figure).

The automatic guided vehicle 10B is already flickering at a predetermined period T2 ((C) in the same figure).

Therefore, if the automatic guided vehicle 10A is receiving only the transmitted waves from the other automatic guided vehicle 10B as shown in FIG. 10(d), the obstacle detection sensor Even when 2OA and 20B are turned on, the received signal repeats on and off, and in such a case, the obstacle recognition device 6 performs the obstacle detection operation assuming that the signal from the oncoming vehicle 10B has been directly received. I'm connected.

As shown in (e) of the same figure, when the automatic guided vehicle 10A receives an obstacle detection signal coincident with the period in which its own obstacle detection sensors 2OA and 20B are turned on, this means that the automatic guided vehicle 10A is completely facing forward. Obstacle 27 present and obstacle recognition device 1
6 makes a judgment, sends an obstacle detection signal to the travel control circuit 15, and the travel control circuit 15 outputs the drive motors 17A and 17B.
Switch to low speed driving.

As shown in FIG. 3(f), when receiving the transmission signal from the oncoming vehicle 10B and also receiving the reflected wave from the obstacle, the obstacle detection sensor 2OA.

Signals are received even during the period t4 to t5 when the sensor 20B is off, but during the period t5 to t5 when the sensors 2OA and 20B are on.
Since the reflected wave from the obstacle 27 is always received at t8,
By detecting the reflected wave received in accordance with this ON operation, it is determined whether an obstacle is present, and a low-speed traveling command is given to the traveling control circuit ]-5.

On the other hand, the same applies to the traveling operation of the other automatic guided vehicle 10B, and the obstacle detection sensor 2O on the front or rear side
When A, 20B, 21A, and 21B are in the opposing section and are flickering, it is determined that there is an obstacle only when there is a signal signal that coincides with the ON operation, and the drive motor is made to run at a low speed.

FIG. 4 shows another embodiment of the present invention, and shows the first embodiment.
Portions with the same reference numerals as those in the embodiment shown in the drawings have common configurations, but this embodiment is particularly distinctive in the means for detecting the opposing section.

That is, a pulse counter 28 is newly provided, and a pulse generator 18A for the drive motors 17A and 1.7B.

1 and 8 B, the current position of the automated guided vehicle is determined from this count value, and the automatic guided vehicle reaches the preset count value, that is, the distance preset as the travel distance before entering the oncoming section. At this time, it is determined that the vehicle is entering an oncoming section, and from then on, the obstacle detection sensors 2OA, 20B, 21A, and 21.8 are flickered in the same manner as in the 11th embodiment to ensure that the obstacle is distinguished from the oncoming vehicle and recognized. I have to.

Furthermore, the pulse generator 18A continues after entering the opposing section.

1 and 8. If the pulse signals from B are counted and the number of pulses corresponding to the opposing section distance is counted, it is determined that the opposing section is over, and the operation returns to the normal obstacle detection operation.

In this way, in the opposing sections where the automatic guided vehicles 10A and 10B are different from each other, the obstacle detection sensors 2OA and 20B are present in either automatic guided vehicle.

21A and 21.8 are flickered at a predetermined period T, T2 that is different from that of the other party, and matches the transmission on period] 7. Only when the signal is received, it is recognized that there is an obstacle and shifts to low-speed driving. By doing so, it is possible to prevent a transmission signal from an oncoming vehicle passing by from being mistakenly recognized as an obstacle, and it is possible to efficiently run a plurality of automatic guided vehicles.

[Effects of the Invention] As described above, according to the present invention, in the section where automatic guided vehicles are facing each other, the obstacle detection sensors are repeatedly activated and deactivated at different cycles, and their own obstacle detection sensors are activated. When the vehicle receives a signal during the period when the vehicle is moving, it recognizes that there is an obstacle and shifts to low-speed driving. Even if the vehicle encounters an obstacle, it will not be mistakenly recognized as an obstacle, and the vehicle will be able to reliably recognize the obstacle and shift to low-speed driving, eliminating time loss caused by unnecessary low-speed driving, and driving more efficiently. Can be secured.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the running state of the automatic guided vehicle in the above embodiment, FIG. 3 is a timing chart explaining the operation of the above embodiment, and FIG. FIG. 4 is a circuit block diagram of another embodiment of the present invention, FIG. 5 is a circuit block diagram of a conventional example, and FIG. 6 is an explanatory diagram of the operation of the conventional example. 10A, IOB...Automated guided vehicle 11...Address setter 12...Route calculator 1
3...Route comparator 14A, 14B...Point detection sensor 15...Traveling control circuit 16...Obstacle recognition device 17A, 17B...Drive motor 18A, 18B...Pulse generator 19A, 19B...electromagnetic brake

Claims (1)

[Claims] In an unmanned guided vehicle control device that detects markers installed on the ground using a detector installed on the unmanned guided vehicle and confirms the current position while driving unmanned to the target point, it is attached to the front and rear of the unmanned guided vehicle. an obstacle detection sensor that detects an obstacle that obstructs the travel of the guided vehicle, an oncoming section detection means that detects a traveling section where the automated guided vehicle faces each other and passes each other, and when the oncoming section detection means detects the oncoming section, the The obstacle detection sensor is repeatedly activated and deactivated at a cycle different from that of other automatic guided vehicles, and an obstacle detection signal is output only when the obstacle detection sensor receives a signal in accordance with the operation period. An automatic guided vehicle control device comprising: obstacle recognition means; and travel control means for switching the automatic guided vehicle from normal travel to low speed travel when the obstacle recognition means outputs an obstacle detection signal.