JPH04297905A - Running control method for unmanned carrier - Google Patents

Abstract

PURPOSE:To obtain the running control method, which can carry an object to be carried in the state of matching the object to the center of the unmanned carrier even when the object to be carried is eccentrically put at a load position, without using any mechanical guide means concerning the unmanned carrier in a system to carry the object to be carried while getting under the object to be carried. CONSTITUTION:At the unmanned carrier, course sensors 7a and 7b for traveling course detection and upward directed non contacting type mark sensors 5a and 5b are provided. At an object 11 to be carried, marks 10 to be detected by the mark sensors 5a and 5b are arranged in the shape of a band in a traveling direction. When no detection signal is outputted from the mark sensors 5a and 5b, the traveling direction of the unmanned carrier is controlled based on the detection signals of the course sensors 7a and 7b and when the detection signals are outputted from the mark sensors 5a and 5b, the traveling direction of the unmanned carrier is controlled based on the detection signals of the mark sensors 5a and 5b.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention carries the object by crawling under the object and lifting the object, or by engaging the object with a mechanical means such as a retractable pin and moving the object. The present invention relates to an operation control method for an unmanned guided vehicle of this type, and particularly relates to an operation control method characterized by controlling the traveling direction of an unmanned guided vehicle when the unmanned guided vehicle sneaks under an object to be transported.

0002

[Prior Art] A trolley-type unmanned guided vehicle, that is, one that carries the object by crawling under it,
A feature of this system is that the loading and unloading of objects to be transported onto the transport vehicle can be done relatively easily and unmanned. The running direction of an automatic guided vehicle is usually controlled by detecting magnetic tape or reflective tape attached to the floor surface, or signal lines buried under the floor using a magnetic sensor, optical sensor, electromagnetic wave sensor, or the like. For example, in the case where a magnetic tape 6 is used as a traveling guide, as shown in FIG. When a detection signal of the magnetic tape 6 is output from one of the magnetic sensors, the automatic guided vehicle 1 is driven to move the sensor away from the magnetic tape 6, thereby causing the automated guided vehicle 1 to detect the magnetic tape 6. I try to drive along the road.

[0003] In such an unmanned guided vehicle, an object to be transported is placed so as to straddle a running path formed with magnetic tape 6 or the like, or a lead-in path is provided that branches off from the running path, and the object is placed to straddle the lead-in path. Place the object to be transported, run the automated guided vehicle along its running path or lead-in path to get under the object, raise the loading surface of the cart to lift the object, or remove the pin 32 from the cart. etc., to mechanically engage the conveyed object and the trolley, and in this state, the automatic guided vehicle 1 is run along the traveling path to a desired position, and there, by the reverse operation to the above, the conveyed object is mechanically engaged with the cart. Objects are transported by opening the door.

0004

[Problems to be Solved by the Invention] However, in the above-mentioned transport method, when the object to be transported is placed unevenly with respect to the running path of the trolley at the loading position, the object is loaded onto the trolley while being biased. Even at the unloading position, there is a problem that the transported object is left unbalanced.To avoid this problem, it is necessary to accurately position the transported object at the center of the trolley travel path at the loading position. However, there was a problem in that the work required considerable accuracy.

[0005]Furthermore, when an object is loaded unevenly on a trolley, the deviation tends to be further exacerbated by vibrations during traveling. This may cause a large deviation, causing inconvenience in automatic handling processing after transportation.

As one method for solving this problem, as shown in FIGS. 4 and 5, guides 33 and 34 are provided on the object 11 and the trolley 1 along the running direction, so that the cart 1
There is a method of forcing the center of the conveyed object 11 to coincide with the center of the trolley 1 by the guiding action of the guides 33 and 34 when the object 11 crawls under the trolley 1.

However, when attempting to align the centers of the conveyed object 11 and the cart 1 using such a mechanical guide, the cart 1 slips under the object placed at a position offset from the center of the travel path. At this time, since a driving force always acts on the bogie 1 to move it toward the center of the running path, the guides 33 and 34 are pressed by this driving force, and the bogie 1
There is a problem in that large running resistance acts on the vehicle. especially guide 3
At the ends of 3 and 34, in order to avoid collision between the ends, oblique introduction parts 30 and 3 are provided as shown in FIGS. 4 and 5.
1, but if the object to be transported is placed out of alignment, this introduction section 30, 3 should be provided when the trolley 1 enters.
The force that tries to deflect the cart 1 caused by the contact between the carts 1 and 1 competes with the driving force that tries to return the cart 1 to the center, and as a result, large running resistance acts and the cart 1 comes to a standstill. Therefore, even if such mechanical guides 33 and 34 are provided, the allowable amount of deviation of the transported object 11 will not become very large.

An object of the present invention is to solve the above-mentioned problems, and even if the object to be transported is placed unevenly at the loading position, the deviation can be corrected and the object to be transported 11 can be placed in the center of the cart 1. It is an object of the present invention to provide a method for controlling the operation of an automatic guided vehicle, which can transport objects in a matched state and, therefore, can place objects to be transported at an accurate position at an unloading position.

[0009]

[Means for Solving the Problems] In the present invention, along with course sensors 7a and 7b for detecting the travel guide 6 provided on or below the floor of the travel path of the automatic guided vehicle 1, a mark sensor 5a directed upward is provided. , 5b are provided on the automatic guided vehicle 1. On the other hand, marks 10 to be detected by the mark sensors 5a, 5b are arranged in a band shape on the lower surface of the transported object 11 along the traveling direction thereof, in accordance with the installation positions of the mark sensors 5a, 5b. and mark sensor 5
When the detection signal of the mark 10 is not outputted from a, 5b, the traveling direction of the automatic guided vehicle 1 is controlled based on the detection signal of the course sensors 7a, 7b, and the mark sensor 5
When a detection signal of the mark 10 is output from a, 5b, the control is switched according to the detection signal, and the traveling direction of the automatic guided vehicle 1 is controlled based on the detection signal of the mark sensors 5a, 5b.

The switching of control based on the detection signals of the mark sensors 5a and 5b is performed when the automatic guided vehicle 1
This is carried out only when the vehicle is traveling without transporting 1. Specifically, for example, if the automatic guided vehicle is of a type that lifts the transported object 11 by raising the loading surface 2 of the truck 1, an AND signal between the lowering detection signal of the loading surface 2 and the detection signal of the mark 10 is used. In addition, if the automatic guided vehicle is of a type in which transportation is carried out by protruding a pin 32 or the like and engaging the conveyed object 11 with the trolley 1, an AND signal of the insertion detection signal of the pin or the like and the detection signal of the mark 10 is sent. , the control is switched to the mark sensors 5a, 5b side, and when the AND signal disappears, the course sensors 7a, 7
Control may be returned to the b side.

As the course sensors 7a and 7b, various conventional sensors such as magnetic sensors, optical sensors, and electromagnetic wave sensors can be used as described above. As the mark sensors 5a and 5b, in addition to those of the same type as the course sensors 7a and 7b, it is also possible to use proximity switches, microswitches with elongated contacts, electrical contacts, and the like. Further, depending on the case, the mark sensor may be configured by combining multiple types of sensors. For example, in addition to attaching magnetic tape to the underside of the transported object, the automatic guided vehicle is equipped with a mark sensor consisting of a magnetic sensor and a proximity switch, and control is switched based on the detection signal of the proximity switch, and the output signal of the magnetic sensor is It is also possible to control the traveling direction of the truck by

0012

[Operation] According to the above method, when the automatic guided vehicle 1 starts to enter under the conveyed object 11 placed at a biased position, the detection signal of the conveyed object 11 is output from the mark sensors 5a and 5b on the upper surface of the truck. As a result, the control of the running direction of the transport vehicle 1 is switched to the control based on the detection signal of the mark 10 on the transported object 11 output from the mark sensors 5a and 5b, so that the transport vehicle 1 After moving downward, the transport vehicle 1 travels in a direction that coincides with the center of the transported object 11 and stops. In this state, when the transported object 11 is lifted by raising the loading surface 2, or when the transported object and the cart are mechanically locked, the control of the traveling direction of the automatic guided vehicle 1 is switched to the course sensors 7a and 7b. Immediately after transporting the transported object 11 and starting traveling, the automatic guided vehicle 1 corrects its traveling direction so as to follow the center of the traveling path defined by the magnetic tape 6 and the like. As a result, the transported object 11 is placed in a biased state at the loading position.
The deviation is corrected so that the center of the automatic guided vehicle 1 and the center of the transported object 11 are aligned, and therefore, at the unloading position, the transported object 11 is always kept at a predetermined and accurate position. It will be left in place.

When the automatic guided vehicle 1 comes out from under the transported object 11 after unloading the transported object 11, it is more preferable that the running direction of the automatic guided vehicle 1 is controlled by the course sensors 7a and 7b. , since the center of the unloaded object 11 and the center of the travel path of the automatic guided vehicle 1 coincide with each other as described above, the mark sensor 5a,
Even if the automatic guided vehicle 1 is caused to travel under control based on the output signal of the automatic conveyance vehicle 1 and the control is switched to the course sensors 7a and 7b when it comes out from under the conveyed object 11, no problem will occur.

[0014]

[Embodiment] Figures 1 to 3 show an embodiment of an automatic guided vehicle according to the method of the present invention, in which 1 is the main body of the automatic guided vehicle, 2 is its loading surface, 3 is a driving wheel, and 4 is a driven vehicle. Wheels 7 (7a to 7b) are magnetic sensors 6 disposed at the front and rear ends of the truck facing downward and symmetrically with respect to the center of the truck.
5 (5a and 5b) are magnetic tapes that define the running path of the truck 1, and magnetic sensors 5 (5a and 5b) are arranged at the front and rear ends of the truck 1 facing upward and symmetrically with respect to the center of the truck.
is a course sensor, and the magnetic sensor 5 is a mark sensor.

FIG. 3 shows the lower surface of the object to be transported 11, and a magnetic tape 10 is attached to the center of the lower surface along the direction in which the automatic conveyance vehicle 1 enters. The drive wheels 3 of the automatic guided vehicle 1 have left and right wheels driven by individual servo motors 12a and 12.
b (FIG. 1), and the running direction of the automatic guided vehicle 1 is controlled by the speed difference between the left and right motors.

FIG. 1 shows a block diagram of the travel control system of the automatic guided vehicle 1, in which the front and rear course sensors 5a, 5b
The signals pass through a signal converter 13 similar to the conventional one, and are output as a first left speed command 14a and a first right speed command 14b. 17a and a servo amplifier 17b of the right wheel drive servo motor 12b, respectively. TG attached to each servo motor 12a, 12b is a speed detector, and B is a brake. The detection signal of the speed detector TG is transmitted to each servo amplifier 17a.
, 17b as a feedback signal.

The switching devices 16a, 16b disposed immediately before the servo amplifiers 17a, 17b are configured so that, under normal conditions, the speed command from the signal converter 13 is switched to the servo amplifiers 17a, 17b.
7b.

When a detection signal of the magnetic tape 10 attached to the lower surface of the conveyed object 11 is output from either one of the mark sensors 5, it means that the loading surface 2 of the cart is in the lowered state, as shown in the example in the figure. Then, on the condition that the lift lowering signal is output from the CPU 22, the detection signal of the mark sensor 5 is given to the switches 16a, 16b via the driver 23, and the switches 16a, 16b are connected to the DA converter 24a.
, switch to the 24b side.

The detection signals of the mark sensors 5a and 5b are simultaneously input to the CPU 22, subjected to signal conversion similar to that of the signal converter 13, and outputted as speed signals to the left DA converter 24a and the right DA converter 24b. This CP
The speed command from U22 is sent to the DA converters 24a, 24
b, the signal is converted into an analog signal, and is inputted to the servo amplifiers 17a, 17b via the switch 16 to drive the servo motors 12a, 12b.

At this time, the CPU 22 and the DA converter 2
2nd left speed command 25a output via 4a, 24b
The relationship between the second right speed command 25b and the outputs of the mark sensors 5a and 5b is the relationship between the first left speed command 14a and the first right speed command 14b in the signal converter 13 and the outputs from the course sensors 7a and 7b. The relationship may be similar to the above, but it is preferable to set the speed command so that a speed command with a small absolute value and a large speed ratio is output.

PIO shown in FIG. 1 is a parallel interface circuit, and at the charging station of the automatic guided vehicle 1, the next traveling route of the automatic guided vehicle 1 is commanded through this parallel interface circuit, and the command is sent to the memory in the CPU 22. is memorized. The chime 27 is for driving while sounding a chime sound to alert the operator, and the obstacle sensor 28 is
As shown in FIG. 2, they are provided on both sides of the front of the automatic guided vehicle 22 in the traveling direction. When an obstacle detection signal is input from this sensor to the CPU 22, the CPU 22 outputs emergency stop commands 29a and 29b, and the servo Amplifiers 17a, 17b
A zero speed command is given to the servo motor 12, and a brake B provided on the servo motor 12 is operated. SWPL is a manually operated start and stop switch.

[0022]

[Effects of the Invention] According to the method for controlling the operation of an automatic guided vehicle of the present invention as described above, even if the transported object is placed in a state where the transported object is considerably biased at the loading position, the automatic guided vehicle can maintain the position of the transported object. It is possible to move in the direction along the trolley and transport the transported object while aligning it with the center of the trolley, and it is possible to transport the transported object in a stable state by correcting the deviation of the transported object at the loading position. At the same time, it is possible to correct the deviation at the loading position and place the transported object at an accurate unloading position.

According to the method of the present invention, the allowable amount of deviation is larger than the method of aligning the unmanned guided vehicle and the transported object using mechanical guides, and when the amount of deviation becomes large, the unmanned Smooth operation of the automatic guided vehicle can be guaranteed without increasing running resistance to the guided vehicle.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a control circuit that implements the method of the present invention.

FIG. 2 is a perspective view showing an example of an automatic guided vehicle.

FIG. 3 is a diagram showing an example of the lower surface of an object to be transported.

FIG. 4 is a perspective view of a conventional automatic guided vehicle.

FIG. 5 is a diagram showing an example of the lower surface of an object to be transported.

[Explanation of symbols]

1 Unmanned guided vehicle 5(a,b) Mark sensor 10 Magnetic tape 11 Object to be transported 22 CPU

Claims (1)

[Claims] Claim 1: Marks (10) are arranged in a band shape on the lower surface of the transported object (11) in the direction along the approach direction of the automated guided vehicle (1), and marks (10) are arranged on the upper surface of the automated guided vehicle (1).
0) is arranged, and when a detection signal is input from the sensor (5a, 5b), the controller (22) operates based on the detection signal of the sensor (5a, 5b). A method for controlling the operation of an unmanned guided vehicle, the method comprising controlling the running direction of the unmanned guided vehicle (1).