JP5051346B2 - Control method for automatic guided vehicle - Google Patents

Description

This invention relates to a control method of the automatic guided vehicle body moving automatically unattended while detecting the induced band provided in the conveyance path by the sensor.

In an assembly line of a vehicle or the like, there are cases where work is performed using a hand cart as a conveying means for conveying the sub and picking parts to the line side. Since this work is a manual work, the material handling is large and it is a wasteful walk.
In general manufacturing sites, a method has been proposed in which work efficiency is improved by utilizing an automated guided vehicle for conveying parts and the like. However, when an automated guided vehicle is used, a space is required to turn the vehicle by a U-turn or the like, so that the range of use is limited and it is difficult to use on the line side as described above. .
In order to solve such a problem, it has been proposed that the unmanned transport cart can be turned, thereby reducing the space for the unmanned transport cart to turn and reducing the restrictions on use ( For example, see Patent Documents 1 and 2).
In the unmanned transport carts shown in these Patent Documents 1 and 2, sensors are respectively provided before and after the cart, and on the transport road surface, a turning point indicating a stop position is provided in the route change unit, and the route direction after the change An induction band extending in the front-rear direction is provided. The automatic guided vehicle temporarily stops at the turning point and turns by rotating one of the drive wheels. In this turn, the front and rear sensors detect the front and rear guide bands along the course direction, thereby enabling the turn of the carriage in a small space.
Japanese Patent Laid-Open No. 2001-22442 JP-A-61-67111

However, in the method disclosed in the above-mentioned patent document, it is necessary to install a turning point, and it is necessary to provide a guidance band not only in the direction of the course after the course is changed but also in the rear thereof. There is a problem that the cost increases. In addition, since the chassis needs to have sensors before and after, there is a problem that the cost of the carriage increases.
The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a control method for an automatic guided vehicle body that enables turning in a small space without incurring high costs such as equipment costs. .

That is, among the control methods for the automatic guided vehicle according to the present invention, the invention according to claim 1 is such that a wheel is provided at the bottom of the vehicle body, and left and right drive wheels of the wheels can be controlled to rotate. In the control method of the automatic guided vehicle body that is driven by the driving wheel and moves while detecting by a sensor, at least a pair of the left and right sensors are provided so as to be positioned on the front side in the traveling direction, and a part of the guide band A path changing portion having a non-detecting cutout portion formed at least one sensor wide on the side opposite to the route changing direction, and one of the sensors is moved during the movement of the automatic guided vehicle body. When the cut-off portion is reached and the detection is turned off, and the detection-off continues for a predetermined time and all the sensors are turned off, it is determined that the automatic guided vehicle body has reached the course changing portion , Opposite sensor Reversing the drive wheels of direction, characterized in that pivoting the vehicle body.

  According to a second aspect of the present invention, there is provided the control method for the automatic guided vehicle body according to the first aspect, wherein when one of the sensors is turned off, the driving wheel in the opposite direction of the one sensor is used for the predetermined time. The vehicle body is skewed while being relatively decelerated or reversed.

  According to a third aspect of the present invention, there is provided a method for controlling the automatic guided vehicle body according to the first or second aspect, wherein after all the sensors are turned on after the determination that the route changing section is present, the vehicle travels normally. It is characterized by shifting to.

An invention of a control method for an automatic guided vehicle according to a fourth aspect is characterized in that, in the invention according to any one of the first to third aspects, the course changing portion is L-shaped .

That is, according to the control method of the automatic guided vehicle body of the present invention, the wheel is provided at the bottom of the vehicle body, the left and right drive wheels among the wheels can be rotationally controlled, and the guidance path of the conveyance path is detected by the sensor In the control method of the automatic guided vehicle that is driven by the driving wheel and moves, at least a pair of the sensors are provided so as to be positioned on the front side in the traveling direction, and a part of the guide band is opposite to the course changing direction. to, at least diversion unit in the sensor one minute width switching chipping unit for non-detection is formed, one of which led to the switching chipped portion before Symbol sensor in said movement of the automated guided vehicle When the detection is turned off, the detection off continues for a predetermined time, and all the sensors are turned off, it is determined that the automatic guided vehicle body has reached the course changing unit , and the direction of the opposite direction of the one sensor is Reverse drive wheels Since the vehicle body is turned, it is possible to detect the course changing portion of the guidance band only with the sensor provided on the traveling direction side, and therefore the guidance band need only be disposed only in the part along the traveling direction at low cost. A system can be constructed. Further, the unmanned transport vehicle body can be reliably moved and turned in a space where the unmanned transport vehicle body can travel without requiring a special space for turning. Further, the minimum turning radius can be covered by the entire length of the automatic guided vehicle body, and further, for example, it is possible to travel and turn at an acute V-turn or I-turn of 60 degrees. As a result, it is sufficient if there is a space where the unmanned transport vehicle body can travel, so that the range of use of the unmanned transport vehicle body is expanded, material handling in the field of use is improved, and the transport loss space can be effectively used.

Below, one Embodiment of this invention is described based on FIGS. 1-3.
The automatic guided vehicle body 1 is provided with free wheels 3... 3 on the front, rear, left and right of the bottom of the chassis 2. The universal wheel 3 is rotatably attached to the chassis 2 by a vertical attachment shaft 3a, and a wheel 3b is rotatably attached to a horizontal shaft fixed to the attachment shaft 3a. Further, fixed wheels 4 and 4 that are rotatable by a horizontal horizontal axis are attached to the left and right ends of the center of the bottom of the chassis 2 in the front-rear direction.
Further, traveling units 10 and 10 are provided between the free wheel 3 and the fixed wheels 4 and 4, respectively. The travel unit 10 is provided with drive wheels 11a and 11b on the left and right sides, and the drive wheels 11a and 11b are connected to the rotation shafts of the drive motors 12a and 12b via drive force transmission members, respectively. ing. The motors 12a and 12b and the drive wheels 11a and 11b can be connected and disconnected by a clutch (not shown).

  In addition, sensors 14a, 14c, and 14b arranged in the lateral direction are provided on the outer side in the front-rear direction (forward in the traveling direction) of the traveling units 10 and 10, respectively, in order to detect a guidance band that will be described later arranged on the conveyance path. Yes. The sensors 14a and 14b can detect a range slightly exceeding the width of the induction band. The detection results of the sensors 14a... 14c described above are output to the common control unit 15, and the control unit 15 can control the motors 12a and 12b in the traveling units 10 and 10 independently of each other. Yes. For example, the control unit 15 can mainly include a CPU and a program that operates the CPU, and can further include a ROM that stores the program, a RAM that secures a work area, a timer that measures control timing, and the like.

  As shown in FIG. 3, a guide belt 20 made of magnetic tape is provided on the transport road surface on which the unmanned transport vehicle 1 travels, and the unmanned transport vehicle 1 detects the magnetism of the guide belt 20. It moves along the guide band 20 based on the detection result of -14c. In addition to the magnetic tape described above, the guide band 20 can be configured by using induced radio waves, optical detection, or the like, and can be configured to be disposed on a surface other than the conveyance path. The sensor may be any sensor that can detect whether the sensor is along or deviates from the induction band according to the magnetic field, radio wave, light reflection, or the like of the induction band. That is, the configuration of the induction band and the sensor for detecting the induction band is not particularly limited as the present invention, and the automatic guided vehicle body is moved along the induction band while detecting the induction band by a combination of the induction band and the sensor. Anything that can be moved is acceptable.

  The guide band 20 has L, T, V, and I-shaped course changing portions that are bent or refracted at a desired location. FIG. 3 shows an L-shaped course changing unit 21, which has a non-detection notch at the end of the course changing unit 21 opposite to the direction of change. A portion 21a is formed. The notch 21a is formed with a width that turns detection off in at least one of the sensors 14a to 14c.

Next, the operation (control method) of the automatic guided vehicle body 1 will be described with reference to FIGS.
On the induction band 20, normal traveling is started with the induction band 20 detected by all the sensors 14a, 14b, 14c on the traveling direction side (step s1). In the traveling, the detection results of the sensors 14a, 14b, and 14c are transmitted to the control unit 15. In the control unit 15, when the detection results of all the sensors are on, the traveling unit on the forward side is set as normal traveling. 10, the drive wheels 11a and 11b are rotated at the same speed in the same direction by the motors 12a and 12b (drive force 50:50, see FIG. 3A). Thereby, the automatic guided vehicle body 1 advances straight along the induction band 20 by the rotational force of the driving wheels 11a and 11b while the universal wheel 3, the non-driven fixed wheel 4 and the driving wheels 11a and 11b rotate. In this movement, good straight-line stability is obtained by the fixed wheels 4 and 4.

In the control unit 15, it is continuously determined whether or not all the sensors are on (step s2). In addition, since the detection ON / OFF of all the sensors is grasped | ascertained by the ON / OFF state of the sensor of both sides, in the following procedures, the ON / OFF condition determination of all the sensors is performed with the detection result of the sensors of both sides. While the above condition (all sensor detection ON) is satisfied, normal running is continued until the power is turned off (steps s3 and s4). In this state, if the automatic guided vehicle 1 meanders to the right side, the sensor 14a is turned off, and the sensors 14b and 14c are kept turned on. Then, the control unit 15 does not detect the detection of the sensors on both sides, and therefore determines that the sensor has meandered and reverses the driving wheel 11b on the side opposite to the detection-off sensor 14a for a predetermined time (0.5 seconds in this embodiment). Is issued and the unmanned transport vehicle body 1 is skewed to the side opposite to the side where the detection-off sensor is located, and returned to the center direction of the guide band 20 (step s 5 ).
In the step s 5, whereas not the reverse side of the drive wheels, (see FIG. 3 (b) driving force) may be one to a relatively decelerated relative to the other side drive wheel. For example, the drive wheel on the other side can be decelerated and the drive wheel on the one side can be further decelerated.
At the time of the above skew, each of the free wheels 3 rotates about the attachment shaft 3a, so that the skew is smoothly performed.

In the above control, the automatic guided vehicle body 1 is skewed because it advances due to inertia even when the driving wheels 11a and 11b are rotated forward and reverse at the same rotational speed. The controller 15 determines whether or not both of the sensors 14a and 14b on both sides have been detected after this skew (step s 6 ). Here, when the sensors 14a and 14b on both sides are turned on by the skew (step s6, YES) , it is determined that the sensors 14a and 14b have returned to the center, and the process proceeds to step s3. The above-described state occurs when the automatic guided vehicle body 1 deviates from the guide band 20 for some reason, or when the guide band 20 is gently curved or bent at a small angle. Therefore, it is not necessary to turn the automatic guided vehicle body 1 in such a state.

On the other hand, if the detection is not turned on by both the sensors 14a and 14b on both sides after the skew (step s6 , NO ), it is determined whether or not both the sensors 14a and 14b are turned off. (Step s 7 ). As shown in FIG. 3B, after the automatic guided vehicle body 1 reaches the course changing unit 21, the sensor 14a reaches the non-detection cutout portion 21a, and the sensor 14a is turned off. As the process proceeds, the sensors 14b and 14c are also removed from the guide band 20 and turned off (see FIG. 3C).

If both of the sensors 14a and 14b on both sides are not turned off in the above determination (step s7, NO) , the skew of the automatic guided vehicle body 1 is insufficient and has not completely returned to the center of the guide band 20, so that the skew is not detected. repeated (to step s 5). On the other hand, when both of the sensors 14a and 14b on both sides are turned off in the above determination (step s7, YES) , the control unit 15 determines that the carriage 2 has reached the course changing unit 21, and first described above. A command is issued to the motor 12b so as to reverse the driving wheel 11b opposite to the sensor 14a whose detection is turned off for a predetermined time (in this embodiment, 0.5 seconds). (Corresponding to the predetermined time continuation of claim 1)

Motor 12b is a driving wheel 11b receives the command to reverse the predetermined time (see step s 8, Figure 3 (c)). As a result, the automatic guided vehicle body 1 that has been skewed starts to turn quickly (see FIG. 3D).
Note that the reverse rotation speed after the course change portion determination and the reverse rotation speed at the time of skew can be made different. In other words, the reverse rotation after the course change portion determination requires that the unmanned transport vehicle body be turned quickly, so that the reverse rotation speed is increased, and there is a case where the turning is not required during skewing. Can be kept small.
Even in the above-mentioned turning, the free wheel 3 rotates about the attachment shaft 3a, so that the turning is smoothly performed.

After performing the turn at the time of the course change portion determination, in order to confirm whether the turn is completed, the sensor 14b on the side of the driving wheel 11b that is reversely rotated (opposite to the first detection-off sensor). in, whether or not a detected oN is determined (step s 9). Herein, when the sensor 14b is detected on (step s9, YES), since both sides of the sensor 14a, is pivoted both 14b is detected on the completed, the process proceeds to step s 6 for the determination . Here, when both of the sensors 14a and 14b on both sides are on, it is assumed that the turn has been completed (see FIG. 3 (e)), and the routine proceeds to step s3 and travels normally along the guide band 20. (Go straight).
On the other hand, if the sensor 14b of the driving wheel that is a reversed step s 9 is determined to be detected off (step s9, NO), did not reach the detection of the induction zone 20, for turning the clearly insufficient , repeating the turning (to step s 8).

  By repeating the above procedure, the automatic guided vehicle body 1 can be turned accurately and in a small space at a desired location. And, in the present invention, it is only necessary to arrange the guide band only on the necessary conveyance path, and it is not necessary to extend the guide band on the opposite side of the traveling direction for turning as in the conventional case, In addition, it is not necessary to provide a turning point in the course changing unit.

  In the embodiment described above, the case where the automatic guided vehicle body is turned along the guide band arranged in an L shape has been described. However, the turn to the other direction, the V shape, the T shape, and the I shape. Even in the induction zone, the automatic guided vehicle can be turned in a small space by the same control method. That is, the present invention is particularly effective when turning to L and V in the middle of a narrow traveling road, or when switching back (reversing back and forth).

In addition, since the automatic guided vehicle body of this embodiment is provided with traveling units in the front-rear direction, it can also move forward and backward as desired, and can turn in the same manner as described above when traveling to the opposite side. it can. In the present invention, only one traveling unit may be used, and driving may be performed only on one side.
If the road end point = terminal (unloading, loading), making an I-turn at the end point creates a gap between the terminal and the carriage, which is not suitable for loading or unloading. The vehicle may be moved forward and backward by a traveling unit that can move forward and backward as described above. Further, in this embodiment, the sensor 14c is provided and used as a spare for the failure of the both-side sensors 14a and 14b or for more detailed control, but the description thereof is omitted because it is not directly necessary for the present invention.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to the content of the said embodiment, A suitable change is possible in the range which does not deviate from the scope of the present invention. is there.

It is the bottom view, front view, and side view which show the automatic guided vehicle body in one Embodiment of this invention. Is a flowchart illustrating the control procedure of the automatic guided vehicle. Similarly, it is a figure which shows the change of the turning state of an automatic guided vehicle body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Unmanned conveyance vehicle body 2 Cart 3 Free wheel 4 Fixed wheel 10 Traveling unit 11a Drive wheel 11b Drive wheel 12a Motor 12b Motor 14a Sensor 14b Sensor 14c Sensor 15 Control part 20 Guidance zone 21 Course change part 21a Undetected notch part

Claims (4)

  In a control method for an unmanned transport vehicle body in which wheels are provided at the bottom of the vehicle body, the left and right drive wheels of the wheels are rotationally controllable, and are driven and moved by the drive wheels while detecting a guide band of a transport path with a sensor. The sensor is provided in at least a pair of left and right so as to be positioned on the front side in the traveling direction, and a non-detection cut with a width of at least one sensor on a part of the guide band opposite to the course changing direction. A path change portion in which a chipped portion is formed, one of the sensors reaches the cutout portion during the movement of the automatic guided vehicle body, the detection is turned off, the detection off continues for a predetermined time, and all When the detection sensor is turned off, it is determined that the unmanned transport vehicle body has reached the route change section, and the vehicle body is turned by reversing the driving wheel in the opposite direction of the one sensor. Car body Control method.   2. When the detection of one of the sensors is turned off, the vehicle body is skewed by decelerating or reversing the driving wheel in the opposite direction of the one sensor for the predetermined time. The control method of the automatic guided vehicle body described.   3. The control method for an automatic guided vehicle according to claim 1 or 2, wherein after all the sensors are turned on after the determination that the route is changed, the vehicle shifts to normal travel.   The method for controlling an automatic guided vehicle according to any one of claims 1 to 3, wherein the course changing unit is L-shaped.

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