JP2010282330A - Traveling control method for unmanned carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unmanned carrier which stably travels in a curved section whose radius is small. <P>SOLUTION: The traveling control method is provided for the unmanned carrier which is provided with: a traveling carrier; a caster wheel by which the traveling carrier is supported on a traveling surface so as to freely travel back and forth and right and left; drive wheels installed at the front and back parts of the traveling carrier so as to be independently steered and driven; and a guide sensor installed at the front and back parts of the traveling carrier for detecting a guide tape on the traveling road. The speeds of the front wheel/rear wheel of the drive wheels are controlled, and when the target value of the steering angle of the rear wheel exceeds the target value of the steering angle of the front wheel, the speed of the front wheel is controlled to be decelerated, and the speed of the rear wheel is set to a set speed, and when the target value of the steering angle of the front wheel is equal to or more than that of the rear wheel, the speed of the front wheel is set to the set speed, and the speed of the rear wheel is controlled to be decelerated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a traveling control method for an automated guided vehicle (so-called AGV) guided by a guide tape laid on a traveling road surface and traveling in a factory or warehouse along a desired transportation route.

  2. Description of the Related Art Conventionally, in a newspaper printing factory or the like, an automatic guided vehicle abbreviated as AGV is often used as a means for conveying a web from a paper storage to a rotary press and collecting the remaining core from the rotary press.

As a guide method for automated guided vehicles,
(1) An electromagnetic induction method (guidance wire burying method) that detects a travel route by burying an electromagnetic induction wire on the road surface and detecting a magnetic field generated by flowing an alternating current therewith by a magnetic sensor on the vehicle body side,
(2) A magnetic induction method for detecting a traveling route by sticking a magnetic tape as a guide line on a traveling road surface and detecting a magnetic flux generated by the magnetic tape by a magnetic sensor on the vehicle body side;
(3) A light guiding method is mainly used in which a light reflecting tape is attached as a guide line on a traveling road surface, the light reflecting tape is detected by a light sensor on the vehicle body side, and a traveling route is detected.

  Such automatic guided vehicles have greatly contributed to automation, labor saving, and improvement of the working environment at the site where the web is conveyed.

  In particular, in recent years, there has been an increasing demand for rationalization of the paper feeding operation of the rotary press, and for this reason, introduction of a higher-performance automatic guided vehicle has been actively promoted. And as a guidance method of such an automated guided vehicle, the magnetic guidance method and the light guidance method described above tend to be adopted from the viewpoint of maintenance management, adaptability to the installation site, economy, and the like.

  Usually, a magnetic induction type or a light induction type automatic guided vehicle has a plurality of magnetic sensors or optical devices installed in a line in a direction perpendicular to the guide tape at the position of a guide tape made of a magnetic tape or a light reflecting tape. Automatic steering / running control is performed by recognizing with a sensor (see, for example, Patent Document 1).

  And in order to make an automatic guided vehicle drive stably along a guide tape, front-wheel speed control and rear-wheel torque control are generally performed (for example, refer to patent documents 1).

JP 2004-86453 A

  However, when the conventional automatic guided vehicle as described above travels on a track having a radius smaller than the distance between the front and rear wheels, the front wheels are on a curved track and the rear wheels are on a straight track, or vice versa. As shown in FIG. 6, when the front wheels pass the curved track and travel on the straight track, the rear wheels are on the curved track and the speed is considerably faster than the front wheels. That is, Vf <Vr. Therefore, there is a problem that the steering control cannot follow and the rear wheels become unstable.

  Therefore, a technical problem to be solved by the present invention, that is, an object of the present invention is to provide a traveling control method for an automatic guided vehicle capable of stably traveling on a track with a small radius.

  The invention according to claim 1 is a traveling vehicle, a caster wheel that supports the traveling vehicle on a traveling road surface so as to be able to travel forward, backward, left, and right, and driving wheels that are installed in front of and behind the traveling vehicle and are independently steered and driven. And a traveling control method for an automatic guided vehicle having a guide sensor installed before and after a traveling carriage for detecting a guide tape on the traveling road surface, wherein the driving wheel is subjected to front wheel speed control and rear wheel torque control, and the rear wheel When the target value of the steering angle of the wheel exceeds the target value of the steering angle of the front wheel, the problem is solved by controlling the speed of the front wheel to be decelerated.

  Further, the invention according to claim 2 is a traveling vehicle, caster wheels that support the traveling vehicle on a traveling road surface so as to be able to travel forward, backward, left, and right, and are installed at the front and rear of the traveling vehicle and are independently steered and driven. In a traveling control method of an automatic guided vehicle having a driving wheel and guide sensors installed before and after a traveling carriage for detecting a guide tape on the traveling road surface, the driving wheel is front wheel / rear wheel speed controlled, and the rear When the target value of the steering angle of the wheel exceeds the target value of the steering angle of the front wheel, the speed of the front wheel is set to deceleration control and the speed of the rear wheel is set to the set speed, and the target value of the steering angle of the front wheel is When the steering angle is equal to or greater than the target value, the problem is solved by setting the speed of the front wheels to the set speed and performing deceleration control of the speed of the rear wheels.

  According to a third aspect of the present invention, in the traveling control method for the automatic guided vehicle according to the second aspect, both the target value of the steering angle of the front wheels and the target value of the steering angle of the rear wheels are equal to or less than the set steering angle. In this case, the problem is further solved by switching to rear wheel torque control.

  According to a fourth aspect of the present invention, in the traveling control method for the automatic guided vehicle according to any one of the first to third aspects, the guide tape is based on an output of a guide sensor installed before and after the traveling carriage. This problem is further solved by calculating a target value of the steering angle of the front wheels and the rear wheels from the deviation.

  According to the first aspect of the present invention, a traveling vehicle, caster wheels that support the traveling vehicle on a traveling road surface so as to be able to travel forward, backward, left, and right, and driving wheels that are installed on the front and rear of the traveling vehicle and are independently steered and driven. And a guide sensor installed at the front and rear of the traveling carriage for detecting the guide tape on the traveling road surface, the driving wheel is controlled by the front wheel speed control / rear wheel torque control, and the rear wheel steering is performed. When the target value of the angle exceeds the target value of the steering angle of the front wheels, the speed of the front wheels is decelerated and controlled so that the speeds of the front and rear wheels do not differ greatly even when traveling on a track with a small radius. Therefore, running stability is improved.

  According to the second aspect of the present invention, the traveling carriage, the caster wheel that supports the traveling carriage on the traveling road surface so as to be able to run forward and backward, left and right, and the front and rear of the traveling carriage are independently steered and driven. In a traveling control method of an automatic guided vehicle having a driving wheel and guide sensors installed before and after a traveling carriage for detecting a guide tape on a traveling road surface, the driving wheel is controlled for front / rear wheel speed, and the rear wheel is steered. If the target value of the angle exceeds the target value of the steering angle of the front wheels, the speed of the front wheels is set to deceleration control, the speed of the rear wheels is set to the set speed, and the target value of the steering angle of the front wheels is the target of the steering angle of the rear wheels. If the value is greater than or equal to the value, the speed of the front wheels is set to the set speed and the speed of the rear wheels is decelerated, so that the speed of the front wheels and the rear wheels is prevented from greatly differing even when traveling on a track with a small radius. So stable running There is improved.

  According to the invention of claim 3, in the traveling control method for the automatic guided vehicle according to claim 2, both the target value of the steering angle of the front wheels and the target value of the steering angle of the rear wheels are equal to or less than the set steering angle. In some cases, by switching to the rear wheel torque control, the control of the front wheel and the rear wheel will not be shared, so that the running stability is further improved.

  And according to the invention concerning Claim 4, in the traveling control method of the automatic guided vehicle according to any one of Claims 1 to 3, the guide tape is based on the outputs of the guide sensors installed before and after the traveling carriage. By detecting the deviation from the wheel and calculating the target value of the steering angle of the front and rear wheels from the deviation, the target value of the steering angle of the front wheel and the target value of the steering angle of the rear wheel can be accurately grasped, so that the running stability The property is further improved.

The perspective view which shows the state which the automatic guided vehicle of a present Example is conveying the cylindrical workpiece. The bottom view when the automatic guided vehicle of a present Example is seen from the bottom. (A) is the perspective view which showed the outline of the internal structure of the automatic guided vehicle shown in FIG. 1, (b) is a figure which shows the definition of the steering angles Sf and Sr of a front wheel and a rear wheel. The flowchart explaining the traveling control of the automatic guided vehicle of a present Example. The flowchart explaining another traveling control of the automatic guided vehicle of a present Example. Explanatory drawing which shows the relationship between the speed of driving | running | working on a curved track and the front wheel and a rear wheel.

  The traveling control method for an automatic guided vehicle according to the present invention includes a traveling carriage, caster wheels that support the traveling carriage on a traveling road surface so that the traveling carriage can freely travel in the front, rear, left, and right directions. In a traveling control method for an automatic guided vehicle having wheels and guide sensors installed before and after a traveling carriage for detecting a guide tape on a traveling road surface, the driving wheels are subjected to front wheel speed control and rear wheel torque control. When the target value of the steering angle exceeds the target value of the steering angle of the front wheels, the speed of the front wheels is controlled to be reduced, or the driving wheels are controlled to control the front and rear wheels, and the target value of the steering angle of the rear wheels is the steering value of the front wheels. When the target angle value is exceeded, the front wheel speed is set to deceleration control, the rear wheel speed is set to the set speed, and the front wheel steering angle target value is greater than or equal to the rear wheel steering angle target value. Set the speed to the set speed and the rear wheel As long as it provides a traveling control method for an automatic guided vehicle that can control the speed at a reduced speed and can stably travel even on a track with a small radius, any specific embodiment can be used. But it doesn't matter.

  For example, the guidance control method used in the automatic guided vehicle of the present invention may be any of a magnetic guidance method and a light guidance method, but is not easily affected by dirt on the guard tape and has a surrounding brightness. The magnetic induction method is particularly preferable from the viewpoint of being hardly affected by changes.

An embodiment of the present invention will be described with reference to FIGS.
Here, FIG. 1 is a perspective view showing a state in which the automatic guided vehicle of the present embodiment is transporting a cylindrical workpiece such as a newspaper web, and FIG. 2 is an automatic guided vehicle of the present embodiment. FIG. 3A is a perspective view showing an outline of the internal structure of the automatic guided vehicle shown in FIG. 1, and FIG. 3B is a front wheel, rear view. It is a figure which shows the definition of the steering angles Sf and Sr of a wheel. FIG. 4 is a flowchart for explaining a traveling control method for the automatic guided vehicle according to the present embodiment. FIG. 5 is a flowchart for explaining another traveling control method for the automatic guided vehicle according to the present embodiment.

  As shown in FIG. 1, the automatic guided vehicle 100 of the present embodiment is guided and moved by a guide tape L laid along a desired conveyance path on a traveling road surface F in a newspaper printing factory or the like.

  First, an overall configuration of the automatic guided vehicle 100 that is a target of the traveling control method of the present embodiment will be described. As shown in FIGS. 1 to 3, the automatic guided vehicle 100 collects the remaining core C from the rotary press, that is, the remaining core, by using up the cylindrical workpiece W along one side of the traveling carriage 110. The remaining core collecting mechanism 160 is provided. The remaining core collecting mechanism 160 includes a mechanism that protrudes in the lateral direction when it rises. After the remaining core is received from the rotary press at the raised position, the remaining core is pulled in the lateral direction and moved to the lowered position to move the traveling carriage 110. In the perspective view of FIG. 1, the remaining core collecting mechanism 160 is stored in the traveling carriage 110. As shown in FIG. 2, the caster wheels 122 are located at the four corners of the remaining portion where the remaining core collecting mechanism 160 is installed, two on the front side, two on the rear side, and each vertex of the rectangle R, 124, 126, and 128 are arranged. Here, the rectangle R means a rectangle connecting the turning centers of the four caster wheels 122, 124, 126, and 128. At this time, the longitudinal center line CV of the traveling carriage 110 and the longitudinal center line CL of the rectangle R are arranged so as to be parallel to each other by a predetermined distance determined by the width of the remaining core collecting mechanism 160.

  In addition, one drive wheel 130 that is independently steered and driven on the front side and the rear side on the longitudinal center line CL of the rectangle R is disposed one by one. Further, it is separated from the longitudinal center line CL of the rectangle R by a predetermined distance, that is, {sensor width / 2 + magnetic tape width + driving wheel width / 2} or more on the front side and rear side on the parallel sensor center line CC. Guide sensors 142 and 144 are arranged one by one. By determining the positions of the drive wheel 130 and the guide sensors 142 and 144 in this way, the drive wheel 130 does not move while stepping on the guide tape L when the automatic guided vehicle 100 moves forward and backward. L damage can be suppressed. In addition, since the four caster wheels 122, 124, 126, and 128 are arranged at positions symmetrical with respect to the line connecting the front and rear drive wheels 130, the weight balance of the automatic guided vehicle 100 is good, and the unmanned The running stability of the transport vehicle 100 is improved. In addition, the member shown with the code | symbol 180 in FIG. 2 is the raising / lowering mechanism for raising / lowering the cylindrical workpiece W. As shown in FIG.

  Next, the traveling control method for the automatic guided vehicle according to the present embodiment will be described. In the traveling control method of the automatic guided vehicle according to the present embodiment, different control is performed for front wheel speed control / rear wheel torque control and for front wheel / rear wheel speed control. First, the case of front wheel speed control / rear wheel torque control will be described based on the flowchart shown in FIG.

  When the traveling control starts (S0), deviations between the front and rear wheels and the guide tape are detected by the guide sensors 142 and 144 (see FIGS. 2 and 3) attached to the front and rear of the traveling carriage (S1). Then, the target values Sf and Sr of the steering angles of the front wheels and the rear wheels are obtained by calculation from this deviation (S2). Then, it is determined whether or not at least one of the front wheel steering angle target value Sf and the rear wheel steering angle target value Sr is larger than the set steering angle Scrv (S3). If the result of S3 is Yes, it is determined whether Sf is equal to or greater than Sr (S4). When the result of S4 is Yes and when the result of S3 is No, the front wheel speed Vf is set to the set speed V (S5). On the other hand, if the result of S4 is No, the front wheel speed Vf is set to a value obtained by multiplying the set speed V by cos (Sr) / cos (Sf) (S6). That is, since Sf <Sr, cos (Sr) / cos (Sf) <1 and the front wheel speed Vf is decelerated. Then, Sf and Sr obtained in S2 are output to the front wheel and rear wheel steering control mechanisms, and Vf obtained in S5 or S6 is output to the front wheel speed control mechanism (S7). In this way, a series of travel control ends (S8).

  Next, the case of front wheel / rear wheel speed control will be described based on the flowchart shown in FIG.

  When the traveling control starts (S0), deviations between the front and rear wheels and the guide tape are detected by the guide sensors 142 and 144 (see FIGS. 2 and 3) attached to the front and rear of the traveling carriage (S1). Then, the target values Sf and Sr of the steering angles of the front wheels and the rear wheels are obtained by calculation from this deviation (S2). Then, it is determined whether or not at least one of the front wheel steering angle target value Sf and the rear wheel steering angle target value Sr is larger than the set steering angle Scrv (S3). If the result of S3 is Yes, it is determined whether Sf is equal to or greater than Sr (S4). When the result of S4 is Yes, the front wheel speed Vf is set to the set speed V, and the rear wheel speed Vr is set to a value obtained by multiplying the set speed V by cos (Sf) / cos (Sr) (S5). That is, since Sf ≧ Sr, cos (Sf) / cos (Sr) ≦ 1 and the rear wheel speed Vr is decelerated. On the other hand, if the result of S4 is No, the front wheel speed Vf is set to a value obtained by multiplying the set speed V by cos (Sr) / cos (Sf), and the rear wheel speed Vr is set to the set speed V (S6). That is, since Sf <Sr, cos (Sr) / cos (Sf) <1 and the front wheel speed Vf is decelerated. Then, the rear wheel speed control is maintained (S7), Sf and Sr obtained in S2 are output to the front wheel and rear wheel steering control mechanisms, and Vf and Vr obtained in S5 or S6 are the front and rear wheels. Is output to the speed control mechanism (S7).

  On the other hand, when the result of S3 is No, the front wheel speed Vf is set to the set speed V (S9), the rear wheel is switched to torque control (S10), and Sf and Sr obtained in S2 are the front wheel and rear wheel steering control. The Vf obtained in S9 is output to the speed control mechanism for the front wheels (S11). In this way, a series of travel control ends (S12).

  As described above, according to the traveling control method of the automatic guided vehicle of the present invention, the traveling stability is reduced because the front wheel speed is reduced so that the rear wheel speed does not become faster than the set speed due to the geometrical effect on the curved track having a small radius. As a result, the rear wheel speed does not become faster than the set speed, and the safety is improved.

DESCRIPTION OF SYMBOLS 100 ... Automatic guided vehicle 110 ... Traveling carts 122, 124, 126, 128 ... Caster wheel 130 ... Drive wheel 132 ... Drive motor 142, 144 ... Guide sensor 160 ... Remaining Core recovery device 180 ... Elevating mechanism CC ... Sensor center line CL ... Longitudinal center line (of rectangle R) CS ... Short axis center line (of rectangle R) CV ... (traveling carriage) ) Longitudinal center line F ... Traveling road surface L ... Guide tape

Claims (4)

A traveling carriage, caster wheels that support the traveling carriage on a traveling road surface so that the traveling carriage can freely travel in the front, rear, left and right directions; drive wheels that are installed on the front and rear sides of the traveling carriage and are independently steered and driven; and a guide tape on the traveling road surface In the traveling control method of the automatic guided vehicle having guide sensors installed before and after the traveling carriage for detecting
The driving wheel is front wheel speed controlled and rear wheel torque controlled,
A traveling control method for an automatic guided vehicle, wherein when the target value of the steering angle of the rear wheel exceeds the target value of the steering angle of the front wheel, the speed of the front wheel is controlled to be reduced. A traveling carriage, caster wheels that support the traveling carriage on a traveling road surface so that the traveling carriage can freely travel in the front, rear, left and right directions; drive wheels that are installed on the front and rear sides of the traveling carriage and are independently steered and driven; and a guide tape on the traveling road surface In the traveling control method of the automatic guided vehicle having guide sensors installed before and after the traveling carriage for detecting
The driving wheels are front / rear wheel speed controlled,
When the target value of the steering angle of the rear wheel exceeds the target value of the steering angle of the front wheel, the speed of the front wheel is set as deceleration control and the speed of the rear wheel is set as a set speed,
When the target value of the steering angle of the front wheels is equal to or larger than the target value of the steering angle of the rear wheels, the traveling control of the automatic guided vehicle is characterized in that the speed of the front wheels is set as a set speed and the speed of the rear wheels is controlled to be decelerated. Method.   3. The driving control of the automatic guided vehicle according to claim 2, wherein when the target value of the steering angle of the front wheel and the target value of the steering angle of the rear wheel are both equal to or less than a set steering angle, the control is switched to the rear wheel torque control. Method.   The deviation from a guide tape is detected based on the output of the guide sensor installed before and behind the traveling carriage, and the target values of the steering angles of the front wheels and the rear wheels are calculated from the deviation. Item 4. A traveling control method for an automatic guided vehicle according to any one of items 3 to 4.

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