JP2007213127A - Speed control method and speed controller for moving object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speed control method and a speed controller for a moving object capable of stopping precisely the moving object in a target stop position. <P>SOLUTION: A speed command value Nc is output to an inverter 4 to make the moving object travel at a slow speed Vc when the moving object approaches to the target stop position, an actual slow speed Vf of the moving object when the moving object travels for a prescribed time is computed when stopped after the moving object travels for the prescribed time, it is judged whether the slow speed Vc is the actual slow speed Vf or more, or not, and the speed command value Nc is corrected to make the actual slow speed Vf equal to the slow speed Vc, when the slow speed Vc is judged not to be the actual slow speed Vf or more. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a speed control method and a speed control device for controlling the traveling speed of a moving body for transporting a load.

FIG. 3A is a diagram showing an existing moving body.
A moving body 30 shown in FIG. 3A is a stacker crane used in an automatic warehouse, for example. The load 32 is transported in a predetermined section such as a section up to a loading table (not shown).

  The moving body 30 includes a carriage 33 for scooping / unloading the load 32 using a frontage or a loading table, a mast 34 for moving the carriage 33 up and down in the up-and-down direction, a traveling operation of the moving body 30 and a carriage. And a control device 35 for controlling the lifting and lowering operation of 33 and the like.

FIG. 3B is a diagram illustrating an example of a relationship between the moving time and the speed of the moving body 30 when the moving body 30 travels from a certain departure point to a target stop position.
First, the control device 35 gradually increases the speed of the moving body 30 from zero to the maximum speed Va (for example, 80 to 180 m / min), and maintains the maximum speed Va when the speed of the moving body 30 reaches the maximum speed Va. The moving body 30 is allowed to travel for a while. Next, when the moving body 30 approaches a certain distance from the target stop position, the control device 35 gradually reduces the speed of the moving body 30 from the maximum speed Va to an intermediate speed Vb (for example, 10 m / min). Next, after moving the moving body 30 at the intermediate speed Vb for a predetermined time, the moving body 30 is gradually decelerated from the intermediate speed Vb to the fine speed Vc (for example, 5 m / min or less). Then, the moving body 30 is stopped after traveling for a predetermined time tc at the slow speed Vc.

Conventionally, the moving body 30 is stopped at the target stop position by such a speed control method of the moving body 30.
However, in this speed control method, the timing at which the speed command value for starting the deceleration of the moving body 30 is output to the inverter that controls the operation of the traveling motor of the moving body 30 and the actual rotational speed of the traveling motor are determined. There is a problem that the moving body 30 cannot be accurately stopped at the target stop position because the timing of starting to fall is displaced.

Accordingly, in order to solve this problem, conventionally, the deceleration travel time t0 (ie, the deceleration of the moving body 30) required to stop the moving body 30 after the deceleration of the moving body 30 is started by the amount of the timing difference. For example, a timing at which a speed command value for starting the operation is output to the inverter) and the predetermined time tc are corrected to finely adjust the stop position of the moving body 30 (see, for example, Patent Document 1).
JP-A-7-187324

  However, as described above, in the configuration in which the deceleration traveling time t0 and the predetermined time tc are corrected, it is possible to correct the deviation between the target stop position of the moving body 30 and the actual stop position caused by the deviation in timing. However, variations such as individual differences for each moving body 30 (for example, variations in grease hardness of the motor for each moving body 30 due to temperature changes and variations in the assembly accuracy of parts during manufacturing for each moving body 30). For example, if the actual machine slow speed of the moving body 30 is higher than the preset slow speed Vc, the moving body 30 exceeds the target stop position, and the moving body 30 is accurately stopped at the target stop position. There is a problem that can not be.

  In particular, when the moving path of the moving body 30 is easily slipped by oil or the like, if the actual machine slow speed of the moving body 30 is larger than the slow speed Vc, the moving body 30 is further increased from the target stop position when the moving body 30 stops. There is a problem of leaving.

  Therefore, an object of the present invention is to provide a speed control method and a speed control apparatus for a mobile body that can stop the mobile body at a target stop position with high accuracy.

In order to solve the above problems, the present invention employs the following method and configuration.
That is, according to the speed control method for a moving body of the present invention, when the moving body approaches the target stop position, a speed command value for causing the moving body to travel at a predetermined speed is output to an inverter that controls the operation of the traveling motor. A speed control method for the moving body that stops the mobile body after traveling for a predetermined time, and outputs the speed command value to the inverter and causes the mobile body to travel for the predetermined time. Obtaining the actual machine speed of the body; determining whether the predetermined speed is greater than or equal to the actual machine speed; and determining that the predetermined speed is not greater than or equal to the actual machine speed, the actual machine speed is equal to or less than the predetermined speed. And correcting the speed command value so that

  As described above, when the predetermined speed is not equal to or higher than the actual machine speed, that is, when the actual machine speed is higher than the predetermined speed, the speed command value is corrected so that the actual machine speed is equal to or lower than the predetermined speed. The moving body can be stopped at the target stop position with high accuracy.

  The speed control method for a moving body according to the present invention outputs a speed command value for causing the moving body to travel at a predetermined speed when the mobile body approaches the target stop position, to an inverter that controls the operation of the traveling motor. A speed control method for the moving body that stops the mobile body after traveling for a predetermined time, and outputs the speed command value to the inverter and causes the mobile body to travel for the predetermined time. Obtaining the actual machine speed of the body; determining whether the predetermined speed is equal to or higher than the actual machine speed; and determining that the predetermined speed is not equal to or higher than the actual machine speed, the actual machine speed and the predetermined speed; Determining whether or not the difference between the actual machine speed and the predetermined speed is appropriate, the speed command so that the actual machine speed is equal to or less than the predetermined speed. Correcting the a step.

  For example, “determining whether or not the difference between the actual machine speed and the predetermined speed is appropriate” means that the difference between the actual machine speed and the predetermined speed is caused by variations such as individual differences for each moving object. This indicates that it is determined whether or not. Then, when it is determined that the difference between the actual machine speed and the predetermined speed is caused by variations such as individual differences for each moving object, by correcting the speed command value, It is possible to correct the deviation between the target stop position of the moving body and the actual stop position. Accordingly, it is possible to prevent the speed command value from being corrected when the predetermined speed is not equal to or higher than the actual machine speed due to reasons other than variations such as individual differences for each moving body.

The speed control method for the moving body may include a step of outputting that the actual machine speed is abnormal when it is determined that the difference between the actual machine speed and the predetermined speed is not appropriate.
Thereby, for example, it is possible to notify the worker that the cause that the predetermined speed is not equal to or higher than the actual machine speed is a cause other than variations such as individual differences for each moving body.

  In addition, the speed control device for a moving body according to the present invention outputs a speed command value for causing the moving body to travel at a predetermined speed when the moving body approaches the target stop position, to an inverter that controls the operation of the traveling motor. The speed control device of the mobile body that stops the mobile body after traveling for a predetermined time, and outputs the speed command value to the inverter and causes the mobile body to travel for the predetermined time. Acquisition means for acquiring the actual machine speed of the body, comparison means for determining whether or not the predetermined speed is equal to or higher than the actual machine speed acquired by the acquisition means, and the predetermined speed is equal to or higher than the actual machine speed by the comparison means If it is determined that the speed command value is not equal, the speed command value is corrected so that the actual machine speed is equal to or lower than the predetermined speed.

  In addition, the speed control device for a moving body according to the present invention outputs a speed command value for causing the moving body to travel at a predetermined speed when the moving body approaches the target stop position, to an inverter that controls the operation of the traveling motor. The speed control device of the mobile body that stops the mobile body after traveling for a predetermined time, and outputs the speed command value to the inverter and causes the mobile body to travel for the predetermined time. Acquisition means for acquiring the actual machine speed of the body, comparison means for determining whether or not the predetermined speed is equal to or higher than the actual machine speed acquired by the acquisition means, and the predetermined speed is equal to or higher than the actual machine speed by the comparison means If it is determined that the difference between the actual machine speed and the predetermined speed is not appropriate, the determination means determines whether or not the difference between the actual machine speed and the predetermined speed is appropriate. When the cross-sectional, and a correcting means for correcting the speed command value so that the actual speed falls below the predetermined speed.

  In addition, the speed control device of the moving body includes an output unit that outputs that the actual machine speed is abnormal when the determination unit determines that the difference between the actual machine speed and the predetermined speed is not appropriate. You may comprise.

  ADVANTAGE OF THE INVENTION According to this invention, the mobile body for conveying a load can be stopped to a target stop position with high precision.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a speed control apparatus for a moving body according to an embodiment of the present invention. The moving body of this embodiment is the same as the moving body 30 shown in FIG. 3A, for example, and the speed control device of this embodiment corresponds to the control device 35.

  A speed control device 1 shown in FIG. 1 includes an encoder 2 (acquisition means) that is provided on a shaft of a traveling tire of a moving body 30 and measures how much the moving body 30 has traveled, and a traveling motor 3 for the moving body 30. And a CPU 5 (comparison means, judgment means, correction means) for controlling the traveling speed of the moving body 30 by outputting a speed command value to the inverter 4 for controlling the operation. Note that the CPU 5 may perform the lifting / lowering operation control of the carriage 33 in addition to the traveling speed control of the moving body 30.

  FIG. 2 is a flowchart for explaining the operation of the CPU 5 when correcting the speed command value Nc for causing the moving body 30 to travel at the fine speed Vc (predetermined speed). Note that the processing of this flowchart is performed by the CPU 5 when the transporting operation of the load by the moving body 30 is not performed.

  First, when entering the learning mode for correcting the speed command value Nc, the CPU 5 outputs the speed command value Nc to the inverter 4 and causes the moving body 30 to travel (step S1). For example, the CPU 5 may be configured to enter the learning mode when a worker operates a button or a switch provided on the moving body 30 during a break of the load transport operation.

  Next, when the CPU 5 causes the moving body 30 to travel for a predetermined time tc, the CPU 5 outputs a speed command value for stopping the moving body 30 to the inverter 4 to stop the moving body 30 (step S2). For example, the predetermined time tc may be measured using a timer or the like.

  Next, the CPU 5 calculates the actual machine fine speed Vf (actual machine speed) of the moving body 30 by dividing the travel distance of the moving body 30 obtained from the encoder 2 at this time by the predetermined time tc (step S3).

Next, the CPU 5 determines whether or not the slow speed Vc is equal to or higher than the actual machine slow speed Vf (step S4).
When it is determined that the slow speed Vc is equal to or higher than the actual machine slow speed Vf (Yes in step S4), the CPU 5 determines that it is not necessary to correct the speed command value Nc and ends the learning mode (step S5).

  On the other hand, when it is determined that the fine speed Vc is not equal to or higher than the actual machine slow speed Vf, that is, when it is determined that the actual machine slow speed Vf is greater than the very slow speed Vc (step S4 is No), the CPU 5 It is determined whether or not the difference from the speed Vc is appropriate (step S6). For example, determining whether or not the difference between the actual machine slow speed Vf and the slow speed Vc is appropriate means that the difference between the actual machine slow speed Vf and the slow speed Vc varies such as individual differences for each moving body 30. It is shown that it is determined whether or not it is caused by the above. In the case of such a configuration, for example, if the difference between the actual machine fine speed Vf and the fine speed Vc is in the range of 3 to 7 m / min, the difference is determined to be appropriate. If the difference between the speed Vf and the fine speed Vc is 2 m / min or less or 8 m / min or more, the difference between the actual machine fine speed Vf and the fine speed Vc is not caused by variations such as individual differences for each moving body 30. Judge. Then, by correcting the speed command value Nc when it is determined that the difference between the actual machine fine speed Vf and the fine speed Vc is caused by variations such as individual differences for each moving body 30, the speed command value Nc is corrected for each moving body 30. The deviation between the target stop position of the moving body 30 and the actual stop position caused by variations such as individual differences can be corrected. Thereby, it is possible to prevent the speed command value Nc from being corrected when the fine speed Vc is not equal to or higher than the actual machine fine speed Vf due to reasons other than variations such as individual differences for each moving body 30.

  If it is determined that the difference between the actual machine slow speed Vf and the slow speed Vc is not appropriate (No in step S6), the CPU 5 outputs that the actual machine slow speed Vf is abnormal (step S7). For example, when it is determined that the difference between the actual machine slow speed Vf and the slow speed Vc is not appropriate, the CPU 5 displays on the display (output means) provided in the moving body 30 that the actual machine slow speed Vf is abnormal. The lamp (output means) provided in the moving body 30 is turned on. Thereby, for example, it is possible to notify the operator that the cause that the fine speed Vc is not equal to or higher than the actual machine fine speed Vf is a cause other than variations such as individual differences.

  On the other hand, when it is determined that the difference between the actual machine slow speed Vf and the slow speed Vc is appropriate (Yes in step S6), the CPU 5 sets the speed command value Nc so that the actual machine slow speed Vf is the same as the slow speed Vc. Correction is performed (step S8). For example, as shown in FIG. 1, when it is determined that the difference between the actual machine slow speed Vf and the slow speed Vc is appropriate, the CPU 5 determines the speed command value so that the actual machine slow speed Vf becomes the same as the slow speed Vc. The speed correction value Nr for correcting Nc is changed. A speed command value Nc corresponding to the difference between the actual machine fine speed Vf and the fine speed Vc is recorded as a speed correction value Nr in a register or the like, and the speed command value Nc is stopped when the moving body 30 is stopped during the load transfer operation. The value Nc may be corrected with the speed correction value Nr. For example, when the fine speed Vc is 5 m / min and the actual machine fine speed Vf is 5.5 m / min, the speed correction value Nr is a value corresponding to −0.5 m / min, and the movable body is moved during the load transfer operation. The speed command value Nc that is actually input to the inverter 3 when stopping 30 is a value corresponding to 5 m / min.

  As described above, when it is determined that the actual machine slow speed Vf is not equal to or less than the slow speed Vc and the difference between the actual machine slow speed Vf and the slow speed Vc is appropriate, the actual machine slow speed Vf becomes the same as the slow speed Vc. Since the speed command value Nc is corrected as described above, the actual machine fine speed Vf does not become larger than the fine speed Vc, and the moving body 30 can be stopped at the target stop position with high accuracy.

  Further, since the speed command value Nc can be automatically corrected, it is possible to shorten the adjustment time of the stop position of the moving body 30 as compared with the case where the speed command value Nc is corrected manually.

  In the above embodiment, when the fine speed Vc is not equal to or higher than the actual machine fine speed Vf (No in step S4), it is determined whether or not the difference between the actual machine fine speed Vf and the fine speed Vc is appropriate (step S6). If the fine speed Vc is not equal to or higher than the actual machine fine speed Vf (No in step S4), the speed command value Nc is corrected so that the actual machine fine speed Vf is the same as the fine speed Vc (step S8). It may be configured. That is, in the flowchart of FIG. 2, the CPU 5 may be configured to omit step S6 and step S7 and perform step S8 when step S6 is No. Even if comprised in this way, the actual machine fine speed Vf does not become larger than the fine speed Vc, and the moving body 30 can be stopped at the target stop position with high accuracy.

  In the above embodiment, the CPU 5 performs the processing of the flowchart shown in FIG. 2 when the CPU 5 enters the learning mode. However, when the mobile body 30 is turned on or once a week, such as periodically, FIG. The CPU 5 may perform the processing of the flowchart shown in FIG. Even in such a configuration, it is desirable that the CPU 5 performs the processing of the flowchart shown in FIG. As described above, the CPU 5 periodically performs the process of the flowchart shown in FIG. 2 to reduce the influence of the stop accuracy of the moving body 30 based on the secular change such as a change in mechanical resistance due to a change in temperature or wear of machine parts. can do. Further, since the speed command value Nc can be automatically corrected periodically, the stopping accuracy of the moving body 30 can be kept constant regardless of the years of use of the moving body 30.

  In the above embodiment, the CPU 5 performs the processing of the flowchart shown in FIG. 2 when the moving object 30 does not carry the load. However, when the moving object 30 is carrying the load. In addition, the CPU 5 may be configured to perform the processing of the flowchart shown in FIG.

  In the above embodiment, in step S8 of the flowchart shown in FIG. 2, the speed command value Nc is corrected so that the actual machine slow speed Vf becomes the same as the slow speed Vc. However, the actual machine slow speed Vf is the slow speed. The speed command value Nc may be corrected so as to be equal to or lower than Vc.

  In the above embodiment, the learning mode is terminated after correcting the speed command value Nc in step S8 of the flowchart shown in FIG. 2. However, after correcting the speed command value Nc in step S8, step S8 is performed. You may comprise so that the process which returns to S4 may be repeated predetermined times.

  Moreover, in the said embodiment, although it is the structure which makes the mobile body 30 a stacker crane, the mobile body 30 is not limited to stacker cranes, such as a tracked carriage.

It is a figure which shows the speed control apparatus of the moving body of embodiment of this invention. It is a flowchart for demonstrating operation | movement of CPU. (A) is a figure which shows the existing mobile body. (B) is a figure which shows an example of the relationship between the moving time and speed of a moving body.

Explanation of symbols

1 Speed Controller 2 Encoder 3 Motor 4 Inverter 5 CPU
30 Moving body 31 Storage shelf 32 Load 33 Carriage 34 Mast 35 Control device

Claims (6)

When the moving body approaches the target stop position, a speed command value for causing the moving body to travel at a predetermined speed is output to an inverter that controls the operation of the traveling motor to stop the mobile body after traveling for a predetermined time. A speed control method for the moving body, comprising:
Outputting the speed command value to the inverter to obtain an actual machine speed of the moving body when the moving body is running for the predetermined time;
Determining whether the predetermined speed is equal to or higher than the actual machine speed;
When determining that the predetermined speed is not equal to or higher than the actual machine speed, correcting the speed command value so that the actual machine speed is equal to or lower than the predetermined speed;
A method of controlling the speed of a moving object having When the moving body approaches the target stop position, a speed command value for causing the moving body to travel at a predetermined speed is output to an inverter that controls the operation of the traveling motor to stop the mobile body after traveling for a predetermined time. A speed control method for the moving body, comprising:
Outputting the speed command value to the inverter to obtain an actual machine speed of the moving body when the moving body is running for the predetermined time;
Determining whether the predetermined speed is equal to or higher than the actual machine speed;
Determining that the predetermined speed is not greater than or equal to the actual machine speed, determining whether or not a difference between the actual machine speed and the predetermined speed is appropriate;
Determining that the difference between the actual machine speed and the predetermined speed is appropriate, correcting the speed command value so that the actual machine speed is equal to or less than the predetermined speed;
A method of controlling the speed of a moving object having It is the speed control method of the moving body according to claim 2,
When determining that the difference between the actual machine speed and the predetermined speed is not appropriate, outputting the fact that the actual machine speed is abnormal;
A method of controlling the speed of a moving object having When the moving body approaches the target stop position, a speed command value for causing the moving body to travel at a predetermined speed is output to an inverter that controls the operation of the traveling motor to stop the mobile body after traveling for a predetermined time. A speed control device for the mobile body,
Obtaining means for outputting the speed command value to the inverter and obtaining an actual machine speed of the moving body when the moving body is running for the predetermined time;
Comparing means for determining whether the predetermined speed is equal to or higher than the actual machine speed acquired by the acquiring means;
Correction means for correcting the speed command value so that the actual machine speed is equal to or less than the predetermined speed when the comparison means determines that the predetermined speed is not equal to or higher than the actual machine speed;
A speed control apparatus for a moving body, comprising: When the moving body approaches the target stop position, a speed command value for causing the moving body to travel at a predetermined speed is output to an inverter that controls the operation of the traveling motor to stop the mobile body after traveling for a predetermined time. A speed control device for the mobile body,
Obtaining means for outputting the speed command value to the inverter and obtaining an actual machine speed of the moving body when the moving body is running for the predetermined time;
Comparing means for determining whether the predetermined speed is equal to or higher than the actual machine speed acquired by the acquiring means;
Determining means for determining whether or not a difference between the actual machine speed and the predetermined speed is appropriate when the comparing means determines that the predetermined speed is not equal to or higher than the actual machine speed;
When the determination unit determines that the difference between the actual machine speed and the predetermined speed is appropriate, the correction unit corrects the speed command value so that the actual machine speed is equal to or less than the predetermined speed;
A speed control apparatus for a moving body, comprising: It is the speed control apparatus of the moving body of Claim 5, Comprising:
An output means for outputting that the actual machine speed is abnormal when the judgment means judges that the difference between the actual machine speed and the predetermined speed is not appropriate;
A speed control apparatus for a moving body, comprising:

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