JPH08202446A - Method and device for stop control of moving body - Google Patents

Abstract

PURPOSE: To precisely stop a moving body at a target stop position in consideration of the follow-up delay of a motor to the output value of a speed control signal. CONSTITUTION: A stacker crane of automated warehouse has its speed controlled through an inverter control of motor. The output frequency of the inverted is set so that the stacker crane is reduced in speed at a constant reduction speed and the moving body stops at the target stop position C after the stacker crane is held at a creep speed Vc for a specific time tc. The stacker crane begins to be reduced in speed from a position A1 before a logical speed reduction start position A found on the basis of the set output frequency of the inverter so that the stacker crane is held at the creep speed Vc for the specific time tc in consideration of the follow-up delay of the motor to the output frequency of the inverter. Therefore, the stacker crane is braked after becoming stable at the creep speed Vc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stop control method and a stop control device for a movable body such as a stacker crane provided in an automatic warehouse, which accurately stops at a predetermined position.

[0002]

2. Description of the Related Art Conventionally, in an automated warehouse, a stacker crane that travels along a rail while facing a shelf is provided with a fork for loading and unloading a load in order to carry out a work for loading and unloading a load with a shelf. Equipped. In order to load and unload loads in a well-balanced manner, the forks need to be accurately arranged facing the accommodating portion, and for that purpose, the positioning of the stacker crane is important. Normally, the stacker crane is speed-controlled by controlling the induction motor with an inverter.

As shown in FIGS. 8 and 9, when the stacker crane reaches the deceleration start position (point A) at a constant speed V, it is decelerated from the speed V at a constant deceleration to a very low creep speed Vc. Retained. When the vehicle reaches a predetermined position, the brake is applied from the creep speed Vc and the destination (C
Stop). The brake timing is set so as to accurately stop at the destination C when braking is applied from the creep speed Vc.

As shown in FIG. 10, immediately after the stacker crane reaches the creep speed Vc, the speed changes due to the change in acceleration when the stacker crane reaches the creep speed Vc.
It takes some time to converge to c. Therefore, the deceleration start position A is set so that a predetermined time or more is secured at the creep speed Vc so that braking cannot be applied in an unstable state before it converges to the creep speed Vc.

Usually, the traveling speed of the stacker crane changes according to the moving distance, and therefore the deceleration start position A differs for each traveling speed. Therefore, the deceleration start position A has been calculated from the traveling speed. That is, the deceleration start position A is determined by the stacker crane at the speed locus theoretically obtained from the set value of the output frequency from the control circuit for controlling the speed of the induction motor, for example, the inverter circuit, as shown by the solid lines in FIGS. As the vehicle traveled, it was calculated based on the set value of the output frequency.

[0006]

By the way, in the deceleration process of the stacker crane, the deceleration is not actually performed so as to draw the velocity locus as calculated, and a deceleration delay occurs due to the device delay. The device delay refers to a delay in following the motor rotation with respect to the output frequency of a control circuit that controls the induction motor, for example, an inverter. This tracking delay causes a delay in the actual velocity locus (broken line) with respect to the calculated velocity locus (solid line), as shown in FIGS. Moreover, when the frequency exceeds a certain frequency, the torque generated by the motor tends to become smaller in the higher frequency range of the inverter output. Therefore, in the higher frequency range where the generated torque is smaller, that is, in the higher speed range, the delay amount with respect to the calculated speed locus becomes larger. Become. for that reason,
The amount of delay varies depending on the traveling speed.

As shown by the broken line in FIG. 8, the equipment delay causes a delay in the position where the stacker crane reaches the creep speed Vc. That is, the creep speed Vc is actually reached at the position B1 which is delayed by a predetermined distance from the theoretical position B at which the creep speed Vc is reached. As a result, the creep speed Vc is not maintained for a predetermined time or longer, and the creep speed Vc
Since the brakes will be applied from the unstable state before convergence to c, the position accuracy will be degraded when stopping at the destination.

In particular, in the deceleration process from the high speed range, there is a possibility that the delay amount becomes large and the brake is applied before the creep speed Vc is reached. In that case, a high speed exceeding the creep speed Vc may be caused. Since the braking is performed from the speed, the vehicle overruns without stopping at the destination C.

Further, in Japanese Unexamined Patent Publication No. 59-58509, a deceleration start position is set in advance, a speed difference Δv between a transport speed and a creep speed (positioning speed) before deceleration start is calculated, and the speed difference Δv is calculated. A conveying device is disclosed in which the smaller the position, the later the position from which the deceleration is started, and the more the deceleration is started. According to this carrying device, if the carrying speed is low, deceleration is started at a time later than the deceleration start position, so that the time period maintained at the creep speed is appropriately shortened, and quick positioning is possible. it can. However, even with this transport device, it was not possible to solve the deterioration of the stop position accuracy due to the delay in following the motor rotation with respect to the output voltage of the speed setting device.

The present invention has been made to solve the above-mentioned problems, and its purpose is to control the stoppage of a moving body, which can accurately stop the moving body in consideration of equipment delay. And to provide a stop control device.

[0011]

In order to solve the above-mentioned problems, in the invention described in claim 1, in the deceleration process of stopping the moving body at the target stop position, the moving body is decelerated at a predetermined deceleration and kept at the creep speed. A method of controlling the stop of a moving body in which the vehicle is braked when it reaches a predetermined position and stopped at the target stop position, in which the output value of the speed control signal output from the control means to the motor driving the moving body is changed. Based on the theoretical deceleration start position obtained so that the creep speed is secured for a predetermined time or more based on the following, the moving body of the moving body is located at the front position in consideration of the following delay amount of the motor with respect to the change in the output value of the speed control signal. I started the deceleration process.

According to the second aspect of the invention, in the deceleration process of stopping the moving body at the target stop position, the moving body is decelerated at a predetermined deceleration to maintain the creep speed, and when the predetermined position is reached, the vehicle is braked to stop at the target stop. A stop control device for a moving body, comprising a control means for stopping at a position, wherein the creep speed is not less than a predetermined time based on a change in output value of a speed control signal output from the control means to a motor for driving the moving body. The theoretical deceleration start position, which is obtained so as to be ensured, is corrected to a front position by an amount corresponding to the delay of the motor following the change in the output value of the speed control signal.

According to a third aspect of the present invention, there is provided the mobile body stop control device according to the second aspect, further comprising position detecting means for detecting the position of the mobile body, wherein the correcting means calculates the corrected position. Means and storage means, the correction position calculation means measures the delay distance that actually reaches the creep speed from the trial run of the moving body, the position before the theoretical deceleration start position by the delay distance. As a result, the corrected deceleration start position is calculated and stored in the storage means, and the control means stores the position of the moving body detected by the position detection means in the storage means after the correction. The deceleration process is started when it coincides with the deceleration start position.

According to a fourth aspect of the present invention, the correction position calculating means is provided with a timer, and the timer measures an actual time required from the trial run of the moving body until the moving body stops at the target stop position. While calculating the time, by calculating the theoretical required time from the speed history of the motor based on the output value change of the speed control signal, the creep speed to the difference between the actual required time and the theoretical required time The delay distance is calculated by multiplication.

In a fifth aspect of the present invention, the speed of the moving body before deceleration is started is predetermined according to the moving distance thereof, and the test operation is performed at least twice at different speeds, and the correction is performed. The position calculation means is provided with correction formula calculation means for calculating an equation of a diagram obtained by plotting two or more delay distances with respect to the speed of the moving body before deceleration is started, and the correction formula calculation means The deceleration start position for each speed is calculated by approximately calculating the delay distance for each speed using the equation of the calculated diagram.

According to the invention of claim 6, the diagram is a straight line. In the invention according to claim 7, the corrected deceleration start position approximately calculated for each speed by the corrected position calculation means using the equation of the diagram is stored in the storage means as a map. .

[0017]

Therefore, according to the first aspect of the present invention, the delay amount of the motor following the change in the output value of the speed control signal output from the control means is taken into consideration with respect to the theoretical deceleration start position. The deceleration of the moving body is started from the position. As a result, the moving body is kept at the creep speed for a predetermined time or longer, and braking is performed after the speed is sufficiently stabilized. Therefore, the moving body stops at the target stop position with high positional accuracy.

According to the second aspect of the invention, the correction means causes the deceleration start position of the moving body to change in the output value of the speed control signal output from the control means with respect to the theoretical deceleration start position. The tracking delay of the motor is corrected to the front position. As a result, the moving body is kept at the creep speed for a predetermined time or longer, and braking is performed after the speed is sufficiently stabilized.

According to the third aspect of the invention, the test run of the moving body is performed to correct the deceleration start position. In this test operation, the corrected position calculation means measures the delay distance at which the creep speed is actually reached, and calculates the corrected deceleration start position as the front position by the delay distance with respect to the theoretical deceleration start position. The calculated deceleration start position after correction is stored in the storage means. The position of the moving moving body is detected by the position detection means, and when the position coincides with the corrected deceleration start position stored in the storage means, the control means starts deceleration. Further, although the tracking delay amount of the motor is different depending on the own weight of the moving body, since the correction is performed for each moving body by the test operation, the stop control device can be commonly used for moving bodies having different weights.

According to the fourth aspect of the invention, the correction position calculating means measures the actual time required for the moving body to stop at the target stop position in the trial run by the timer, and the speed output from the control means. Calculate the theoretical required time from the theoretical speed history of the motor based on the output value change of the control signal,
The delay distance is calculated by multiplying the difference between the actual required time and the theoretical required time by the creep speed.

According to the fifth aspect of the present invention, the test run of the moving body is performed at least twice at different speeds (moving distances). The correction position calculation means calculates, in the correction formula calculation means, an equation of a diagram obtained by plotting two or more delay distances obtained from the two or more trial runs with respect to the speed of the moving body before deceleration is started. Then, the delay distance for each speed is approximately calculated using the equation of the diagram, and the deceleration start position for each speed is calculated using these delay speeds.

According to the invention described in claim 6, since the diagram is a straight line, the equation is calculated by two trial runs. According to the invention described in claim 7, in the storage means,
The deceleration start position after correction, which is approximately calculated using the equation in the diagram, is stored as a map for each speed, so the deceleration start position after correction can be immediately read from the speed of the moving body. Becomes Further, it is not necessary to perform complicated arithmetic processing for reading the data.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a stacker crane in an automatic warehouse will be described below with reference to FIGS.

As shown in FIG. 7, the stacker crane 1 as a moving body is movably mounted on two rails 4 via a plurality of traveling rollers 2 provided at the bottom of the carriage 1a. The traveling roller 2 is composed of a driving roller and a driven roller, and the driving roller is a motor 5 provided on the carriage 1a.
Operatively connected to the drive shaft of. By driving the motor 5 in the forward and reverse directions, the stacker crane 1 travels along the rails 4 between the shelves 6 (only one side is shown) standing upright on both sides. A large number of accommodating parts (not shown) are arranged in a matrix on the shelf 6. A measuring wheel 3 is provided on the bottom of the carriage 1a so as to be rollable while being pressed against the upper surface of the rail 4.

A wire 9 extending from a winch 8a is hooked on a pulley 7 provided on the top of a mast 1b erected on the carriage 1a, and the carriage 1 is attached to the tip of the wire 9.
0 is supported in a suspended state. When the motor 8 that drives the winch 8a is driven in the forward and reverse directions, the carriage 10 moves up and down along the mast 1b.
The carriage 10 is equipped with a fork 11 that can be retracted / removed in the horizontal direction (the direction orthogonal to the paper surface of FIG. 7), and the fork 11 can be ejected in a state where the carriage 10 is arranged so as to face a predetermined accommodating portion constituting the shelf 6. By being withdrawn, the load can be put in and taken out from the accommodation section.

A dog 6a is provided at the lowermost stage of the shelf 6 for each accommodation portion along the traveling lane direction (direction orthogonal to the paper surface of FIG. 7), and the carriage 12a has a sensor 12 capable of detecting the dog 6a.
Is provided. When the sensor 12 detects the dog 6a corresponding to the target stop position, the stacker crane 1 is braked.

The stacker crane 1 is equipped with a control device C shown in FIG. The control device C is a microcomputer M
Built-in C. As shown in FIG. 2, the microcomputer MC includes a central processing unit (hereinafter referred to as CPU) 1
3, a program memory 14 including a read-only memory (ROM), and a work memory 15 including a read / write memory (RAM). The CPU 13 is connected to the timer 16 and the counter 17, and operates based on the program data stored in the program memory 14.

The CPU 13 is connected to the input / output interface 18. The motor drive circuits 19 and 20 connected to the input / output interface 18 include inverters 21 and 22.
The motors 5 and 8 are respectively connected via. The motors 5 and 8 are induction motors, and the inverters 21 and 21
The speed is controlled based on the output frequency of 2. An electromagnetic brake 24 provided on the drive shaft of the motor 5 is connected to the excitation / demagnetization circuit 23 connected to the input / output interface 18.
The motor 5 is operated based on the excitation signal from the CPU 13.
Mechanically brake the drive shaft of.

Further, the sensor 12 and the encoder 25 are connected to the input / output interface 18. The encoder 25 is connected to the measuring wheel 3 and outputs a pulse signal having a pulse number proportional to the amount of rotation of the measuring wheel 3. CP
U13 causes the counter 17 to count the number of pulses of the pulse signal input from the encoder 25. The counter 17 has
The count value (pulse value) with the position where the stacker crane 1 is located at the home position as a reference (for example, the count value “0”) is counted, and the position of the stacker crane 1 is recognized from the pulse value of the counter 17. Has become. Further, the CPU 13 calculates the traveling speed of the stacker crane 1 based on the number of pulses of the signal input from the encoder 25 per unit time. When the CPU 13 inputs a detection signal for detecting the dog 6a at the target stop position from the sensor 12,
An excitation signal is output to the excitation / demagnetization circuit 23, and the electromagnetic brake 24
Is designed to operate. It should be noted that the dog 6a has a creep speed V, which will be described later, when the traveling speed of the stacker crane 1 is below.
Assuming that the electromagnetic brake 24 is activated at the time of c, the electromagnetic brake 24 is activated at a timing that allows for the shift amount at the time of braking so that the stacker crane 1 can be accurately stopped at the target stop position. Is set to.

The work memory 15 has a stacker crane 1
The speed pattern during traveling is stored in advance. The velocity pattern consists of an acceleration process, a constant velocity process and a deceleration process. In the acceleration process, it is set to accelerate at a constant acceleration, and when it reaches a speed at which a constant speed process for a constant time can be secured, the speed is maintained at that time. In other words, the speed (constant speed) in the constant speed process is determined according to the moving distance of the stacker crane 1, and the longer the moving distance, the higher the speed.
In the deceleration process, as shown by the solid line in FIG. 1, the deceleration is set at a constant deceleration to the creep speed Vc, and the creep speed Vc is maintained for a predetermined time tc. In addition,
The work memory 15 stores the pulse value at each stop position in the traveling lane direction, and the travel distance is the travel start position (pulse value) read from the counter 17 before the start of travel and the work memory 15 from the work memory 15. It is calculated using the read target stop position (pulse value).

The work memory 15 stores the map data MD shown in FIG. The map data MD is created by the method described below using the learning function set in the program data, and is a constant speed process for each speed V _k (k = 1, 2, ..., N) of the stacker crane 1. The pulse value P _{k at} the deceleration start position (point A1 in FIG. 1) at which the shift from the to the deceleration process is set. The pulse value P _k is represented by a pulse value corresponding to the distance to the target stop position, and the following delay of the motor 5 with respect to the output frequency of the inverter 21 is taken into consideration.

Next, the map data MD using the learning function
How to create is explained. In the program memory 14, the theoretical deceleration start position (point A in FIG. 1) pulse value P _A (theoretical number of pulses required from point A to the target stop position) is calculated using the speed V of the stacker crane 1. A calculation formula for doing is stored in advance. This calculation formula is based on the inverter 21 in which the stacker crane 1 controls the speed of the motor 5.
The theoretical velocity locus shown by the solid line in FIG. 1 based on the set value of the output frequency is drawn so that the pulse value P _A corresponding to the distance to the target stop position can be calculated. Therefore, the pulse value P _A at the deceleration start position A calculated using this calculation formula is set to the inverter 21
The following delay of the motor 5 with respect to the output frequency is not taken into consideration.

First, when the learning function mode is selected, C
The PU 13 has different moving distances (that is, traveling speeds) 2
Request a trial run. In response to the request, an appropriate travel distance is selected and two trial runs are performed.

During the trial run, if the vehicle moves to the constant speed process,
The CPU 13 sequentially calculates the pulse value P _S corresponding to the distance to the target stop position and the current speed V. Then, using the calculation formula read from the program memory 14, the pulse value P _A of the deceleration start position A at the speed V in the constant speed process
Is calculated, the pulse value P _A is compared with the actual pulse value P _S, and when P _S ≦ P _A is satisfied, deceleration is started and the output frequency of the inverter 21 is decreased as set. After the stacker crane 1 decelerates to the creep speed Vc in this deceleration process, when the detection signal for detecting the dog at the target stop position is input from the sensor 12, the electromagnetic brake 24 is operated to stop the stacker crane 1.

As a result of the two trial runs, it is assumed that a deceleration process from speed V1 as shown in FIG. 3A and a deceleration process from speed V2 as shown in FIG. 3B are performed. In FIG. 3, the solid line is the theoretical velocity locus, and the broken line is the actual velocity locus. The CPU 13 creates the map data MD using the data obtained from the two trial runs.

As can be seen from FIG. 3, the actual velocity locus (broken line) is maintained at a higher speed than the theoretical velocity locus (solid line) due to the following delay of the motor 5 with respect to the output frequency of the inverter 21 during deceleration. Therefore, the stacker crane 1 reaches the target stop position at times T1 and T2 earlier than the scheduled stop times t1 and t2.

FIG. 4 is a graph showing the speed change in the trial run with respect to the position up to the target stop position, where the solid line is the theoretical speed locus and the broken line is the actual speed locus. As can be seen from the figure, due to the following delay of the motor 5 during deceleration, the deceleration completion position B at which the creep speed Vc was actually reached
1 already exceeds the theoretical deceleration completion position B. This means that the creep speed Vc can be reached at the planned arrival position B by shifting the deceleration start position A forward by the excess distances Δs1 and Δs2. Where the distance Δ
s1 and Δs2 are equal to the shaded area of FIG. Further delayed distances (hereinafter referred to as deceleration delay distances) Δs1 and Δs
Since the time for maintaining the creep speed Vc by 2 is shortened, Δs1 = Vc · (t1−T1), Δs2 = Vc
-The relationship of (t2-T2) is established. This relational expression is stored in the program memory 14 as program data.

During the trial run, the CPU 13 causes the timer 16 to operate.
Is started and the required time T1 and T2 from the start of traveling of the stacker crane 1 to the stop of traveling are measured. Then, after each test operation, theoretical required times t1 and t2 are calculated from the moving distance and the theoretical velocity locus, and the actual required times T1 and T2 and the theoretical required times t1 and t2 are used to calculate the above. The deceleration delay distances Δs1 and Δs2 are calculated from the relational expression.

Next, the CPU 13 determines the data obtained by the test operation, that is, the two points M (V1, Δs1), N (V2, Δ).
s2) is plotted as shown in FIG. 5, and a straight line L connecting the two points M and N is obtained. Using the equation of this straight line L, the deceleration delay distance Δs _k for each speed V _k (k = 1, 2, ..., N)
Is calculated approximately, and the calculated deceleration delay distance Δs _k is converted into a pulse value ΔP _k . Then, the pulse value P of the theoretical deceleration start position A calculated from each speed V _k using the above-mentioned calculation formula
From _Ak, pulse value P _k after correction by subtracting the pulse value ΔP _k
Calculate (= P _Ak −ΔP _k ). The pulse value P _k is the speed V
_It is stored in a predetermined storage area of the work memory 15 in association with _k, and the map data MD shown in FIG. 6 is created. The speed V _k is finely set so as not to affect the stop position accuracy.

Next, the stop control of the stacker crane 1 using the map data MD will be described. The work memory 15 has already stored the map data MD created by the learning function. When the CPU 13 inputs a conveyance command signal from a main control device (not shown) that controls the automatic warehouse, the CPU 13 starts the stacker crane 1 toward the designated target stop position. The CPU 13 obtains a moving distance (pulse value) from the traveling start position to the target stop position, accelerates the stacker crane 1 at a constant acceleration after traveling, and reaches a constant velocity when a constant speed process for a certain time is secured. Shift to the process. The stacker crane 1 travels at a constant speed V as shown in FIG.

When the stacker crane 1 shifts to the constant speed process, the CPU 13 sequentially calculates the current speed V and the pulse value P _S corresponding to the distance to the target stop position. And
The velocity V that is the closest to the velocity V from the map data MD
A pulse value P _k corresponding to _k (k = 1, 2, ..., N) is obtained, and the pulse value P _k and the pulse value P _S are compared in magnitude,
When P _S ≦ P _k is satisfied, a deceleration command signal is output to the motor drive circuit 19. The position when the deceleration command signal is output becomes the deceleration start position (point A1 in FIG. 1).

From the deceleration start position A1 in FIG. 1 to the inverter 2
Although the output frequency of No. 1 decreases, the stacker crane 1 is shown in FIG.
Draw a speed locus indicated by the broken line to decelerate. Since the deceleration is started from the front position A1 in consideration of the following delay of the motor 5 at the speed V from the theoretical deceleration start position A, the creep speed Vc is reached at the theoretical deceleration completion position B. Then, after a predetermined time tc is maintained at the creep speed Vc, a detection signal for detecting the dog 6a corresponding to the target stop position is input from the sensor 12. Then, the electromagnetic brake 24 is activated based on the detection signal. At this time, the stacker crane 1 has already reached the creep speed Vc.
Since it converges to and is stable, it stops accurately at the target stop position.

As described above in detail, according to the stop control device for the stacker crane 1 of this embodiment, the following delay of the motor 5 with respect to the output frequency of the inverter 21 is ensured so that the creep speed Vc can ensure the predetermined time tc. Deceleration starts from the expected deceleration start position A1 and the creep speed V with stable fluctuation immediately after reaching the creep speed Vc is stable.
Since the braking is always applied from c, stacker crane 1
Can be stopped at the target stop position with high positional accuracy. Further, the deceleration delay distance Δs differs due to the difference in the traveling speed V before the deceleration start because the torque generated by the motor 5 differs depending on the output frequency, but the pulse value P _k corresponding to the corrected deceleration start position A1 is set. Since it is set for each speed V _k , the stacker crane 1 can be accurately stopped at the target stop position from any traveling speed V. Therefore, it is possible to balance the loading and unloading of the load with the storage portion by the fork 11.

Further, the pulse value P _k corresponding to the corrected deceleration start position A1 for each speed V _k is approximated by using the equation of the straight line L obtained by plotting two data obtained from the trial run. Since it is calculated, it is possible to perform the trial operation required for correcting the deceleration start position only twice. In the trial operation, the deceleration delay distance Δs can be calculated only by measuring the time required for the stacker crane 1 to reach the target stop position with the timer 16. Further, since the data of the pulse value P _k corresponding to the corrected deceleration start position A1 for each speed V _k is stored in the working memory 15 as a map, it is possible to perform a complicated calculation process from the traveling speed V. The corresponding pulse value P _k can be determined immediately. Then, the processing load on the CPU 13 can be reduced by the amount that the arithmetic processing therefor is unnecessary.

Further, the correction amount of the deceleration start position varies depending on the weight of the stacker crane 1, but the deceleration start position is corrected for each stacker crane 1 by the trial run, so the weight of the stacker crane 1 is different. It is possible to use a common stop control device between types of automated warehouses. Therefore, it is not necessary to manufacture a stop control device for each model.

The present invention is not limited to the above-described embodiments, but may be configured as follows, for example, within the scope of the invention. (1) The map data MD may be created by the following method. After a predetermined time tc is maintained at the creep speed Vc, a test operation is performed so as to operate the brake 24, and the deviation between the actual stop position and the target stop position is obtained as the deceleration delay distance Δs. Further, during the test operation, the deceleration delay distance Δs is directly obtained from the difference between the position B1 (pulse value Pc) when the creep speed Vc is reached and the planned arrival position B (pulse value Pb). During the test run, deceleration is started at a timing earlier than the deceleration start position A by a predetermined distance (pulse value ΔPo), and the position (pulse value Pc) when the creep speed Vc is reached is calculated, and the planned arrival position B ( Pulse value Pb)
A method of correcting ΔP _k = ΔPo − (Pb −Pc) from the above may be adopted. According to this method, the brake is applied after surely converging on the creep speed V _C during the test operation, so that the reliability of the data obtained from the test operation is reduced due to the application of the brake from the unstable speed. It is possible to prevent that.

(2) The corrected deceleration start position may be obtained from the line L obtained by plotting three or more points by three or more trial runs. Further, the line L is not limited to a straight line and may be a curve, and the deceleration start position after correction may be calculated from the equation of the curve.

(3) The formula for the line such as the straight line L obtained from the data of the trial run or the formula for calculating the corrected deceleration start position derived by using the formula is used for the work regardless of the map data MD. The memory 15 may be stored in advance and the pulse value P at the deceleration start position may be sequentially calculated from the traveling speed V. According to this configuration, the deceleration start position A1 that matches the traveling speed V can be calculated.

(4) The constant speed V in the constant speed process may be the speed V _k corresponding to the map data MD first reached after the speed V at the completion of the acceleration process. According to this configuration, the data speed V _k stored in the map data MD
It is permissible to increase the step size of, and the number of stored data can be reduced. Therefore, it is possible to reduce the calculation processing load of the CPU 13 and the storage capacity of the work memory 15 when the map data MD is created by the learning function. Further, since the appropriate pulse value P _k that matches the traveling speed V _k before the start of deceleration is used, the position accuracy of the deceleration start position can be improved.

(5) When the learning function mode is selected,
So that braking can be applied after the creep speed stabilizes,
Select the travel speed (or travel distance) selection range for trial operation to C
You may instruct from PU13. The reliability of the data obtained from the test run can be increased.

(6) It is also possible to store the corrected deceleration start position data created in advance by trial operation in the work memory 15 regardless of the learning function. (7) The calculation for calculating the deceleration start position from the speed V in the constant speed process may be performed several times or once instead of being sequentially performed. If the calculation is performed after stabilizing at the constant speed V, the reliability of the calculated value is high, and the calculation processing load of the CPU 13 can be reduced.

(8) The speed pattern is not particularly limited as long as the creep speed Vc is set to be maintained before the stop. For example, there may be no constant speed process. Further, the acceleration and deceleration may not be constant. Further, a constant speed may be set regardless of the moving distance.

(9) The present invention may be applied to the conveying device disclosed in Japanese Patent Laid-Open No. 59-58509. It is possible to correct the positional deviation of the stop position that occurs due to the delay of the motor following the output voltage. The delay time T may be added with the following delay amount of the motor with respect to the output voltage of the speed setting device.

(10) The moving body is not limited to the stacker crane. The present invention can be applied to other moving bodies that require stop control for positioning. The invention grasped from the above-mentioned embodiment and not described in the scope of claims is described below together with its effect.

(A) In any one of claims 1 to 7, the movable body is a stacker crane equipped in an automatic warehouse. According to this configuration, the stacker crane can be stopped at the target stop position with high position accuracy, and the load can be put in and taken out from the shelf in a stable manner.

[0056]

As described in detail above, according to the first and second aspects of the invention, the moving body is delayed due to the delay in following the motor with respect to the change in the output value of the speed control signal output from the control means. Even if the theoretical velocity locus is not drawn during deceleration, the deceleration starts from the correction position that allows for the following delay of the motor, so the creep speed is reliably maintained for the specified time or longer, and the moving body converges to the creep speed. Since the braking is applied from the stable state, the moving body can be stopped at the target stop position with high position accuracy.

According to the third aspect of the invention, since the correction of the deceleration start position is performed for each moving body by the test operation, it is excellent that a common stop control device can be used between moving bodies having different weights. Produce an effect.

According to the fourth aspect of the invention, the timer measures the actual time required until the moving body stops at the target stop position without performing a special driving operation for correction in the trial run. The delay distance can be calculated only by itself.

According to the fifth aspect of the present invention, the deceleration start position for each speed is calculated using the diagram obtained by plotting the data obtained from two or more trial runs.
The deceleration start position for each speed can be obtained in detail by a small number of trial runs.

According to the invention described in claim 6, since the diagram is a straight line, there is an excellent effect that the correction of the deceleration start position can be completed by two trial runs. According to the invention described in claim 7, since the corrected deceleration start position is stored as a map for each speed, the corrected deceleration start position can be immediately calculated from the speed of the moving body without performing complicated calculation processing. Can be read.

[Brief description of drawings]

FIG. 1 is a graph showing a change in deceleration with time of a moving body according to an embodiment.

FIG. 2 is a block diagram showing an electrical configuration of a mobile body stop control device.

FIG. 3 is a graph showing a change in deceleration with respect to time of a moving body during a test operation.

FIG. 4 is a graph showing changes in deceleration with respect to the position of a moving body during test operation.

FIG. 5 is a graph plotting the relationship between speed V and deceleration delay distance Δs.

FIG. 6 is a map data diagram.

FIG. 7 is a side view of the stacker crane.

FIG. 8 is a graph showing changes in deceleration of a moving body with respect to position in the related art.

FIG. 9 is a graph showing a change in deceleration of a moving body with respect to time in the related art.

FIG. 10 is a graph showing the time when the creep speed is reached in the prior art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stacker crane as a moving body, 3 ... Measuring wheel which comprises a position detection means, 5 ... Motor, 13 ... CPU which constitutes a control means, a correction means and a correction position calculation means, and also as a correction type calculation means, 15 ... Working memory as storage means, which constitutes correction means, 16 ... Timer which constitutes correction means and correction position calculation means, 17 ... Counter which constitutes position detection means, 19 ... Motor drive circuit which constitutes control means, 21 ... Inverter constituting control means, 25 ... Encoder constituting position detection means, Vc ...
Creep speed, Δs ... deceleration delay distance as delay distance,
L ... Straight line as a diagram, MD ... Map data.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G05D 13/62 B H // B66C 13/22 H

Claims (7)

[Claims] 1. In a deceleration process of stopping a moving body at a target stop position, the moving body is decelerated at a predetermined deceleration and held at a creep speed, and when reaching a predetermined position, a brake is applied to stop the moving body at the target stop position. A stop control method, which is a theoretical deceleration start position obtained so that the creep speed is secured for a predetermined time or longer based on a change in an output value of a speed control signal output from a control means to a motor for driving a moving body. On the other hand, a stop control method for a moving body, in which a deceleration process of the moving body is started at a front position in consideration of a tracking delay amount of the motor with respect to a change in an output value of the speed control signal. 2. A control means for decelerating at a predetermined deceleration to maintain a creep speed in a deceleration process of stopping a moving body at a target stop position, and braking when reaching a predetermined position to stop at the target stop position. A stop control device for a moving body, comprising: a creep speed that is secured for a predetermined time or longer based on a change in an output value of a speed control signal output from the control means to a motor that drives the moving body. A stop control device for a moving body, comprising a correction means for correcting a theoretical deceleration start position to a front position by an amount corresponding to a delay in following the motor with respect to a change in the output value of the speed control signal. 3. The mobile body stop control device according to claim 2, further comprising position detection means for detecting the position of the mobile body, wherein the correction means includes a corrected position calculation means and a storage means. The corrected position calculation means measures a delay distance that actually reaches the creep speed from the trial run of the moving body, and corrects the deceleration start position as the preceding position by the delay distance from the theoretical deceleration start position. Is calculated and stored in the storage means, and the control means determines that the position of the moving body detected by the position detection means coincides with the corrected deceleration start position stored in the storage means. A stop control device for a moving body that starts the deceleration process. 4. The corrected position calculating means includes a timer, and the actual time required from the test run of the moving body until the moving body stops at the target stop position is measured by the timer, and the speed is also increased. The theoretical required time is calculated from the speed history of the motor based on the output value change of the control signal, and the delay distance is calculated by multiplying the difference between the actual required time and the theoretical required time by the creep speed. The stop control device for a moving body according to claim 3. 5. The speed of the moving body before starting deceleration is predetermined according to the moving distance thereof, the test operation is performed at least two times at different speeds, and the correction position calculating means is two. The above delay distance is plotted against the speed of the moving body before deceleration is started, and a correction formula calculating means for calculating the equation of the diagram obtained is provided, and the diagram of the diagram calculated by the correction formula calculating means is provided. The stop control device for a moving body according to claim 3 or 4, wherein a deceleration start position for each speed is calculated by approximately calculating a delay distance for each speed using an equation. 6. The stop control device for a moving body according to claim 5, wherein the diagram is a straight line. 7. The corrected deceleration start position, which is approximately calculated for each speed using the equation of the diagram by the corrected position calculation unit, is stored in the storage unit as a map. The stop control device for a moving body according to claim 5 or claim 6.