JPH01247308A - Moving speed control method for stacker crane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for controlling the running, speed and positioning of a stacker crane used for loading and unloading cargo in multi-level warehouses and automated warehouses, as well as the speed and positioning of FN4.

(Conventional technology) Conventionally, the speed and positioning of the stacker crane's travel, fT lowering, and positioning were controlled by ■Acceleration and deceleration controllers were treated as the number of strokes in time, and the speed was controlled by time. For example, 2 seconds after the start, the speed was 2rrL per second.
The speed is controlled to a speed of 10 m/s at 5 second intervals. Also, the final stop of the target shelf is achieved by mechanical brakes.

Saranko IIJ! Examples of methods that have been adopted include: (1) controlling the speed in stages based on shelf address or number information; and (2) determining the deceleration starting point from the shelf immediately before the start of deceleration by measuring time using a timer.

(Problems to be Solved by the Invention) Conventional speed control methods that use time as the number of strokes have the disadvantage that errors are likely to occur in the deceleration end point and stop position due to variations in initial speed, load, etc. In addition, since the final stop is a mechanical brake, there are: ■ Variations in the operating time of the mechanical brake's 0N10FF control, ■ Changes in the brake over time, ■ Effects of the braking force on the surrounding environment such as temperature and humidity No. 1, @Replacement of the brake no. and changes in brake force due to wear and tear, ■Load,
Barano with initial velocity? There has been a problem in that the final stop F position varies due to variations in stop distance and other factors.

In addition, the conventional control method of speed control based on single location/distance information based only on the shelf address or (number of items) can only perform coarse stepwise speed control, so accurate speed control and position control cannot be performed. No.Also, even with the method ■:l, 11R, the timer varies by 1V, the initial speed varies, etc. (Thus, the error in the deceleration start point becomes large, and the speed and speed with high accuracy as above)
There is a problem that position; 11 control cannot be performed.

The problems to be solved by the present invention are to solve these conventional problems, shorten the loading/unloading cycle of stacker cranes, improve stoppage accuracy, and reduce the number of periodic brake replacements. be.

(Means for Solving the Problem) The gist of the present invention that solves the problem is as follows: 1) Calculate the specified speed value necessary for a series of operations such as acceleration, constant speed, deceleration, and stop of the stacker crane as the number of strokes of distance. Then, the distance and speed are stored in a memory device in advance, and the distance information is stored as the actual rotational speed of the shaft of the drive system such as the wheel or motor.
Moving speed control of a stacker crane, characterized in that q is calculated from the 111 value, and the movement speed of the stacker crane is controlled based on the information of the distance calculated by q, and the minute-by-moment speed of traveling or ascending and descending is controlled according to the speed pattern of the above-mentioned range, which is calculated in advance. Method 2) Request
In the method for controlling the moving speed of a stacker crane described in item 1, in a long-distance moving section where there is one or more shelves moving at a constant speed, the distance is calculated by counting the number of times until the closing position is reached just before the start of deceleration or acceleration, A method for controlling the moving speed of a stacker crane by giving priority to using the calculated distance as distance information for that section 3) Installing two non-contact distance sensors near the moving side of the stacker crane, and A symmetrical dog made in a chevron shape is arranged to face the fixed side of the warehouse/stay/37, etc., and two distance sensors detect the symmetrical dog, totaling 4! 'I
A floating positioning control method for a stacker crane is characterized in that the final positioning is performed by controlling the travel motor of the stacker crane so that the difference in values becomes zero.

(Function) In the present invention, the designated value of the speed is the distance (both numbers), the distance speed pattern 7 is stored in advance, and the distance y!n information is obtained from the rotation speed of the heavy wheels etc. by means such as a pulse generation circuit. , 11, and adopted a method of controlling the speed using the distance information. Factors such as initial speed and load have no effect on the actual speed of the distance 1 t from the rotation speed. , the correct position is distance nine?
calculation, and speed control becomes accurate. Also, shelf address,
Instead of stepwise speed control based on the number of times, continuous or highly accurate digital control of speed can be performed using quadruple continuous distance and position information, making high speed and position control possible with ITT functionality.

Here, in the case of long-distance movement where the constant speed movement distance is one shelf or more, count the number of times in that constant speed shelf section,
If a method is adopted that determines the number of times or the shelf address, maintains a constant speed until the shelf position immediately before deceleration or acceleration, and then controls the speed based on the distance actually measured from the above rotation speed, the control can be simplified and errors can be avoided. You can do less.

Historically, when stopping a stacker crane at a predetermined position, by using two distance sensors and a symmetrical chevron-shaped dog, the difference between the two distance sensor measurements can be calculated from the center of the chevron-shaped dog and the two distance sensors. This indicates a shift in the intermediate position, and the travel motor of the star crane is adjusted so that the difference between the measured values of both sensors becomes zero.
If controlled, floating mold positioning can be performed accurately with simple control.

(Example) Hereinafter, the F1 embodiment will be explained based on Drawing 2.

This example was used to control the speed and position iZ of a stacker crane for loading and unloading a multi-level warehouse with many shelves and openings.
This is an embodiment in which all the inventions described in each claim in the scope of claims are embodied.

In the figure, +11 is the central part of the present invention, a micro combinator that performs l, ll m/memory, and (2) is a D/A change I9! (3) is a signal switch, (4) is an amplifier, (5) is a motor control unit, (6) is a travel motor, (7) is a pulse generator that measures the rotation speed of the vehicle shaft, ( 8) is a non-contact distance sensor, (9) is a chevron-shaped symmetrical dog provided for each time, and (1) is a non-contact distance sensor.
1 is a comparator, and (11) is an amplifier.

In this embodiment, the rotation speed of the traveling motor (6) that drives i['ff of the stacker crane is converted into a pulse number by the pulse generator (7),
), the number of pulses is counted, multiplied by a required constant, and subjected to complementary IF to calculate the distance. From this calculated distance, the target speed corresponding to the distance speed pattern set and stored in the built-in RAM or ROM of the microcomputer (1) is read out, and is output as an analog signal via the D/A converter (2). The signal is amplified by the amplifier (4) to a required signal level and is input to the motor control section (5).

In response to the input value, the motor control section (5) controls the travel motor (6) to reach its target speed.

The distance is set and stored in the microcomputer 111 here;? t velocity pattern is created by commands to move at the required shelf positions from this computer's external commands (14) or from internal commands.

An acceleration/deceleration speed pattern suitable for the crane is stored in advance in the ROM or RAM in the micro combinator (1). In these acceleration/deceleration patterns, the position and the predetermined speed at that time are sequentially stored. These patterns are prepared in advance at the time of clay/installation.
It may be written in the OM, or it may be calculated each time just before the crane starts and stored in the RAM, or it may be sent from the parent computer.

Microcomputer 9 (1) is subject to an f-hyperactive tfM command up to one shelf, and its 111? Distance (number of pulses) to i's shelf? calculate.

Next, it is determined whether the calculated distance is longer or shorter than the distance required to accelerate and decelerate to MAX speed (constant speed + L range). If there is not enough distance to accelerate to the MAX speed, calculate the sum of the acceleration distance, deceleration distance, and distance to match the travel distance, and then calculate the demarcation point of acceleration and deceleration (if acceleration and deceleration are on the same curve, l /2 points) according to the pre-stored pattern, and thereafter decelerated in the same manner.

In addition, if the target value is farther than the acceleration/deceleration distance + yt, start from the target value! The distance required for +n seat reduction is subtracted, and the remainder is a constant speed section at the MAX speed. First, follow the acceleration pattern to MAX
Accelerate to the speed M and from that point the distance calculated above
Move at AX speed. Next, it is decelerated according to the deceleration putter 7.

If the travel section at MAX speed is II or F, only the shelf is connected to the distance sensor (8) when traveling at MAX speed.
The microcomputer 9f1) instructs the microcomputer 9f1 to maintain a constant speed up to the shelf position immediately before the start of deceleration. If the constant speed driving section is long like this, use the pulse generator (7
) pulse signal? Since it is not used, errors caused by wheel slip and wheel wear in this pulse signal can be kept to a minimum. Then, when the constant speed shelf section ends and the rotating period of acceleration and deceleration begins, the distance is calculated from the rotational speed by the pulse generator (7) in the same manner as described above, and the speed is controlled to the distance speed pattern corresponding to the calculated distance. Furthermore, at the end of deceleration, the signal switch (3) is placed on the distance sensor (8) side, and the two distance sensors (8) detect the chevron-shaped symmetrical dog (9) and output a signal according to the distance. Then, the output signals of the two distance sensors (8) are compared by the comparator (I4), the difference is amplified and inputted to the motor control section (5), and the traveling motor (6) is adjusted to the two distances. The sensor (8) is operated so that the signals have the same value, and is stopped when the signals converge to the same value.

With such a stop F positioning control method, it is possible to accurately stop at an absolute position without deviation from the shelf position due to wheel slip or wear.

(Effects of the Invention) As described above, according to the present invention, speed is stored as a function of distance, and speed control is performed by determining the distance using the actual value of the rotational speed of wheels, etc., so that initial speed, cocoon weight, etc. It is possible to obtain high speed and position control accuracy without being affected by variations in speed and position. Also, if the final stop is controlled based on the difference between the total ill values of the symmetrical dog and the distance sensor, the mechanical brake's 0N10F
Variations in F control operating time, changes in brake force over time,
It is possible to accurately stop the player at an absolute position regardless of variations in player force due to the influence of the surrounding environment.

Furthermore, in sections where the constant speed movement distance is 151 or more, instead of controlling the speed, constant speed maintenance control that only counts the number of times will not be affected by wheel slip or wear.
Furthermore, highly accurate speed/position control can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a control block diagram of an embodiment of the present invention. (1) Two microcomputers (21: D/A converter (3); Signal switcher +
41, (l1): Amplifier (5): So-
Control unit (6) Two travel motors (7): Pulse generator (8): Distance sensor (9) Two-pair type dog (II: Comparator)

Claims (1)

[Claims] 1) A speed specification value necessary for a series of operations such as acceleration, constant speed, deceleration, and stopping of the stacker crane is calculated as a distance value, and the relationship between the distance and speed is stored in advance in a storage device. The distance information is calculated from the actual measured value of the rotational speed of the shaft of the drive system such as a wheel or motor, and based on the calculated distance information, the minute-by-moment speed of travel or elevation is calculated in advance over the above-mentioned distance. A method for controlling the moving speed of a stacker crane, which is characterized by controlling using a multi-speed pattern. 2) In the method for controlling the movement speed of a stacker crane according to claim 1, in a long-distance moving section where there is one or more shelves moving at a constant speed, the distance is calculated by counting the number of times to reach the shelf position immediately before the start of deceleration or acceleration. A method for controlling the moving speed of a stacker crane in which the calculated distance is given priority as distance information in that section. 3) Two non-contact distance sensors are placed close to the moving side of the stacker crane, and two symmetrical chevron-shaped dogs are placed facing each other on the fixed side of the shelf, warehouse, station, etc. A method for controlling stop positioning of a stacker crane, characterized in that final positioning is performed by controlling a traveling motor of the stacker crane so that the difference between the measured values detected by the symmetrical dog of the distance sensor becomes zero.