JP3117861B2 - Speed control method of load carrier and its control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luggage carrier for transferring a luggage by a picker body to a storage location in a storage shelf unit of a three-dimensional warehouse or the like, according to the magnitude of the load of the luggage. The present invention relates to a speed control method and a control device for stopping a load carrier before a predetermined storage location.

[0002]

2. Description of the Related Art As shown in Japanese Patent Publication No. 54-11591 as a prior art, this type of cargo transporter has
Along the front surface of the storage shelf unit, the load carrier equipped with a picker body for transferring luggage to and from the storage location in the storage shelf unit is stopped at the front position of the predetermined storage location. It has been proposed to gradually reduce the traveling speed of a traveling load carrier from a high speed state to a low speed state.

[0003]

However, in this prior art, the timing of transition from high-speed running to low-speed running is the same (at least the time length from the final timing of high-speed running to the start of low-speed running is the same). Since the magnitude of the load of the load loaded on the load carrier is not taken into account, if the timing is set based on a light load,
When the load is large, the running inertia becomes large, so the vehicle stops beyond the stop position.When the heavy load is used as a reference, the vehicle stops before the predetermined stop position, so that a stop position error occurs. was there.

[0004] In order to avoid this inconvenience, even if the load is large, if the vehicle is stopped at a predetermined position, an overload acts on the brake mechanism of the drive motor, or the capacity is increased in the case of a power generation brake. There was another problem that had to be done. The present invention has been made to solve these problems, and an object of the present invention is to realize speed control in consideration of a load to be mounted on a load carrier. It is intended to execute the speed control without directly measuring the speed control.

[0005]

According to a first aspect of the present invention, there is provided a method for controlling the speed of a load transporter, comprising the steps of: In a load transporter configured to take out and store the load between the load transporter and a storage location in the storage shelf unit, the empty time required for the picker body to move by a reference distance in an empty state. The actual load required time for the picker body to move by the reference distance in the state of transporting the load is stored, and the timing for changing from high-speed traveling to low-speed traveling of the load transporter traveling along the front of the storage shelf unit, A function corresponding to the ratio between the unloading time and the actual load required time as a proportional constant,
The timing is controlled so that the timing at the time of actual load is advanced .

According to a second aspect of the present invention, there is provided a speed control apparatus for a load carrier, wherein the picker body of the load transporter traveling along the front surface of the storage rack unit transfers the load to the load transporter and the storage rack unit. In a load carrier configured to be taken out and stored between storage locations, a time measuring means for measuring an elapsed time when the picker body is moved a predetermined distance, and a reference distance when the picker body is empty. Storage means for storing the empty load required time for moving the loader and the actual load required time for moving the picker body by the reference distance in a state of transporting the load, and a drive circuit of a traveling motor for moving the load transporter. The timing at which the load transporter traveling along the front of the storage shelf unit changes from high-speed traveling to low-speed traveling depends on the ratio between the empty load required time and the actual load required time.
Function as a proportionality constant,
And a control device for controlling the timing so that the timing is advanced .

[0007]

FIG. 1 is a partially cutaway side view of a three-dimensional warehouse 1 of the present invention, FIG. 2 is a partially omitted perspective view, and FIG. It is sectional drawing of the picker body 3 in the transporter 2. The three-dimensional warehouse 1 has a pair of storage shelf units 4 arranged with a passage through which a self-propelled load carrier 2 passes.
The luggage storage units 5 are arranged in a matrix of right, left, up and down. On the front surface of the pair of storage shelf units 4, 4, rails 8, 8 are provided along the longitudinal direction of the storage shelf unit 4 for each of the above-mentioned stages, and the cargo is transported along each of these stages along the rails 8, 8. The pair of left and right pickers 3, 3 in each load transporting machine 2 engage with the left and right side surfaces of the container 6 and move, so that The loaded luggage 7 can be stored.

[0008] At the ends of the pair of storage shelving units 4 and 4, there are provided loading and unloading sections 10 and 10 in which lift tables 9 which are respectively lifted and lowered by driving means (not shown) are provided. The machine 2 takes in and out the cargo 7 together with the container 6 between the machine 2 and the elevator 9 via the picker body 3. Arrow A in FIG.
A pair of left and right moving frames 1 that move forward and backward in the direction
The rotation forces from the first drive motor 15, which can rotate forward and reverse, are actuated via the chain 16 and the reciprocating mechanism 17. The picker bodies 3, 3 disposed on the inner surfaces of the pair of left and right moving frames 14, 14 are respectively arranged along the longitudinal direction of the moving frame 14, and attached to a chain 20 wound around chain sprockets 18, 19. The left and right picker bodies 3, 3 are synchronized by the rotational force of a second drive motor 21, which is provided so as to be able to reciprocate integrally with the moving frame 14, and can be rotated forward and backward.
4 can be moved to the front and rear ends.

The inner surface of each picker body 3 is engaged with and retracted from a hole-shaped or concave-shaped engaging portion 22 formed on both left and right sides of the container 6. A claw 23 is provided, and is operated by an actuator 24 such as an electromagnetic solenoid and a transmission mechanism not described in detail. As can be understood from FIG. 3 and FIG.
When the container 6 located at the left is taken out, the pair of left and right moving frames 14
a, 5a, the picker body 3 located at the front end of each moving frame 14 is engaged with the locking portions 2 on the left and right sides of the container 6 on the two shelves 5a, 5a.
2 and 22 (moves forward in the direction of arrow B). At this position, the locking claws 23 project and lock the locking portions 22, 22, and then the moving frame 14 and the picker body 3 are moved by the arrows. A
The container 6 on which the luggage 7 is placed is moved backward on the load transporting machine 2. At this time, the lower surface of the container 6 comes into sliding contact with the upper surfaces of the two shelf plates 5a, 5a and a sliding piece (not shown) having a small friction coefficient on the support frame 13. When storing the container 6 on which the load 7 is loaded from the load carrier 2 into the load storage unit 5, the operation is the reverse of the above.

Next, a speed control method and a control device thereof according to the present invention will be described with reference to FIG. Control device 3
Reference numeral 0 denotes an electrical control unit such as a microcomputer mounted on the load carrier 2. A central processing unit (CPU) 31 stores a read-only memory (ROM) 32 for storing a control program and the like described later and various data. A read / write memory (RAM) 33 and a timer 34 which is a part of the time measuring means. The input interface detects the movement of the picker body 3 in the forward and backward directions (the directions of arrows A and B). (A part of the time measuring means) is connected. The output interface of the central processing unit 31 includes an actuator 2 for operating the locking claw.
4 drive circuit 36, first drive motor 15 drive circuit 3
7. A drive circuit 38 for driving the second drive motor and a drive circuit 40 for driving the traveling motor 39 of the load carrier 2 are connected.

The sensor 35 and the timer 34 serve as time measuring means for measuring an elapsed time when the picker body 3 is moved by a predetermined distance, and the RAM 33 moves by a reference distance when the picker body 3 is empty. The storage means stores the required empty load time To and the required actual load time T1 during which the picker body moves by a reference distance while carrying the load.

The CPU 31 controls the traveling speed of the load carrier 2 along the front surface of the storage shelf unit 1. The CPU 31 determines the timing at which the load carrier 2 changes from high-speed traveling to low-speed traveling. Control is performed so as to change according to the ratio (T1 / To) of the required load time To and the required actual load time T1. Next, a method of controlling the speed of the load carrier 2 by the control device 30 will be described.

First, in a state where the empty container 6 is locked by the pair of left and right picker bodies 3, 3,
The time required for unloading To when moving up is measured. As an example, a light reflection type or magnetic proximity type sensor 35 is fixed on the support frame 13 at a position (origin) that is a half of the length in the front-rear direction (directions of arrows A and B), and the picker body 3 is fixed. The length in the directions of arrows A and B is defined as Lo as a reference distance,
The required time To when the picker body 3 passes the side of the sensor 35 is measured by the timer 34, and this time is defined as the unloaded required time To. When the sensor 35 is installed at the origin in this way, the storage shelf units 4 and
In order to take out or store the luggage 7 for any of them, a function of confirming the moving direction of the picker body 3 and the passage of the origin can be used together.
Note that the reference distance Lo may be the distance between two marks (not shown) separated on the outer surface of the picker body 3 on the left and right, and even if the sensor 35 measures the time for detecting these two marks. good.

Next, the weight W from the loading / unloading section 10 shown in FIG.
Each time the container 6 loaded with the luggage 7 is transferred onto the load carrier 2, the actual load required time T1 required for the picker body 3 to pass the location of the sensor 35 is measured, and these data (empty load) The required time To and the required load time T1) are input and stored in the RAM 33. Next, the ratio of the required empty load time To and the required load time T1 (T1 / To =
R) is calculated and the result is stored.

On the other hand, an empty container 6 on which no luggage 7 is loaded is previously locked on the picker body 3 and loaded on the load carrier 2,
After the load carrier 2 is run at high speed, the storage rack unit 4
In the RAM 33, a speed control pattern of running for a predetermined period of time at a low speed immediately before stopping at the front of the predetermined luggage storage unit 5 and then stopping is stored. The speed control pattern is shown by a solid line in FIG. In this figure, the horizontal axis is time, the vertical axis is traveling speed, Vs is a high speed traveling speed, Vm is a low speed traveling speed, Tm is a time from the end of the high speed traveling to a stop at a predetermined position, and Tn is a low speed traveling speed. The time from the end to the stop at a predetermined position is shown.

In this case, the deceleration tan θ from high-speed running to low-speed running is (Vs-Vm) / (Tm-Tn). Next, the timing at which the load transporting machine 2 loaded with the load 7 having the weight W together with the container 6 travels at a high speed at the speed Vs and then shifts from the high speed traveling to the low speed traveling when the low speed traveling at the speed Vm is executed. When executing the control to advance the time Tα as compared with the case where the package 7 is not mounted, the time Tα and the like are changed according to the function of the ratio R.

As an example, the time Tmα (= Tm + Tα) from the end of the high-speed traveling of the load transporting machine 2 carrying the load 7 with the container 6 together with the container 6 to the stop at a predetermined position is defined as the time from the end of the low-speed traveling. A time Tnβ (= Tn + Tβ) until stopping at a predetermined position is defined as Tnβ. In this case, the deceleration tan θ1 from the high-speed running to the low-speed running is (Vs−Vm) / (T
mα−Tnβ).
Here, Tmα−Tnβ = Tm + Tα
−Tn−Tβ = Tm−Tn + Tα−Tβ,
The value of (Tα−Tβ), that is, the timing deviation, is defined as a function of the ratio R = f (T1 / To), and Tmα−Tnβ
= F (T1 / To) x (Tm-Tn), the deceleration
It can be expressed as tan θ1 = tan θ / f (T1 / To). If the deceleration tan θ when there is no load is set in advance, the deceleration tan θ1 when there is a load can be easily obtained.

For simplicity, if Tβ = 0, then Tα
= F (T1 / To), and at this time, the low-speed traveling time immediately before the stop is the same as that when there is no luggage. Therefore, the deceleration and the timing deviation are obtained by calculation from the time measurement data and the like, and based on the result, the drive circuit 40 is operated by the instruction of the central processing unit 31 to control the rotation speed of the traveling motor 39. It is only necessary to execute speed control.

When the physical meaning of R = (T1 / To) is considered, the picker body 3 is empty and the reference distance L
It can be easily understood that the time required for moving the distance Lo (load required time T1) while pulling the load W with the load W becomes longer than the time required for moving by o (the required empty time To). Like. Thus, the value of (T1 / To) indicates the ratio of the extra amount in the case of empty luggage while the picker body 3 moves the container 6 together with the luggage 7 with the load W by the reference distance Lo. Therefore, it means that the control to shift the deceleration and the timing from the above equation is executed in accordance with the magnitude of the load mounted on the load carrier 2.

In other words, by slowing down the deceleration as the load mounted on the load carrier increases, and by advancing the timing of transition from high-speed running to low-speed running, low-speed running can be kept constant regardless of the load. Thus, the load carrier can be accurately stopped at the predetermined stop position. Further, by the load to be mounted on the load transporter is loosely larger the reduction rate, because not overload the brake mechanism associated with the reduction brings about an effect that the brake mechanism does not need to be large.

Further, the value of (T1 / To) or Tα = f
The value of (T1 / To) may be preliminarily made into a table map so that a plurality of stepwise values can be quickly extracted, and the calculation after the measurement of the actual load required time T1 may be speeded up. good. The present invention can also be applied to a case in which a change in the load of the load to be loaded greatly affects the load of the load transporting machine 2 including the movable platform that moves up and down with respect to the stacker crane.

[0022]

As described above, according to the speed control method of the present invention, the load is transported by the picker body of the load transporting machine traveling along the front surface of the storage rack unit. In the cargo transporter configured to be taken out and stored between the storage locations, the empty time required for the picker body to move a reference distance in an empty state and the picker body transporting the load The actual load required time to move by the reference distance is stored, and the timing at which the load transporter traveling along the front of the storage shelf unit is changed from high-speed travel to low-speed travel is the empty load required time and the actual load required time. The function corresponding to the ratio of
The timing at the time of actual load is compared with the timing of empty load.
Since the control is performed so that the speed is accelerated, it is possible to accurately execute the stop of the load carrier at a predetermined position as compared with the conventional method of controlling the deceleration speed without considering the load to be mounted on the load carrier. it can.

According to the second aspect of the present invention, the load is transported along the front surface of the storage rack unit by the picker body of the load transporter, and the load is transferred between the load transporter and the storage rack unit. In a load carrier configured to be taken out and stored between storage locations, a time measuring means for measuring an elapsed time when the picker body is moved a predetermined distance, and a reference distance when the picker body is empty. Storage means for storing the empty load required time for moving the loader and the actual load required time for moving the picker body by the reference distance in a state of transporting the load, and a drive circuit of a traveling motor for moving the load transporter. The timing at which the load transporter traveling along the front of the storage shelf unit changes from high-speed traveling to low-speed traveling depends on the ratio between the empty load required time and the actual load required time.
Function as a proportionality constant,
And a control device for controlling the timing so that the timing of the load is accelerated. Since the load of the load is measured by the ratio of the required time of the empty load to the required time of the actual load, the load of the load is taken into the load carrier. And the load measurement can be shared by one sensor, and the structure is extremely simple.

Therefore, according to the present invention, the timing of deceleration from high-speed running to decelerated running and the speed change (change from high-speed running to low-speed running) according to the magnitude of the load loaded on the load carrier. Therefore, it is possible to accurately stop the load transporting machine at the predetermined position, and it is not necessary to increase the size of the brake mechanism.

[Brief description of the drawings]

FIG. 1 is a partial side view of a three-dimensional warehouse.

FIG. 2 is a partial perspective view of a three-dimensional warehouse.

FIG. 3 is a sectional view of a main part of the load carrier.

FIG. 4 is a functional block diagram of a control device.

FIG. 5 is a speed control diagram.

[Explanation of symbols]

 2 Load Carrier 3 Picker Body 4 Storage Shelf Unit 5 Luggage Storage Unit 6 Container 7 Luggage 8 Rail 15, 21 Drive Motor 22 Locking Unit 23 Locking Claw 24 Actuator 30 Controller 31 Central Processing Unit 33 RAM 34 Timer 35 Sensor 35 Sensor 36 , 37, 38, 40 Drive circuit 39 Traveling motor

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B65G 1/00-1/20

Claims (2)

(57) [Claims] 1. A picker body in a load transporter traveling along the front surface of a storage shelf unit, wherein a load is taken out and stored between the load transporter and a storage location in the storage shelf unit. The load transporter stores and stores an empty load required time for the picker body to move by a reference distance in an empty state and an actual load required time for the picker body to move by a reference distance in a state of transporting a load. The timing at which the load transporter traveling along the front of the shelf unit changes from high-speed travel to low-speed travel is defined as a proportional constant that is a function corresponding to the ratio between the empty load required time and the actual load required time.
The timing at the time of actual load is compared with the timing of empty load.
A speed control method for a load carrier, wherein the speed is controlled so as to be advanced . 2. A picker body in a load transporter traveling along the front surface of a storage shelf unit, wherein the picker body is configured to take out and store the luggage between the load transporter and a storage location in the storage shelf unit. A time-measuring means for measuring an elapsed time when the picker body is moved by a predetermined distance in the load transporting machine, an empty time required for the picker body to move by a reference distance in an empty state, and the picker body transporting a load. Storage means for respectively storing the actual load required time to move by the reference distance in a state in which the load carrier is moved, and a drive circuit of a traveling motor for moving the load carrier, and a load carrier for traveling along the front surface of the storage shelf unit. The timing of transition from high-speed running to low-speed running is determined by using a function corresponding to the ratio between the empty load required time and the actual load required time as a proportionality constant.
A speed control device for a load carrier, characterized by comprising a control device for controlling the timing to be advanced in the case of (1) .