JP2821193B2 - Collision control system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a collision control system, and more particularly to a collision control system of two transfer mechanisms for taking out and transporting articles from a storage shelf in which a large number of articles are stored.

2. Description of the Related Art Conventionally, collision control of this type of transfer mechanism includes a method of emergency stop when the distance between the two transfer mechanisms is within a certain distance, or a means for detecting the speed of each of the two transfer mechanisms. In addition, there was a method of emergency stop if dangerous due to the speed and distance.

However, regarding the control method based on the distance, in order to calculate the distance (braking distance) from when the stop command is received to when the transfer mechanism actually stops, the stopping distance at the maximum speed must be considered. When the moving speed is slow, there is a disadvantage that time loss is large.

Further, the control method based on the distance and the speed has a disadvantage that the speed detection method detects the position of the transfer mechanism at every set period, and the apparatus is complicated and the manufacturing cost is high.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a collision control system which has been made in order to compensate for the above-mentioned drawbacks and which can perform highly accurate control with a simple device.

The collision control system of the present invention is a collision control system of two transfer mechanisms that independently reciprocate on the same route, wherein a plurality of position markers provided at equal intervals on the route, Position indicator reading means provided in each of the two transfer mechanisms for reading the position indicator; and measuring means for measuring each time from when each of the position indicator readers reads one position indicator to when the other position indicator is read. And a memory in which the correspondence between the stopping distance from when the transfer mechanism is braked to when the transfer mechanism stops and the measurement result of the measuring means is stored in advance, and the distance between the two transfer mechanisms is determined by the reading result by the position marker reading means. It is characterized by including a distance detecting means for detecting, and means for controlling generation of an emergency stop command for the transfer mechanism using the stop distance and the distance between the transfer mechanisms.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, referring to FIG. 2, FIG. 2 is a plan view of a magnetic tape storage shelf on which the collision control device of the present invention can be installed.
A storage shelf 7 for storing a large number of magnetic tapes, and a magnetic tape 8
And two pairs of rails 9a and 9b, which serve as moving paths for the transfer mechanisms A and B, are required as peripheral equipment.

FIG. 1 is a block diagram showing one embodiment of the present invention.
In the figure, a collision control system according to an embodiment of the present invention includes position reading means 1 and 2 provided in transfer mechanisms A and B, respectively.
And distance detecting means 3 for detecting the distance between the two transfer mechanisms A and B from the position data read by the position reading means 1 and 2, and set and reset in conjunction with the position reading means 1 and 2, respectively. A possible timer 4, a memory 5 in which the correspondence between the time measured by the timer 4 and the stopping distance is stored in advance, and whether the danger or safety is determined from the distance data of the distance detecting means 3 and the stopping distance data from the memory 5. A control means 6 for issuing an emergency stop command when it is determined that the danger is present;
Position markers 11, 12, provided at regular intervals on the travel path of
…, 20.

In such a configuration, the position marker reading means 1 is provided in the transfer mechanism A, and the position marker reading means 2 is provided in the transfer mechanism B.
It is provided in. The position marker reading units 1 and 2 that have read the position markers confirm the current positions of the transport mechanisms A and B from the read information, hold the position data until reading the next position, and read the newly read position. It is assumed that the position data of the sign is updated each time.

The distance detecting means 3 detects the distance between the two transfer mechanisms from the position data of the transfer mechanisms A and B.

The timer 4 measures the time from when one of the position marker reading units 1 and 2 reads one position marker to when the other position marker is read.
When one position marker is read, it is necessary to stop the timer currently being measured and start a new measurement at the same time, and the other reading means measures time in the same manner as described above. That is, the stay time in the section constituted by the two position markers is measured.

Assuming that the position marker reading means 1 reads the position marker Pn at time t1, and reads the position marker Pn '(n' is n + 1 or n-1) at time t2.
The distance between the two position markers is l
In this case, the transfer mechanism A has moved by the distance 1 during the time Δt (= t2−t1). In this case, the speed vA of the transfer mechanism A at the position marker Pn ′ is 1 / Estimated by Δt. The speed obtained as described above is updated every time the position marker is read, and the latest speed is always recognized.

As a special case, when the position marker Pk is read, the U-turn is performed in the direction in which the vehicle has stopped, and the position marker Pk is read again, the speed is not calculated because the data is insufficient and the speed cannot be calculated.

The speed calculation is similarly performed for the transfer mechanism B.

Here, if all the intervals of the position markers are provided at equal intervals, the speed depends only on the measured time, and in the above-described example, vA is proportional to 1 / Δt.

The stop distance detecting means 5 calculates the speed from the time measured by the timer 4, and furthermore, the distance traveled by the emergency stop command at that speed until the vehicle stops. The stop distance is the transfer mechanism, the driving part, and the storage shelf. It is assumed that the distance includes a preset distance in order to prevent a sudden shock to the articles and the like stored in the storage area.

Since this stopping distance is proportional to the speed and the speed is inversely proportional to time, the stopping distance is inversely proportional to time. If the correspondence between the time and the stopping distance is obtained in advance, the stopping distance can be obtained directly from the time measured by the timer 4. Therefore, it is assumed that data indicating this relationship is stored in the memory 5 in advance.

The control means stores the position data of the distance detection means 3 and the memory 5
If it is determined that the danger is dangerous based on the stop distance data read out from the CPU, an emergency stop command is issued to the transfer mechanisms A and B.

The position markers 11, 12, ..., 19 are provided on the movement path of the transfer mechanisms A, B, and can be distinguished from each other so as to determine whether the movement is rightward, leftward, or U-turn. It has become.

FIG. 3 is a graph showing the relationship between the position marker and the position data read by the position marker reading means. The horizontal axis indicates the physical position, and the vertical axis indicates the position read by the reading means. In the figure, the position markers are placed at equal intervals on the movement path of the transfer mechanism.
Are provided. The transfer mechanism holds the position data of the read position marker until the next position marker is read.

FIG. 4 is a flowchart showing the operation of one embodiment of the collision control device of the present invention. In this embodiment, it is assumed that a position marker is provided so that position data can be read at an arbitrary point on the movement path of the transfer mechanism.

When the program starts, position data is read in step 21. In step 21, the currently read position data is compared with the previously held position data. If the position data has changed, the process goes to step 23, and if not, the position data is read again. In step 23, the timer is stopped in response to a change in the position data. Next, the time of the timer is read (step 24), and this time is converted to speed as described above (step 25). Then, the speed is converted to the stopping distance (step 26). In the present invention, as described above, the stopping distance is directly obtained by directly reading the memory 5 from the time. Then, it is analyzed whether it is safe or dangerous from the positions of the two transfer mechanisms, that is, the distance between them and the stop distance (step 27).

Next, when it is determined from the analysis result in step 27 that the risk is dangerous, an emergency stop command is generated, and when it is determined that the risk is not dangerous, the timer is reset (steps 28 and 2).
9,31). Immediately after resetting, the timer is started again (step 30), and the process returns to step 21.

FIG. 5 shows a typical case when performing a risk analysis,
Fig. 5 (a) assumes that both are moving inward, and Fig. 5 (b) assumes that one is moving outward and the other is moving inward to follow it. ing.

In FIG. 5 (a), the transfer mechanism A has a speed from left to right.
Moving at vA, the transfer mechanism B is moving from right to left at a speed vB. Here, the stop distance SA is a distance that the transfer mechanism A that is moving at the speed vA is moved before stopping when an emergency stop command is issued to the transfer mechanism A. The SB is an emergency distance to the transfer mechanism B that is moving at the speed vB. This is the distance traveled before stopping when a stop command is issued. d is the distance between the two transfer mechanisms when stopped by the emergency stop command, and it is necessary to provide a certain margin, and indicates the margin.

Here, if d = 0, it means that both touch each other, and if d <0, it means collision. Therefore,
In the collision control, some distance d is given as a margin, and this distance d needs to be obtained in advance by an experiment.

In FIG. 5 (b), the transfer mechanism A has a speed vA to the left.
The transfer mechanism B is also moving to the left at a speed vB, respectively.
The stopping distances are assumed to be SA and SB, respectively.

Assuming that the distance between the two transfer mechanisms is D, in the case of FIG. 5A, if D = SA + SB + r, it is determined to be dangerous. Also,
In the case of FIG. 5 (b), if D = SB−SA + r, it is determined to be dangerous.

Although the data table is used to convert the time measured by the timer into the stopping distance, finer control can be performed by increasing the number of position markers.

Effects of the Invention The collision control system of the present invention determines a stopping distance from the time, that is, the speed, at which two position markers are read, and determines whether or not to generate an emergency stop command based on the stopping distance and the distance between the two transfer mechanisms. Judgment is made, and collision control can be performed with simplified equipment without requiring a complicated device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the collision control system of the present invention, FIG. 2 is a system configuration diagram including a transfer mechanism which enables the installation of the collision control system of the present invention, and FIG. Diagram corresponding to the position recognized by the position marker reading means,
FIG. 4 is a flowchart showing the operation of the collision control system of the present invention, and FIG. 5 is a block diagram showing an embodiment when the emergency command generating means performs a danger analysis. Description of Signs of Main Parts 1, 2… Position marker reading means 3… Distance detecting means 4… Timer 5… Memory 6… Control means 11-20… Position markers A, B… Transfer mechanism

Continuation of the front page (56) References JP-A-2-15695 (JP, A) JP-A-64-88809 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G05D 1 / 02

Claims (1)

(57) [Claims] 1. A collision control system of two transfer mechanisms independently reciprocating on the same path, wherein a plurality of position markers provided at equal intervals on the path and the two transfer mechanisms are respectively provided. A position marker reading unit provided for reading the position marker, measuring unit for measuring each time from when each of the position marker reading units reads one position marker to when reading the other position marker, and when the transfer mechanism is braked. A memory that stores in advance a correspondence between a stop distance from receiving the stop to the stop and a measurement result of the measurement unit, and a distance detection unit that detects a distance between the two transfer mechanisms based on a result of reading by the position marker reading unit. Means for controlling the generation of an emergency stop command for the transfer mechanism using the stop distance and the distance between the transfer mechanisms.