Collision prevention circuit

Abstract

To provide a collision prevention circuit for preventing collision between devices.SOLUTION: A collision prevention circuit according to an embodiment prevents a collision between first and second devices in control of movement of the first and second devices based on first and second information. The second device is a device that moves on the same track as the first device. The first and second information indicates first and second moving operations in which the first and second devices move by first and second moving amounts at first and second moving speeds. The collision prevention circuit is configured to perform determination processing of determining, based on the first information and the second information, a possibility that the first device executing the first move operation collides with the second device executing the second move operation. When the collision prevention circuit determines that the first and second devices collide with each other, the collision prevention circuit calculates a waiting time based on at least the first movement speed, the first movement amount, and the second movement speed, and causes the first device to start the first movement operation after causing the first device to wait for the waiting time.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION An embodiment of the present invention relates to an anti-collision circuit. [Background technology]

[0002] There is a technology (automatic position control: APC) in which a control unit controls the positions of multiple devices moving on the same track. In this position control, for example, when the control unit moves each device, it sends a command to each device instructing that movement. When each device receives a command from the control unit, it moves as instructed by the command. Depending on the command from the control unit, multiple devices may collide with each other. For example, when multiple devices with different speeds operate simultaneously, there is a possibility that the devices may collide with each other depending on the timing of their operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-115821 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a collision prevention circuit that prevents collisions between devices. [Means for solving the problem]

[0005] A collision prevention circuit according to an embodiment prevents collision between a first device and a second device by controlling movement of the first device based on first information and movement of the second device based on second information. The second device is a device that moves on the same trajectory as the first device. The first information indicates a first movement operation in which the first device moves a first movement amount at a first movement speed. The second information indicates a second movement operation in which the second device moves a second movement amount at a second movement speed. The collision prevention circuit performs a determination process based on the first information and the second information to determine whether the first device will collide with the second device that is performing the second movement operation when the first device performs the first movement operation. When the collision prevention circuit determines that the first device will collide with the second device, it calculates a waiting time based on at least the first movement speed, the first movement amount, and the second movement speed, and starts the first movement operation after making the first device wait for the waiting time. [Effects of the Invention]

[0006] According to the embodiment, it is possible to provide a collision prevention circuit that prevents collisions between devices. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating a plurality of devices. [Figure 2] FIG. 2 is a block diagram illustrating a position control system including a collision prevention circuit according to an embodiment. [Figure 3] FIG. 3 is a table illustrating a case where device A and device B collide. [Figure 4] FIG. 4 is a schematic diagram illustrating the processing in the collision prevention circuit according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, elements similar to those already explained are given the same reference numerals and detailed explanations will be omitted as appropriate.

[0009] FIG. 1 is a schematic diagram illustrating a plurality of devices. In this embodiment, the positions of device A (e.g., first device) and device B (e.g., second device) are controlled by a control unit 10 (collision prevention circuit) described below. The control unit 10 (collision prevention circuit) controls the movement (movement distance, movement direction, and movement speed) of each device, the movement timing, and the stop of movement.

[0010] Device A moves on trajectory L1. Device B moves on the same trajectory L1 as device A. The direction in which devices A and B move toward one side of trajectory L1 is the + direction, and the direction in which they move toward the opposite side of the + direction is the - direction. In this example, the direction from device A toward device B is the + direction.

[0011] More specifically, device A and device B are, for example, devices that move on the same axis or on the same rail. Device A and device B may be independent moving bodies, or may be two moving parts included in one device.

[0012] As an example, each of device A and device B is a movable part included in a processing device such as a rolling mill. For example, devices A and B are first and second rollers (pressing parts) included in a rolling mill. These rollers are driven by a hydraulic cylinder or a motor controlled by a control unit and move on the same axis. A rolling mill presses metal placed between the rollers with the rollers to elongate it to a desired thickness. Note that in the embodiment, devices A and B are not necessarily limited to rolling mills.

[0013] FIG. 2 is a block diagram illustrating a position control system including a collision prevention circuit according to an embodiment. The positions of devices A and B are controlled (automatic position control: APC) by a control unit 10. A collision prevention circuit 11 is included in the control unit 10. The control unit 10 (collision prevention circuit 11) acquires, via an acquisition unit 12, first information I1 indicating the movement operation of device A and second information I2 indicating the movement operation of device B. In this example, the first information I1 and the second information I2 are transmitted from a higher-level control circuit 20 to the control unit 10. The first information I1 is a command signal with which the higher-level control circuit 20 instructs the movement operation of device A. The second information I2 is a command signal with which the higher-level control circuit 20 instructs the movement operation of device B.

[0014] For example, the movement operations to be performed by devices A and B are programmed in the upper control circuit 20, and a command signal is sent to the control unit 10 at the timing of performing each movement operation. Note that in the embodiment, the first information I1 and the second information I2 do not have to be input in this manner, and may be input to the control unit 10 (collision prevention circuit 11) in any manner. For example, the movement operations to be performed by devices A and B do not have to be pre-programmed, and the user may input the first information I1 and the second information I2 to the control unit 10 without providing the upper control circuit 20.

[0015] When the acquisition unit 12 acquires the first information I1 and the second information I2, the calculation unit 13 of the collision prevention circuit 11 performs calculations including a determination process to determine the possibility of a collision between the devices A and B based on the acquired first information I1 and second information I2. Details of the calculations in the collision prevention circuit 11 will be described later.

[0016] When the acquisition unit 12 acquires the first information I1, the processing unit 14 of the control unit 10 transmits an operation command C1 (a command to perform the operation indicated by the first information) to the device A based on the calculation result of the collision prevention circuit 11 and the first information I1. For example, the collision prevention circuit 11 determines the possibility of a collision when (e.g., each time) it acquires the first information I1, and if it determines that there is no collision, the processing unit 14 immediately transmits an operation command based on the first information I1 to the device A. For example, if there is no risk of a collision, the processing unit 14 transmits an operation command C1 based on the first information I1 each time it acquires the first information I1. Each time the device A receives the operation command C1 from the processing unit 14, the device A immediately executes a movement operation in accordance with the operation command C1. In this way, the control unit 10 can control the movement of the device A by transmitting an operation command based on the acquired first information I1.

[0017] Similarly, the control unit 10 can control the movement of the device B by transmitting an operation command based on the acquired second information I2. That is, for example, when the acquisition unit 12 acquires the second information I2, the processing unit 14 transmits to the device B an operation command C2 (a command to perform the operation indicated by the second information) based on the calculation result of the collision prevention circuit 11 and the second information I2. For example, when the collision prevention circuit 11 acquires the second information I2 (for example, each time it acquires it), it determines whether there is a possibility of a collision, and if it determines that there is no collision, the processing unit 14 immediately transmits an operation command based on the second information I2 to the device B. For example, if there is no risk of a collision, the processing unit 14 transmits the operation command C2 based on the second information I2 every time it acquires the second information I2. Every time the device B receives the operation command C2 from the processing unit 14, it immediately executes a movement operation in accordance with the operation command C2.

[0018] The control unit 10 (the calculation unit 13 and the processing unit 14) may be, as appropriate, a circuit including a CPU (Central Processing Unit). Any storage device, such as a RAM or a ROM, may be included to store information about movement, programs, and the like. The acquisition unit 12 is, for example, a communication module or an input terminal that transmits and receives signals. The transmission and reception of each signal may be performed by any communication method, such as wired or wireless. Note that the blocks of the control unit (the control unit 10 and the higher-level control circuit 20) shown in FIG. 2 are functional concepts for the sake of convenience, and may not necessarily be physically configured as shown. In the control unit shown in FIG. 2, some or all of the multiple blocks may be integrated, or the blocks may be distributed, as appropriate.

[0019] FIG. 3 is a table illustrating a case where device A and device B collide. As shown in FIG. 3, cases in which device A and device B collide include group (i) and group (ii). The example in FIG. 3 is a case in which device A and device B move simultaneously, with device A moving from its current location to a target position (first target position) at a set speed (first movement speed), and device B moving from its current location to a target position (second target position) at a set speed (second movement speed). This example is a case in which the magnitude of the first movement speed of device A is greater than the magnitude of the second movement speed of device B. Furthermore, the target position of device B is on the positive side of device A's current location.

[0020] Group (i) is the case where the movement direction of device A and the movement direction of device B are both in the positive direction, and device A moves toward device B. Group (i) includes a pattern in which a collision occurs due to a speed difference (pattern 1), and a pattern in which a collision occurs due to the target position settings of each device (pattern 2). Pattern 1 is a pattern in which device A catches up with device B while it is moving. Pattern 2 is a pattern in which device A cannot reach its target position unless it passes through the target position of device B.

[0021] Group (ii) is the case where device A moves in the + direction and device B moves in the - direction, and devices A and B move in directions that move closer to each other. Group (ii) includes a pattern (pattern 3) where collisions occur due to the setting of the target positions of each device. Pattern 3 is a pattern where device A cannot reach its target position unless it passes through the target position of device B. Patterns 2 and 3 are patterns where collisions occur due to, for example, an error in setting the target positions.

[0022] As shown in Figure 3, when device A is moving in the negative direction and device B is moving in the positive direction, device A and device B move away from each other, so there is no risk of collision. When device A and device B are both moving in the negative direction, device B cannot catch up with device A, so there is no risk of collision.

[0023] FIG. 4 is a schematic diagram illustrating the processing in the collision prevention circuit according to the embodiment. FIG. 4 shows the operation of the anti-collision program executed in the anti-collision circuit 11. As described above, the collision prevention circuit 11 acquires the first information I1 (see FIG. 2) indicating the movement operation of the device A. For example, the first information I1 indicates the movement operation (first movement operation) of the device A after the acquisition of the first information I1. In other words, the first information I1 indicates the first movement operation of the device A after a certain time (first time). For example, the first information I1 is a command to make the device A perform the first movement operation. In this example, the first movement operation is performed at a first movement speed (v A (mm / sec)) for the first movement (ΔY A (millimeters). Device A moves to a first target position by the first movement operation.

[0024] Similarly, the collision prevention circuit 11 acquires second information I2 (see FIG. 2) indicating the movement of device B. For example, the second information I2 indicates a second movement of device B after the first time (after the acquisition of the first information I1). In this example, the second movement is performed at a second movement speed (v B (mm / sec)) and the second movement amount (ΔY B(millimeters). Device B moves to a second target position by the second movement operation.

[0025] 1st movement speed (v A ) is the magnitude of the second movement speed (v B ) is larger than the magnitude of v A and v B is a constant, but v A and v B may be a value that changes over time. A , ΔY B ) is a positive value when the movement direction is in the positive direction, and a negative value when the movement direction is in the negative direction. The absolute value of the movement amount is the movement distance.

[0026] The first time is, for example, the start time of APC. For example, device A and device B may be stopped until the first time. The first time is the time when device B starts the second movement operation. The collision prevention circuit 11 (acquisition unit) acquires the inter-device distance (M (millimeters)) at the first time. The inter-device distance (M) is the distance between the position of device A before the first movement operation and the position of device B before the second movement operation. For example, the collision prevention circuit 11 acquires the position information of each device at the first time.

[0027] The method for acquiring the position information (distance between devices) of devices A and B is arbitrary. For example, a position sensor or distance sensor may be provided, or the position information (distance between devices) may be calculated from the initial positions of devices A and B and the distance traveled thereafter, or the position information (distance between devices) may be received from devices A and B or the upper control circuit 20.

[0028] For example, when the collision prevention circuit 11 (calculation unit 13) acquires the first information I1, it performs a determination process to determine the possibility of a collision. The determination process is a process that determines the possibility of a collision between device A, which performs a first movement operation, and device B, which performs a second movement operation, based on the first information I1 and the second information I2. The determination process determines whether or not devices A and B will collide when device A starts the first movement operation and device B starts the second movement operation immediately after acquiring the first information I1, for example. In other words, the collision prevention circuit 11 determines in advance (before the first time) whether or not a collision will occur if devices A and B both start the first and second movement operations from the first time.

[0029] Specifically, as shown in Figure 4, for example, ΔY A J0 is checked to see if it is greater than 0. A If ΔY is greater than 0, this corresponds to group (i) and group (ii) described with reference to FIG. 3, and therefore it is considered that there is a possibility that device A and device B may collide. A If it is >0, the collision prevention circuit 11 further performs decision J1 (and decision J2 if necessary).

[0030] The decision J1 is M+ΔY B <ΔY A (1) is satisfied (i.e., the distance between the devices (M) and the second movement amount (ΔY B ) is the first movement amount (ΔY A ) is determined. When formula (1) is true, it corresponds to patterns 2 and 3 described with reference to FIG. 3, for example. In other words, when formula (1) is true, it is considered that the first target position and the second target position have been set incorrectly. In this case, one of device A and device B cannot reach the target of that device without passing through the target position of the other device. In other words, for example, one device cannot reach the target position unless it overtakes the other device, resulting in a collision between the devices.

[0031] If formula (1) is satisfied, it is determined that device A will collide with device B, and the collision prevention circuit 11 stops device A without causing it to perform the first movement operation. That is, for example, the control unit 10 does not send an operation command C1 (see FIG. 2) to device A to cause it to perform the first movement operation. As a result, device A stops after the first time.

[0032] In the example of Fig. 4, when formula (1) is satisfied, a signal is input to set S of flip-flop circuit FF. This sets a flag indicating that movement of device A is to be waited for. When this flag is set, control unit 10 does not transmit operation command C1.

[0033] The moving direction of device A in the first moving operation is the same as the moving direction of device B in the second moving operation, and the first moving speed (v A ) is the second movement speed (v B ), then the second decision J2 is made. M / (v A -v B )-ΔY A / v A <0 (2) If formula (2) is true, it corresponds to pattern 1 described with reference to Fig. 3. That is, in this case, due to the speed difference between the devices, device A will catch up with device B and they will collide.

[0034] If the formula (2) is satisfied, it is determined that device A will collide with device B, and the collision prevention circuit 11 sets a waiting time (t w Calculate the waiting time (t w ) is the first movement speed (v A ), first movement amount (ΔY A ) and second movement speed (v B ) For example, the waiting time is t w =(ΔY A -M) / v B +t d +t m -ΔY A / v A (3) It is calculated by t d (seconds) is the time until device B starts moving, and t m (seconds) is a margin. d , t m is not necessarily added, and can be set arbitrarily as needed. A -M) / v B ) is the time (first required time) required for device B to move the distance that is the difference between the first movement amount and the inter-device distance through the second movement operation. The fourth term in equation (3) is the time (second required time) required for device A to move the first movement amount through the first movement operation.

[0035] The collision prevention circuit 11 (control unit 10) instructs the device A to wait for a waiting time (t w ) and then starts the first moving operation. This allows device A to reach the first target position (the target position of device A) after device B has passed the first target position. This prevents device A from colliding with device B.

[0036] That is, the control unit 10 starts the standby time (t w ) after the first time, device A starts the first movement operation. It is possible that there is a time lag between the time when the operation command C1 is transmitted and the time when device A actually starts the first movement operation. In such a case, the collision prevention circuit 11 may adjust the transmission timing as needed, taking into account the time lag, etc., and may adjust the transmission timing after the waiting time (t w ) after the time corresponding to the time elapses, the processor 14 is made to transmit the operation command C1.

[0037] In the example of FIG. 4, if the formula (3) is satisfied, a signal is input to the set S of the flip-flop circuit FF. This sets a flag to indicate that the device A is waiting to move. The waiting time (t w), a signal is input to the reset R of the flip-flop circuit FF by the delay circuit TD. Then, the flag is cleared and the control unit 10 transmits the operation command C1. Meanwhile, device B performs the second movement operation from the first time without waiting, for example, based on the operation command C2 (see FIG. 2).

[0038] In this way, when the collision prevention circuit 11 (control unit 10) determines through the determination process that device A will catch up with and collide with moving device B, it makes device A wait for the waiting time.

[0039] As described above, in this embodiment, when multiple devices with different speeds operate simultaneously, the possibility of a collision is determined from the amount of movement. The standby time for one device is calculated from the operating speed of each device, and by delaying operation by that amount, a collision can be prevented, for example, in the shortest possible time. Furthermore, the possibility of a collision is determined from the amount of movement of each device, and if a collision is due to a setting error, the device is stopped.

[0040] For example, one example is to use multiple devices with different speeds, and operate one device (the slower one) after the other has completed its operation. However, in this example, the waiting time increases as the movement distance increases and the speed decreases. Also, if the settings are incorrect, the devices may operate and collide.

[0041] In contrast, in the embodiment, as described with respect to equation (3), the waiting time (t w ) is calculated based on the first and second required times. This allows the waiting time to be set as short as possible.

[0042] In the embodiment, for example, the waiting time is set so that device A can start the first movement operation while device B is moving with the second movement operation. In other words, the waiting time is a time shorter than the time it takes for device B to complete the second movement operation. In this way, the control unit 10 can execute control to cause device A to start the first movement operation after waiting for device A and before device B completes the second movement operation.

[0043] Furthermore, for example, the waiting time may be determined so that device A can start the first movement operation before device B moves to the first target position (the target position of device A). In other words, the waiting time may be shorter than the time it takes for device B to move to the first target position. In this way, the control unit 10 may be able to execute control to cause device A to start the first movement operation before device B reaches the first target position. According to the embodiment, it is possible to shorten the waiting time compared to the reference example.

[0044] It should be noted that devices A and B do not necessarily have to be stopped before the first time. For example, device B may move continuously from before the first time to after the first time based on an operation command received before the first time. In this case, the movement of device B after the first time corresponds to the second movement. Also, the same trajectory does not necessarily have to be strictly the same, but may be trajectories that extend alongside each other and are close to each other so that there is a possibility of collision between the devices depending on the movement of the devices.

[0045] Embodiments may include the following features. (Configuration 1) a collision prevention circuit configured to prevent a collision between a first device and a second device in controlling a movement of the first device based on first information and a movement of the second device based on second information, the second device is a device that moves on the same track as the first device, the first information indicates a first movement operation in which the first device moves a first movement amount at a first movement speed; the second information indicates a second movement operation in which the second device moves a second movement amount at a second movement speed; The collision prevention circuit performing a determination process based on the first information and the second information to determine a possibility of a collision between the first device and the second device performing the second movement operation when the first device performs the first movement operation; a collision prevention circuit that, when it is determined that the first device will collide with the second device, calculates a waiting time based on at least the first movement speed, the first movement amount, and the second movement speed, and starts the first movement operation after making the first device wait for the waiting time. (Configuration 2) The collision prevention circuit of configuration 1, wherein when the movement direction of the first device in the first movement operation is the same as the movement direction of the second device in the second movement operation, if the determination process determines that the first device will catch up with and collide with the moving second device, the collision prevention circuit causes the first device to wait for the waiting time. (Configuration 3) The collision prevention circuit described in configuration 2, wherein, when the distance between the position of the first device before the first movement operation and the position of the second device before the second movement operation is defined as the inter-device distance, the waiting time is based on the time required for the first device to move the first movement amount by the first movement operation and the time required for the second device to move the distance difference between the first movement amount and the inter-device distance by the second movement operation. (Configuration 4) 3. The collision prevention circuit according to configuration 2, wherein the waiting time is set so that the first device can start the first movement operation while the second device is moving in the second movement operation. (Configuration 5) the first movement operation is an operation in which the first device moves to a first target position, 5. The collision prevention circuit of configuration 4, wherein the waiting time is set so that the first device can start the first movement operation before the second device moves to the first target position. (Configuration 6) A collision prevention circuit according to any one of configurations 1 to 5, which, if it is determined that the first device and the second device will collide based on the first movement amount, the second movement amount, and the distance between the position of the first device before the first movement operation and the position of the second device before the second movement operation, stops the first device from performing the first movement operation.

[0046] According to the embodiment, it is possible to provide a collision prevention circuit that prevents collisions between devices.

[0047] Although several embodiments of the present invention have been described above, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. Furthermore, the above-described embodiments can be implemented in combination with each other. [Explanation of symbols]

[0048] 10: Control unit 11: Collision prevention circuit 12: Acquisition part 13: Arithmetic section 14: Processing section 20: Upper control circuit A, B: Equipment C1, C2: Operation command FF: Flip-flop circuit I1: First information I2: Second information J0, J1, J2: Judgment L1: Orbit

Claims

1. a collision prevention circuit configured to prevent collision between a first device and a second device in controlling movement of the first device based on first information and movement of the second device based on second information, the second device is a device that moves on the same track as the first device, the first information indicates a first movement operation in which the first device moves a first movement amount at a first movement speed; the second information indicates a second movement operation in which the second device moves a second movement amount at a second movement speed; The collision prevention circuit performing a determination process based on the first information and the second information to determine a possibility of a collision between the first device and the second device performing the second movement operation when the first device performs the first movement operation; a collision prevention circuit that, when it is determined that the first device will collide with the second device, calculates a waiting time based on at least the first movement speed, the first movement amount, and the second movement speed, and starts the first movement operation after making the first device wait for the waiting time.

2. 2. The collision prevention circuit of claim 1, wherein when the direction of movement of the first device in the first movement operation is the same as the direction of movement of the second device in the second movement operation, if the judgment process determines that the first device will catch up with and collide with the moving second device, the first device is made to wait for the waiting time.

3. 3. The collision prevention circuit of claim 2, wherein, when the distance between the position of the first device before the first movement operation and the position of the second device before the second movement operation is defined as the inter-device distance, the waiting time is based on the time required for the first device to move the first movement amount by the first movement operation and the time required for the second device to move the distance difference between the first movement amount and the inter-device distance by the second movement operation.

4. 3. The collision prevention circuit according to claim 2, wherein the waiting time is determined so that the first device can start the first movement operation while the second device is moving in the second movement operation.

5. the first movement operation is an operation in which the first device moves to a first target position, 5. The collision prevention circuit according to claim 4, wherein the waiting time is determined so that the first device can start the first movement operation before the second device moves to the first target position.

6. A collision prevention circuit as described in any one of claims 1 to 5, which, when it is determined that the first device and the second device will collide based on the first movement amount, the second movement amount, and the distance between the position of the first device before the first movement operation and the position of the second device before the second movement operation, stops the first device from performing the first movement operation.

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