Control device, conveyance control system, and control method of conveyance device

Abstract

To perform a calculation properly for preventing load swings.SOLUTION: A conveyance control system has a speed pattern generation unit 412 for a shaking prevention during travelling to generate a travel speed pattern 432 for controlling the conveyance speed which is the speed of a girder 602. The speed pattern generation unit 412 for a shaking prevention during travelling generates the travelling speed pattern 432 to stop the girder 602 after the girder travels at a constant speed for a specified time using a second speed corresponding to the speed less than the maximum speed of the girder 602 before the girder 602 stops, cause the girder to travel at a constant speed for a specified time using the first speed which is less than the maximum speed and larger than the second speed before the conveyance device travels at the second speed, and control the speed of the girder 602 so that the time from the end of travel at the first speed to the end of travel at the second speed is half the swing cycle of a suspended load by the girder 602.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a control device, a transport control system, and a control method for a transport device. [Background technology]

[0002] In transport control systems such as overhead crane systems, anti-sway control of a suspended load during traverse and travel is performed during acceleration and deceleration to a low speed (creep speed) just before stopping. This reduces the sway and then decelerates to a stop. However, the deceleration during deceleration and stopping can cause the sway that had been suppressed to reoccur. This can result in the sway exceeding the tolerance after stopping. If the sway exceeds the tolerance after stopping, it is necessary to wait until the sway converges or to operate at a low speed for a short period of time to bring the sway within the tolerance. This waiting and low-speed operation increase the overall transport time. Therefore, in order to eliminate the waiting time until the sway is within the tolerance after stopping and the time required for low-speed operation, a control system is needed that can suppress the sway with a single deceleration stop and ensure stopping accuracy.

[0003] In this way, in conveyance control systems such as overhead crane systems, sway control is performed in which speed is controlled using an inverter or the like to suppress load sway during movement, and load sway approaches zero when the conveyance device stops at the target stopping position. This type of sway control performs one of the following controls (1) and (2): (1) To ensure stopping accuracy, the conveyance device operates at a low speed (creep speed) by decelerating while performing sway control just before the target stopping position, and then begins decelerating and stops just before the target stopping position. (2) As described above, if the load sway after stopping exceeds the allowable value, the conveyance device operates at a low speed for a short period of time in accordance with the load sway, performing sway control and ensuring stopping accuracy.

[0004] Patent Document 1 discloses a method for controlling the sway of a load suspended by a rope-suspended crane while the crane is traveling at a constant speed. The method stops the sway by accelerating or decelerating the crane carriage in the direction of the load's sway for approximately 1 / 6 of the load's sway period, including the time when the load is at its lowest point of sway (see abstract). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 06-144777 Summary of the Invention [Problem to be solved by the invention]

[0006] In conventional technology, the equation for calculating the timing for ending creep travel is complicated, which places a heavy burden on the manager of the overhead crane system.

[0007] The present invention has been made in view of the above background, and an object of the present invention is to appropriately perform calculations for preventing load sway. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention has a speed control pattern generation unit that generates a speed control pattern for controlling the conveying speed, which is the speed of the conveying device, and the speed control pattern generation unit generates the speed control pattern by running the conveying device at a constant speed for a predetermined time at a second speed that is lower than the maximum conveying speed before stopping, and then stopping the conveying device, and running the conveying device at a constant speed for a predetermined time at a first speed that is lower than the maximum speed and higher than the second speed before running the conveying device at the second speed, so that the time from the end of running at the first speed to the end of running at the second speed is half the sway period of the load suspended by the conveying device. Other solutions will be described as appropriate in the embodiments. [Effects of the Invention]

[0009] According to the present invention, calculations for preventing load swing can be performed appropriately. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an overhead crane device according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a control system according to an embodiment of the present invention. [Figure 3] FIG. 2 is a functional block diagram showing details of a PLC according to the present embodiment. [Figure 4] FIG. 2 is a functional block diagram showing a drive mechanism of the overhead crane device. [Figure 5] FIG. 10 is a diagram for explaining a pendulum length and a movement distance. [Figure 6A] This is a diagram (part 1) showing the state in which the crab trolley is moving at a constant speed in the direction of travel. [Figure 6B] This is a diagram (part 2) showing the state in which the crab trolley is accelerating in the direction of travel. [Figure 7A] FIG. 10 is a diagram showing an example of a traveling speed pattern of a girder. [Figure 7B] FIG. 10 is a diagram showing the change in load sway angle over time and the state of the suspended load. [Figure 8] 1 is a diagram (part 1) showing the anti-sway control performed in this embodiment by a phase plane trajectory on the phase plane. FIG. [Figure 9] FIG. 10 is a diagram (part 2) showing the anti-sway control performed in this embodiment by a phase plane trajectory on the phase plane. [Figure 10A] FIG. 1 is a diagram (part 1) showing an example of a traveling speed pattern of a girder according to a first comparative example. [Figure 10B] This is a diagram (part 2) showing the change in load sway angle over time and the state of the suspended load. [Figure 11] FIG. 4 is a diagram showing the anti-sway control performed in the first comparative example by a phase plane trajectory on the phase plane. [Figure 12] FIG. 10 is a diagram showing an example of a traveling speed pattern of a girder according to a second comparative example. [Figure 13] FIG. 2 is a diagram illustrating a hardware configuration of a PLC used in the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, modes for carrying out the present invention (referred to as "embodiments") will be described in detail with reference to the drawings as appropriate.

[0012] (Overhead crane device 6) FIG. 1 is a schematic diagram of an overhead crane device 6 according to this embodiment. The overhead crane device (overhead crane) 6 has a crab trolley 601 and a girder 602 which are transport devices for suspending and transporting a load S.

[0013] Crab trolley 601 has traversing wheels 612 for traversing (moving in the direction of arrow A1) on girder 602, and a winding device 611 for winding up or down wire 605. A hoisting tool 606 for suspending a load S is attached to the tip of wire 605. The load S is a coil or the like made by winding a steel plate into a roll.

[0014] The girder 602 is provided with a traverse rail 603 along which the club trolley 601 travels, and is also provided with running wheels 613 for the girder 602 to travel on the running rails 604. The traverse wheels 612 of the club trolley 601 allow the club trolley 601 to move laterally in the longitudinal direction of the girder 602. In addition, the running wheels 613 of the girder 602 allow the girder 602 to travel in the longitudinal direction of the traveling rail 604 (the direction of arrow A2).

[0015] Here, movement of the girder 602 in the longitudinal direction (i.e., movement in the direction of arrow A1) is referred to as "traverse." Similarly, movement of the traveling rail 604 in the longitudinal direction (i.e., movement in the direction of arrow A2) is referred to as "travel." Note that "traverse" and "travel" will be collectively referred to as "travel" as appropriate.

[0016] The load S is transported to the target location by the girder 602 traveling on the traveling rail 604 and the club trolley 601 moving laterally on the girder 602. The winding device 611 provided on the club trolley 601 then winds up and down the wire 605, thereby raising and lowering the load S.

[0017] The speed control of the crab trolley 601 and the winding control of the wire 605 by the winding device 611 are performed by a control system Z1, which is a transport control system.

[0018] (System Configuration) Fig. 2 is a diagram showing an example of the configuration of a control system Z1 according to this embodiment. In Fig. 2, the same components as those in Fig. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

[0019] The control system Z1 has a management control PC3, a PLC (Programmable Logic Controller) 1 which is a control device that outputs commands to control the crab trolley 601 and the girder 602. The control system Z1 also has a speed control device 5 which controls the speed of the crab trolley 601 and the girder 602 based on the speed commands for the crab trolley 601 and the girder 602 sent from the PLC1.

[0020] The management control PC3 acquires the traverse target position 122 (see FIG. 3) and the traveling target position 127 (see FIG. 3), which are target stopping positions, from the host system 2. The traverse target position 122 and the traveling target position 127 are positions to which the load S is transported by the club trolley 601 and the girder 602. The club trolley 601 and the girder 602 transport the load S toward the traverse target position 122 and the traveling target position 127, and when they stop at the traverse target position 122 or the traveling target position 127, they lower the load S. The traverse target position 122 and the traveling target position 127, which are transport destination positions, are input into the host system 2 by manual input or the like.

[0021] PLC1 acquires the current traverse position of the club trolley 601 (current traverse position 123: see Figure 3) from the traverse position detector 622. Similarly, PLC1 acquires the current traveling position of the club trolley 601 (current traveling position 126: see Figure 3) from the traveling position detector 623. Incidentally, the traverse position detector 622 measures the current traverse position 123 by laser ranging. Similarly, the traveling position detector 623 measures the current traveling position 126 by laser ranging.

[0022] Furthermore, the PLC1 acquires the sway angle of the load S from the sway angle detector 624. The sway angle detector 624 detects the current sway angle of the load S with respect to the lateral direction as a lateral sway angle 124 (see FIG. 3) by an inclinometer, and also detects the current sway angle of the load S with respect to the traveling direction as a traveling sway angle 125 (see FIG. 3).

[0023] Furthermore, the PLC1 acquires the current winding position (current winding position 121: see FIG. 3) from the winding position detector 621. The winding position detector 621 detects the current winding position by an encoder.

[0024] Based on the acquired information, PLC1 calculates a shake period 139, a lateral movement distance 133, a lateral movement speed 134, a lateral shake angular velocity 135, a traveling movement distance 138, a traveling movement speed 137, a traveling shake angular velocity 136, and the like, which are shown in Fig. 3. Based on this information, PLC1 generates a lateral movement speed pattern 431 and a traveling speed pattern 432 (see Fig. 3, respectively) by machine learning. The lateral movement speed pattern 431 and the traveling speed pattern 432 will be described later.

[0025] Then, the PLC 1 generates a traverse speed command 143 and a traveling speed command 144 (see FIG. 3) based on the generated traverse speed pattern 431 and traveling speed pattern 432, etc., and outputs them to the speed control device 5. The speed control device 5 controls the speed of the crab trolley 601 and the girder 602, thereby moving the crab trolley 601.

[0026] In this embodiment, the current traverse position 123 and the current travel position 126 are measured by laser distance measurement, the current swing angle is measured by an inclinometer, and the current hoisting position 121 is measured by an encoder. However, the measurement methods are not limited to these.

[0027] (PLC1) Fig. 3 is a functional block diagram showing details of the PLC 1 according to this embodiment. In Fig. 3, the same components as those described in Fig. 1 and Fig. 2 are denoted by the same reference numerals, and the description thereof will be omitted.

[0028] PLC1 has a pendulum length calculation unit 101, a swing period calculation unit 102, a lateral movement distance calculation unit 103, and a lateral movement speed calculation unit 104. Furthermore, PLC1 has a lateral swing angular velocity calculation unit 105, a traveling swing angular velocity calculation unit 106, a traveling movement speed calculation unit 107, and a traveling movement distance calculation unit 108. Furthermore, PLC1 has a lateral movement maximum swing width calculation unit 111, a traveling maximum swing width calculation unit 112, and a driving control unit 113.

[0029] The pendulum length calculation unit 101 calculates the current pendulum length 132 based on the pendulum length 131 at the hoisting reference position LW1 (see FIG. 5) stored in advance in the PLC1 and the current hoisting position 121 input from the hoisting position detector 621. The pendulum length 131 at the hoisting reference position LW1 will be described later, and is the pendulum length that serves as the reference when calculating the current pendulum length 132. The pendulum length 131 at the hoisting reference position LW1 is set in advance in the PLC1 as an initial setting value.

[0030] The swing period calculation unit 102 calculates the swing period 139 of the suspended load S based on the current pendulum length 132 calculated by the pendulum length calculation unit 101.

[0031] The traverse movement distance calculation unit 103 calculates the current traverse movement distance 133 based on the traverse target position 122 input from the supervisory control PC 3 and the traverse current position 123 previously input from the traverse position detector 622 .

[0032] Furthermore, the traverse movement speed calculation unit 104 calculates the current traverse movement speed 134 based on the current traverse position 123 input from the traverse position detector 622 and the current traverse position 123 a predetermined time ago.

[0033] The lateral movement shake angular velocity calculation unit 105 calculates a lateral movement shake angular velocity 135, which is the shake angular velocity in the lateral movement direction, based on the lateral movement shake angle 124 input from the shake angle detector 624 and the lateral movement shake angle 124 a predetermined time ago.

[0034] Further, the travel shake angular velocity calculation unit 106 calculates a travel shake angular velocity 136, which is the shake angular velocity in the travel direction, based on the travel shake angle 125 input from the shake angle detector 624 and the travel shake angle 125 a predetermined time ago.

[0035] The travel speed calculation unit 107 calculates the current travel speed 137 based on the current travel position 126 input from the travel position detector 623 and the current travel position 126 a predetermined time ago.

[0036] Then, the travel distance calculation unit 108 calculates the current travel distance 138 based on the travel target position 127 input from the management control PC 3 and the travel current position 126 previously input from the travel position detector 623 .

[0037] The maximum lateral swing width calculation unit 111 calculates the maximum lateral swing width 141, which is the maximum swing width in the lateral direction, based on the pendulum length 132, the lateral swing angle 124, and the lateral swing angular velocity 135. The swing width is the distance between the center of the load S and a vertical line (vertical line) passing through the fulcrum. The fulcrum is the fulcrum of the pendulum, which is made up of the load S and the wire 605.

[0038] The maximum travel swing width calculation unit 112 calculates a maximum travel swing width 142, which is the maximum swing width in the travel direction, based on the pendulum length 132, the travel swing angle 125, and the travel swing angular velocity 136.

[0039] On the other hand, a traverse anti-sway speed pattern generation unit 411, which is a speed control pattern generation unit, generates a traverse speed pattern 431, which is a speed control pattern. The traverse speed pattern 431 is generated based on the initial traverse travel value 421, the sway period 139, the traverse travel distance 133, the traverse travel speed 134, the traverse sway angular velocity 135, and the traverse sway angle 124 stored in PLC1. In addition, the traverse anti-sway speed pattern generation unit 411 generates the traverse speed pattern 431 using a phase plane, etc., which will be described later. The traverse speed pattern 431 is specifically a time change in the traverse speed of the club trolley 601. The traverse anti-sway speed pattern generation unit 411 inputs the generated traverse speed pattern 431 to the operation control unit 113 of PLC1.

[0040] The initial traverse travel settings 421 are the first traverse operating speed to the nth traverse operating speed, the acceleration during acceleration, the acceleration during deceleration, the stopping accuracy, and the allowable swing width of the club trolley 601. The first traverse operating speed to the nth traverse operating speed are the traverse operating speeds that the club trolley 601 can operate at, that is, discretely divided into several stages. The stopping accuracy is an index related to the deviation from the target point when the club trolley 601 stops.

[0041] Furthermore, a traveling anti-sway speed pattern generation unit 412, which is a speed control pattern generation unit, generates a traveling speed pattern 432, which is a control pattern. The traveling speed pattern 432 is generated based on an initial traveling setting value 422, a sway period 139, a traveling movement distance 138, a traveling movement speed 137, a traveling sway angular velocity 136, and a traveling sway angle 125, all of which are stored in PLC1. Furthermore, the traveling anti-sway speed pattern generation unit 412 generates the traveling speed pattern 432 using a phase plane, etc., which will be described later. Specifically, the traveling speed pattern 432 is a time change in the traveling speed of the girder 602. The traveling anti-sway speed pattern generation unit 412 inputs the generated traveling speed pattern 432 to the operation control unit 113 of PLC1.

[0042] The traverse speed pattern 431 and the traveling speed pattern 432 are speed control patterns for controlling the conveying speed, which is the speed of the girder 602 and the crab trolley 601. In this way, the traverse anti-vibration speed pattern generation unit 411 and the traveling anti-vibration speed pattern generation unit 412 generate the traverse speed pattern 431 and the traveling speed pattern 432.

[0043] The initial travel setting values ​​422 are the first to nth travel speeds, the acceleration during acceleration, the acceleration during deceleration, the stopping accuracy, and the allowable swing width of the club trolley 601. The first to nth travel speeds are the travel speeds that the girder 602 can achieve, that is, they are divided into several discrete stages.

[0044] Then, the operation control unit 113, which is a conversion unit, converts the traverse speed pattern 431 and the traveling speed pattern 432 into a traverse speed command 143 and a traveling speed command 144, which are speed commands for the club trolley 601 and the girder 602. Specifically, the operation control unit 113 generates the traverse speed command 143 based on the traverse speed pattern 431, the current traverse position 123, and the maximum traverse swing width 141. Similarly, the operation control unit 113 of the PLC1 generates the traveling speed command 144 based on the traveling speed pattern 432, the current traveling position 126, and the maximum traveling swing width 142. The traverse speed command 143 is a command related to the current speed in the traverse direction of the club trolley 601. Similarly, the traveling speed command 144 is a command related to the speed in the current traveling direction of the girder 602.

[0045] The operation control unit 113 sends the generated traverse speed command 143 and traveling speed command 144 to the speed control device 5.

[0046] (Overhead crane device 6) FIG. 4 is a functional block diagram showing the drive mechanism of the overhead crane device 6. As shown in FIG. The overhead crane device 6 has a power supply 631, a traverse drive motor 632, and a traverse reducer 633 which is a brake. The overhead crane device 6 further has a travel drive motor 635 and a travel reducer 636 which is a brake.

[0047] The power supply 631 supplies power to the traverse drive motor 632, the traverse reducer 633, the traveling drive motor 635, and the traveling reducer 636. In Fig. 4, the dashed dotted line indicates the power supply.

[0048] Then, when the speed control device 5 receives the traverse speed command 143 from the operation control unit 113 of the PLC 1, it controls the traverse drive motor 632 and the traverse reducer 633 to achieve a traverse speed based on the traverse speed command 143. In this way, the rotation speed of the traverse wheels 612 is controlled by the traverse drive motor 632 and the traverse reducer 633.

[0049] Similarly, when the speed control device 5 receives a traveling speed command 144 from the operation control unit 113 of the PLC 1, it controls the traveling drive motor 635 and the traveling reducer 636 to achieve a traveling speed based on the traveling speed command 144. In this way, the rotation speed of the traveling wheels 613 is controlled by the traveling drive motor 635 and the traveling reducer 636.

[0050] (Pendulum length 132 and travel distance) Fig. 5 is a diagram for explaining the pendulum length 132 and the movement distance. In Fig. 5, the same reference numerals are used for the components that have already been explained in Fig. 1 and Fig. 3, and the explanation thereof will be omitted.

[0051] First, we will explain the pendulum length 132.

[0052] Pendulum length 132 is obtained by adding the distance LP0 between the current hoisting position 121 and the hoisting reference position LW1 to the pendulum length 131 at the hoisting reference position LW1. As shown in FIG. 5, the pendulum length 131 at the hoisting reference position LW1 and the pendulum length 132 are defined by the distance between the center of the load S and the fulcrum. As described above, the fulcrum is the fulcrum of the pendulum formed by the load S and the wire 605. The hoisting reference position LW1 may be any point that is vertical to the club trolley 601.

[0053] Furthermore, the lateral movement distance 133 is indicated by the difference between the lateral movement target position 122 and the lateral movement current position 123. In this embodiment, as shown in Fig. 5, the lateral movement current position 123 and the lateral movement target position 122 are defined by the position of the wire 605, but this is not limitative. Furthermore, the lateral movement distance 133 may be indicated by the difference between the lateral movement start position of the club trolley 601 and the lateral movement current position 123.

[0054] Although FIG. 5 illustrates the lateral travel distance 133, the running travel distance 138 is calculated in a similar manner.

[0055] (Definition of swing angle and swing center tilt angle) 6A and 6B are diagrams showing the definitions of the shake angle and the shake center tilt angle.

[0056] 6A and 6B, the white arrow indicates the direction of travel of the club trolley 601.

[0057] Figure 6A is a diagram showing a state in which the club trolley 601 is moving at a constant speed in the direction of travel. Figure 6B is a diagram showing a state in which the club trolley 601 is moving at an accelerated speed in the direction of travel. In Figure 6B, to make the drawing easier to understand, the tilt of the load S is exaggerated compared to the tilt caused by the actual accelerated motion.

[0058] As shown in FIGS. 6A and 6B, the swing angle "θ" is defined as an angle relative to the swing angle center L11.

[0059] Therefore, when the club trolley 601 is moving at a constant speed as shown in Figure 6A, the sway angle center L11 is perpendicular to the horizontal plane (ground surface) (vertical direction relative to the ground surface). Therefore, the sway angle "θ" is the angle relative to the vertical direction relative to the ground surface. Hereinafter, the vertical direction relative to the ground surface will be simply referred to as the vertical direction.

[0060] In contrast, when the club trolley 601 is accelerating, the swing angle center L11 is tilted relative to the vertical direction as shown in Fig. 6B. In such a case, the swing angle "θ" is defined as the angle relative to the swing angle center L11 which is tilted relative to the vertical direction.

[0061] In addition, in FIGS. 6A and 6B, "ω" represents the shake angular velocity, that is, dθ / dt (t is time).

[0062] (Changes in running speed over time) 7A and 7B are diagrams showing the relationship (time change) between the speed control, the sway angle, the sway angular velocity, and the movement time of the girder 602 in the sway prevention control performed in this embodiment. Please refer to FIGS. 1, 3, and 5 as appropriate.

[0063] Fig. 7A is a diagram showing an example of a traveling speed pattern 432 of the girder 602. That is, Fig. 7A is a diagram showing the speed control of the girder 602. The upper part of Fig. 7A shows the speed control of the girder 602. Moreover, Fig. 7B is a diagram showing the change over time of the sway angle "θ" and the state of the suspended load S.

[0064] 7A and 7B onward, traveling is described, but similar control is performed for traversing. A control method for the conveyance device will be described with reference to Fig. 7A and 7B. In Fig. 7A onward, the sway angle is the traveling sway angle 125 in Fig. 3, and the sway angular velocity is the traveling sway angular velocity 136 in Fig. 3.

[0065] 7A is the traveling speed pattern 432 shown in FIG. 3. Incidentally, the traveling speed pattern 432 is generated before the girder 602 moves. The same is true for the traverse speed pattern 431. The detection of the current traveling position 126 by the traveling position detector 623 shown in FIG. 3 and the detection of the current traverse position 123 by the traverse position detector 622 are used to generate the traveling speed pattern 432 and the traverse speed pattern 431 for the next time.

[0066] First, the speed control of the girder 602 will be described with reference to FIG. 7A. As shown in FIG. 7A, the speed control device 5 (see FIGS. 2 and 3) accelerates the girder 602 until time t1 (symbol T1) after the girder 602 starts traveling at time t0 (transportation start position) when traveling starts.

[0067] Then, the speed control device 5 performs speed control (constant speed control) of the girder 602 so that the girder 602 moves at a constant speed at a predetermined speed from time t1 to time t2 (symbol T2).

[0068] Thereafter, the speed control device 5 accelerates the girder 602 from time t2 to time t3 (symbol T3). Thereafter, the speed control device 5 performs constant speed control of the girder 602 at a predetermined speed from time t3 to time t4 (symbol T4), and then accelerates the girder 602 from time t4 to time t5 (symbol T5). As a result, the speed of the girder 602 reaches the maximum speed Vmax of the conveying speed. The maximum speed Vmax of the conveying speed means the maximum speed Vmax of the girder 602 from when the girder 602 starts traveling at time t0 to when it stops at time t15. In other words, the maximum speed Vmax of the conveying speed is the maximum speed in the traveling speed pattern 432.

[0069] The maximum speed Vmax is, for example, the rated maximum speed of the girder 602 (club trolley 601) or the maximum speed Vmax limited by a speed limiter. In other words, the maximum speed Vmax differs depending on the specifications of the girder 602 (club trolley 601). If the output of the traveling drive motor 635 is large, the maximum speed Vmax also becomes large (fast).

[0070] However, the maximum speed Vmax may be a rated maximum speed of the girder 602 (club trolley 601) or a speed other than the maximum speed limited by a speed limiter. In other words, the maximum speed Vmax may be the maximum speed in the traveling speed pattern 432 (the maximum speed from when the girder 602 starts traveling at time t0 to when it stops at time t15).

[0071] In one traveling speed pattern 432, the rated maximum speed may be set as the maximum speed vmax, and in another traveling speed pattern 432, a speed lower than the rated maximum speed may be set as the maximum speed Vmax.

[0072] Then, the speed control device 5 controls the girder 602 at a constant speed at the maximum speed Vmax from time t5 to time t6 (reference T6). That is, at reference T6, the speed control device 5 performs a maximum speed traveling step in which the girder 602 travels at a constant speed at the maximum speed Vmax for a predetermined time.

[0073] Thereafter, the speed control device 5 decelerates the girder 602 from time t6 to time t7 (symbol T7). Then, the speed control device 5 controls the girder 602 at a predetermined speed at a constant speed from time t7 to time t8 (symbol T8), and then decelerates the girder 602 from time t8 to time t9 (symbol T9). Then, the speed control device 5 controls the girder 602 at a constant speed from time t9 to time t10 (symbol T10), and then decelerates the girder 602 from time t10 to time t11 (symbol T11). At this time, the speed control device 5 controls the speed of the girder 602 to become a first speed v12 at time t11. The specific value of the first speed v12 will be described later.

[0074] Thus, at symbol T12, after the maximum speed traveling step at symbol T6, the speed control device 5 performs a first speed traveling step in which the girder 602 travels at a constant speed at a first speed v12, which is a speed less than the maximum speed Vmax, for a predetermined period of time.

[0075] The speed control device 5 controls the girder 602 to move at a constant speed of a first speed v12 from time t11 to time t12 (symbol T12), and then decelerates the girder 602 from time t12 to time t13 (symbol T13). At this time, the speed control device 5 performs deceleration control so that the speed of the girder 602 becomes a second speed v14 at time t13. Here, the second speed v14 is a speed that satisfies the following formula (1).

[0076] 0.05~0.1×Vmax≦v14<τ / 6 / tb×Vmax (1)

[0077] Vmax is the maximum speed Vmax. τ is the swing period of the suspended load S (unit: seconds), and is 2 × (L / g) 1 / 2 where L is the current pendulum length 132 (see Figure 3: unit: m), and g is the gravitational acceleration (= 9.8 m / s 2 ) where tb is the time during which deceleration occurs from the maximum speed Vmax until the vehicle stops. The time during which deceleration occurs is the time during which negative acceleration occurs, and specifically, tb is Δt7+Δt9+Δt11+Δt13+Δt15 (unit: seconds). However, formula (1) is only an example, and the second speed v14 does not necessarily have to be the speed expressed by formula (1).

[0078] Then, the speed control device 5 controls the girder 602 to move at a constant speed at the second speed v14 from time t13 to time t14 (reference symbol T14), and then decelerates the girder 602 from time t14 to time t15 (reference symbol T15). In this way, the traveling anti-sway speed pattern generation unit 412 generates the traveling speed pattern 432 so that the girder 602 travels at a constant speed at the second speed v14 for a predetermined time before stopping, and then stops the girder 602. The second speed v14 is a speed lower than the maximum speed Vmax of the girder 602. Then, the speed control device 5 stops the girder 602 at time t15. The second speed v14 may be referred to as a creep speed. The creep speed is a speed at which the girder 602 is moved at a low speed to prevent load sway at the target stop position (travel target position 127 in FIG. 3).

[0079] Then, the traveling vibration prevention speed pattern generation unit 412 generates a traveling speed pattern 432 so that the girder 602 travels at a constant speed at the first speed v12 for a predetermined time before traveling at the second speed v14. The traveling of the girder 602 at the second speed v14 is the control indicated by the symbol T14, and the control of traveling the girder 602 at a constant speed at the first speed v12 for a predetermined time is the control indicated by the symbol T12. Furthermore, the first speed v12 is less than the maximum speed Vmax and greater than the second speed v14.

[0080] In this way, at reference symbol T14, after the control by reference symbol T12, the speed control device 5 performs a second speed traveling step in which the girder 602 travels at a constant speed at a second speed v14 that is lower than the first speed v12 for a predetermined time. Then, after reference symbol T14, at reference symbol T15, the speed control device 5 performs a deceleration step in which the girder 602 is decelerated to stop it.

[0081] "Δt1" to "Δt15" indicating the periods during which the controls of symbols T1 to T15 are performed are expressed by the following equations (2-1) to (2-4). Note that the times Δt1 to Δt11 shown in Figures 7A and 7B are just examples.

[0082] Δt1=Δt2=Δt4=Δt5=Δt7=Δt8=Δt10=Δt11=τ / 6 (2-1) Δt3=ta-τ / 3 (2-2) Δt9=tb×(1-2×v14 / Vmax)-τ / 3 ··· (2-3) Δt13=Δt15=tb×v14 / Vmax ··· (2-4)

[0083] Note that ta is the time it takes for acceleration to occur from a stopped state to the maximum speed Vmax. Specifically, ta is Δt1+Δt3+Δt5 (unit: seconds).

[0084] Δt6 depends on the distance traveled, and Δt12 is 1 to 5 seconds.

[0085] The speed of the girder 602 in the constant speed control indicated by the symbol T2 (referred to as an eleventh speed v2) is, for example, a speed expressed by the following equation (3-1).

[0086] v2=τ / 6 / 6×Vmax (3-1)

[0087] Moreover, the speed of the girder 602 in the speed control indicated by the symbol T4 (referred to as a twelfth speed v4) is, for example, a speed expressed by the following equation (3-2).

[0088] v4=(1-τ / 6 / ta)×Vmax ··· (3-2)

[0089] The speed of the girder 602 in the constant speed control indicated by the symbol T8 (referred to as a thirteenth speed v8) is, for example, a speed expressed by the following equation (3-3).

[0090] v8=(1-τ / 6 / tb)×Vmax ··· (3-3)

[0091] Moreover, the speed of the girder 602 in the constant speed control indicated by the symbol T10 (referred to as a fourteenth speed v10) is, for example, a speed expressed by the following equation (3-4).

[0092] v10=2×v14+τ / 6 / tb×Vmax ··· (3-4)

[0093] Incidentally, ta and tb in the formulas (3-1) to (3-4) are the same as those used in the formulas (2-2) to (2-4).

[0094] Furthermore, when the detected distance to the target stop position (travel target position 127) reaches D1 expressed by the following equation (5-1), the speed control device 5 starts speed control (deceleration control) indicated by the symbol T7.

[0095] D1=Vmax×(tb / 2+τ / 6)+v14×(τ×2 / 3+tb×v14 / Vmax+2×t12) ··· (5-1)

[0096] Note that the determination of D1 using equation (5-1) is just an example. The speed control device 5 may determine the start point of the speed control indicated by reference symbol T7 so that the period "Δt12" during which the speed control indicated by reference symbol T12 is performed is about 1 to 5 seconds, taking into consideration delays and errors in distance detection.

[0097] Furthermore, when the distance between the current position of the girder 602 and the target stop position of the girder 602 is "D2" that satisfies the following formula (2), the speed control device 5 starts speed control (deceleration control) indicated by reference symbol T13. That is, the speed control device 5 starts deceleration from the first speed v12 to the second speed v14. Note that the distance "D2" is calculated in advance when the girder 602 travels, that is, when the traveling speed pattern 432 is generated.

[0098] D2=v14×(τ / 2+tb×v14 / Vmax) ··· (5-2)

[0099] By performing such speed control, the period of time T13 and T14 combined (Δt13+Δt14=Δτ) becomes τ / 2. In other words, after deceleration starts at time t12, the girder 602 stops after approximately τ / 2.

[0100] In this way, the traveling anti-sway speed pattern generation unit 412 generates a traveling speed pattern 432 that controls the speed of the girder 602. At this time, the time from the end of traveling at the first speed v12 (time t12) to the end of traveling at the second speed v14 (time t14) is set to be half the sway period τ of the load S suspended by the club trolley 601.

[0101] Such speed control makes it possible to calculate the deceleration start point (start point of symbol T13) for performing anti-sway control with a simple calculation. In other words, the manager only needs to set the system to start deceleration (start of control of symbol T13) at the point where the swing period (τ) is half (τ / 2). This allows the manager to set the system to perform anti-sway control (speed control for controlling the swing of the suspended load S) without performing complex calculations.

[0102] Also, the first speed v12, which is the speed of the guard 602 at the symbol T12, may be such that v14 < v12 < Vmax. Preferably, the first speed v12 is approximately twice the second speed v14, but it does not necessarily have to be approximately twice. The speed control device 5 determines whether the distance to the target stop position reaches "D2" shown in Equation (5-2) by the traveling position detector 623 (or the lateral movement position detector 622). At this time, a time lag occurs until the signal sent from the traveling position detector 623 reaches the PLC1. If the first speed v12 is too fast, the error caused by this time lag becomes large. Also, if the first speed v12 is too slow, the period "Δt12" of the symbol T12 becomes long, and the conveyance time increases. By setting the first speed v12 to be approximately twice the second speed v14, it is possible to suppress the error and also suppress the increase in the conveyance time. Incidentally, the position detection by the lateral movement position detector 622 and the traveling position detector 623 is always performed while the suspended load S is being conveyed.

[0103] Regarding the symbol LB in FIG. 7A, it will be described later.

[0104] (Time change of the swing angle, state change of the suspended load S) Next, referring to FIG. 7B, the time change of the swing angle when the guard 602 is traveling will be described.

[0105] FIG. 7B is a diagram showing the time change of the swing angle and the state change of the suspended load S.

[0106] In FIG. 7B, the times t0 to t15, the periods "Δt1" to "Δt15", and Δτ correspond to the times t0 to t15, the periods "Δt1" to "Δt"15, and "Δτ" in FIG. 7A. Refer to FIG. 7A as appropriate. Also, the white arrows in the lower part of FIG. 7B indicate that the suspended load S is swinging in the direction of the arrow. Also, the white circles indicate that the swing angle is maintained at the position indicated by the white circles for the suspended load S. Further, the swing angle is positive with respect to the traveling direction of the guard 602, and the side opposite to the traveling direction is negative.

[0107] First, as shown in Figure 7A, during the period "Δt1", the girder 602 is accelerated, causing the load S to swing to the negative side. After that, through reference symbol T2 (period "Δt2"), the girder 602 is accelerated at reference symbol T3 (period "Δt3"), causing the sway angle to reach its minimum value (maximum absolute value in the negative direction: minimum sway angle) "-θmax". During reference symbol T3 (period "Δt3"), the load sway angle remains at the minimum sway angle.

[0108] Thereafter, when the constant speed control is performed at reference symbol T4 (period "Δt4"), the acceleration becomes 0, and the load S swings in the positive direction. Then, at the timing when the load S is positioned vertically below the girder 602, the girder 602 is accelerated at reference symbol T5. As a result, an inertial force acts in a direction (negative direction) that cancels out the movement of the load S in the positive direction caused by the constant speed control at reference symbol T4. As a result, the swing angle becomes 0 as shown at time t5 in FIG. 7B.

[0109] Then, while the constant speed control is being performed during the period T6 (period "Δt6"), the swing angle is maintained at 0.

[0110] Then, due to the deceleration control at symbol T7 (period "Δt7") and the deceleration control at symbol T9, the sway angle becomes maximum (the sway angle is in the positive direction and the absolute value of the sway angle is maximum) during the control at symbol T9 (period "Δt9"). Then, during symbol T9 (period "Δt9"), the sway angle maintains the maximum value (maximum sway angle) "θmax" (maximum traveling sway width 142: see FIG. 3).

[0111] Next, at reference symbol T10 (period "Δt10"), constant speed control of the girder 602 is performed, causing the load S to swing in the negative direction due to inertial force, and the sway angle decreases. Then, at reference symbol T11 (Δt11), the girder 602 is decelerated again, causing the load S to swing in the positive direction. Then, the inertial force due to deceleration and the inertial force due to the load swing in the negative direction cancel each other out, and the sway angle becomes zero.

[0112] Then, the swing angle remains at 0 during the period T12 (period "Δt12").

[0113] In this state, if deceleration is performed to stop the girder 602, the load S will swing in the positive direction due to the influence of the deceleration control. As a result, the load S will be in a swinging state (a state in which the swing angle is not 0) when it is stopped.

[0114] Therefore, in this embodiment, the speed control device 5 performs deceleration control by reference symbol T13 and constant speed control by reference symbol T14 as shown in Fig. 7A. At this time, the PLC1 (traveling vibration prevention speed pattern generation unit 412) determines the control start point of reference symbol T13 so that the total time of the period "Δt13" and the period "Δt14" becomes τ / 2 (τ is the vibration period).

[0115] As a result, an inertial force acts on the load S in the positive direction as shown in FIG. 7B due to the deceleration control by reference symbol T13. As described above, the total time of the periods "Δt13" and "Δt14" is set to be τ / 2. At the start point (time t12) of the deceleration control by reference symbol T13 (period "Δt13"), the load S is positioned vertically below the girder 602. The total time of the periods "Δt13" and "Δt14" is also set to be τ / 2. As a result, the load S, which began to sway due to the deceleration in period "Δt13", returns to be positioned vertically below the girder 602 at the end point (time t14) of the constant speed control by reference symbol T14 (period "Δt14").

[0116] The traveling vibration suppression speed pattern generation unit 412 generates the traveling speed pattern 432 so that the acceleration at reference symbol T13 and the acceleration at reference symbol T15 are the same. The acceleration at reference symbol T13 is the acceleration (deceleration) when the girder 602 is decelerated from the first speed v12 to the second speed v14. The acceleration at reference symbol T15 is the acceleration (deceleration) when the girder 602 is stopped from the second speed v14. By doing so, the periods "Δt13" and "Δt15" have the same length, which simplifies the calculation of tb. This simplifies the calculation of equation (5-2).

[0117] At time t14, as shown in Figure 7B, the load S is present vertically below the girder 602, but is swinging in the negative direction. Therefore, after time t14, deceleration control is performed at reference symbol T15, and an inertial force acts in the positive direction on the load S. Therefore, the inertial force due to the load swing and the inertial force due to the deceleration control at reference symbol T15 cancel each other out, and the load S comes to a (substantially) stop vertically below the girder 602 at time t15.

[0118] (phase plane) Next, the anti-sway control performed in this embodiment will be described in terms of phase with reference to Figures 8 and 9. Figures 7A and 7B will also be referenced as appropriate.

[0119] 8 and 9 are diagrams showing the anti-sway control performed in this embodiment by a phase plane trajectory on the phase plane. The phase plane trajectory is a trajectory that shows the time change of the sway angle "θ" of the suspended load S and the sway angular velocity "ω" of the suspended load S. Fig. 8 shows the phase plane trajectory from time t0 to time t12 in Figs. 7A and 7B, and Fig. 9 shows the phase plane trajectory from time t12 to time t15 in Figs. 7A and 7B.

[0120] 8 and 9, the vertical axis (y) is represented by the following equation (6-1).

[0121] y=θ / arctan(Vmax / ta / g) ··· (6-1)

[0122] In addition, in FIGS. 8 and 9, the horizontal axis (x) is expressed by the following equation (6-2).

[0123] x=ω / {(L / g) / arctan(Vmax / ta / g)} 1 / 2 (6-2)

[0124] Here, ω is the angular velocity of the swing of the suspended load (=2π / τ: unit rad / s).

[0125] Equations (6-1) and (6-2) are used to normalize the radii of circles C11 to C13 shown in FIG. 8 to 1, which means that the vertical axis represents the swing angle "θ" and the horizontal axis represents the swing angular velocity "ω."

[0126] Moreover, the circles C11 to C13 shown in FIG. 8 are expressed by the following equations (7-1) to (7-3), respectively, on the phase plane shown in FIG.

[0127] x 2 +(y-1) 2 =1 (7-1) x 2 +y 2 =1 (7-2) x 2 +(y+1) 2 =1 (7-3)

[0128] The symbols T1 to T12 shown in FIG. 8 correspond to the symbols T1 to T12 shown in FIG. 7A.

[0129] When the phase plane trajectory is on the circumference of a circle C12 centered at the origin of the phase plane shown in Fig. 8, the suspended load S performs pendulum motion centered in the vertical direction, which is the direction in which gravity acts. In the example shown in Fig. 8, the phase plane trajectory is indicated by a thick solid line. Note that hereinafter, the origin of the phase plane will be referred to simply as the origin as appropriate.

[0130] Furthermore, when the phase plane locus is on a circle C13 centered at y=-1, the load S performs a pendulum motion centered at the minimum sway angle ("-θmax" in FIG. 7A). Similarly, when the phase plane locus is on a circle C11 centered at y=1, the load S performs a pendulum motion centered at the maximum sway angle ("θmax" in FIG. 7A).

[0131] Next, the phase plane trajectory of the suspended load S on the phase plane will be described.

[0132] First, at reference symbol T1, a phase plane locus is drawn on the circumference of circle C13 from the origin (corresponding to time t0 in FIG. 7A) to phase point P1 (corresponding to time t1 in FIG. 7A). A signal point is a point indicated by coordinates on the phase plane. In this embodiment, coordinates refer to coordinates on the phase plane.

[0133] Next, at symbol T2, a phase plane trajectory is drawn on the circumference of circle C12 from signal point P1 to signal point P2 (corresponding to time t2 in FIG. 7A) with coordinates (0, -1). The phase plane trajectory then remains at signal point P2 during symbol T3. Therefore, signal point P3, which corresponds to time t3 in FIG. 7A, is equal to signal point P2.

[0134] Next, at symbol T4, a phase plane trajectory is drawn on the circumference of circle C12 from signal point P3 to signal point P4 (corresponding to time t4 in FIG. 7A). Furthermore, at symbol T5, a phase plane trajectory is drawn on the circumference of circle C13 from signal point P4 to signal point P5 (corresponding to time t5 in FIG. 7A = origin). Thereafter, during symbol T6, the phase plane trajectory remains at signal point P5 (= origin). Therefore, signal point P6 (corresponding to time t6 in FIG. 7A) = signal point P5.

[0135] Next, at reference symbol T7, a phase plane trajectory is drawn on the circumference of circle C11 from signal point P6 to signal point P7 (corresponding to time t7 in FIG. 7A). Furthermore, at reference symbol T8, a phase plane trajectory is drawn on the circumference of circle C12 from signal point P7 to signal point P8 (corresponding to time t8 in FIG. 7A) whose coordinates are (0, 1). Thereafter, during reference symbol T9, the suspended load S remains at signal point P8. Therefore, signal point P9 (corresponding to time t9 in FIG. 7A) = signal point P8.

[0136] Next, at reference symbol T10, a phase plane trajectory is drawn on the circumference of circle C12 from signal point P9 to signal point P10 (corresponding to time t10 in FIG. 7A). Furthermore, at reference symbol T11, a phase plane trajectory is drawn on the circumference of circle C11 from signal point P10 to signal point P11 (corresponding to time t11 in FIG. 7A = origin). Thereafter, during reference symbol T12, the phase plane trajectory remains at signal point P11. Therefore, signal point P12 (corresponding to time t12 in FIG. 7A) = signal point P11.

[0137] In addition, in FIG. 8, ψ11 to ψ18=π / 3.

[0138] 8, 9, and 11, arrows indicating angles include bidirectional and unidirectional arrows. An angle with a unidirectional arrow indicates that the angle is related to the drawing of the phase plane locus on the phase plane. For example, "ψ11" in FIG. 8 has a unidirectional arrow. This angle indicates the angle that the phase plane locus (reference T11) forms with the center of the phase plane locus (i.e., the center of circle C11) when the phase plane locus is drawn from signal point P10 to signal point P11. In this case, since the phase plane locus is drawn from signal point P10 to signal point P11, the arrow of "ψ11" is also shown in the same direction.

[0139] In contrast, angles with double-headed arrows, such as "ψ24" in Fig. 9, indicate angles other than those related to the phase plane locus. For example, "ψ24" in Fig. 9 indicates the angle formed by the line connecting signal points P12 and P13 and the line at x=0, and is not directly related to the drawing of the phase plane locus on the phase plane.

[0140] Next, with reference to FIG. 9, the drawing of the phase plane trajectory at reference symbols T13 to T15 in FIG. 7A will be described.

[0141] In FIG. 9, the horizontal and vertical axes are the same as those in FIG.

[0142] And the circle C21 is similar to the circle C11 in FIG.

[0143] Moreover, the circle C22 is expressed by the following equation (8).

[0144] x 2 +y 2 =(sinφ) 2 +(1-cosφ) 2 =(2×sin(φ / 2)) 2 ··· (8)

[0145] The symbols T13 to T15 in Fig. 8 correspond to the symbols T13 to T15 in Fig. 7A. Note that φ in equation (8) represents the rotation angle (rad) on the phase plane. The rotation angle on the phase plane is the angle that the phase plane trajectory makes on the phase plane from the second speed v14 in Fig. 7A until the girder 602 decelerates and stops.

[0146] Next, the phase plane trajectory on the phase plane will be described.

[0147] First, at reference symbol T13, a phase plane trajectory is drawn on the circumference of circle C21 from signal point P12 (=origin) to signal point P13 (corresponding to time t13 in FIG. 7A). Then, at reference symbol T14, a phase plane trajectory is drawn on the circumference of circle C22 from signal point P13 to signal point P14 (corresponding to time t14 in FIG. 7A). Furthermore, at reference symbol T15, a phase plane trajectory is drawn on the circumference of circle C21 from signal point P14 to signal point P15 (corresponding to time t15 in FIG. 7A = origin).

[0148] If the coordinates of signal point P13 are (x13, y13), then x13=sinφ and y13=1-cosφ. Also, if the coordinates of signal point P14 are (x14, y14), then the relationships are x14=-x13 and x14=y14.

[0149] In addition, in FIG. 9, ψ21 and ψ22 are expressed by the following equation (9-1).

[0150] ψ21=ψ22=2π / τ×tb×v14 / Vmax ··· (9-1)

[0151] In FIG. 9, ψ23 to ψ25 are expressed by the following equations (9-2) and (9-3).

[0152] ψ23=π-ψ21 (9-2) ψ24=ψ25=(π―ψ21) / 2 ··· (9-3)

[0153] In this embodiment, as shown in Fig. 7A, deceleration is performed from a speed (first speed v12) that is approximately twice the low speed (second speed v14) to the low speed (second speed v14) (reference symbol T13). At this time, on the phase plane shown in Fig. 9, a phase plane trajectory is drawn in the counterclockwise direction on the circumference of a circle C21 centered at coordinates (0, 1) by a rotation angle proportional to the deceleration time.

[0154] Next, as shown in Fig. 7A, operation is performed at a low speed (second speed v14: constant speed) for a time (reference symbol T14) obtained by subtracting the previous deceleration time (the time of reference symbol T13: period "Δt13") from 1 / 2 the swing period τ. At reference symbol T14, a phase plane trajectory is drawn around the y-axis on the circumference of a circle C22 centered at coordinates (0,0) on the phase plane, from the coordinate (phase point P13) at which deceleration from a speed twice the low speed is completed to the coordinate of a symmetrical position (phase point P14), as shown in Fig. 9.

[0155] Next, deceleration and stop are performed from the low speed (second speed v14) (reference symbol T15 in FIG. 7A). As a result, a phase plane trajectory is again drawn counterclockwise around the circumference of circle C21 centered at coordinates (0,1) on the phase plane by a rotation angle proportional to the deceleration time, and returns to coordinates (0,0). This indicates that if the sway is 0 (sway angle is 0) at the time when deceleration starts from a speed twice the low speed (first speed v12) (time t12 in FIG. 7A, phase point P12 in FIG. 9), the sway will also be 0 when the girder 602 stops.

[0156] Note that the controls indicated by symbols T1 to T11 in Fig. 7A do not have to be the controls shown in Fig. 7A. For example, symbols T2 and T4 may be omitted. Alternatively, uniform speed control may be added while symbol T3 is being performed. Similarly, symbol T8 may be omitted, or uniform speed control may be added while symbol T9 is being performed.

[0157] [First Comparative Example] Next, a first comparative example for this embodiment will be described with reference to FIGS. 10A to 11. FIG.

[0158] A commonly used speed control method for preventing sway is a feedback method in which a sensor detects the sway angle, etc., and controls the speed of the girder 602, etc. so that the suspended load S does not sway. Alternatively, there is a speed pattern method in which the speed per time period is determined in advance according to the travel distance of the girder 602, etc. In the first comparative example, we will explain a speed pattern method that maintains a constant speed for 1 / 6 of the sway period during acceleration and deceleration, which is widely used in the transport control of indoor overhead cranes that are easy to control and have little disturbance.

[0159] (Changes in running speed over time) Fig. 10A is a diagram showing an example of a traveling speed pattern 432A of the girder 602 according to the first comparative example. That is, Fig. 10A is a diagram showing the speed control of the girder 602 according to the first comparative example. Fig. 10B is a diagram showing the change over time of the sway angle "θ" and the state of the suspended load S.

[0160] In FIG. 10A, symbols T1 to T10 (times t0 to t10) are the same as in FIG. 7A, so the same symbols are used and the description will be omitted (symbol LB in FIGS. 7A and 10A).

[0161] From time t10 to time t20 (reference symbol T11a), the speed control device 5 decelerates the girder 602 from the speed at reference symbol T10 to a 21st speed v25. The 21st speed v25 is approximately the same as the second speed v14 shown in FIG. 7A. Then, from time t20 to time t21 (reference symbol T12a), the speed control device 5 controls the girder 602 to a constant speed at the 21st speed v25. Thereafter, from time t21 to time t22 (reference symbol T22), the speed control device 5 decelerates and stops the girder 602.

[0162] At time t22, the girder 602 stops. For the same reason as at symbol T12 in Fig. 7A, the sway angle is also 0 at symbol T12a in Fig. 10A. However, since an inertial force is generated in the suspended load S due to the deceleration control at symbol T22, load sway often occurs at time t22.

[0163] To eliminate such load sway during stoppage, the speed control device 5 performs low-speed operation control (reference symbols T24 to T26) shown at times t23 to t26 after the stoppage period shown at reference symbol T23. The speed of the low-speed operation control from reference symbols T24 to T26 varies depending on the load sway. Note that if the load sway at time t22 is small, the low-speed operation control from reference symbols T24 to T26 may be omitted.

[0164] The period "Δt11a" during which T11a is performed is τ / 6, similar to Δt11 shown in Fig. 7A. The period "Δt12a" during which T12a is performed is 1 to 5 seconds, similar to the period "Δt12" shown in Fig. 7A.

[0165] The periods "Δt22" to "Δt26" during which the symbols T22 to T26 are performed are respectively expressed by the following equations (10-1) to (10-3).

[0166] Δt22=Δt26=v25 / Vmax×tb ··· (10-1) Δt23=Δt25=(arctan(y23 / x23)-φ / 2) / 2π×τ (10-2) Δt24=v25 / Vmax×ta... (10-3)

[0167] In addition, y23 and x23 in equation (10-2) are the coordinates of a phase point P23 on the phase plane, which will be described later in Fig. 11. In other words, the length of the period "Δt23" is calculated based on the phase plane.

[0168] Furthermore, during the constant speed control indicated by reference symbol T12a, when the distance to the target stop position (travel target position 127 in Figure 3) reaches "D11" indicated in the following equation (11), the speed control device 5 starts deceleration control indicated by reference symbol T22.

[0169] D11=v25×(tb×v25 / Vmax×3 / 2+Δt25) (11)

[0170] Thus, a complex calculation is required to calculate the timing to start the deceleration process of reference symbol T22. In contrast, according to this embodiment, as shown in Fig. 7A, the calculation can be performed in half the swing period (τ / 2) of the suspended load S, which simplifies the calculation and makes it easier to set the speed control device 5.

[0171] Next, with reference to Fig. 10B, a description will be given of the change in the swing angle over time when the girder 602 is traveling in the first comparative example. Fig. 10A will also be referred to as appropriate.

[0172] (Changes in swing angle over time, changes in the state of the suspended load S) FIG. 10B is a diagram showing the change in the swing angle over time and the change in the state of the suspended load S in the first comparative example.

[0173] In Fig. 10B, times t0 to t10 and t20 to t26 correspond to times t0 to t10 and t20 to t26 in Fig. 10A. Also, in Fig. 10B, periods "Δt1" to "Δt11a", "Δt12a", and "Δt22" to "Δt26" correspond to periods "Δt1" to "Δt11a", "Δt12a", and "Δt22" to "Δt26" in Fig. 10A.

[0174] In addition, in FIG. 10B, times t0 to t10 (periods "Δt1" to "Δt10") are the same as in FIG. 7B, so the same reference numerals are used and the description will be omitted.

[0175] At symbol T9 (period "Δt9"), the sway angle is maintained at its maximum, and then at symbol T10 (period "Δt10"), constant speed control of the girder 602 is performed. As a result, an inertial force acts on the load S in the negative direction, decreasing the sway angle. Then, at symbol T11a (period "Δt11a"), the girder 602 is decelerated again, causing an inertial force to act on the load S in the positive direction. As a result, the inertial force due to deceleration and the inertial force due to the load swing in the negative direction cancel each other out, and the sway angle becomes zero.

[0176] Therefore, during the constant speed control at reference symbol T12a (period "Δt12a"), the sway angle remains at 0. From this state, deceleration control is performed at reference symbol T22 (period "Δt22"), causing the girder 602 to stop. However, as shown in FIG. 10B, the inertial force caused by the deceleration control at reference symbol T22 (period "Δt22") acts on the load S, causing the load to sway in the positive direction. Therefore, load sway occurs at time t22 when the girder 602 stops. When such load sway occurs, workers cannot perform tasks such as raising and lowering the load S. Furthermore, it takes a long time for the load sway to naturally resolve.

[0177] For this reason, low-speed operation control is generally performed as indicated by symbols T24 to T26 in FIG. 10A (period "Δt24" to "Δt26" in FIG. 10B). This means temporary low-speed operation, as shown in FIG. 10A. Acceleration control of the girder 602 is performed at symbol T24 (period "Δt24"), thereby causing a negative inertial force due to acceleration of the girder 602 to act on the load swing that occurred in the positive direction at time t22, thereby canceling out the inertial force due to the load swing. Furthermore, thereafter, deceleration of the girder 602 is performed at symbol T26 (period "Δt26"), thereby further canceling out the inertial force of the suspended load S that occurred due to the acceleration at symbol T24.

[0178] In this way, the load swing can be eliminated.

[0179] (phase plane) Next, the anti-sway control performed in the first comparative example will be described in terms of phase with reference to Fig. 11. Fig. 10A and Fig. 10B will also be referenced as appropriate.

[0180] Fig. 11 is a diagram showing the phase plane trajectory of the sway prevention control performed in the first comparative example, which shows the phase plane trajectory of the suspended load S from time t21 to time t26 in Figs. 10A and 10B.

[0181] 10A and 10B are similar to those in FIG. 8, except that the symbol T11 is replaced by the symbol T11a and the symbol T12 is replaced by the symbol T12a, as shown in FIG. 10A and 10B. The phase plane trajectories of the symbols T11a and T12a are similar to those of the symbols T11 and T12 shown in FIG. 8. Therefore, the illustration and description of the phase plane trajectories of the symbols T0 to t21 in FIG. 10A and 10B will be omitted.

[0182] In FIG. 11, the vertical axis (y) and horizontal axis (x) are the same as those in FIGS.

[0183] Moreover, the circles 31 to 33 shown in FIG. 11 are expressed by the following equations (12-1) to (12-3), respectively.

[0184] x2+(y-1)2=1 (12-1) x2+y2=(sinφ)2+(1-cosφ)2=(2×sin(φ / 2))2 (12-2) x2+(y+1)2=(cos(φ / 2)+sin(φ / 2)×3 1 / 2 )2 (12-3)

[0185] Next, the phase plane trajectory at the points T22 to T26 in Fig. 10A will be described with reference to Fig. 11. In the following, times t21 to t26 correspond to times t21 to t26 shown in Fig. 10A.

[0186] First, at reference symbol T22, a phase plane trajectory is drawn on the circumference of circle C31 from phase point P21 (=origin: corresponding to time t21) to phase point P22 (corresponding to time t22). Next, at reference symbol T23, a phase plane trajectory is drawn on the circumference of circle C32 from phase point P22 to phase point P23 (corresponding to time t23).

[0187] Next, at reference symbol T24, a phase plane trajectory is drawn on the circumference of circle C33 from signal point P23 to signal point P24 (corresponding to time t24). After that, at reference symbol T25, a phase plane trajectory is drawn on the circumference of circle C32 from signal point P24 to signal point P25 (corresponding to time t25). Then, at reference symbol T26, a phase plane trajectory is drawn on the circumference of circle C31 from signal point P25 to signal point P26 (= origin: corresponding to time t26).

[0188] Furthermore, if the coordinates of the phase point P22 are (x22, y22), the x-coordinate value and the y-coordinate value are expressed as x22=sinφ and y22=1−coxφ, where φ is the same as φ in equation (8).

[0189] If the coordinates of the phase point P23 are (x23, y23), then x23 and y23 are expressed by the following equations (13-1) and (13-2).

[0190] x23=K×sin(φ / 2) ··· (13-1) y23=K×cos(φ / 2)-1 ··· (13-2) However, K=cos(φ / 2)+sin(φ / 2)×3 1 / 2

[0191] Moreover, the straight line L21 is expressed by the following equation (14).

[0192] y={cos(φ / 2) / sin(φ / 2)}x-1 ··· (14)

[0193] The coordinates of P23 are the coordinates of the intersection of the line L21 and the circle C32.

[0194] Furthermore, if the coordinates of P24 are (x24, y24), then the relationship is x24=-x23, y24=y23. Similarly, if the coordinates of P25 are (x25, y25), then the relationship is x25=-x22, y25=y22.

[0195] In FIG. 11, ψ31 and ψ32 are expressed by the following equation (15-1).

[0196] ψ31=ψ32=2π / τ×tb×v14 / Vmax ··· (15-1)

[0197] Moreover, ψ33 is expressed by the following equation (15-2).

[0198] ψ33=ψ31 / 2 (15-2)

[0199] Then, ψ34 and ψ35 are expressed by the following equation (15-3).

[0200] ψ34=ψ35=arctan((y24 / x24)-ψ31 / 2) (15-3)

[0201] In equation (15-3), x24 and y24 are the coordinates of P24.

[0202] Then, ψ36 to ψ38 are respectively expressed by the following equations (15-4) and (15-5).

[0203] ψ36=ψ37=ψ31 / 2 ··· (15-4) ψ38=ψ31 (15-5)

[0204] According to the method shown in the first comparative example, when the distance to the target stop position (travel target position 127 in FIG. 3) satisfies the above-mentioned formula (11), code T22 starts. In other words, the administrator needs to set the starting point of code T22 using the complicated formula (11) and formulas (13-1) to (13-2).

[0205] Furthermore, as mentioned above, since load swing often occurs at time t22 in Fig. 10A, the speed control shown by symbols T24 to T26 is often performed. However, in the speed control shown in Fig. 10A, the girder 602 is stopped once at symbol T23 and then started again. This increases the overall transportation time.

[0206] In other words, with conventional anti-sway control, if the load sway after stopping exceeds the allowable value, it is necessary to wait until the load sway converges or to operate at a low speed for a short period of time to bring the sway within the allowable value. As a result, it takes time for the load sway to stop, which leads to an increase in the transport time. With the method shown in the first comparative example, it is necessary to stop the sway with a single deceleration stop from a low speed (creep speed), ensuring stopping accuracy and shortening the transport time.

[0207] Furthermore, in the speed control shown in Fig. 10A, the girder 602 is stopped once and then started again as described above. In this way, when the girder 602 is stopped once and then started again, a timing error of the traveling reducer 636 (see Fig. 4) and a rotation error of the traveling drive motor 635 (see Fig. 4) occur. For this reason, the error in equation (11) etc. becomes large.

[0208] In contrast, in the speed control of this embodiment shown in Fig. 7A, as described above, the start point of code T13 is set so that the total time of periods "Δt13" and "Δt14" is τ / 2. This allows the administrator to appropriately set the start point of code T13 with simple calculations.

[0209] Furthermore, the speed control of this embodiment shown in Fig. 7A does not perform control to stop the girder 602 once and then start it again as in Fig. 10A. In this way, the speed control shown in Fig. 7A can shorten the overall transportation time more than the speed control shown in Fig. 10A. Furthermore, the speed control shown in Fig. 7A is less susceptible to the influence of timing errors in the traveling reducer 636 and rotation errors in the traveling drive motor 635 than the speed control shown in Fig. 10A.

[0210] In this way, the speed control of this embodiment can reduce the vibration after stopping at the target position, eliminating the need to wait until the vibration settles, thereby shortening the transport time. In addition, the speed control of this embodiment can improve the vibration prevention accuracy while ensuring stopping accuracy, thereby shortening the transport time.

[0211] [Second Comparative Example] Next, a second comparative example will be compared with this embodiment with reference to FIG.

[0212] FIG. 12 is a diagram showing an example of a traveling speed pattern 432A of the girder 602 according to the second comparative example.

[0213] For example, Japanese Patent Laid-Open Publication No. 1-267297 discloses vibration suppression control by speed control as shown in Fig. 12 of this embodiment. A similar technique is also disclosed in Japanese Patent Laid-Open Publication No. 60-153390.

[0214] In the anti-sway control (traveling speed pattern 432B) shown in Fig. 12 of this embodiment, the sequence of symbols T31 (acceleration control) → symbol T32 (constant speed control) → symbol T33 (acceleration control) → symbol T34 (constant speed control) is performed. Thereafter, in the anti-sway control shown in Fig. 12, the sequence of symbols T35 (deceleration control) → symbol T36 (constant speed control) → symbol T37 (deceleration control) → stop is performed.

[0215] At reference T34, the trolley moves at the maximum speed Vmax. At references T32 and T36, the trolley moves at the 31st speed VH. In this case, Japanese Patent Laid-Open Publication No. 1-267297 states that there is a relationship of VH = Vmax / 2.

[0216] Therefore, it can be interpreted that the reference symbol T34 shown in FIG. 12 corresponds to the reference symbol T12 in FIG. 7A of this embodiment, and the reference symbol T36 shown in FIG. 12 corresponds to the reference symbol T14 in FIG. 7A.

[0217] 7A, it is desirable that the velocity "v12" at reference symbol T12 is approximately twice the velocity "v14," but the velocity "v14" at reference symbol T14 is a velocity that satisfies equation (1). Therefore, the first velocity v12 complies with the following equation (16).

[0218] 0.1~0.2×Vmax <v12<τ / 3 / tb×Vmax···(16)

[0219] In contrast, in the anti-sway control shown in Fig. 12, the speed at symbol T34, which corresponds to symbol T12 in Fig. 7A, is the maximum speed Vmax. Therefore, because the speed at symbol T34 is large (fast), an error may occur when measuring the start timing of symbol T35. In the anti-sway control shown in Fig. 7A, the speed "v12" at symbol T12 is sufficiently slow compared to the maximum speed Vmax, so it is possible to reduce the error when measuring the start timing of symbol T13.

[0220] Furthermore, the method described in this embodiment uses sensors that are generally used in transporting a suspended load S, such as a hoisting position detector 621, a traveling position detector 623, a traverse position detector 622, and a sway angle detector 624. However, the method described in this embodiment does not require an anti-sway sensor, which is a dedicated sensor for anti-sway control.

[0221] (PLC1 hardware configuration) FIG. 13 is a diagram showing the hardware configuration of the PLC 1 used in this embodiment. The PLC 1 has a memory 151 and an arithmetic unit 152 such as a CPU (Central Processing Unit). The PLC 1 also has an input device 153, an output device 154, and a communication device 155. The communication device 155 communicates with the management control PC 3, the speed control device 5, etc.

[0222] Then, the program stored in memory 151 is executed by arithmetic device 152. As a result, the pendulum length calculation unit 101 to traveling distance calculation unit 108, lateral movement maximum swing width calculation unit 111 to operation control unit 113, lateral movement anti-sway speed pattern generation unit 411, and traveling anti-sway speed pattern generation unit 412 shown in FIG.

[0223] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0224] Furthermore, the above-described components, functions, pendulum length calculation unit 101 to traveling distance calculation unit 108, lateral maximum swing width calculation unit 111 to driving control unit 113, lateral swing stop speed pattern generation unit 411, and traveling swing stop speed pattern generation unit 412 may be partly or entirely implemented in hardware, for example, by designing them as integrated circuits. As shown in FIG. 13 , the above-described components, functions, and the like may be implemented in software by a processor, such as calculation device 152, interpreting and executing a program that realizes each function. Information such as the program, table, and file that realizes each function can be stored in a recording device, such as memory 151 or SSD (Solid State Drive), or a recording medium, such as an IC (Integrated Circuit) card, an SD (Secure Digital) card, or a DVD (Digital Versatile Disc). In addition, in each embodiment, the control lines and information lines shown are those that are considered necessary for explanation, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are interconnected. [Explanation of symbols]

[0225] 1 PLC (control device) 5 Speed ​​control device 6. Overhead crane equipment 101 Pendulum length calculation unit 102 Runout period calculation unit 103 Traverse movement distance calculation unit 104 Traverse movement speed calculation section 105 Horizontal vibration angular velocity calculation unit 106 Running vibration angular velocity calculation unit 107 Traveling speed calculation unit 108 Travel distance calculation unit 111 Maximum traverse swing calculation unit 112 Maximum travel swing calculation unit 113 Operation control unit (conversion unit) 124 Traverse swing angle 125 Running swing angle 126 Current driving position 127 Travel target position 131 Pendulum Length 132 Pendulum Length 133 Traverse distance 134 Traverse Speed 135 Transverse deflection angular velocity 136 Running sway angular velocity 137 Running Speed 138 Travel distance 139 Swing Period 141 Maximum swing width of horizontal movement 142 Maximum running swing 143 Traverse speed command (speed command) 144 Travel speed command (speed command) 411 Traverse vibration prevention speed pattern generation unit (speed control pattern generation unit) 412 Traveling vibration prevention speed pattern generation unit (speed control pattern generation unit) 431 Traverse speed pattern (speed control pattern) 432 Running speed pattern (speed control pattern) 601 Crab trolley (transport device) 602 Girder (transportation device) 621 Hoisting position detector 622 Traverse position detector 623 Travel position detector 624 Deflection Angle Detector P1~P15,P21~P26 phase points S hanging load T1~T15,T11a,T12a,T22~T26 code T6 code (maximum speed step) T12 code (first speed run step) T14 code (second speed travel step) T15 sign (deceleration step) t0~t15,t20~t26 time v12 First Speed v14 Second Speed Vmax maximum speed Z1 Control System (Transport Control System)

Claims

1. a speed control pattern generation unit that generates a speed control pattern for controlling a conveying speed, which is the speed of the conveying device; The speed control pattern generation unit before the conveying device is stopped, the conveying device is caused to travel at a constant speed for a predetermined time at a second speed that is lower than the maximum conveying speed, and then the conveying device is stopped; Before the transport device travels at the second speed, the transport device is caused to travel at a constant speed for a predetermined time at a first speed that is less than the maximum speed and greater than the second speed; The speed control pattern is generated to control the speed of the transport device so that the time from the end of the travel at the first speed to the end of the travel at the second speed is half the swing period of the load suspended by the transport device. Control device.

2. The second speed is a speed that satisfies the following formula (1):

2. The control device according to claim 1. 0.05~0.1×Vmax≦v14<τ / 6 / tb×Vmax...(1) In equation (1), v14 is the second speed, Vmax is the maximum speed, τ is the swing period of the load, and tb is the time during which deceleration occurs from the maximum speed to a stop.

3. The speed control pattern generation unit When the distance between the current position of the transport device and the target stop position of the transport device satisfies the following formula (2), deceleration from the first speed to the second speed is started.

2. The control device according to claim 1. D2=v14×(τ / 2+tb×v14 / Vmax)... (2) In equation (2), v14 is the second speed, Vmax is the maximum speed, τ is the swing period of the load, and tb is the time during which deceleration occurs from the maximum speed to a stop.

4. The first speed is approximately twice the second speed.

2. The control device according to claim 1.

5. The speed control pattern generation unit The speed control pattern is generated so that an acceleration when the transport device is decelerated from the first speed to the second speed is the same as an acceleration when the transport device is stopped from the second speed.

2. The control device according to claim 1.

6. a control device that outputs a command to control a transport device that suspends and transports a load; a speed control device that controls the speed of the conveying device based on a speed command of the conveying device sent from the control device; A transport control system having: The control device a speed control pattern generation unit that generates a speed control pattern for controlling a conveying speed, which is the speed of the conveying device; a conversion unit that converts the speed control pattern into a speed command for the conveyance device; and The speed control device before the conveying device is stopped, the conveying device is caused to travel at a constant speed for a predetermined time at a second speed that is lower than the maximum conveying speed, and then the conveying device is stopped; Before the transport device travels at the second speed, the transport device is caused to travel at a constant speed for a predetermined time at a first speed that is less than the maximum speed and greater than the second speed; The speed of the transport device is controlled so that the time from the end of travel at the first speed to the end of travel at the second speed is half the swing period of the load suspended by the transport device. Conveyance control system.

7. a control device that outputs a command to control a transport device that suspends and transports a load; a speed control device that controls a conveying speed, which is the speed of the conveying device, based on a speed command of the conveying device sent from the control device; A transport control system having a maximum speed running step of running the conveying device at a constant speed at the maximum conveying speed for a predetermined time; a first speed running step of running the conveying device at a constant speed for a predetermined time at a first speed that is lower than the maximum speed after the maximum speed running step; a second speed traveling step of traveling the conveying device at a constant speed for a predetermined time at a second speed that is lower than the first speed after the first speed traveling step; a deceleration step of decelerating the conveying device to stop the conveying device after the second speed traveling step; and The speed of the transport device is controlled so that the time from the end of travel at the first speed to the end of travel at the second speed is half the swing period of the load suspended by the transport device. A method for controlling a transport device.

Images