Crane and method of controlling a crane

Abstract

The present invention provides a crane comprising: a horizontal moving device capable of moving in a horizontal direction; a winch device mounted on the horizontal moving device and having a winch motor capable of raising a sling; a hook mounted on the sling; a control unit having a processor and a memory for controlling the horizontal moving device and the winch device, the control unit comprising: a sling tension state determination unit for determining whether the sling is in a tensioned state without slack; a state measurement unit for measuring the state quantity of the crane when the winch device is driven to raise the sling to the tensioned state; and a travel control unit for moving the horizontal moving device, wherein the state measurement unit, when the load is on the ground, confirms the position of the load by using the position of the horizontal moving device with the sling in a tensioned state and the measurement result of the state quantity, and moves the horizontal moving device to the confirmed load position.

Description

[0001] This application claims priority to Japanese Application Special Purpose 2021-55350, filed on March 29, 2021 (Reiwa 3), the contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to a crane that suspends a load for transport and a method for controlling the crane. Background Technology

[0003] In recent years, with the aging of skilled crane operators and the increase in the number of cranes leading to manpower shortages, there has been an increase in inexperienced operators taking over crane operations. Inexperienced operators are particularly ill-equipped to stop the swaying of loads (cargo sway), increasing the risk of accidents such as collisions or jamming caused by cargo swaying. Furthermore, the time required to restore the load to its original position lengthens the operation time. Therefore, for safety and improved efficiency, technology that automatically suppresses cargo swaying is needed.

[0004] However, when the load separates from the ground, if there is a horizontal positional deviation between the load and the horizontal moving device (trolley) that suspends the load via slings, the load will start pendulum motion the instant it leaves the ground, resulting in a situation where the load swings (initial swing).

[0005] As a technique to suppress this initial swaying, for example, there is the technique disclosed in Patent Document 1. In the prior art described in Patent Document 1, before separation from the ground, the sling is wound up to a tensioned state without slack, the length of the sling at this time is measured, and the trolley is moved slightly in the direction where the sling length becomes shorter. By repeatedly performing this operation, the trolley is moved to a position directly above the suspended weight where the sling length is minimized and there is no positional deviation. Furthermore, the criterion for determining whether the sling length is minimized is set as follows: the change in sling length caused by the movement of the trolley decreases to a predetermined value, or the change in sling length changes from decreasing to increasing.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-119583

[0009] Patent Document 2: International Publication No. 2018 / 211739 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] In existing technologies, the minimum sling length is determined based on the change in sling length. However, since the change in sling length also decreases as the positional deviation between the load and the trolley decreases, there is a limit to the accuracy of detecting the position where the sling length is at its minimum, and there is also a limit to the reduction of positional deviation.

[0012] In addition, due to the repeated lifting, the tensioning of the sling, the measurement of the sling length, and the slight movement of the trolley, when the positional deviation is large, the number of times the trolley movement is repeated is large, which creates a problem in the time (action time) for the trolley to move directly above the suspended load.

[0013] The present invention was made in view of the following problems, and its purpose is to provide a crane and a crane control method that can further reduce the horizontal positional deviation between the load and the trolley during ground separation, further shorten the trolley's movement time before ground separation, and shorten the time to ground separation.

[0014] Methods for solving problems

[0015] The present invention is a crane comprising: a horizontal moving device having an electric motor capable of moving horizontally; a winch device mounted on the horizontal moving device having a winch motor capable of winding a sling; a hook mounted on the sling for suspending a load; and a control unit having a processor and a memory for controlling the horizontal moving device and the winch device. In this crane, the control unit includes: a sling tension state determination unit that determines whether the sling is in a tensioned state without slack; a state measurement unit that measures the state quantity of the crane when the winch device is driven to wind the sling to the tensioned state; and a travel control unit that moves the horizontal moving device. The state measurement unit, when the load is on the ground, confirms the load position using the position of the horizontal moving device with the sling in a tensioned state and the measurement result of the state quantity. The travel control unit moves the horizontal moving device towards the confirmed load position, positioning the sling directly above the load.

[0016] Invention Effects

[0017] According to the present invention, the horizontal positional deviation between the suspended weight and the trolley during ground separation can be further reduced, the movement time of the trolley before ground separation can be further shortened, and the time until ground separation can be shortened.

[0018] Details of implementation of at least one of the subjects disclosed in this specification are illustrated by the accompanying drawings and the following description. Other features, methods, and effects of the subject matter of this invention will become more apparent from the following disclosure, drawings, and claims. Attached Figure Description

[0019] Figure 1 The figure shown is an example of a crane, illustrating Embodiment 1 of the present invention.

[0020] Figure 2 Embodiment 1 of the present invention is a block diagram showing the structure of a crane control device.

[0021] Figure 3A The diagram illustrating Embodiment 1 of the present invention is a diagram illustrating the operation of the crane during ground separation.

[0022] Figure 3B The diagram illustrating Embodiment 1 of the present invention is a diagram illustrating the operation of the crane during ground separation.

[0023] Figure 4 This is a flowchart representing one example of the processing of an existing instance.

[0024] Figure 5 This is a diagram illustrating the operation of a crane as an example of the processing of an existing case.

[0025] Figure 6 The first embodiment of the present invention is illustrated by a diagram showing the relationship between the position of the trolley, the load, and the length of the sling.

[0026] Figure 7 Embodiment 1 of the present invention is a graph showing the relationship between positional deviation and sling length.

[0027] Figure 8 Embodiment 1 of the present invention is a graph illustrating the principle of the present invention and showing the relationship between the position of the trolley and the length of the sling.

[0028] Figure 9 The diagram shown is of Embodiment 1 of the present invention and illustrates the operation of a crane.

[0029] Figure 10 Embodiment 1 of the present invention is a flowchart illustrating an example of the process.

[0030] Figure 11 Embodiment 1 of the present invention is a detailed flowchart of the process for confirming the position where the sling length is minimized.

[0031] Figure 12 The figure shown is an example of controlling the position of the suspended load by using the swing angle of the sling to indicate an embodiment of the present invention.

[0032] Figure 13 Embodiment 3 of the present invention is illustrated in a diagram showing an example of controlling the position of the suspended load by utilizing the release amount of the sling and the lifting time until the tension is reached.

[0033] Figure 14This is a block diagram illustrating the structure of the crane control device according to embodiments 3, 4, and 5 of the present invention. Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments, and various modifications or applications are also included within the scope of the technical concept of the present invention.

[0035]

Example 1

[0036] <Description of the structure and operation of the crane>

[0037] The structure and operation of the crane 1 according to Embodiment 1 of the present invention will be described. Furthermore, in the figures, the same reference numerals are used to label the same machines (devices, components), and descriptions of machines already described may be omitted in the following description.

[0038] Figure 1 The diagram shows a general structure of an overhead mobile crane. The crane 1 consists of a slide 2 installed along the side walls of a building (not shown) such as a factory, a main beam 3 that moves along the upper surface of the slide 2, and a trolley 4 that moves along the lower surface of the main beam 3.

[0039] The main beam 3 and the trolley 4 are equipped with wheels (not shown in the figure) driven by an electric motor, allowing them to move. The main beam 3 travels along the slide 2, and the trolley 4 moves laterally (horizontally: left and right in the figure) on the lower surface of the main beam 3 between slides 2 and 2.

[0040] Additionally, a winch device (winch) 5 is provided on the trolley 4. The winch device 5 is equipped with a drum (not shown in the figure) driven by an electric motor. By rotating the drum, the sling 6 is raised or lowered, thereby raising or lowering the hook 7 at the front end of the sling 6.

[0041] The load 9 is suspended directly from the hook 7 or via the metal wire 8, and the load 9 rises and falls along with the hook 7. The crane 1 moves the load 9 horizontally by moving the main beam 3 horizontally (traveling) and the trolley 4 horizontally (lateral movement), and the hoisting device 5 can raise and lower the load 9 vertically (up and down).

[0042] Furthermore, the component for suspending the load 9 on the hook 7 is not limited to the metal wire 8, but can also use suspension components such as chains or slings.

[0043] exist Figure 1The trolley 4 and the main beam 3 are equivalent to the "horizontal moving device", and at least one of the trolley 4 or the main beam 3 can also be used as the "horizontal moving device". Alternatively, the trolley 4 that moves along the main beam 3 can be used as the first horizontal moving device, and the main beam 3 that moves along the slide 2 can be used as the second horizontal moving device.

[0044] In addition, the hoisting device 5 is equipped with an encoder 5a for detecting the rotation angle of the drum (see reference). Figure 2 It can measure the length (sling length) of the sling 6 released from the drum.

[0045] <Description of the Control Device>

[0046] Figure 2 The structure of the control device for the crane 1 in this embodiment is shown. Furthermore, in Figure 2 To simplify the explanation, the control of lateral movement based on the trolley 4 and lifting based on the hoisting device 5 is shown, while the movement based on the main beam 3 is omitted.

[0047] Furthermore, the drive unit for the electric motor, etc., is omitted. The control device 100 of the crane 1 includes an arithmetic control unit, a horizontal motor control device 300 for controlling the electric motor (horizontal motor) of the trolley 4, a winch motor control device 310 for controlling the electric motor (winch motor) of the hoisting device 5, an operation input device 200, and a display device 210. In addition, although not shown, the control device 100 includes a travel motor control device for controlling the electric motor (travel motor) that drives the main beam 3 along the slide rail 2.

[0048] The control device 100 performs calculations and outputs speed command values ​​to the trolley 4 or the hoisting device 5, and outputs information to the display device 210 based on the operation input from the operation input device 200 and the information acquired from the encoder 5a (first sensor) and other sensors.

[0049] The arithmetic control unit of the control device 100 is generally a general-purpose computer, consisting of a microprocessor unit (MPU) 101 that performs control or arithmetic processing using built-in programs or data, a memory 102 that stores programs or data, and an input / output control unit 103 that receives data or signals from the outside or outputs signals processed by the MPU 101 to the outside. The MPU 101, memory 102, and input / output control unit 103 are connected via a bus 104 for receiving and transmitting signals or data.

[0050] The operation input device 200 is connected to the operation terminal device 201 for operation by the operator of the crane 1, etc. The operation terminal device 201 is provided with operation buttons 202 corresponding to the movement direction of the suspended load, namely front, back, right, left, top and bottom.

[0051] Display device 210 displays information such as the status of crane 1. The operation terminal device 201 and control device 100 can be connected via wired or wireless connection. Furthermore, display device 210 and operation terminal device 201 can be housed in the same casing.

[0052] The horizontal motor control device 300 and the winch motor control device 310 control the motors of the trolley 4 and the winch device 5 based on the speed command values ​​output from the control device 100. The specific structures of the horizontal motor control device 300 and the winch motor control device 310 are not shown, but they can be constructed using a general-purpose computer and inverter circuit, similar to the control device 100. Furthermore, the horizontal motor control device 300 and the winch motor control device 310 can be housed in the same casing as the control device 100.

[0053] In addition, although Figure 2 (The text is omitted here.) The control device 100 outputs speed command values ​​not only for the trolley 4 and the hoisting device 5, but also for the main beam 3. Based on these speed command values, the main beam 3 controls the motor via a motor (travel motor) control device (not shown).

[0054] In memory 102, the sling tension state determination unit 21, the state measurement unit 22, the hoisting control unit 23, and the travel control unit 24 are loaded as programs and executed by MPU 101.

[0055] MPU101 performs processing according to the programs of each functional unit, thereby operating as a functional unit that provides the specified functions. For example, MPU101 functions as a sling tension determination unit 21 by performing processing according to a sling tension determination program. The same applies to other programs. Furthermore, MPU101 also operates as a functional unit that provides the respective functions of multiple processes for the execution of each program. A computer and a computer system are devices and systems that include these functional units.

[0056] The sling tension determination unit 21 determines whether the sling 6 is in a tensioned state without slack based on the current value of the motor of the winch device 5. As described later, the state measurement unit 22, with the load on the ground, winds the sling 6 to a tensioned state and measures state quantities such as the sling length and the positions of the trolley 4 and the main beam 3. Based on the state quantities, it infers the position of the load, moves the trolley 4 and the main beam 3 towards the position of the load, and moves the sling 6 directly above the load 9 for positioning.

[0057] The travel control unit 24 receives command values ​​from the operation terminal device 201 and the load position from the status measurement unit 22, drives the trolley 4 through the horizontal motor control device 300, and drives the main beam 3 to move horizontally through the travel motor control device (not shown).

[0058] The hoisting control unit 23 outputs command values ​​to the hoisting motor control unit 310 based on the command values ​​from the operation terminal device 201 and the command values ​​from the status measurement unit 22.

[0059] <Ground Separation Action>

[0060] However, there is a possibility that the load may swing (initial swing) when it separates from the ground (or floor) after being lifted 9. Figure 3A , Figure 3B This illustrates the movement of crane 1 during ground separation. For example... Figure 3A As shown, when there is a horizontal positional deviation D between the suspended weight 9 placed on the ground and the trolley 4, as... Figure 3B As shown, after the sling 6 is wound up and the load 9 is lifted off the ground, the load 9 begins to vibrate with amplitude D (position deviation D) and angular frequency (g / L). 1 / 2 The pendulum motion (L: distance from trolley 4 to the suspended weight 9, g: acceleration due to gravity) is the initial swing.

[0061] <Explanation and Issues of the Prior Art>

[0062] To suppress this initial sway, it is sufficient to reduce the horizontal positional deviation between the suspended weight 9 and the trolley 4 when separating from the ground; this can be achieved by moving the trolley 4 directly above the suspended weight 9 before separation from the ground. The prior art disclosed in the aforementioned Patent Document 1 is known as a means to achieve this.

[0063] In this prior art, before separation from the ground, the sling is wound up to a tensioned state without slack, the length of the sling is measured at this time, and the trolley is moved slightly in the direction where the sling length becomes shorter. By repeating this operation, the trolley is moved to the position directly above the suspended weight where the sling length is minimized and there is no positional deviation.

[0064] Furthermore, the criterion for determining whether the sling length is at its minimum is set as follows: the change in sling length caused by the movement of the trolley decreases to a specified value, or the change in sling length changes from decreasing to increasing.

[0065] Figure 4 A flowchart illustrating an example of prior art control is shown below. Details are as follows. Furthermore, an example of control of a load being moved using a trolley and a winch is shown below.

[0066] First, the control device does not allow the hoisting operation (S101). Next, the control device commands the hoisting device to hoist the sling to a tensioned state without slack (S102). The control device detects the sling length from the encoder or other components installed on the hoisting device as a status quantity Ψ (S103).

[0067] In step S104, the control device performs a termination judgment based on the state quantity Ψ. The termination condition is set as follows: the change in sling length becomes less than a predetermined value, or the sling length changes from decreasing to increasing. If the termination condition is not met, proceed to step S105; if the condition is met, proceed to step S107.

[0068] In step S105, the control device determines the direction of movement of the trolley and takes the direction in which the sling length becomes shorter as the transport (lateral) direction of the trolley. In step S106, the trolley is transported only a predetermined distance in the direction determined by the control device in step S105. After the transport is completed, the process returns to step S102 and repeats the above process.

[0069] On the other hand, in step S107, the control device determines that the termination condition has been met and the trolley has been moved directly above the load, and the operator allows the lifting operation.

[0070] in addition, Figure 5 This describes the operation of the crane 1 in the prior art. In the prior art, the tensioning of the sling 6 based on the coiling, the measurement of the sling length, and the minute movement of the trolley 4 are repeatedly performed, causing the trolley 4 to gradually move directly above the suspended load 9.

[0071] The prior art presents the following two challenges. One is the limit to reducing positional deviation based on the detection accuracy of the sling length. Figure 6 This indicates the relationship between the position of the trolley 4 and the load 9 and the length of the sling. Let the horizontal positional deviation between the trolley 4 and the load 9 be D, and the height from the load 9 to the trolley 4 be H. The distance from the trolley 4 to the load 9, i.e. the length L of the sling 6 including the metal wire 8, is shown in the following formula (1).

[0072]

[0073] Figure 7 This is a graph showing the relationship between the positional deviation D obtained according to equation (1) and the sling length L. Based on this... Figure 7 It can be seen that when the position deviation D becomes smaller, the change in the sling length L becomes smaller, and the necessary moving distance of the trolley 4 to detect the change in the sling length L becomes longer. The sling length L can be detected by the encoder 5a. Let the detection resolution of the sling length L based on the encoder 5a be ΔL, then the minimum value of the position deviation D, Dmin, is shown in the following equation (2).

[0074]

[0075] As shown above, the minimum value Dmin of the position deviation D is determined by the detection resolution of the encoder 5a, and there is a limit to the reduction of the position deviation D.

[0076] Another issue is that when the positional deviation D increases, the time required for the trolley 4 to move directly above the suspended load 9 becomes longer. For example... Figure 4 As shown, in the prior art, the tensioning of the sling based on the coiling mechanism, the measurement of the sling length, and the minute movement of the trolley 4 are repeatedly performed. Therefore, when the positional deviation D is large, there is a problem that the number of repetitions increases and the action time becomes longer.

[0077] <Summary and Principles of the Invention>

[0078] In this invention, the above-mentioned problems are solved as described below. Figure 8 This is a graph illustrating the relationship between the sling length L and the trolley position x, demonstrating the principle of the present invention. Additionally, Figure 9 This is a diagram illustrating the operation of the crane 1 of the present invention. The trolley position x(i) of the trolley 4 in the transverse direction and the distance L(i) between the trolley 4 and the load 9 (including the sling length of the metal wire 8) in the tensioned state at trolley position x are related as shown in the following equation (3). Wherein, i is a natural number representing the number of measurements of the sling length L.

[0079]

[0080] exist Figure 8 In the equation (3), the load position xp is the position of the trolley where the trolley 4 moves in the transverse (main beam 3) direction and the sling length L is minimized. It is the transverse position (load position) xp of the load 9. By squaring the two variables in equation (3), we obtain the following equation (4).

[0081] x(i) 2 -2xp×x(i)-L(i) 2 +xp 2 +H 2 =0…(4)

[0082] Here, let H be the height from the load 9 to the trolley 4 (or the winch 5), and let p1 and p2 be the coefficients including the load position xp. Then, the above equation (4) becomes as shown in equation (5) below.

[0083] x(i) 2 -L(i) 2 +p1×x(i)+p2=0…(5)

[0084] The square of the sling length L(i) can be represented by a quadratic function of the trolley position x(i). Therefore, the trolley 4 is moved in the lateral direction, and the trolley position x(i) at at least two locations and the sling length L(i) in the tensioned state are measured as state variables. The obtained trolley position x(i) and sling length L(i) are fitted to the above equation (5) using a well-known or known method such as the least squares method to calculate the coefficients p1 and p2. In addition, the fitting in this embodiment uses curve fitting or curve fitting to obtain the curve that best fits the measured data (the above equation (5)).

[0085] Then, based on the calculated coefficients p1 and p2, the control device 100 can calculate the load position xp of the trolley 4 in the transverse direction of the load 9 using the following formula (6).

[0086]

[0087] Similarly, at least two main beam positions y(i) and sling lengths L(i) are measured in the travel direction of the main beam 3, thereby enabling the calculation of the lifting position yp in the travel direction of the main beam 3, where the sling length L of the trolley 4 is transformed into the minimum lifting position 9, in the same manner as the aforementioned lifting position xp.

[0088] By moving the trolley 4 to the obtained load position (xp, yp) in the lateral and travel directions, the horizontal positional deviation D between the load 9 and the trolley 4 can be reduced, thus suppressing the initial sway.

[0089] As shown above, in this invention, by fitting the sling length L(i) and the trolley position x(i) to the quadratic curve shown in equation (5), the position directly above the load 9 can be determined with higher precision than the precision determined by the detection resolution of the encoder in the prior art, and the position deviation D can be reduced more.

[0090] Furthermore, in this invention, the tensioning of the lifting sling 6, the measurement of the sling length L, and the movement of the trolley 4 are performed at least twice in the lateral and traveling directions. Compared with the prior art, this reduces the number of repetitions and shortens the operation time.

[0091] <Control of the Invention>

[0092] Figure 10 This is a flowchart illustrating an example of a process performed in the control device 100 of the present invention. This process begins based on an operator's instruction. Details are as follows.

[0093] In step S201, the control device 100 switches the initial position adjustment mode of the trolley movement before ground separation according to the present invention to the operation mode. The operation mode switching can be achieved, for example, by setting an operation mode switching switch in the operation input device 200, which can be operated by the operator.

[0094] In addition, to make the surroundings aware of the operation mode, for example, the operation mode can be displayed on the display device 210, or an indicator light for displaying the operation mode can be installed on the crane 1.

[0095] In step S202, the control device 100 moves the trolley 4 to confirm the load position xp in the transverse direction. Details of this control are described later. Furthermore, in step S203, the control device 100 moves the main beam 3 in the direction of the slide rail 2 to confirm the load position yp of the main beam 3 in the traveling direction.

[0096] Then, in step S204, the trolley and main beam 3 are moved to the confirmed lifting positions (xp, yp). As a result, the sling 6 hanging from the trolley 4 is positioned directly above the lifting weight 9.

[0097] In step S205, the control device 100 switches to a normal operating mode in which the load 9 moves in the direction of the operation button 202 located on the operation terminal device 201 being pressed. This switching can be performed not only by explicit operation such as by switching the operation mode of the operation terminal device 201, but also automatically if the trolley 4 reaches the load position (xp, yp).

[0098] In addition, to ensure safety, in the above steps S202, S203, and S204, the trolley moves only during the period when the operation button 202 provided on the operation terminal device 201 is pressed.

[0099] Figure 11 It means in Figure 10 The flowchart details the confirmation process for the load position xp performed in step S202. The details are described below. Furthermore, the details of step S203 above are as follows: the horizontal direction described below is replaced with the traveling direction.

[0100] In step S301, the control device 100 winds up the sling 6 at the initial trolley position x(1) of the trolley 4 until the sling 6 is tensioned, and measures the sling length L(1) when the sling 6 is in a tensioned state according to the detection value of the encoder 5a.

[0101] Whether the sling 6 is tensioned can be determined, for example, by checking whether the current value of the winch motor exceeds a threshold, or by installing a tension sensor on the sling 6 and judging whether the tension exceeds a threshold, using well-known or publicly known techniques.

[0102] In step S302, the control device 100 moves the trolley 4 from trolley position x(1) to trolley position x(2) which is only a predetermined distance dx away from it. At this position, the sling 6 is wound up until it is taut, and the length L(2) of the sling is measured by the encoder 5a. The horizontal position of the trolley 4 can be calculated, for example, based on the movement time of the trolley 4, or measured by installing a laser distance sensor on the trolley 4.

[0103] In addition, the control device 100 also performs the above steps S301 and S302 in the same way in the traveling direction of the main beam 3, so that the main beam 3 moves from the main beam position y(1) to the main beam position y(2) which is only a predetermined distance away from the main beam position dy. At this position, the sling 6 is wound up to tension, and the sling length L(2) is measured by the encoder 5a.

[0104] In step S303, the control device 100 fits the car position (x(1), L(1)) and car position (x(2), L(2)) measured in steps S301 and S302 into the above equation (5) using a well-known or common method such as the least squares method, and confirms the coefficients p1 and p2 of the car 4 in the transverse direction.

[0105] In addition, the control device 100 uses the same method as described above to fit the main beam position (y(1), L(1)) and main beam position (y(2), L(2)) of the main beam 3 in the traveling direction to the above formula (5) using a well-known or common method such as the least squares method, and confirms the coefficients p1 and p2 of the main beam 3 in the traveling direction.

[0106] In step S304, the control device 100 uses the coefficient of the trolley 4 in the transverse direction as p1x in the diagram, and determines the sling length L (state quantity) at the minimum sling position xp in the transverse direction using the above equation (6). Additionally, the control device 100 uses the coefficient of the main beam 3 in the travel direction as p1y in the diagram, and determines the sling length L at the minimum sling position yp in the travel direction using the above equation (6).

[0107] Furthermore, in step S302 above, the load 9 may be dragged when the trolley 4 is moved while the sling 6 is taut. Therefore, the sling 6 is released before the trolley 4 is moved, and then the movement of the trolley 4 begins. The same applies to the direction of travel of the main beam 3.

[0108] In this example, the trolley is moved in the transverse direction, and the trolley position and sling length are measured at two points. However, in order to improve the detection accuracy of the load position xp, the number of measurement points can also be increased.

[0109] As shown above, the positions x(1), x(2) of the trolley and the lengths L(1), L(2) of the sling under tension are fitted together. Figure 8The quadratic curve shown allows for more precise determination of the position of the suspended weight 9, thus reducing positional deviations.

[0110] In addition, in this embodiment, the tensioning of the lifting cable 6 of the trolley 4, the measurement of the cable length L, and the movement of the trolley 4 (or the main beam 3) in the lateral and traveling directions are performed at least twice. Since the number of repetitions can be reduced, the movement time of the trolley 4 before ground separation can be shortened, and the time until ground separation can be shortened.

[0111] <Variation Example 1>

[0112] However, when looking at the constant terms in equations (4) and (5) above, the height H can be calculated using the following equation (7).

[0113]

[0114] Subtract the length Lr (x = xp) of the sling from the trolley 4 to the hook 7 when the trolley 4 is under tension directly above the load 9 from the height H, and calculate the length Lw of the metal wire 8 from the hook 7 to the load 9 according to the following formula (8).

[0115] L w =H-Lr(x=xp)…(8)

[0116] Based on the above, the length of the metal wire 8 (hereinafter, the metal wire length) Lw can be automatically obtained. Adding the length of the sling 6 from the trolley 4 to the hook 7, which is detected by the encoder 5a, to the metal wire length Lw, the distance L from the trolley 4 to the load 9 can be automatically obtained. Furthermore, this distance L is the same as the sling length L from the trolley 4 to the load 9 mentioned above.

[0117] This distance L is a necessary parameter for suppressing and controlling the swaying of the load 9 during transport. The swaying of the load during transport exerts an inertial force on the load 9 due to the acceleration and deceleration of the trolley 4, with an angular frequency ωr.

[0118]

[0119] The swaying occurs through excitation. To suppress the swaying of the cargo, for example, cargo sway suppression control can be performed by removing the frequency component of the angular frequency ωr from the speed command value of the trolley 4, as shown in International Publication No. 2018 / 211739 (hereinafter, known examples).

[0120] However, the aforementioned known examples either preset the metal wire length Lw or read a recorded value, without disclosing a method for automatically obtaining the metal wire length Lw based on the metal wire 8 used. As shown above, automatically obtaining the metal wire length Lw can improve the suppression performance of cargo swaying during handling.

[0121] <The effect of variation example 1>

[0122] Furthermore, as shown above, the height H from the load 9 to the trolley 4 can also be automatically obtained. This allows for the automatic setting of the lower limit during descent, preventing accidental collisions between the load and the ground due to excessive descent, or the metal wire slackening and falling off the hook, thus improving the safety of the crane 1.

[0123]

Example 2

[0124] Next, the crane 1 of Embodiment 2 of the present invention will be described. Furthermore, repeated descriptions of commonalities with the above embodiments are omitted. Moreover, the structure of the crane 1 and the control device 100 is the same as that of Embodiment 1 described above.

[0125] In the crane 1 of Embodiment 1, the distance between the trolley 4 and the suspended load 9 (including the length of the sling 6 of the metal wire 8) is used as a state quantity to confirm the position of the suspended load. However, as Figure 1 As shown, a hook 7 is installed at the front end of the sling 6 that is suspended from the trolley 4, and a weight 9 is suspended from the hook 7 via a metal wire 8.

[0126] The encoder mounted on the hoisting device 5 can detect the distance from the trolley 4 to the hook 7, i.e., the length of the sling 6. Typically, there is no device to directly detect the distance from the hook 7 to the load 9, i.e., the length of the metal wire 8. Therefore, in this embodiment, the length of the metal wire 8 is also treated as an unknown to determine the load position xp (yp).

[0127] When the length of the sling is set as Lr(i), the length of the metal wire is set as Lw, the position of the trolley 4 is set as x(i), the position of the load is set as xp, and the height from the load 9 to the trolley 4 is set as H, they form the relationship shown in equation (9).

[0128]

[0129] Squaring both sides yields the following equation (10).

[0130] x(i) 2 -2xp×x(i)+xp 2 -Lr(i) 2 -2Lr(i)×Lw-Lw 2 +H 2 =0…(10)

[0131] Here, when the metal wire length Lw, height H, and coefficients including the hanging position xp are set as p1, p2, and p3, it is as shown in equation (11) below.

[0132] x(i) 2-Lr(i) 2 +p1×x(i)+p2×Lr(i)+p3=0…(11)

[0133] Here, the trolley 4 is moved in the transverse direction, and the trolley position x(i) and the sling length Lr(i) in the tensioned state are measured at at least three locations. The obtained trolley position x(i) and sling length Lr(i) are fitted to the above equation (11) using the least squares method, and the coefficients p1, p2, and p3 are calculated. Furthermore, the sling position xp of the sling 9 in the transverse direction can be calculated from the calculated coefficients according to the following equation (12).

[0134]

[0135] Similarly, at least three main beam positions y(i) and sling lengths Lr(i) are measured in the travel direction, thereby enabling the calculation of the load position yp in the travel direction where the sling length Lr is minimized when the main beam 3 moves in the travel direction.

[0136] By moving the trolley 4 and the main beam 3 to the positions (xp, yp) obtained in this way, the horizontal positional deviation between the load 9 and the trolley 4 and the main beam 3 can be eliminated, and the initial sway can be suppressed.

[0137] Based on the above, even if the distance from hook 7 to weight 9, i.e. the length of the metal wire Lw, is unknown, the position of weight 9 can still be determined.

[0138] <Variation Example 2>

[0139] However, when considering the coefficients of the sling length Lr(i) in equations (10) and (11) above, the wire length Lw can be calculated using the following equation (13).

[0140]

[0141] Furthermore, when looking at the constant terms in equations (10) and (11) above, the height H can be calculated using the following equation (14).

[0142]

[0143] Based on the calculated height H and the sling length Lr (x=xp) from trolley 4 to hook 7 under tension when trolley 4 is directly above the load 9, the length Lw of the metal wire can also be calculated using the above formula (8).

[0144] Based on the above, the ability to automatically obtain the metal wire length Lw improves the performance of cargo sway control during handling. Furthermore, the ability to automatically obtain the height H enhances the safety of crane 1 by automatically setting the lower limit during descent.

[0145]

Example 3

[0146] Next, the crane 1 of Embodiment 3 of the present invention will be described. Furthermore, repeated descriptions of commonalities with the above embodiments are omitted.

[0147] Figure 14 The structure of the control device for crane 1 in Embodiment 3 is shown. Furthermore, the same reference numerals are used for structures identical to those in Embodiment 1 above, and repeated descriptions are omitted. Figure 14 In this embodiment, based on the structure of Example 1 described above, a force sensor 4a (fourth sensor) is added to the trolley 4 to detect the force acting in the lateral direction, a tension sensor 5b (third sensor) is added to the winch device 5 to detect the tension of the sling 6, and a swing angle sensor 7a (second sensor) is added to the hook 7 to detect the angle of the sling 6. Furthermore, the control device 100 is further equipped with a horizontal force detection unit 301 (another implementation of the fourth sensor) to detect the force applied to the trolley 4 in the lateral direction, and a tension detection unit 311 (another implementation of the third sensor) to measure the tension of the sling 6.

[0148] Figure 12 The operation of the crane 1 in Embodiment 3 is illustrated. In this Embodiment 3, the angle (sling swing angle) formed by the sling 6 relative to the vertical direction of the trolley 4 when the sling 6 is taut is detected by the swing angle sensor 7a, and the sling swing angle is used as a state quantity to confirm the position of the suspended load.

[0149] The sling swing angle can be detected, for example, by using an encoder to detect the angle formed by a weight mounted in a manner suspended on the hook 7, as described in Patent Document 1 above, or by using a gyroscope sensor mounted on the hook 7.

[0150] When the swing angle of the sling is set as θ(i), the position of the trolley 4 is set as x(i), the position of the load 9 is set as xp (or yp), and the height from the load 9 to the trolley 4 is set as H, they form the following relationship (15).

[0151] x(i)-xp=H×tanθ(i)…(15)

[0152] Here, when the height H and the coefficients including the load position xp are set as p1 and p2, it becomes the following equation (16).

[0153] x(i)+p1×tanθ(i)+p2=0…(16)

[0154] Therefore, the control device 100 moves the trolley 4 in the transverse direction, measures the trolley position x(i) and the sling swing angle θ(i) at at least 2 locations, fits the obtained trolley position x(i) and sling swing angle θ(i) to the above equation (16) using the least squares method, and calculates the coefficients p1 and p2.

[0155] Furthermore, the control device 100 calculates the minimum trolley position, i.e. the position xp of the sling 9 in the transverse direction, by using the calculated coefficients p1 and p2 through the following formula (17).

[0156] xp=-p2…(17)

[0157] Similarly, at least two main beam positions y(i) and sling swing angles θ(i) are measured in the travel direction of the main beam 3, thereby enabling the calculation of the position yp of the sling swing angle of the suspended weight 9 in the travel direction that minimizes the sling swing angle when the main beam 3 moves.

[0158] The position of the suspended weight is obtained in this way (xp, yp). The control device 100 moves the trolley 4 and the main beam 3 toward the position of the suspended weight, thereby eliminating the horizontal positional deviation between the suspended weight 9 and the trolley 4 and the main beam 3 and suppressing the initial sway.

[0159] As described above, by using the swing angle θ of the tensioned sling 6 as a state quantity, the position of the suspended weight 9 can be determined.

[0160] <Variation Example 3>

[0161] However, when looking at the coefficients of tanθ in equations (15) and (16) above, the height H can be calculated using equation (18).

[0162] H = -p1…(18)

[0163] The control device 100 can calculate the length of the metal wire Lw using the above formula (8) based on the calculated height H and the length of the sling Lr (x=xp) from the trolley 4 to the hook 7 under tension directly above the load 9.

[0164] Based on the above, the ability to automatically obtain the metal wire length Lw improves the performance of cargo sway suppression control during handling based on the trolley 4. Furthermore, the ability to automatically obtain the height H enhances the safety of the crane 1 by automatically setting the lower limit during descent.

[0165]

Example 4

[0166] Next, the crane 1 of Embodiment 4 of the present invention will be described. Furthermore, repeated descriptions of commonalities with the above embodiments are omitted. In addition, the crane 1 and control device 100 of this embodiment are similar to those of Embodiment 3 above. Figure 14It's the same.

[0167] Figure 13 The operation of the crane 1 in Embodiment 4 is illustrated. In this embodiment, the tension of the sling 6 in its taut state and the force acting on the trolley 4 in the horizontal direction are used as state quantities to determine the position of the suspended load.

[0168] The tension of the sling 6 can be detected, for example, by a tension sensor 5b installed in the winch device 5, or by a tension detection unit 311 that calculates the tension of the sling 6 by obtaining the current value of the winch motor from the winch motor control device 310.

[0169] In addition, the force acting on the car 4 in the horizontal direction can be detected by, for example, a force sensor 4a or a horizontal force detection unit 301 that detects the motor current when the car 4 is in a horizontal lateral position.

[0170] When the tension of the sling 6 is set as T(i), the force acting in the horizontal direction relative to the trolley 4 is set as F(i), the position of the trolley is set as x(i), the position of the load 9 is set as xp (or xy), and the height from the load to the trolley 4 is set as H, they become the following relationships (19) and (20).

[0171]

[0172] x(i)-xp=H×tanθ(i)…(20)

[0173] Here, when the height H and the coefficients including the load position xp are set as p1 and p2, it becomes the following equation (21).

[0174] x(i)+p1×tanθ(i)+p2=0…(21)

[0175] Here, the control device 100 moves the trolley 4 in the transverse direction, measures the trolley position x(i) and the tension T(i) of the sling at at least two locations, and the force F(i) acting on the trolley 4 in the horizontal direction. The obtained trolley position x(i), tension T(i), and force F(i) are fitted to the above equation (21) using the least squares method, and the coefficients p1 and p2 are calculated.

[0176] Furthermore, the control device 100 can calculate the position xp of the suspended weight where the swing angle θ(i) is minimized, i.e., the position xp of the suspended weight 9 in the lateral direction, using the following formula (22) based on the calculated coefficient.

[0177] xp=-p2…(22)

[0178] Similarly, the control device 100 also measures at least two main beam positions as y(i), the tension of the sling 6 as T(i), and the force acting in the horizontal direction relative to the trolley 4 as F(i) in the main beam 3's travel direction, and can calculate the position yp of the traveling direction of the load 9 that minimizes the swing angle θ(i) when the main beam 3 moves in the travel direction.

[0179] By moving the trolley 4 and the main beam 3 to the positions (xp, yp) obtained in this way, the horizontal positional deviation between the load 9 and the trolley 4 and the main beam 3 can be eliminated, and the initial sway can be suppressed.

[0180] Based on the above, by using the tension of the sling 6 and the force acting in the horizontal direction relative to the trolley 4 as state variables, the position of the suspended weight 9 can be determined.

[0181] <Variation Example 4>

[0182] Furthermore, in this modified example 4, the metal wire length Lw and height H can be confirmed in the same way as in embodiment 4. It is possible to achieve improved performance in controlling cargo sway during handling due to the automatic acquisition of the metal wire length Lw, and improved safety of crane 1 due to the automatic setting of the lower limit during descent by the automatic acquisition of the height H.

[0183]

Example 5

[0184] Next, the crane 1 of Embodiment 5 of the present invention will be described. Furthermore, repeated descriptions of commonalities with the above embodiments are omitted. In addition, the crane 1 and control device 100 of this embodiment are similar to those of Embodiment 3 above. Figure 14 It's the same.

[0185] In the crane 1 of embodiment 5, when the trolley 4 is moved while the load 9 is on the ground, the sling 6 is released before the trolley 4 moves to prevent the load 9 from floating or being dragged. Furthermore, the control device 100 uses the time from the release of the sling 6 until it is wound up to a tensioned state as a state quantity to confirm the position of the load.

[0186] When the release amount of sling 6 is set as Lf(i), the time for sling 6 to be wound to the tensioned state is set as Tf(i), the winding speed during winding is set as V, the initial sling length when wound to the tensioned state is set as L0, the position of trolley 4 is set as x(i), and the position of the load 9 is set as xp, they become the relationships shown in equations (23) and (24) below. Furthermore, the winding speed V can be calculated by the control device 100 based on the time Tf for sling 6 to be wound to the tensioned state and the change in the sling length L0 when wound to the tensioned state. Additionally, the winding time Tf for sling 6 to be wound to the tensioned state can be measured using a timer included in the control device 100. Furthermore, the sling length L0 can be measured by the encoder 5a in the same way as in Embodiment 1 described above.

[0187] dL(i)=Lf(i)-V×Tf(i)…(23)

[0188]

[0189] When both sides are squared, we get the following equation (25).

[0190] x(i) 2 -2xp×x(i)+xp 2 -L0 2 -2L0×dL(i)-dL(i) 2 +H 2 =0…(25)

[0191] Here, when the sling length L0, height H, and coefficients including the load position xp are set as p1, p2, and p3, it becomes the following equation (26).

[0192] x(i) 2 -dL(i) 2 +p1×x(i)+p2×dL(i)+p3=0…(26)

[0193] Here, the control device 100 moves the trolley 4 in the transverse direction, measures the trolley position x(i) at at least three points, the amount of sling 6 released Lf(i) before the trolley moves, and the time Tf(i) for raising the sling 6 to a tensioned state. The obtained trolley position x(i), release Lf(i), and raising time Tf(i) are used to calculate coefficients p1, p2, and p3 using a least squares fitting formula (25). Furthermore, the control device 100 uses the calculated coefficients to calculate the position xp in the transverse direction where dL is maximized, i.e., the position of the suspended weight, using the following formula (27).

[0194]

[0195] Similarly, the control device 100 also measures at least three main beam positions y(i) and the amount of sling 6 released before the main beam 3 moves, Lf(i), and the time Tf(i) to wind the sling 6 to tension in the direction of travel of the main beam 3, thereby calculating the position yp of the direction of travel in which dL of the main beam 3 moves in the direction of travel when the maximum load 9 is reached.

[0196] The control device 100 moves the trolley 4 and the main beam 3 to the positions (xp, yp) of the load 9 obtained in this way, thereby eliminating the horizontal positional deviation between the load 9 and the trolley 4 and the main beam 3 and suppressing the initial sway.

[0197] Based on the above, by using the amount of sling 6 released before the movement of the trolley 4 and the time it takes to wind the sling 6 to a tensioned state as state parameters, the position of the suspended weight 9 can be determined.

[0198] <Variation Example 5>

[0199] However, when looking at the coefficients and constant terms of dL(i) in equations (24) and (25) above, the height H can be calculated using equations (28) and (29) below.

[0200]

[0201]

[0202] The control device 100 can calculate the length of the metal wire Lw using the above formula (8) based on the calculated height H and the sling length Lr (x=xp) from the trolley 4 to the hook 7 under tension when the trolley 4 is directly above the load 9.

[0203] Based on the above, the ability to automatically obtain the metal wire length Lw improves the performance of cargo sway control during handling. Furthermore, the ability to automatically obtain the height H enhances the safety of crane 1 by automatically setting the lower limit during descent.

[0204] As described in Examples 1 to 5 above, the present invention is effective for all types of cranes 1 capable of moving the load 9 horizontally. It can be applied to cranes 1 that utilize the trolley 4 and main beam 3 to move the load 9 laterally and travel laterally (e.g., overhead mobile cranes), and also to cranes that only move laterally or travel laterally (e.g., unloaders). That is, the term "crane" as used below encompasses all types of cranes capable of moving the load 9 horizontally.

[0205] In addition, the goods (lifted loads) transported by the crane 1 are suspended by slings 6 or chains, etc. However, in this invention, there are no limitations on any hanging device (suspension component) that can be used to suspend goods, and of course, there are no limitations on the type of material or shape.

[0206] Therefore, as mentioned above, the term "sling" is used as a general term for slinging equipment (suspension components) used to suspend goods. That is, "sling" includes not only so-called slings, but also chains, belts, metal wires, cables, ropes, cords, etc.

[0207] <Summary>

[0208] As described above, the scope of the request in the above embodiments includes the following configuration.

[0209] (1) A crane comprising: a horizontal moving device (trolley 4) having an electric motor and capable of moving horizontally; a winch device (5) mounted on the horizontal moving device (4) having a winch electric motor capable of lifting a sling (6); a hook (7) mounted on the sling (6) for suspending a load (9); and a control unit (control device 100) having a processor (MPU 101) and a memory (102) for controlling the horizontal moving device (4) and the winch device (5), characterized in that: the control unit (100) has: a sling tension determination unit (21) for determining whether the sling (6) is not slack. The crane has a state measurement unit (22) that measures the state quantity of the crane when the hoisting device (5) is driven to raise the sling (6) to the tensioned state; and a travel control unit (24) that moves the horizontal moving device (4). The state measurement unit (22) confirms the position of the load (9) by using the position of the horizontal moving device (4) with the sling (6) in the tensioned state and the state quantity measurement results when the load (9) is on the ground. The travel control unit (24) moves the horizontal moving device (4) to the confirmed position of the load (9) and positions the sling (6) directly above the load (9).

[0210] Through the above structure, the control device 100 fits the trolley positions x(1), x(2) and the tensioned cable lengths L(1), L(2) to the [structure described above]. Figure 8 The quadratic curve shown allows for more precise determination of the position of the suspended weight 9, thus reducing positional deviations.

[0211] (2) The crane described in (1) above is characterized in that: the state quantity is the distance L from the horizontal moving device (4) to the suspended load (9) when the sling (6) is wound to a tensioned state; the state measuring unit (22) uses a first sensor (encoder 5a) installed on the horizontal moving device (4) to measure the position x of the horizontal moving device (4) and the distance L from the horizontal moving device (4) to the suspended load (9) at at least two points in the moving direction, and uses the measurement results for x 2 -L 2 +p1×x+p2=0 Calculate the above coefficients p1 and p2, and calculate the position of the above horizontal moving device (4) with the minimum distance L from the calculated coefficients p1 and p2 as the position xp of the above suspended weight (9).

[0212] Based on the above structure, the control device 100 of Embodiment 1 only needs to perform the tensioning of the lifting cable 6 of the trolley 4, the measurement of the cable length L, and the movement of the trolley 4 (or the main beam 3) in the lateral and traveling directions at least twice, which can reduce the number of repetitions and thus shorten the action time of the trolley 4 before ground separation, and shorten the time until ground separation.

[0213] (3) The crane described in (1) above is characterized in that: the sling (6) is equipped with the hook (7) at its end, and a suspension member for suspending the load (9) is installed on the hook (7); the state quantity is the length of the sling (6) when the sling (6) is wound up to a tensioned state; the state measurement unit (22) uses a first sensor (5a) provided on the horizontal moving device (4) to measure the position x of the horizontal moving device (4) and the length Lr of the sling (6) at at least three points in the moving direction, and uses the measurement results for x 2 -Lr 2 +p1×x+p2×Lr+p3=0 Calculate the above coefficients p1, p2, p3, and calculate the length Lr of the above sling (6) based on the calculated above coefficients p1, p2, p3. The position of the above horizontal moving device (4) with the minimum value is taken as the position xp of the above suspended weight (9).

[0214] Based on the above structure, the control device 100 can automatically obtain the length Lw of the metal wire, and can confirm the position of the weight 9 even if the distance from the hook 7 to the weight 9, that is, the distance including the length Lw of the metal wire, is unknown.

[0215] (4) The crane described in (1) above is characterized in that: the state quantity is the swing angle (θ) of the sling (6) relative to the horizontal moving device (4) when the sling (6) is wound to a tensioned state; the state measuring unit (22) uses a second sensor (swing angle sensor 7a) provided on the horizontal moving device (4) to measure the position x of the horizontal moving device (4) and the swing angle θ of the sling (6) at at least two points in the moving direction; and uses the measurement results to calculate coefficients p1 and p2 for x+p1×tanθ+p2=0; and calculates the position of the horizontal moving device (4) where the swing angle θ is minimized by the calculated coefficients p1 and p2 as the position xp of the suspended weight (9).

[0216] According to the above structure, the control device 100 uses the swing angle θ of the tensioned sling 6 as a state quantity to confirm the position of the load 9, and moves the trolley 4 and the main beam 3 toward the position of the load. This can eliminate the horizontal positional deviation between the load 9 and the trolley 4 and the main beam 3, and suppress the initial swing.

[0217] (5) The crane described in (1) above is characterized in that: the state quantity is the tension of the sling (6) when the sling (6) is wound to a tensioned state, and the force acting in the horizontal direction relative to the horizontal moving device (4). The state measuring unit (22) uses the third sensor (tension sensor 5b) provided on the hoisting device (5) to measure the position x of the horizontal moving device (4) and the tension T of the sling (6) at at least two points in the moving direction. The fourth sensor (horizontal force detection unit 301) provided on the horizontal moving device (4) measures the force F acting in the horizontal direction. The swing angle θ of the sling (6) is calculated from the measurement results according to θ = arcsin(F / T). The swing angle θ is used to calculate coefficients p1 and p2 using x + p1 × tanθ + p2 = 0. The position of the horizontal moving device (4) with the swing angle θ being the smallest calculated from the coefficients p1 and p2 is taken as the position xp of the load (9).

[0218] According to the above structure, the control device 100 uses the tension of the sling 6 and the force acting in the horizontal direction relative to the trolley 4 as state quantities to confirm the position of the load 9, which can eliminate the horizontal positional deviation between the load 9 and the trolley 4 and the main beam 3, and can suppress the initial sway.

[0219] (6) The crane described in (1) above is characterized in that: the state quantity is the length Lf of the sling (6) released before the horizontal moving device (4) moves and the time Tf until the sling (6) is wound up to the tensioned state; the state measuring unit (22) measures the position x of the horizontal moving device (4), the length Lf of the released sling (6), and the time Tf until the sling (6) is wound up to the tensioned state at at least 3 locations; the winding speed V of the sling (6) is calculated from the change t of the length Lf of the released sling (6) and the time Tf until the sling (6) is wound up to the tensioned state; and the measurement results are used for dL=Lf-V×Tf and x. 2 -dL 2 +p1×x+p2×dL+p3=0 Calculate the coefficients p1, p2, p3, and calculate the position of the horizontal moving device (4) with the minimum dL calculated from the above-mentioned coefficients p1, p2, p3 as the position xp of the above-mentioned load (9).

[0220] According to the above structure, the control device 100 uses the amount of the sling 6 released before the movement of the trolley 4 and the time until the sling 6 is wound up to the tension state as state quantities, which can confirm the position of the load 9. By moving the trolley 4 and the main beam 3 toward the position (xp, yp) of the load 9, the horizontal positional deviation between the load 9 and the trolley 4 and the main beam 3 can be eliminated, and the initial swing can be suppressed.

[0221] (7) The crane described in any one of (1) to (6) above is characterized in that: the state measurement unit (22) determines the height H from the suspended weight (9) to the horizontal moving device (4) based on the state quantity and the position x of the horizontal moving device (4).

[0222] Based on the above structure, the control device 100 can also automatically obtain the height H from the load 9 to the trolley 4, automatically set the lower limit during descent, prevent accidental collision between the load and the ground or the metal wire from slackening and falling off the hook due to excessive descent, and improve the safety of the crane 1.

[0223] (8) The crane described in (7) above is characterized in that: based on the state quantity and the position x of the horizontal moving device (4), the height H from the load (9) to the horizontal moving device (4) is determined, and the length Lw of the suspension component is determined based on the length Lr of the sling (6) and the height H.

[0224] Based on the above structure, the control device 100 can automatically obtain the length Lw of the metal wire, thereby improving the performance of the control over the suppression of cargo swaying during handling. In addition, the height H can also be obtained automatically.

[0225] (9) The crane described in (3) above is characterized in that: the length Lw of the suspension component is determined based on the state quantity and the position x of the horizontal moving device (4).

[0226] Based on the above structure, the control device 100 can automatically obtain the length Lw of the metal wire, thereby improving the performance of the control over the suppression of cargo swaying during handling.

[0227] Furthermore, the present invention is not limited to the embodiments described above, but includes various modifications. For example, the embodiments described above are detailed descriptions for easier understanding of the present invention and are not limited to having all the structures described. Additionally, a portion of the structure of one embodiment can be replaced with the structure of another embodiment, and the structure of another embodiment can be added to the structure of one embodiment. Furthermore, any addition, deletion, or replacement of other structures with respect to a portion of the structure of each embodiment can be performed individually or in combination.

[0228] Furthermore, some or all of the aforementioned structures, functions, processing units, and processing methods can be implemented in hardware, for example, by designing with integrated circuits. Alternatively, the aforementioned structures and functions can be implemented in software by a processor interpreting and executing the programs that implement each function. Information such as programs, tables, and files that implement each function can be stored in a memory, a recording device such as a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD.

[0229] Furthermore, control lines and information lines represent the control lines and information lines that are considered necessary in the specifications, but may not represent all the control lines or information lines that are necessary on the product. In fact, it should be assumed that almost all structures are interconnected.

Claims

1. A crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; and A control unit having a processor and memory controls the horizontal moving device and the hoisting device. The crane is characterized in that: The control unit has: The sling tension determination unit determines whether the sling is in a tensioned state without slack. A state measurement unit measures the state of the crane when the hoisting device is driven to raise the sling to the tensioned state; and The walking control unit that moves the horizontal moving device. The state measurement unit, with the load on the ground, uses the position x of the horizontal moving device where the sling is in a taut state and the measurement result of the state quantity to confirm the position xp of the load. The walking control unit moves the horizontal movement device toward the confirmed load position xp, thereby positioning the sling directly above the load. The state quantity is the distance L from the horizontal moving device to the suspended weight when the sling is wound to a tensioned state. The state measurement unit, The position x of the horizontal moving device and the distance L from the horizontal moving device to the suspended load are measured at at least two points in the direction of movement using a first sensor installed on the horizontal moving device. use the measurement result for x 2 -L 2 + p1 x x + p2 = 0 calculate coefficients p1, p2, and calculate the position x of the horizontal movement device for which the distance L becomes smallest from the calculated coefficients p1, p2 as the load position xp.

2. A crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; and A control unit having a processor and memory controls the horizontal moving device and the hoisting device. The crane is characterized in that: The control unit has: The sling tension determination unit determines whether the sling is in a tensioned state without slack. A state measurement unit measures the state of the crane when the hoisting device is driven to raise the sling to the tensioned state; and The walking control unit that moves the horizontal moving device. The state measurement unit, with the load on the ground, uses the position x of the horizontal moving device where the sling is in a taut state and the measurement result of the state quantity to confirm the position xp of the load. The walking control unit moves the horizontal movement device toward the confirmed load position xp, thereby positioning the sling directly above the load. The sling has a hook installed at one end, and a suspension component for suspending the load is installed on the hook. The state quantity is the length Lr of the sling when the sling is wound up to a tensioned state. The state measurement unit uses a first sensor installed on the horizontal moving device to measure the position x of the horizontal moving device and the length Lr of the sling at at least three points in the direction of movement. The measurement result is used for x 2 -Lr 2 +p1x + p2x Lr + p3 = 0 to calculate coefficients p1, p2, p3, and to calculate the position x of the horizontal movement device, at which the length Lr of the sling is smallest, as the load position xp from the calculated coefficients p1, p2, p3.

3. A crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; and A control unit having a processor and memory controls the horizontal moving device and the hoisting device. The crane is characterized in that: The control unit has: The sling tension determination unit determines whether the sling is in a tensioned state without slack. A state measurement unit measures the state of the crane when the hoisting device is driven to raise the sling to the tensioned state; and The walking control unit that moves the horizontal moving device. The state measurement unit, with the load on the ground, uses the position x of the horizontal moving device where the sling is in a taut state and the measurement result of the state quantity to confirm the position xp of the load. The walking control unit moves the horizontal movement device toward the confirmed load position xp, thereby positioning the sling directly above the load. The state quantity is the swing angle θ of the sling relative to the horizontal moving device when the sling is wound to a tensioned state. The state measurement unit uses a second sensor installed on the horizontal moving device to measure the position x of the horizontal moving device and the swing angle θ of the sling at at least two points in the direction of movement. The measurement results are used to calculate coefficients p1 and p2 using x + p1 × tanθ + p2 = 0, and the position x of the horizontal moving device where the swing angle θ is minimized is calculated from the calculated coefficients p1 and p2 as the load-bearing position xp.

4. A crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; and A control unit having a processor and memory controls the horizontal moving device and the hoisting device. The crane is characterized in that: The control unit has: The sling tension determination unit determines whether the sling is in a tensioned state without slack. A state measurement unit measures the state of the crane when the hoisting device is driven to raise the sling to the tensioned state; and The walking control unit that moves the horizontal moving device. The state measurement unit, with the load on the ground, uses the position x of the horizontal moving device where the sling is in a taut state and the measurement result of the state quantity to confirm the position xp of the load. The walking control unit moves the horizontal movement device toward the confirmed load position xp, thereby positioning the sling directly above the load. The state quantities are the tension T of the sling when it is wound up to a tensioned state, and the force F acting in the horizontal direction relative to the horizontal moving device. The state measurement unit uses a third sensor installed on the horizontal moving device to measure the position x of the horizontal moving device and the tension T of the sling at at least two points in the moving direction, and uses a fourth sensor installed on the horizontal moving device to measure the force F acting in the horizontal direction. The swing angle θ of the sling is calculated based on the measurement result according to θ=arcsin(F / T), and then used to calculate coefficients p1 and p2 using x+p1×tanθ+p2=0. The position x of the horizontal moving device with the swing angle θ minimized by the calculated coefficients p1 and p2 is taken as the position xp of the suspended weight.

5. A crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; and A control unit having a processor and memory controls the horizontal moving device and the hoisting device. The crane is characterized in that: The control unit has: The sling tension determination unit determines whether the sling is in a tensioned state without slack. A state measurement unit measures the state of the crane when the hoisting device is driven to raise the sling to the tensioned state; and The walking control unit that moves the horizontal moving device. The state measurement unit, with the load on the ground, uses the position x of the horizontal moving device where the sling is in a taut state and the measurement result of the state quantity to confirm the position xp of the load. The walking control unit moves the horizontal movement device toward the confirmed load position xp, thereby positioning the sling directly above the load. The state quantity is the length Lf of the sling released before the horizontal moving device moves and the time Tf from when the sling is wound up to the tensioned state. The state measurement unit measures the position x of the horizontal moving device, the length Lf of the released sling, and the time Tf until the sling is wound up to the tensioned state at at least three locations. The winding speed V of the sling is calculated from the change t of the length Lf of the released sling and the time Tf until the sling is wound up to the tensioned state. using the measurement results for dL = Lf - V x Tf and x 2 -dL 2 + p1 x x + p2 x dL + p3 = 0 calculating coefficients p1, p2, p3, calculating the position x of the horizontal moving device for which the dL becomes the smallest from the calculated coefficients p1, p2, p3 as the suspended weight position xp.

6. The crane as described in claim 2, characterized in that: The state measurement unit determines the height H from the suspended weight to the horizontal moving device based on the state quantity and the position x of the horizontal moving device.

7. The crane as described in claim 6, characterized in that: Based on the state quantity and the position x of the horizontal moving device, the height H from the suspended weight to the horizontal moving device is determined, and the length Lw of the suspension component is determined according to the length Lr of the sling and the height H.

8. The crane as described in claim 2, characterized in that: Based on the state quantity and the position x of the horizontal moving device, the length Lw of the suspension component is determined.

9. A method for controlling a crane, the crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; The crane control method, characterized by a control unit having a processor and a memory for controlling the horizontal moving device and the hoisting device, comprises: The sling tension determination step involves the control unit determining whether the sling is in a tensioned state without slack. In the state measurement step, the control unit measures the state quantity of the crane when the hoisting device is driven to raise the sling to the tensioned state; and In the walking control step, the control unit moves the horizontal movement device. In the state measurement step, with the load on the ground, the position xp of the load is confirmed using the position x of the horizontal moving device with the sling in a taut state and the measurement result of the state quantity. In the walking control step, the horizontal movement device is moved towards the confirmed position of the suspended load, positioning the sling directly above the suspended load. The state quantity is the distance L from the horizontal moving device to the suspended weight when the sling is wound to a tensioned state. In the state measurement step, the position x of the horizontal moving device and the distance L from the horizontal moving device to the suspended load are measured at at least two points in the direction of movement using a first sensor installed on the horizontal moving device. Use the measurement results for x 2 -L 2 The coefficients p1 and p2 are calculated by adding p1×x+p2=0, and the position x of the horizontal moving device that minimizes the distance L is calculated from the calculated coefficients p1 and p2 as the load position xp.

10. A method for controlling a crane, the crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; The crane control method, characterized by a control unit having a processor and a memory for controlling the horizontal moving device and the hoisting device, comprises: The sling tension determination step involves the control unit determining whether the sling is in a tensioned state without slack. In the state measurement step, the control unit measures the state quantity of the crane when the hoisting device is driven to raise the sling to the tensioned state; and In the walking control step, the control unit moves the horizontal movement device. In the state measurement step, with the load on the ground, the position xp of the load is confirmed using the position x of the horizontal moving device with the sling in a taut state and the measurement result of the state quantity. In the walking control step, the horizontal movement device is moved towards the confirmed position of the suspended load, positioning the sling directly above the suspended load. The sling has a hook installed at one end, and a suspension component for suspending the load is installed on the hook. The state quantity is the length Lr of the sling when the sling is wound up to a tensioned state. In the state measurement step, the position x of the horizontal moving device and the length Lr of the sling are measured at at least three points in the direction of movement using a first sensor installed on the horizontal moving device. Use the measurement results for x 2 -Lr 2 The coefficients p1, p2, and p3 are calculated by adding p1×x+p2×Lr+p3=0, and the length Lr of the sling is calculated from the calculated coefficients p1, p2, and p3. The position x of the horizontal moving device that is minimized is taken as the load position xp.

11. A method for controlling a crane, the crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; The crane control method, characterized by a control unit having a processor and a memory for controlling the horizontal moving device and the hoisting device, comprises: The sling tension determination step involves the control unit determining whether the sling is in a tensioned state without slack. In the state measurement step, the control unit measures the state quantity of the crane when the hoisting device is driven to raise the sling to the tensioned state; and In the walking control step, the control unit moves the horizontal movement device. In the state measurement step, with the load on the ground, the position xp of the load is confirmed using the position x of the horizontal moving device with the sling in a taut state and the measurement result of the state quantity. In the walking control step, the horizontal movement device is moved towards the confirmed position of the suspended load, positioning the sling directly above the suspended load. The state quantity is the swing angle θ of the sling relative to the horizontal moving device when the sling is wound to a tensioned state. In the state measurement step, the position x of the horizontal moving device and the swing angle θ of the sling are measured at at least two points in the direction of movement using a second sensor installed on the horizontal moving device. The measurement results are used to calculate coefficients p1 and p2 using x + p1 × tanθ + p2 = 0, and the position x of the horizontal moving device where the swing angle θ is minimized is calculated from the calculated coefficients p1 and p2 as the load-bearing position xp.

12. A method for controlling a crane, the crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; The crane control method, characterized by a control unit having a processor and a memory for controlling the horizontal moving device and the hoisting device, comprises: The sling tension determination step involves the control unit determining whether the sling is in a tensioned state without slack. In the state measurement step, the control unit measures the state quantity of the crane when the hoisting device is driven to raise the sling to the tensioned state; and In the walking control step, the control unit moves the horizontal movement device. In the state measurement step, with the load on the ground, the position xp of the load is confirmed using the position x of the horizontal moving device with the sling in a taut state and the measurement result of the state quantity. In the walking control step, the horizontal movement device is moved towards the confirmed position of the suspended load, positioning the sling directly above the suspended load. The state quantities are the tension T of the sling when it is wound up to a tensioned state, and the force F acting in the horizontal direction relative to the horizontal moving device. In the state measurement step, the position x of the horizontal moving device, the tension T of the sling, and the force F acting in the horizontal direction are measured at at least two points in the moving direction using a third sensor installed on the horizontal moving device. The swing angle θ of the sling is calculated based on the measurement result according to θ=arcsin(F / T), and then used to calculate coefficients p1 and p2 using x+p1×tanθ+p2=0. The position x of the horizontal moving device with the swing angle θ minimized by the calculated coefficients p1 and p2 is taken as the position xp of the suspended weight.

13. A method for controlling a crane, the crane comprising: A horizontally moving device equipped with an electric motor, capable of moving in the horizontal direction; A winch device equipped with a winch motor capable of winding slings, mounted on the horizontal moving device; A hook installed on the sling for suspending the load; The crane control method, characterized by a control unit having a processor and a memory for controlling the horizontal moving device and the hoisting device, comprises: The sling tension determination step involves the control unit determining whether the sling is in a tensioned state without slack. In the state measurement step, the control unit measures the state quantity of the crane when the hoisting device is driven to raise the sling to the tensioned state; and In the walking control step, the control unit moves the horizontal movement device. In the state measurement step, with the load on the ground, the position xp of the load is confirmed using the position x of the horizontal moving device with the sling in a taut state and the measurement result of the state quantity. In the walking control step, the horizontal movement device is moved towards the confirmed position of the suspended load, positioning the sling directly above the suspended load. The state quantity is the length Lf of the sling released before the horizontal moving device moves and the time Tf from when the sling is wound up to the tensioned state. In the state measurement step, the position x of the horizontal moving device, the length Lf of the released sling, and the time Tf until the sling is wound up to the tensioned state are measured at at least three points. The winding speed V of the sling is calculated from the change t of the length Lf of the released sling and the time Tf until the sling is wound up to the tensioned state. The measurement results are used in dL=Lf-V×Tf and x 2 -dL 2 The coefficients p1, p2, and p3 are calculated by adding p1×x, p2×dL, and p3=0. The position x of the horizontal moving device that minimizes dL based on the calculated coefficients p1, p2, and p3 is taken as the position xp of the suspended load.

14. The crane control method as described in claim 10, characterized in that: In the state measurement step, the height H from the suspended weight to the horizontal moving device is determined based on the state quantity and the position x of the horizontal moving device.

15. The crane control method as described in claim 14, characterized in that: Based on the state quantity and the position x of the horizontal moving device, the height H from the suspended weight to the horizontal moving device is determined, and the length Lw of the suspension component is determined according to the length Lr of the sling and the height H.

16. The crane control method as described in claim 10, characterized in that: Based on the state quantity and the position x of the horizontal moving device, the length Lw of the suspension component is determined.

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