Method and system for measuring rotation angle of lifting appliance based on displacement sensor

Abstract

The invention discloses a method and system for measuring the rotation angle of a lifting appliance based on a displacement sensor, and the method comprises the following steps: installing the displacement sensor at a lifting appliance twisting execution mechanism, and enabling the displacement sensor and the lifting appliance twisting execution mechanism to be coaxially arranged; the displacement sensors are used for measuring the real-time lengths of the first steel wire rope, the second steel wire rope, the third steel wire rope and the fourth steel wire rope; and fitting the relationship between the real-time length variation of the steel wire ropes and the real-time angle of the lifting appliance, and establishing a multivariate function model containing the real-time lengths of the first steel wire rope, the second steel wire rope, the third steel wire rope and the fourth steel wire rope. According to the method for measuring the rotating angle of the lifting appliance based on the displacement sensor, accurate measurement of the rotating angle of the lifting appliance is achieved, and the working efficiency and accuracy of an automatic crane are improved.

Description

Technical Field

[0001] The present application relates to the field of hoisting system transportation, and in particular to a method and system for measuring the rotation angle of a hoist based on a displacement sensor. Background Art

[0002] During automated yard lifting operations, a crane uses a spreader to grab and release containers. To ensure the spreader's alignment with the target container, the spreader's front, back, left, and right positions, as well as its angle, must be adjusted. Traditional spreaders are suspended from a trolley using four steel cables, and angle adjustment is accomplished by adjusting the cables on the same side.

[0003] However, because the spreader is connected to the trolley via a flexible structure called a wire rope, it inevitably twists when adjusting the spreader angle, making it difficult to accurately determine the spreader angle. This is especially true in automated crane systems. While the system can sense the spreader angle in real time, it cannot eliminate twisting, causing the spreader angle to fluctuate around the target angle.

[0004] Therefore, it is necessary to provide a method and system for measuring the rotation angle of a sling based on a displacement sensor to solve the above problems. Summary of the Invention

[0005] The present application provides a method and system for measuring the rotation angle of a spreader based on a displacement sensor, so as to achieve accurate measurement of the rotation angle of the spreader and improve the efficiency and accuracy of automated crane operations.

[0006] In a first aspect, the present application provides a method for measuring the rotation angle of a spreader based on a displacement sensor, the method comprising the following steps:

[0007] A displacement sensor is installed at the spreader torsion actuator, wherein the displacement sensor and the spreader torsion actuator are coaxially arranged;

[0008] Using the displacement sensor to measure the real-time lengths of the first steel rope, the second steel rope, the third steel rope, and the fourth steel rope;

[0009] The relationship between the real-time length change of the wire rope and the real-time angle of the spreader is fitted, and a multivariate function model including the real-time lengths of the first wire rope, the second wire rope, the third wire rope, and the fourth wire rope is established.

[0010] Preferably, the real-time length change of the steel wire rope is the real-time length change of the first steel wire rope or the second steel wire rope.

[0011] Preferably, the expression of the multivariate function model is as follows:

[0012] θ=f(Δx,l1,l2,l3,l4)+θ0

[0013] Wherein, θ is the sling angle, Δx is the real-time length change of the first or second wire rope, l1, l2, l3, and l4 are the real-time lengths of the first, second, third, and fourth wire ropes, respectively, θ0 is the initial angle of the sling, and f is the multivariate function mapping relationship.

[0014] Preferably, the multivariate function mapping relationship is obtained by fitting experimental data using the least squares method.

[0015] Preferably, the displacement sensor is a linear encoder, and the displacement sensor includes a single-point laser displacement sensor and a pull-wire sensor.

[0016] In a second aspect, the present application further provides a system for measuring the rotation angle of a spreader based on a displacement sensor, the system comprising:

[0017] A displacement sensor is installed at the spreader torsion actuator, wherein the displacement sensor and the spreader torsion actuator are coaxially arranged;

[0018] A steel wire rope real-time length measurement module, which is used to measure the real-time lengths of the first steel wire rope, the second steel wire rope, the third steel wire rope, and the fourth steel wire rope using the displacement sensor;

[0019] A multivariate function model establishment module is used to fit the relationship between the real-time length change of the wire rope and the real-time angle of the sling, and establish a multivariate function model including the real-time lengths of the first wire rope, the second wire rope, the third wire rope, and the fourth wire rope.

[0020] Preferably, the real-time length change of the steel wire rope is the real-time length change of the first steel wire rope or the second steel wire rope.

[0021] Preferably, the expression of the multivariate function model is as follows:

[0022] θ=f(Δx,l1,l2,l3,l4)+θ0

[0023] Wherein, θ is the sling angle, Δx is the real-time length change of the first or second wire rope, l1, l2, l3, and l4 are the real-time lengths of the first, second, third, and fourth wire ropes, respectively, θ0 is the initial angle of the sling, and f is the multivariate function mapping relationship.

[0024] Preferably, the multivariate function mapping relationship is obtained by fitting experimental data using the least squares method.

[0025] Preferably, the displacement sensor is a linear encoder, and the displacement sensor includes a single-point laser displacement sensor and a pull-wire sensor.

[0026] Compared with the prior art, the present application has the following beneficial effects: the present application provides a method and system for measuring the rotation angle of a sling based on a displacement sensor, the method comprising the following steps: installing a displacement sensor at a sling torsion actuator, wherein the displacement sensor and the sling torsion actuator are coaxially arranged; using the displacement sensor to measure the real-time length of a first steel wire rope, a second steel wire rope, a third steel wire rope, and a fourth steel wire rope; fitting the relationship between the real-time length change of the steel wire rope and the real-time angle of the sling, and establishing a multivariate function model including the real-time lengths of the first steel wire rope, the second steel wire rope, the third steel wire rope, and the fourth steel wire rope, so as to achieve accurate measurement of the rotation angle of the sling and improve the efficiency and accuracy of automated crane operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0028] Figure 1 This is a flow chart of a method for measuring the rotation angle of a spreader based on a displacement sensor in an embodiment of the present application;

[0029] Figure 2 This is a structural diagram of a system for measuring the rotation angle of a spreader based on a displacement sensor in an embodiment of the present application;

[0030] Figure 3 This is another structural schematic diagram of a system for measuring the rotation angle of a sling based on a displacement sensor in an embodiment of the present application.

[0031] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0032] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0033] In order to solve the above problems, the embodiments provided in this application provide a method and system for measuring the rotation angle of a sling based on a displacement sensor, so as to achieve accurate measurement of the rotation angle of the sling and improve the efficiency and accuracy of automated crane operations.

[0034] Figure 1 This is a flow chart of a method for measuring the rotation angle of a sling based on a displacement sensor in an embodiment of the present application. Figure 1 An embodiment of the present invention provides a method for measuring the rotation angle of a spreader based on a displacement sensor, the method comprising the following steps:

[0035] Step S101: installing a displacement sensor at a spreader torsion actuator, wherein the displacement sensor and the spreader torsion actuator are coaxially arranged;

[0036] Step S102: using the displacement sensor to measure the real-time lengths of the first steel rope, the second steel rope, the third steel rope, and the fourth steel rope;

[0037] Step S103: fitting the relationship between the real-time length change of the wire rope and the real-time angle of the spreader, and establishing a multivariate function model including the real-time lengths of the first wire rope, the second wire rope, the third wire rope, and the fourth wire rope.

[0038] Specifically, the displacement sensor and the spreader's torsion actuator are coaxially mounted to ensure that changes in wire rope length are fully synchronized with changes measured by the displacement sensor. The displacement sensor must be installed so that its axis of motion aligns with the direction of wire rope length change, directly capturing the actual length change Δx of the first and second wire ropes. The sensor's output signal is connected to a data processing module, transmitting real-time data with an accuracy of no less than 0.1 mm. The results can be displayed or transmitted to the crane's control system.

[0039] By installing the displacement sensor at the spreader's torsion actuator and making it coaxial with the spreader's torsion actuator, the measurement deviation caused by mechanical structure gap or transmission error in the traditional installation method is eliminated, ensuring that the change in wire rope length Δx is completely consistent with the displacement sensor measurement value, thereby improving the accuracy of the original data.

[0040] In a specific implementation, the real-time length change of the steel wire rope is the real-time length change of the first steel wire rope or the second steel wire rope.

[0041] In a specific implementation, the expression of the multivariate function model is as follows:

[0042] θ=f(Δx,l1,l2,l3,l4)+θ0

[0043] Wherein, θ is the sling angle, Δx is the real-time length change of the first or second wire rope, l1, l2, l3, and l4 are the real-time lengths of the first, second, third, and fourth wire ropes, respectively, θ0 is the initial angle of the sling, and f is the multivariate function mapping relationship.

[0044] The multivariate function model comprehensively reflects the impact of changes in spreader height and wear of a single wire rope on the angle, improving the universality of the model.

[0045] The length of the first, second, third, and fourth wire ropes is approximately 20 meters, and the measurement accuracy must reach the centimeter level. High-precision length measuring instruments, such as laser rangefinders, can be used to measure the length of the wire ropes before operation or regularly.

[0046] In a specific implementation, the multivariate function mapping relationship is obtained by fitting experimental data using the least squares method.

[0047] In a specific implementation, the displacement sensor is a linear encoder, and the displacement sensor includes a single-point laser displacement sensor and a pull-wire sensor.

[0048] The use of linear encoders such as single-point laser displacement sensors and rope sensors with millimeter-level accuracy breaks through the accuracy limitations of traditional measurement methods. The accuracy can be improved to the millimeter level, providing more accurate basic data for angle fitting.

[0049] Figure 2 This is a structural diagram of a system for measuring the rotation angle of a spreader based on a displacement sensor in an embodiment of the present application; Figure 3 This is another structural diagram of a system for measuring the rotation angle of a sling based on a displacement sensor in an embodiment of the present application. Figure 2 and Figure 3 The embodiment of the present invention further provides a system for measuring the rotation angle of a spreader based on a displacement sensor, the system comprising:

[0050] A displacement sensor 21 is mounted on the spreader torsion actuator 35, wherein the displacement sensor 21 and the spreader torsion actuator 35 are coaxially arranged;

[0051] A steel wire rope real-time length measurement module 22 is configured to use the displacement sensor 21 to measure the real-time lengths of the first steel wire rope 31 , the second steel wire rope 32 , the third steel wire rope 33 , and the fourth steel wire rope 34 ;

[0052] The multivariate function model establishment module 23 is used to fit the relationship between the real-time length change of the wire rope and the real-time angle of the sling, and establish a multivariate function model including the real-time lengths of the first wire rope 31, the second wire rope 32, the third wire rope 33, and the fourth wire rope 34.

[0053] In a specific implementation, the real-time length change of the steel wire rope is the real-time length change of the first steel wire rope 31 or the second steel wire rope 32 .

[0054] In a specific implementation, the expression of the multivariate function model is as follows:

[0055] θ=f(Δx,l1,l2,l3,l4)+θ0

[0056] Among them, θ is the angle of the sling, Δx is the real-time length change of the first wire rope 31 or the second wire rope 32, l1, l2, l3, l4 are the real-time lengths of the first wire rope 31, the second wire rope 32, the third wire rope 33, and the fourth wire rope 34 respectively, θ0 is the initial angle of the sling, and f is the multivariate function mapping relationship.

[0057] In a specific implementation, the multivariate function mapping relationship is obtained by fitting experimental data using the least squares method.

[0058] In a specific implementation, the displacement sensor 21 is a linear encoder, and the displacement sensor 21 includes a single-point laser displacement sensor and a pull-wire sensor.

[0059] The following is an example of a method and system for measuring the rotation angle of a spreader based on a displacement sensor:

[0060] A pull-rope displacement sensor with an accuracy of 0.1mm is coaxially installed at the axis of the spreader's torsion actuator. The pull-rope end of the sensor is fixedly connected to the movable end of the first wire rope. When the first wire rope is extended and the second wire rope is shortened, the pull-rope sensor moves synchronously with the spreader's torsion actuator and directly measures Δx (Δx A =-Δx B The spreader twisting actuator may be, for example, a wire rope guide wheel or a connecting shaft.

[0061] Before the operation, a laser rangefinder was used to measure the lengths of the first, second, third and fourth steel ropes, and the results showed that the length of the first steel rope was l1 = 20.00 m, the length of the second steel rope was l2 = 20.00 m, the length of the third steel rope was l3 = 20.00 m, and the length of the fourth steel rope was l4 = 20.00 m. The initial angle of the sling was θ0 = 0°.

[0062] The crane system controls the first wire rope to extend by 10 cm (Δx = +0.1 m) and the second wire rope to shorten by 10 cm (Δx = -0.1 m). The displacement sensor outputs data of Δx = 0.1 m in real time. The real-time length of the first wire rope is l1 = 20.1 m, the real-time length of the second wire rope is l2 = 19.9 m, and the real-time lengths of the third and fourth wire ropes are l3 = l4 = 20.00 m.

[0063] The system dynamically adjusts the wire rope length based on the difference between the calculated angle and the target angle until the spreader angle reaches the preset value.

[0064] In summary, the embodiments of the present application provide a method and system for measuring the rotation angle of a sling based on a displacement sensor, and the method includes the following steps: installing a displacement sensor at a sling torsion actuator, wherein the displacement sensor and the sling torsion actuator are coaxially arranged; using the displacement sensor to measure the real-time length of a first steel wire rope, a second steel wire rope, a third steel wire rope, and a fourth steel wire rope; fitting the relationship between the real-time length change of the steel wire rope and the real-time angle of the sling, and establishing a multivariate function model including the real-time length of the first steel wire rope, the second steel wire rope, the third steel wire rope, and the fourth steel wire rope, so as to achieve accurate measurement of the rotation angle of the sling and improve the efficiency and accuracy of automated crane operations.

[0065] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered merely as exemplary, and the true scope and spirit of the present application are indicated by the claims.

[0066] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for measuring the rotation angle of a spreader based on a displacement sensor, characterized in that: The method comprises the following steps: A displacement sensor is installed at the spreader torsion actuator, wherein the displacement sensor and the spreader torsion actuator are coaxially arranged; Using the displacement sensor to measure the real-time lengths of the first steel rope, the second steel rope, the third steel rope, and the fourth steel rope; The relationship between the real-time length change of the wire rope and the real-time angle of the spreader is fitted, and a multivariate function model including the real-time lengths of the first wire rope, the second wire rope, the third wire rope, and the fourth wire rope is established.

2. The method for measuring the rotation angle of a spreader based on a displacement sensor according to claim 1, characterized in that: The real-time length change of the steel wire rope is the real-time length change of the first steel wire rope or the second steel wire rope.

3. The method for measuring the rotation angle of a spreader based on a displacement sensor according to claim 1, characterized in that: The expression of the multivariate function model is as follows: θ=f(Δx,l1,l2,l3,l4)+θ0 Wherein, θ is the sling angle, Δx is the real-time length change of the first or second wire rope, l1, l2, l3, and l4 are the real-time lengths of the first, second, third, and fourth wire ropes, respectively, θ0 is the initial angle of the sling, and f is the multivariate function mapping relationship.

4. The method for measuring the rotation angle of a spreader based on a displacement sensor according to claim 3, characterized in that: The multivariate function mapping relationship is obtained by fitting experimental data using the least squares method.

5. The method for measuring the rotation angle of a spreader based on a displacement sensor according to claim 1, characterized in that: The displacement sensor is a linear encoder, and the displacement sensor includes a single-point laser displacement sensor and a pull-wire sensor.

6. A system for measuring the rotation angle of a spreader based on a displacement sensor, characterized in that: The system comprises: A displacement sensor is installed at the spreader torsion actuator, wherein the displacement sensor and the spreader torsion actuator are coaxially arranged; A steel wire rope real-time length measurement module, which is used to measure the real-time lengths of the first steel wire rope, the second steel wire rope, the third steel wire rope, and the fourth steel wire rope using the displacement sensor; A multivariate function model establishment module is used to fit the relationship between the real-time length change of the wire rope and the real-time angle of the sling, and establish a multivariate function model including the real-time lengths of the first wire rope, the second wire rope, the third wire rope, and the fourth wire rope.

7. The system for measuring the rotation angle of a spreader based on a displacement sensor according to claim 6, characterized in that: The real-time length change of the steel wire rope is the real-time length change of the first steel wire rope or the second steel wire rope.

8. The system for measuring the rotation angle of a spreader based on a displacement sensor according to claim 6, characterized in that: The expression of the multivariate function model is as follows: θ=f(Δx,l1,l2,l3,l4)+θ0 Wherein, θ is the sling angle, Δx is the real-time length change of the first or second wire rope, l1, l2, l3, and l4 are the real-time lengths of the first, second, third, and fourth wire ropes, respectively, θ0 is the initial angle of the sling, and f is the multivariate function mapping relationship.

9. The system for measuring the rotation angle of a spreader based on a displacement sensor according to claim 8, characterized in that: The multivariate function mapping relationship is obtained by fitting experimental data using the least squares method.

10. The system for measuring the rotation angle of a spreader based on a displacement sensor according to claim 6, characterized in that: The displacement sensor is a linear encoder, and the displacement sensor includes a single-point laser displacement sensor and a pull-wire sensor.

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