Crane variable amplitude control method based on electric cylinder

Abstract

The invention discloses a crane variable-amplitude control method based on an electric cylinder. The crane variable-amplitude control method comprises the following steps: acquiring real-time parameter data of a crane to be controlled and a required speed of the electric cylinder; calculating the actual load rate of the crane according to the real-time parameter data; the maximum allowable speed of the electric cylinder is obtained by calculating the rated speed of the electric cylinder according to the actual load rate of the crane; controlling the electric cylinder of the crane based on the maximum allowable speed of the electric cylinder in response to the condition that the required speed of the electric cylinder is greater than or equal to the maximum allowable speed of the electric cylinder; otherwise, controlling the electric cylinder of the crane based on the required speed of the electric cylinder so as to realize variable amplitude control of the crane. After the maximum allowable speed of the electric cylinder is dynamically calculated based on the actual load rate of the crane, the maximum allowable speed is compared with the required speed of the electric cylinder, full-automatic closed-loop control is achieved, and collaborative optimization is achieved in the four dimensions of safety, efficiency, energy consumption and service life.

Description

Technical Field

[0001] The invention relates to a crane luffing control method based on an electric cylinder, belonging to the technical field of crane luffing control. Background Art

[0002] In modern construction projects, due to construction schedule constraints and the goal of reducing operating costs, high demands are placed on the efficiency and endurance of cranes. Crane luffing refers to the process of raising and lowering the boom, driven by the luffing cylinder, thereby changing the boom angle. The luffing mechanism of existing cranes primarily consists of a boom, turntable, hydraulic cylinder, and counterbalance valve. The boom, driven by the cylinder, rotates around the turntable's rear hinge axis, achieving the raising and lowering of the boom. The luffing counterbalance valve primarily controls the speed of the lowering process. This valve creates backpressure in the return line. As load pressure increases, while the pilot pressure remains constant, the valve automatically closes, reducing the output flow. This reduces the speed of the luffing as the boom angle decreases, achieving adaptive load-dependent speed control. Furthermore, the luffing counterbalance valve utilizes a conical seal, virtually eliminating leakage and allowing the hydraulic cylinder to reliably stop at any position.

[0003] In the existing crane boom control, the operating speed is related to the output flow of the pump and the opening of the handle-controlled electric proportional valve. The adaptive load control of the boom cylinder's extension and retraction speed requires the combination of engine, pump, valve and other controls. The control is complex and difficult, and the expected control effect cannot be achieved. At the same time, there are defects such as the inability to accurately adjust the speed based on the load and the large power loss during the boom-down of the hydraulic system, which is not energy-saving. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a crane luffing control method based on an electric cylinder. The maximum allowable speed of the electric cylinder is dynamically calculated based on the actual load rate of the crane, and then compared with the required speed of the electric cylinder. When the required speed exceeds the maximum allowable speed, it is forced to operate at the maximum allowable speed, thereby blocking safety accidents caused by human operational errors or sudden working conditions at the source. Fully automatic closed-loop control achieves coordinated optimization in the four dimensions of safety, efficiency, energy consumption, and life. To achieve the above objectives, the present invention is implemented by adopting the following technical solutions:

[0005] The present invention discloses a crane luffing control method based on an electric cylinder, comprising the following steps:

[0006] Obtain real-time parameter data of the crane to be controlled and the required speed of the electric cylinder;

[0007] Calculating the actual load rate of the crane according to the real-time parameter data;

[0008] According to the actual load rate of the crane, the rated speed of the electric cylinder is calculated to obtain the maximum allowable speed of the electric cylinder;

[0009] In response to the electric cylinder required speed being greater than or equal to the maximum allowable speed of the electric cylinder, the crane electric cylinder is controlled based on the maximum allowable speed of the electric cylinder; otherwise, the crane electric cylinder is controlled based on the electric cylinder required speed to achieve luffing control of the crane.

[0010] Furthermore, the real-time parameter data includes boom amplitude, boom length and actual crane lifting weight.

[0011] Furthermore, the calculation method of the actual load rate of the crane is as follows:

[0012] Obtaining the rated lifting capacity of the crane according to the boom amplitude and boom length;

[0013] According to the rated lifting capacity of the crane and the actual lifting capacity of the crane, the actual load rate of the crane is calculated. The calculation expression is as follows:

[0014]

[0015] Where, Indicates the actual load rate of the crane; Indicates the actual lifting weight of the crane; Indicates the rated lifting weight of the crane.

[0016] Furthermore, the calculation method of the rated speed of the electric cylinder includes a rated speed formula method or a load distribution segmentation method.

[0017] Furthermore, the calculation expression of the rated speed formula method is as follows:

[0018]

[0019] Where, Indicates the rated speed of the electric cylinder; Indicates the set power of the electric cylinder; Indicates the rated load force of the electric cylinder.

[0020] Furthermore, the load distribution segmentation method includes the following steps:

[0021] In response to the actual lifting weight of the crane being within a preset first interval, the first preset speed is used as the rated speed of the electric cylinder;

[0022] In response to the actual lifting weight of the crane being within a preset second interval, the second preset speed is used as the rated speed of the electric cylinder;

[0023] In response to the actual lifting weight of the crane being in a preset third interval, the third preset speed is used as the rated speed of the electric cylinder.

[0024] Furthermore, the calculation method of the maximum allowable speed of the electric cylinder includes a maximum speed formula method or a load rate segmentation method.

[0025] Furthermore, the maximum speed formula method calculates the maximum allowable speed of the electric cylinder according to the rated speed of the electric cylinder and the actual load rate of the crane. The calculation expression is as follows:

[0026]

[0027] Where, Indicates the maximum permissible speed of the electric cylinder; Indicates the rated speed of the electric cylinder; Indicates the actual load rate of the crane; Indicates the correction factor.

[0028] Furthermore, the load rate segmentation method calculates the maximum allowable speed of the electric cylinder according to the rated speed of the electric cylinder and the actual load rate of the crane, including the following steps:

[0029] In response to the actual load rate of the crane being less than or equal to a preset first threshold, setting a preset first proportion of the rated speed of the electric cylinder as the maximum allowable speed of the electric cylinder;

[0030] In response to the actual load rate of the crane being less than or equal to a preset second threshold and greater than a preset first threshold, setting a preset second proportion of the rated speed of the electric cylinder as the maximum allowable speed of the electric cylinder;

[0031] In response to the actual load rate of the crane being less than or equal to a preset third threshold and greater than a preset second threshold, setting a preset third ratio of the rated speed of the electric cylinder as the maximum allowable speed of the electric cylinder;

[0032] In response to the actual load rate of the crane being less than or equal to a preset fourth threshold and greater than a preset third threshold, a preset fourth ratio of the rated speed of the electric cylinder is used as the maximum allowable speed of the electric cylinder.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The electric cylinder-based crane boom control method of the present invention firstly realizes the dynamic binding of the control logic with the current working conditions by obtaining the real-time parameters of the crane and the required speed of the electric cylinder, rather than relying on the fixed threshold of the traditional method. Secondly, the maximum allowable speed of the electric cylinder is calculated based on the actual load rate, which directly avoids the risk of overload and prevents excessive torque or structural damage caused by excessive speed. In addition, the speed limit is only activated when the required speed exceeds the allowable speed, rather than forcibly reducing the speed throughout the process, so as to maximize the operating efficiency within the safety boundary and improve energy efficiency by dynamically matching the speed requirements. Finally, through the logical process of real-time parameter update-load rate calculation-speed decision, the rapid response of the control command is ensured, which is particularly suitable for scenarios with sudden load changes and improves control stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a flow chart of the crane boom length control method based on the electric cylinder provided in Example 1. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0037] This embodiment provides a crane luffing control method based on an electric cylinder, comprising the following steps:

[0038] Obtain real-time parameter data of the crane to be controlled and the required speed of the electric cylinder;

[0039] Calculate the actual load rate of the crane based on real-time parameter data;

[0040] According to the actual load rate of the crane, the rated speed of the electric cylinder is calculated to obtain the maximum allowable speed of the electric cylinder;

[0041] In response to the electric cylinder required speed being greater than or equal to the maximum allowable speed of the electric cylinder, the crane electric cylinder is controlled based on the maximum allowable speed of the electric cylinder; otherwise, the crane electric cylinder is controlled based on the electric cylinder required speed to achieve luffing control of the crane.

[0042] The technical concept of the present invention is as follows: First, by obtaining the real-time parameters of the crane and the required speed of the electric cylinder, the control logic is dynamically bound to the current working conditions, rather than relying on the fixed threshold of the traditional method. Secondly, the maximum allowable speed of the electric cylinder is calculated based on the actual load rate, which directly avoids the risk of overload and prevents excessive torque or structural damage caused by excessive speed. In addition, the speed limit is only activated when the required speed exceeds the allowable speed, rather than forcibly reducing the speed throughout the process, so as to maximize the operating efficiency within the safety boundary and improve energy efficiency by dynamically matching the speed requirements. Finally, through the logical process of real-time parameter update-load rate calculation-speed decision-making, the rapid response of the control command is ensured, which is especially suitable for scenarios with sudden load changes and improves control stability.

[0043] like Figure 1 The specific steps are as follows:

[0044] Step 1: Obtain the real-time parameter data of the crane to be controlled and the required speed of the electric cylinder.

[0045] 1.1. Real-time parameter data includes boom amplitude, boom length and actual lifting weight of the crane.

[0046] In this embodiment, the real-time parameter data of the crane is identified by the crane's built-in force limiter.

[0047] 1.2. The required speed of the electric cylinder is obtained according to the actual situation, such as the speed signal obtained by the control handle:

[0048] Step 2: Calculate the actual load rate of the crane based on real-time parameter data.

[0049] The calculation method of the actual load factor of the crane is as follows:

[0050] According to the boom amplitude and boom length, the rated lifting capacity of the crane is obtained. This step is obtained by looking up the preset working condition table. Part of the working condition table is shown below:

[0051]

[0052] According to the rated lifting weight and actual lifting weight of the crane, the actual load rate of the crane is calculated. The calculation expression is as follows:

[0053]

[0054] Where, Indicates the actual load rate of the crane; Indicates the actual lifting weight of the crane; Indicates the rated lifting weight of the crane.

[0055] Step 3: According to the actual load rate of the crane, the rated speed of the electric cylinder is calculated to obtain the maximum allowable speed of the electric cylinder.

[0056] 3.1. Rated speed of electric cylinder.

[0057] There are two methods for calculating the rated speed of an electric cylinder: the rated speed formula method and the load distribution segmentation method. The rated speed formula method is suitable for preliminary estimation, and the overall process is simple, fast, and intuitive. The load distribution segmentation method, on the other hand, fully considers the dynamic changes in load and speed in actual applications. The calculated rated speed is closer to actual operating conditions, ensuring reliable system operation in all phases.

[0058] Specifically, the calculation expression of the rated speed formula method is as follows:

[0059]

[0060] Where, Indicates the rated speed of the electric cylinder; Indicates the set power of the electric cylinder; Indicates the rated load capacity of the electric cylinder, which is calculated based on the rated lifting capacity of the crane.

[0061] The load distribution segmentation method includes the following steps:

[0062] In response to the actual lifting weight of the crane being within a preset first interval, the first preset speed is used as the rated speed of the electric cylinder;

[0063] In response to the actual lifting weight of the crane being in a preset second interval, the second preset speed is used as the rated speed of the electric cylinder;

[0064] In response to the actual lifting weight of the crane being in the preset third interval, the third preset speed is used as the rated speed of the electric cylinder.

[0065] In this embodiment, the preset first interval is [0t, 20t); the preset second interval is [20t, 30t); the preset third interval is [30t, 40t); the first preset speed is 60 mm / s; the second preset speed is 35 mm / s; and the third preset speed is 15 mm / s.

[0066] 3.2. Maximum permissible speed of the electric cylinder.

[0067] Methods for calculating the maximum allowable speed of an electric cylinder include the maximum speed formula method and the load factor segmentation method. The maximum speed formula method is suitable for scenarios where the load is stable and control efficiency is important, such as constant-speed transportation. The load factor segmentation method is suitable for scenarios where the load is dynamically changing, subject to shock or periodic overload, such as crane luffing mechanisms. Choose the method based on your specific situation.

[0068] Specifically, based on the rated speed of the electric cylinder and the actual load rate of the crane, the maximum allowable speed of the electric cylinder is calculated using the preset maximum speed formula method; the calculation expression of the maximum speed formula method is as follows:

[0069]

[0070] Where, Indicates the maximum permissible speed of the electric cylinder; Indicates the rated speed of the electric cylinder; Indicates the actual load rate of the crane; Indicates the correction factor.

[0071] Based on the rated speed of the electric cylinder, the maximum allowable speed of the electric cylinder is calculated using the preset load factor segmentation method. The load factor segmentation method includes the following steps:

[0072] In response to the actual load rate of the crane being less than or equal to a preset first threshold, a preset first proportion of the rated speed of the electric cylinder is used as the maximum allowable speed of the electric cylinder;

[0073] In response to the actual load rate of the crane being less than or equal to a preset second threshold and greater than a preset first threshold, a preset second proportion of the rated speed of the electric cylinder is used as the maximum allowable speed of the electric cylinder;

[0074] In response to the actual load rate of the crane being less than or equal to a preset third threshold and greater than a preset second threshold, a preset third ratio of the rated speed of the electric cylinder is used as the maximum allowable speed of the electric cylinder;

[0075] In response to the actual load rate of the crane being less than or equal to a preset fourth threshold and greater than a preset third threshold, a preset fourth ratio of the rated speed of the electric cylinder is used as the maximum allowable speed of the electric cylinder.

[0076] In this embodiment, the preset first threshold is 0.25, the preset second threshold is 0.5, the preset third threshold is 0.75, and the preset fourth threshold is 1. The preset first ratio is 100%, the preset second ratio is 75%, the preset third ratio is 50%, and the preset fourth ratio is 25%.

[0077] Step 4: In response to the electric cylinder required speed being greater than or equal to the maximum allowable speed of the electric cylinder, the electric cylinder of the crane is controlled based on the maximum allowable speed of the electric cylinder to achieve luffing control of the crane; otherwise, the electric cylinder of the crane is controlled based on the electric cylinder required speed to achieve luffing control of the crane.

[0078] The crane in this embodiment includes a force limiter, a controller, a driver, a power supply, an electric cylinder, and a boom. The force limiter acquires real-time parameter data for the crane to be controlled. The controller calculates the maximum permissible speed of the electric cylinder based on the real-time parameter data and the required speed of the electric cylinder. The driver controls the crane's electric cylinder, and the power supply provides driving energy to the electric cylinder via the driver.

[0079] In summary, this method realizes the adaptive speed regulation function of the electric cylinder under different lifting weights, different arm lengths, and different amplitude combinations, thereby improving operation safety; and replaces the original hydraulic amplitude variation system with electrification technology, thereby simplifying the system layout and improving energy saving.

[0080] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0081] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0082] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0083] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0084] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A crane luffing control method based on an electric cylinder, characterized in that: The following steps are involved: Obtain real-time parameter data of the crane to be controlled and the required speed of the electric cylinder; Calculating the actual load rate of the crane according to the real-time parameter data; According to the actual load rate of the crane, the rated speed of the electric cylinder is calculated to obtain the maximum allowable speed of the electric cylinder; In response to the electric cylinder required speed being greater than or equal to the maximum allowable speed of the electric cylinder, the crane electric cylinder is controlled based on the maximum allowable speed of the electric cylinder; otherwise, the crane electric cylinder is controlled based on the electric cylinder required speed to achieve luffing control of the crane.

2. The crane luffing control method based on electric cylinder according to claim 1 is characterized in that: The real-time parameter data includes boom amplitude, boom length and actual lifting weight of the crane.

3. The crane luffing control method based on electric cylinder according to claim 2 is characterized in that: The calculation method of the actual load rate of the crane is as follows: Obtaining the rated lifting capacity of the crane according to the boom amplitude and boom length; According to the rated lifting capacity of the crane and the actual lifting capacity of the crane, the actual load rate of the crane is calculated. The calculation expression is as follows: ； Where, Indicates the actual load rate of the crane; Indicates the actual lifting weight of the crane; Indicates the rated lifting weight of the crane.

4. The crane luffing control method based on electric cylinder according to claim 2 is characterized in that: The calculation method of the rated speed of the electric cylinder includes a rated speed formula method or a load distribution segmentation method.

5. The crane luffing control method based on electric cylinder according to claim 4 is characterized in that: The calculation expression of the rated speed formula method is as follows: ； Where, Indicates the rated speed of the electric cylinder; Indicates the set power of the electric cylinder; Indicates the rated load force of the electric cylinder.

6. The crane luffing control method based on electric cylinder according to claim 4 is characterized in that: The load distribution segmentation method comprises the following steps: In response to the actual lifting weight of the crane being within a preset first interval, the first preset speed is used as the rated speed of the electric cylinder; In response to the actual lifting weight of the crane being within a preset second interval, the second preset speed is used as the rated speed of the electric cylinder; In response to the actual lifting weight of the crane being in a preset third interval, the third preset speed is used as the rated speed of the electric cylinder.

7. The crane luffing control method based on electric cylinder according to claim 1 is characterized in that: The calculation method of the maximum allowable speed of the electric cylinder includes a maximum speed formula method or a load rate segmentation method.

8. The crane luffing control method based on electric cylinder according to claim 5 is characterized in that: The maximum speed formula method calculates the maximum allowable speed of the electric cylinder based on the rated speed of the electric cylinder and the actual load rate of the crane. The calculation expression is as follows: ； Where, Indicates the maximum permissible speed of the electric cylinder; Indicates the rated speed of the electric cylinder; Indicates the actual load rate of the crane; Indicates the correction factor.

9. The crane luffing control method based on electric cylinder according to claim 5, characterized in that: The load rate segmentation method calculates the maximum allowable speed of the electric cylinder according to the rated speed of the electric cylinder and the actual load rate of the crane, including the following steps: In response to the actual load rate of the crane being less than or equal to a preset first threshold, setting a preset first proportion of the rated speed of the electric cylinder as the maximum allowable speed of the electric cylinder; In response to the actual load rate of the crane being less than or equal to a preset second threshold and greater than a preset first threshold, setting a preset second proportion of the rated speed of the electric cylinder as the maximum allowable speed of the electric cylinder; In response to the actual load rate of the crane being less than or equal to a preset third threshold and greater than a preset second threshold, setting a preset third ratio of the rated speed of the electric cylinder as the maximum allowable speed of the electric cylinder; In response to the actual load rate of the crane being less than or equal to a preset fourth threshold and greater than a preset third threshold, a preset fourth ratio of the rated speed of the electric cylinder is used as the maximum allowable speed of the electric cylinder.

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