WO2013004022A1

WO2013004022A1 - Method and system for controlling rotary movement of rotary crane

Info

Publication number: WO2013004022A1
Application number: PCT/CN2011/076965
Authority: WO
Inventors: 高一平; 黄赞; 黎伟福
Original assignee: 长沙中联重工科技发展股份有限公司; 湖南中联重科专用车有限责任公司
Priority date: 2011-07-07
Filing date: 2011-07-07
Publication date: 2013-01-10

Abstract

Provided are a method and system for controlling rotary movement of a rotary crane, to solve the problems in the prior art that the control effect is undesirable when the rotary jitter of the rotary crane is to be alleviated, the power utilization efficiency is low, and the equipment cost is increased. The method comprises: when a crane is in rotary movement, recording current values input into an electromagnetic valve of a rotary pump, and detecting the current pressure of a rotary system; and comparing the current pressure of the rotary system with a pump standard pressure, corresponding to the current values, of the crane to obtain a pressure difference, and when the pressure difference exceeds a preset value, performing pressure compensation on a hydraulic system in rotary movement. This solution helps to improve the control effect on the rotary movement of the crane, achieve high power utilization efficiency, and reduce the rotary jitter.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method and a control system for a rotary motion of a rotary crane. BACKGROUND OF THE INVENTION A rotary crane is a commonly used construction machine that can be rotated at a relatively arbitrary angle under the driver's operation. The current slewing drive of a rotary crane is usually realized by a hydraulic system. The hydraulic pump, the hydraulic motor, the valve member and the like in the hydraulic system have the characteristics of sealing leakage, and the leakage amount varies depending on the load and the pressure, resulting in the crane. In the actual hoisting process, the slewing speed will change with the hoisting load and pressure, and different degrees of jitter will occur. In order to reduce the effects of rotary jitter, manufacturers mainly achieve the following objectives through the following technologies:

1. Improve the back pressure of the swing system; this method sacrifices power utilization, so the efficiency of power utilization is low;

2. Reduce the leakage of the hydraulic system, such as the closed circuit control of the hydraulic system, or the use of high-precision hydraulic components; because the leakage of the hydraulic system is limited, the control effect of this mode is reduced. Poor, in addition to the use of high-precision hydraulic components also increase equipment costs. In the prior art, there is a problem that the control effect is poor, the power utilization efficiency is low, and the equipment cost is increased in attenuating the swing jitter of the rotary crane. For this problem, an effective solution has not been proposed yet. SUMMARY OF THE INVENTION A primary object of the present invention is to provide a control method and a control system for a rotary motion of a rotary crane to solve the problem of poor control effect and low power utilization efficiency in the prior art in reducing the swing jitter of the rotary crane. Increased equipment cost issues. In order to solve the above problems, according to an aspect of the present invention, a control method of a rotary motion of a rotary crane is provided. The control method for the swinging motion of the rotary crane of the present invention comprises: recording a current value of a solenoid valve input to the swing pump when the crane performs a swing motion, and detecting a pressure of the current swing system; ^! Comparing the pressure of the current swing system with the standard pressure of the swing pump of the crane corresponding to the current value to obtain a pressure difference, and the hydraulic system for the rotary motion if the pressure difference is greater than a preset value Perform pressure compensation. According to another aspect of the present invention, a control system for a rotary motion of a rotary crane is provided. The control system for the rotary motion of the rotary crane of the present invention comprises: a recording module for recording a current value of a solenoid valve input to the rotary pump when the crane performs a swing motion; and a pressure detecting module for rotating the crane During the movement, detecting the pressure of the current swing system; the pressure compensation module is configured to compare the pressure of the current swing system with the standard pressure of the swing pump corresponding to the current value of the crane to obtain a pressure difference, where the pressure difference is When the value is greater than the preset value, the hydraulic system of the rotary motion is pressure compensated. According to the technical solution of the present invention, the pressure compensation is performed according to the actual pressure of the hydraulic system of the crane and the pre-stored standard pressure, which helps to keep the rotation consistent with the operation requirements, and has a better control effect. In addition, the technical solution of the embodiment does not need to improve the back pressure of the swing system, and has high power utilization efficiency; and does not rely on high-precision hydraulic components, which helps to reduce equipment costs. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are intended to provide a further understanding of the invention BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing main steps of a method for controlling a swinging motion of a rotary crane according to an embodiment of the present invention; FIG. 2 is a schematic diagram showing main steps of adjusting a swing speed of a crane according to an embodiment of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 4 is a schematic diagram of an optional component of a control system for a rotary motion of a rotary crane according to an embodiment of the present invention. FIG.

P46465 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. The invention will be described in detail below with reference to the drawings in conjunction with the embodiments. In the present embodiment, when the crane performs the swinging motion, if the leakage of the hydraulic system exceeds the limit, pressure compensation is performed to reduce the swing jitter. The specific steps are shown in FIG. 1. FIG. 1 is a schematic diagram showing the main steps of a method for controlling the swinging motion of a rotary crane according to an embodiment of the present invention. The method can be performed by the controller of the crane, and mainly includes the following steps: Step S11: Recording the current value of the solenoid valve input to the swing pump. The solenoid valve is a solenoid valve that controls the output flow of the rotary pump. Step S12: Detecting the pressure of the current swing system. Specifically, the pressure of the rotary pump or the swing motor is detected in this step. The pressure of the rotary pump can be obtained by a pressure sensor mounted on the outlet line of the rotary pump. The pressure of the rotary motor can be obtained by a pressure sensor mounted on the inlet line of the rotary motor, and the pressure sensor is connected to the controller, thereby A signal of the detected pressure is sent to the controller. It should be noted that the rotary pump can be reversed or reversed, and the outlet and inlet positions of the rotary pump are interchanged during forward rotation and reverse rotation. Step S11 and step S12 are performed when the crane performs a swinging motion. Step S12 can also be performed before or at the same time as step S11. Step S13: The pressure difference is obtained by comparing the pressure of the current swing pump with the standard pressure of the swing system of the crane corresponding to the recorded current value. Step S14: Determine whether the pressure difference is greater than a preset value, and if yes, proceed to step S15, otherwise return to step 4 to gather S12. Step S15: Pressure compensation is performed on the hydraulic system of the swing motion. Specifically, the current input to the solenoid valve of the swing pump is increased to increase the opening thereof. This step returns to step S11 and step S12. In the present embodiment, the current input to the solenoid valve of the swing system and the correspondingly obtained swing pump pressure are determined in advance by trial-and-risk. In the trial-risk environment, the leakage of the hydraulic system is smaller than the leakage of the crane during actual operation. The slewing system pressure obtained from an input current in the test environment can be used as the standard pressure value of the slewing system. The pressure is again calculated as a standard pressure value. Data for multiple current values and corresponding standard pressure values for the swing system are saved after a series of tests. In this way, when the crane is actually working, the current value of the solenoid valve currently input to the swing system is recorded,

3 P46465 In this way, the standard pressure value corresponding to the current value can be determined. If there is a leak in the system, the actual pressure of the swing system is smaller than the standard pressure value, and a threshold value of the pressure difference can be preset. When the pressure difference is greater than the threshold value, It is considered that there is a large leak in the system, and the hydraulic system of the swing motion is pressure compensated at this time. It can be seen that this method is directly adjusted for the pressure of the swing system to match the current value of the current input to the solenoid valve of the swing system (the adjustment of the current magnitude comes from the driver's operation of the operating handle). In accordance with this, the output pressure is matched with the driver's operation and the swing jitter is reduced. When the crane is working, due to environmental influences, such as the crane being on a slope, or the presence of wind loads, the speed of the crane will not match the speed required by the operation. The speed required for operation comes from the operating handle, and the different operating ranges of the operating handle correspond to different speed requirements, which are determined during the design phase of the crane. In order to make the rotation speed of the crane coincide with the speed required for the operation, the speed adjustment of the rotation is also performed in this embodiment. The specific steps are shown in Fig. 2. Fig. 2 is a schematic diagram showing the main steps of the adjustment of the swing speed of the crane according to an embodiment of the present invention. Step S21: Acquire the current speed of the swing motion when the crane performs the swing motion. An angle sensor can be used to obtain the swing speed. Specifically, the rotation angle of the swing motion is detected multiple times, and the current speed of the swing motion is obtained according to the plurality of rotation angles and the detection interval time obtained by the detection. For example, the difference between the two angles obtained by the two adjacent detections is divided by the detection time difference to obtain the rotation speed. Step S22: Determine the required speed corresponding to the operation according to the swing operation of the crane. Data of the required speed corresponding to different operations can be saved in the storage element of the controller. In this way, when the data is queried when the swing operation occurs, the required speed corresponding to the operation can be determined. Step S23: Compare the above required speed with the current speed of the swing motion. Step S24: Perform speed adjustment on the swing motion according to the comparison result. Depending on the actual working environment in which the crane is located, its speed of rotation may be greater than or equal to the speed required from the driver's operation. For example, when the rotary platform is tilted, the rotation may be accelerated by gravity. Therefore, in the case where the current turning speed is less than the required speed, the current input to the solenoid valve is increased; and in the case where the current turning speed is greater than the required speed, the current input to the solenoid valve is reduced. This adjustment helps to match the speed of the crane to the requirements of the operation and to reduce the rotational jitter.

P46465 Hereinafter, a control system for the rotary motion of the rotary crane according to the embodiment of the present invention will be described. Fig. 3 is a schematic view showing the essential components of a control system for a rotary motion of a rotary crane according to an embodiment of the present invention. As shown in FIG. 3, the control system 30 mainly includes the following modules: a recording module 31 for recording a current value of a solenoid valve input to a rotary pump when the crane performs a swing motion; and a pressure detecting module 32 for performing a swing motion of the crane When the pressure of the current swing system is detected, the pressure compensation module 33 is configured to compare the pressure of the current swing system with the standard pressure of the swing pump corresponding to the current value of the crane to obtain a pressure difference, where the pressure difference is greater than a preset In the case of a value, the hydraulic system of the rotary motion is pressure compensated, and can also be used to increase the electrical input to the solenoid valve if the pressure difference is greater than a preset value. 4 is a schematic illustration of an optional component of a control system for a rotary motion of a rotary crane in accordance with an embodiment of the present invention. In this embodiment, as shown in FIG. 4, the control system 40 for the rotary motion of the rotary crane may further include a speed detecting module 41 and a speed adjusting module 42, wherein the speed detecting module 41 is configured to obtain the turning motion when the crane performs the turning motion. The current speed can also be used to detect the rotation angle of the rotary motion multiple times, and the current speed of the rotary motion is obtained according to the detected multiple rotation angles and the detection interval time. The speed adjustment module 42 is configured to determine a required speed corresponding to the operation according to the swing operation of the crane, compare the required speed with the current speed, and adjust the speed of the swing motion according to the comparison result, and can also be used for the current rotation of the crane. The current input to the solenoid valve is increased if the speed is less than the required speed given by the operation; and the current input to the solenoid valve is reduced if the current speed is less than the required speed. According to the technical solution of the embodiment of the present invention, the pressure is compensated according to the actual pressure of the hydraulic system of the crane and the pre-stored standard pressure, and the rotation speed of the crane can also be compensated, thereby helping to keep the rotation consistent with the operation requirements. Have a good control effect. In addition, the technical solution of the embodiment does not need to improve the back pressure of the swing system, and has high power utilization efficiency; and does not rely on high-precision hydraulic components, which helps to reduce equipment costs. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device, or they may be separately fabricated into individual integrated circuit modules, or they may be Multiple modules or steps are made into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software.

P46465 The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the present invention are intended to be included within the scope of the present invention.

6 P46465

Claims

Claim

A control method for a rotary motion of a rotary crane, characterized in that it comprises:

Recording a current value of a solenoid valve input to the swing pump when the crane performs a swing motion, and detecting a pressure of the current swing system;

Comparing the pressure of the current swing system with the pump standard pressure of the crane corresponding to the current value to obtain a pressure difference value, and performing the hydraulic system of the swing motion if the pressure difference value is greater than a preset value Pressure compensation.

2. The control method according to claim 1, wherein the pressure compensation of the hydraulic system of the rotary motion comprises: increasing a current input to the solenoid valve.

The control method according to claim 1, wherein the method further comprises:

Obtaining a current speed of the swing motion when the crane performs a swing motion; determining a required speed corresponding to the operation according to the swing operation of the crane, comparing the requested speed with the current speed, and comparing the results Speed adjustment is performed on the rotary motion.

The control method according to claim 3, wherein the speed adjustment of the return motion according to the comparison result comprises:

When the current speed is less than the required speed, increasing the power input to the solenoid valve;

In the event that the current speed is greater than the required speed, the electrical input to the solenoid valve is reduced.

The control method according to claim 3 or 4, wherein acquiring the current speed of the turning motion comprises: detecting a turning angle of the turning motion a plurality of times, according to the plurality of turning angles and detecting intervals obtained by the detecting Time gives the current speed of the swivel motion.

6. A control system for a rotary motion of a rotary crane, comprising:

a recording module, configured to record a current value of a solenoid valve input to the rotary pump when the crane performs a rotary motion;

P46465 a pressure detecting module, configured to detect a pressure of the current swing system when the crane performs a swing motion;

a pressure compensation module, configured to compare a pressure of the current swing system with a standard pressure of the swing pump corresponding to the current value of the crane to obtain a pressure difference value, where the pressure difference is greater than a preset value The hydraulic system of the rotary motion performs pressure compensation.

7. The control system according to claim 6, wherein the pressure compensation module is further configured to increase a current input to the solenoid valve if the flow rate difference is greater than a preset value.

The control system according to claim 6, wherein the control system further comprises: a speed detecting module, configured to acquire a current speed of the swing motion when the crane performs a swing motion;

And a speed adjustment module, configured to determine a required speed corresponding to the operation according to the swing operation of the crane, compare the required speed with the current speed, and perform speed adjustment on the swing motion according to the comparison result.

9. The control system according to claim 8, wherein the speed adjustment module is further configured to:

The control system according to claim 8 or 9, wherein the speed detecting module is further configured to detect the turning angle of the turning motion a plurality of times, and then according to the detected multiple turning angles and detecting intervals. Time gives the current speed of the swivel motion.

P46465