Intelligent electronic anti-swing system of crawler crane and control method

Abstract

The invention discloses an intelligent electronic anti-swing system of a crawler crane and a control method, and belongs to the technical field of crawler crane control. Comprising a programmable controller, an electromagnetic valve, an industrial personal computer, a steel wire rope length detection module, an angle detection module and a communication module. And an anti-swing algorithm operation module and a motion control module are loaded into the industrial personal computer. The method is simple to operate, the labor intensity of workers is effectively reduced, and the system can automatically generate the running speed parameters of the crane only by inputting the variable amplitude target angle and the rotation target angle of the crane boom and the target length of the steel wire rope by the workers. The length of the steel wire rope is obtained based on coordinate calculation of the GNSS module, the air deflection frequency of the hoisted object is calculated according to the length, and the advantages of being rapid in response and accurate in measurement are achieved. The system does not need additional mechanical devices, the original structure of the crane is completely reserved, and safety and reliability are ensured. And in case of emergency, the system can immediately exit the anti-swing control mode and execute sudden stop operation, so that the operation safety is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of crawler crane control, and particularly to an intelligent anti-sway control system and control method for a lifted object during the hoisting process of a crawler crane. Background Art

[0002] At present, with the rapid development of China's economy, the national infrastructure construction market is getting larger and larger. Crawler cranes are widely used in industries such as wind turbine hoisting, power construction, petrochemical industry, bridge and water conservancy, port and ship, etc. due to their excellent performance such as large lifting weight, high lifting height, and ability to travel with load.

[0003] When a crawler crane is in hoisting operation, the steel wire rope itself is flexible, and there are external forces acting during the movement of the boom. Inevitably, the lifted object will have a spatial swing. Due to the large slenderness ratio structure of the crawler crane boom, during the crane operation, the rigid body movement, elastic vibration of the boom and the swing of the lifted object exist simultaneously, seriously affecting the safety and efficiency of the crane operation. Currently, during the hoisting operation of a crawler crane, it is usually performed by an experienced operator, and the swing angle of the lifted object is reduced by reducing the running speed and moving the suspension position of the lifted object back and forth. The above methods can reduce the swing of the lifted object to meet the hoisting requirements to a certain extent, but they rely too much on the experience of the operator and have low efficiency. The traditional anti-sway solutions can no longer meet the current increasingly strict hoisting operation standards. Therefore, the present invention proposes a more advanced active anti-sway control method for crawler cranes. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of serious swing of the lifted object during the hoisting process of a crawler crane, and a lifted object anti-sway control system and control method for a crawler crane are proposed to improve the safety and working efficiency of the hoisting operation.

[0005] The technical solution of the present invention is as follows:

[0006] An intelligent electronic anti-sway system for a crawler crane, an anti-sway control strategy considering the coupling effect of the boom vibration and the swing of the lifted object, includes the following contents;

[0007] The intelligent electronic anti-sway system of the crawler crane includes a programmable logic controller, a solenoid valve, an industrial personal computer, a steel wire rope length detection module, an angle detection module, and a communication module. An anti-sway algorithm operation module and a motion control module are loaded on the industrial personal computer.

[0008] The wire rope length detection module consists of two sets of GNSS modules (integrated navigation systems), which are respectively installed at the head position of the crane boom and the hook position. By calculating the position coordinates of the two GNSS modules, the length information of the wire rope can be obtained. The GNSS modules at the boom head and the hook positions are each connected to a LoRa wireless communication module as data sending ends, and transmit the coordinate information to the industrial control computer. The industrial control computer is equipped with two LoRa modules as receiving ends, which respectively receive the positioning data of the GNSS modules from the boom head and the hook.

[0009] The angle detection module consists of a slewing angle sensor, a luffing angle sensor and a dynamic inclination sensor. The slewing angle sensor is installed at the slewing center position to detect the slewing angle of the boom; the luffing angle sensor is installed on the boom structure to measure the luffing angle of the boom; the dynamic inclination sensor is installed at the hook to monitor the yaw angle of the lifted object. Among them, the slewing angle sensor and the luffing angle sensor are connected to the industrial control computer through wired optical fiber communication, while the dynamic inclination sensor uses Zigbee wireless communication technology to transmit data to the industrial control computer.

[0010] The anti-sway algorithm operation module is implemented through the PID input shaping control algorithm, and includes a position PID control unit and an input shaping unit; among them:

[0011] The position PID control unit is based on the real-time data collected by the wire rope length detection module and the angle detection module, including the slewing angle of the boom, the luffing angle and the length of the wire rope. Through closed-loop control, it ensures that the crane can accurately lift the lifted object from the initial position to the target position. The position PID control unit calculates and outputs the slewing speed, luffing speed and wire rope lifting speed of the boom in real time. Among them, the three key parameters of the position PID controller, namely the proportional coefficient Kp, the integral time Ki and the differential time Kd, need to be determined through on-site actual debugging.

[0012] The input shaper unit is responsible for shaping the three motion speeds output by the position PID control unit. For the wire rope lifting motion, theoretically the lifted object should not swing, but in actual operation, the vibration of the boom will cause the lifted object to swing. Therefore, a single-mode ZVD input shaper is designed to suppress the boom vibration, thereby eliminating the swing of the lifted object. For the slewing and luffing motions of the boom, since there is both the swing of the lifted object caused by the boom vibration and the swing effect of the lifted object generated by the motion itself, another single-mode ZVD shaper is specially configured to suppress the swing of the lifted object caused by the slewing and luffing motions. The specific design process is as follows:

[0013] The pulse amplitude and time delay of each single-mode ZVD input shaper are:

[0014]

[0015] Among them, ξ is the damping ratio during the swinging process of the lifted object or the vibration process of the crane boom, ω n is the natural frequency during the swinging process of the lifted object or the vibration process of the crane boom, A i is the pulse amplitude, t i is the time delay. Among them, the damping ratio during the swinging process of the lifted object or the vibration process of the crane boom is obtained by actually measuring the free decay response curve of the vibration, and the damping ratio is obtained by using the free decay response curve of the vibration.

[0016] The spatial swinging model of the lifted object is set as a simple pendulum model, so the swinging frequency of the lifted object is:

[0017]

[0018] In the formula, l is the length of the wire rope, g is the acceleration due to gravity, ω is the swinging frequency of the lifted object, take g = 9.8 N / kg, π = 3.1416.

[0019] The single-mode ZVD shaper for the swinging of the lifted object is designed based on the swinging frequency of the lifted object.

[0020] The vibration frequency of the boom is obtained through finite element simulation analysis, and the single-mode ZVD shaper for the boom vibration is designed accordingly. This shaper shapes the lifting and lowering speed of the wire rope output by the position PID unit.

[0021] The dual-mode ZVD input shaper is obtained by convolution calculation of the single-mode ZVD shaper for the boom vibration and the single-mode ZVD shaper for the swinging of the lifted object. It is used to shape the slewing speed during the slewing motion of the crane boom obtained by the position PID control unit and the luffing speed during the luffing motion of the crane boom.

[0022] The described motion control module is used to convert the speed data calculated by the anti-sway algorithm operation module into corresponding handle signals.

[0023] The described programmable controller is used to convert the handle signal into a current signal to drive the solenoid valve to operate the hydraulic valve.

[0024] An intelligent electronic anti-sway control method for a crawler crane, and an intelligent electronic anti-sway system for a crawler crane. Before starting the hoisting operation, the system is initialized first. The wire rope length detection module and the angle detection module start to monitor the wire rope length, the slewing angle of the boom, the luffing angle of the boom, and the spatial sway angle of the lifted object, and transmit the monitored data to the anti-sway algorithm operation module of the industrial control computer. The operator inputs the slewing target angle, luffing target angle, and wire rope target length of the crane boom into the system. The anti-sway algorithm operation module in the industrial control computer calculates the slewing speed, luffing speed, and wire rope lifting speed of the boom after shaping processing by using the monitored data and the input parameters. The motion control module converts the shaped speed signal into a handle control signal and transmits it to the programmable logic controller through the communication module. The programmable logic controller converts the signal into a current command and outputs it to the solenoid valve. The solenoid valve adjusts the hydraulic valve flow according to the output command of the programmable logic controller to achieve precise control of the slewing speed, luffing speed, and wire rope lifting speed of the boom, and finally achieves the purpose of suppressing the sway of the lifted object.

[0025] The beneficial effects of the present invention are as follows: simple operation, effectively reducing the labor intensity of workers. Workers only need to input the luffing target angle, slewing target angle, and wire rope target length of the crane boom, and the system can automatically generate the operating speed parameters of the crane. The wire rope length is obtained through coordinate calculation based on the GNSS module, and the in-air sway frequency of the lifted object is calculated accordingly, with the characteristics of fast response and accurate measurement. The system does not need to install additional mechanical devices, completely retaining the original structure of the crane, ensuring safety and reliability. When an emergency occurs, the system can immediately exit the anti-sway control mode and execute an emergency stop operation, effectively improving the operation safety. Description of the Drawings

[0026] Figure 1 It is a diagram of the sensor installation position of the present invention.

[0027] Figure 2 It is a control principle diagram of the present invention. Detailed Embodiments

[0028] The following further elaborates on the content of the present invention in detail through examples in combination with the drawings for those skilled in the same industry to understand:

[0029] As Figure 1 shown, it is a schematic diagram of the sensor installation position of a crane applying the anti-sway system and control method of the present invention, which is mainly applied to crawler cranes.

[0030] An intelligent electronic anti-sway system for crawler cranes, an anti-sway control strategy considering the coupling effect of the vibration of the crawler crane boom and the sway of the lifted object. The crane in this example should include the following equipment: programmable logic controller, solenoid valve, industrial control computer, wire rope length detection module, angle detection module and communication module. The anti-sway algorithm operation module and the motion control module are loaded on the industrial control computer.

[0031] System deployment: The wire rope length detection module consists of two GNSS (integrated navigation systems), which are respectively installed at the boom tip and the hook of the crane boom. Each GNSS module at the boom tip and the hook is connected to a LoRa module (transmitter), and two LoRa modules (receivers) are configured at the industrial control computer section to receive the GNSS module data. The angle detection module includes a slewing angle sensor installed at the slewing center position to detect the slewing angle of the boom, a luffing angle sensor installed on the boom to detect the luffing angle of the boom, and a dynamic inclination sensor installed on the hook to detect the sway angle of the lifted object. The slewing angle sensor and the luffing angle sensor are connected to the industrial control computer through wired optical fiber communication, and the dynamic inclination sensor is connected through Zigbee wireless communication. The anti-sway algorithm operation module is implemented through the PID input shaping control algorithm, which includes a position PID unit and an input shaping unit; the three key parameters of the proportional coefficient Kp, integral time Ki, and derivative time Kd involved in the position PID need to be set on-site according to the characteristics of the crane, such as the characteristics of the solenoid valve and the hydraulic valve, after multiple experiments, so that the crane runs at a speed that conforms to the actual operating conditions. The input shaper unit is used to shape the three speeds obtained by the position PID unit. The programmable logic controller is connected to the industrial control computer through the CAN bus and receives the control signal of the industrial control computer.

[0032] The vibration frequency of the boom is analyzed by finite element software for the boom structure to extract its natural frequency.

[0033] According to the calculation formula for the sway frequency of the lifted object Update the shaper parameters.

[0034] Obtain the free decay response curves of the boom vibration and the sway of the lifted object through on-site excitation tests, and calculate the damping ratios ξ of the boom vibration and the sway of the lifted object. In this example, the damping ratio of the boom vibration is calculated to be 0.05, and the damping ratio of the sway of the lifted object is 0.01.

[0035] Job initialization: Before starting the hoisting operation, first initialize the system. The wire rope length detection module and the angle detection module start to monitor the wire rope length, the slewing angle of the boom, the luffing angle of the boom, and the spatial sway angle of the lifted object, and transmit the monitored data to the anti-sway algorithm operation module of the industrial control computer; the operator inputs the slewing target angle, luffing target angle, and wire rope target length of the crane boom into the system.

[0036] Algorithm operation and shaping calculation:

[0037] Step 1: The anti-sway algorithm operation module calculates the sway frequency of the suspended load and designs a single-mode ZVD shaper for the sway of the suspended load based on this frequency.

[0038] Step 2: Based on the boom vibration frequency from finite element simulation, design a single-mode ZVD shaper for boom vibration.

[0039] Step 3: Synthesize the two single-mode ZVD shapers into a dual-mode ZVD shaper through convolution operation.

[0040] Step 4: The position PID unit generates initial velocity commands (boom slewing velocity, boom luffing velocity, wire rope hoisting and lowering velocity) according to the deviation between the target and the measured data.

[0041] Step 5: The input shaping unit shapes the velocity commands: The wire rope hoisting and lowering velocity is processed by the single-mode ZVD shaper for boom vibration to suppress the sway caused by boom vibration. The boom slewing velocity and the boom luffing velocity are processed by the dual-mode ZVD shaper to suppress the sway caused by the coupling of boom movement and vibration.

[0042] Control signal output: The programmable controller is used to convert the handle signal into a current signal to drive the solenoid valve to operate the hydraulic valve.

[0043] In the specific implementation process of this case, the suspended load is a 5t weight, simulating typical hoisting operation conditions. The suspended load is hoisted from the initial position to the target position. The crane successively undergoes wire rope hoisting movement, boom luffing movement, boom slewing movement, and finally wire rope lowering movement.

[0044] When there is no anti-sway control system, the maximum sway angles of the suspended load at the final parking stage of the crane are 3.378° (sway angle in the luffing plane) and 3.373° (sway angle in the slewing plane) respectively. After being controlled by the anti-sway system, the maximum sway angles of the suspended load at the parking stage are 0.341° (sway angle in the luffing plane) and 0.401° (sway angle in the slewing plane) respectively, achieving a sway reduction rate of 89.93% and 88.11% compared with the uncontrolled situation of the suspended load. And at the final stage when the suspended load is in place, without the anti-sway control system, due to the serious sway of the suspended load, manual assistance is required for positioning. However, with the anti-sway control system, since the system greatly suppresses the sway of the suspended load, no manual assistance is required for positioning.

[0045] The anti-sway system designed in the present invention also includes an emergency stop button. When an emergency occurs, the operator presses the emergency stop button, and the system immediately exits the anti-sway mode and stops urgently.

Claims

1. An intelligent electronic anti-sway system for a crawler crane, characterized in that, The intelligent electronic anti-sway system of the crawler crane includes a programmable logic controller, a solenoid valve, an industrial computer, a wire rope length detection module, an angle detection module, and a communication module; the anti-sway algorithm operation module and the motion control module are loaded on the industrial computer; The wire rope length detection module consists of two sets of GNSS modules, which are respectively installed at the boom head position and the hook position of the crane; by calculating the position coordinates of the two GNSS modules, the length information of the wire rope can be obtained; each of the GNSS modules at the boom head and the hook position is connected to a LoRa wireless communication module as a data sender to transmit the coordinate information to the industrial computer; two LoRa modules are equipped at the industrial computer end as receivers to receive the positioning data of the GNSS modules from the boom head and the hook respectively; The angle detection module consists of a slewing angle sensor, a luffing angle sensor, and a dynamic inclination sensor; the slewing angle sensor is installed at the slewing center position to detect the slewing angle of the boom; the luffing angle sensor is installed on the boom structure to measure the luffing angle of the boom; the dynamic inclination sensor is installed at the hook to monitor the yaw angle of the lifted object; among them, the slewing angle sensor and the luffing angle sensor are connected to the industrial computer through wired optical fiber communication, while the dynamic inclination sensor uses Zigbee wireless communication technology to transmit data to the industrial computer; The anti-sway algorithm operation module is implemented by the PID input shaping control algorithm, which includes a position PID control unit and an input shaping unit; where: The position PID control unit is based on the real-time data collected by the wire rope length detection module and the angle detection module, including the boom slewing angle, the luffing angle, and the wire rope length, and ensures that the crane can accurately lift the lifted object from the initial position to the target position through closed-loop control; the position PID control unit calculates and outputs the boom slewing speed, the luffing speed, and the wire rope lifting speed in real time; among them, the three key parameters of the position PID controller, namely the proportional coefficient Kp, the integral time Ki, and the differential time Kd, need to be determined through on-site actual debugging; The input shaper unit is responsible for shaping the three motion speeds output by the position PID control unit; for the wire rope lifting motion, theoretically the lifted object should not yaw, but in actual operation, the boom vibration will cause the lifted object to yaw, so a single-mode ZVD input shaper is designed to suppress the boom vibration, thereby eliminating the yaw of the lifted object; for the boom slewing and luffing motions, since there is both the yaw of the lifted object caused by the boom vibration and the yaw effect of the lifted object generated by the motion itself, another single-mode ZVD shaper is specially configured to suppress the yaw of the lifted object caused by the slewing and luffing motions; the specific design process is as follows: The pulse amplitude and time delay of each single-mode ZVD input shaper are: Among them, ξ is the damping ratio during the swinging process of the lifted object or the vibration process of the crane boom, ω n is the natural frequency during the swinging process of the lifted object or the vibration process of the crane boom, A i is the pulse amplitude, t i is the time delay; among them, the damping ratio during the swinging process of the lifted object or the vibration process of the crane boom is obtained by measuring the free decay response curve of the vibration, and the damping ratio is obtained by using the free decay response curve of the vibration; The spatial yaw model of the lifted object is set as a simple pendulum model, so the yaw frequency of the lifted object is: In the formula, l is the wire rope length, g is the acceleration due to gravity, ω is the yaw frequency of the lifted object, take g = 9.8 N / kg, π = 3.1416; The single-mode ZVD shaper for the yaw of the lifted object is designed based on the yaw frequency of the lifted object; The boom vibration frequency is obtained through finite element simulation analysis, and a single-mode ZVD shaper for boom vibration is designed accordingly; this shaper shapes the lifting speed of the wire rope output by the position PID unit; The dual-mode ZVD input shaper is obtained by convolution calculation of the single-mode ZVD shaper for boom vibration and the single-mode ZVD shaper for the swing of the lifted object; it is used to shape the slewing speed during the slewing motion of the crane boom and the luffing speed during the luffing motion of the crane boom obtained by the position PID control unit; The described motion control module is used to convert the speed data calculated by the anti-sway algorithm operation module into corresponding handle signals; The described programmable controller is used to convert the handle signal into a current signal to drive the solenoid valve to operate the hydraulic valve.

2. An intelligent electronic anti-sway control method for a crawler crane using the intelligent electronic anti-sway system of the crawler crane described in claim 1, characterized in that, For the intelligent electronic anti-sway system of the crawler crane, the system is first initialized before the hoisting operation starts. The wire rope length detection module and the angle detection module start to monitor the wire rope length, the slewing angle of the boom, the luffing angle of the boom, and the spatial swing angle of the lifted object, and transmit the monitored data to the anti-sway algorithm operation module of the industrial control computer; the operator inputs the slewing target angle, luffing target angle, and wire rope target length of the crane boom into the system; the anti-sway algorithm operation module in the industrial control computer calculates the slewing speed, luffing speed, and wire rope lifting speed after shaping processing by using the monitored data and the input parameters; The motion control module converts the shaped speed signal into a handle control signal and transmits it to the programmable controller through the communication module; the programmable controller converts the signal into a current command and outputs it to the solenoid valve, and the solenoid valve adjusts the hydraulic valve flow according to the output command of the programmable controller to achieve precise control of the slewing speed, luffing speed, and wire rope lifting speed of the boom, and finally achieves the purpose of suppressing the swing of the lifted object.

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