CN114084802A - Double-closed-loop master-slave synchronous control system for multiple mechanisms of tower crane - Google Patents

Double-closed-loop master-slave synchronous control system for multiple mechanisms of tower crane Download PDF

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Publication number
CN114084802A
CN114084802A CN202111390852.2A CN202111390852A CN114084802A CN 114084802 A CN114084802 A CN 114084802A CN 202111390852 A CN202111390852 A CN 202111390852A CN 114084802 A CN114084802 A CN 114084802A
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China
Prior art keywords
speed
variable frequency
slave
master
frequency driving
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CN202111390852.2A
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Chinese (zh)
Inventor
米成宏
衣磊
安健
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Xuzhou Construction Machinery Group Co Ltd XCMG
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Xuzhou Construction Machinery Group Co Ltd XCMG
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Priority to CN202111390852.2A priority Critical patent/CN114084802A/en
Publication of CN114084802A publication Critical patent/CN114084802A/en
Priority to PCT/CN2022/133027 priority patent/WO2023088449A1/en
Pending legal-status Critical Current

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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66CCRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C13/00Other constructional features or details
    • B66C13/18Control systems or devices
    • B66C13/22Control systems or devices for electric drives
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66CCRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C13/00Other constructional features or details
    • B66C13/18Control systems or devices
    • B66C13/48Automatic control of crane drives for producing a single or repeated working cycle; Programme control
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66CCRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C23/00Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
    • B66C23/62Constructional features or details

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Control Of Multiple Motors (AREA)
  • Control And Safety Of Cranes (AREA)

Abstract

The invention discloses a multi-mechanism double-closed-loop master-slave synchronous control system of a tower crane in the technical field of tower crane control, which comprises: a plurality of variable frequency driving devices controlled by a master and a slave are adopted, and each variable frequency driving device drives a winding drum to move through a driving motor based on a control signal; the speed encoders are arranged at the positions of the motors, and feed back real-time speed signals to the corresponding variable-frequency driving devices after detecting the speeds of the motors, and the variable-frequency driving devices perform synchronous control on the speeds of the motors in real time based on the real-time speed signals; and the position encoders are arranged at the positions of the winding drums and used for feeding back winding drum position signals to the controller after detecting the positions of the winding drums, and the position encoders are used for synchronously correcting the positions of the winding drums when responding to the exceeding of the deviation of the positions of the winding drums. The invention can adopt a master-slave control mode, and the redundant double closed-loop control of the inner layer speed closed loop and the outer layer position closed loop can guarantee the accuracy and the reliability of the multi-mechanism synchronous control of the tower crane.

Description

Double-closed-loop master-slave synchronous control system for multiple mechanisms of tower crane
Technical Field
The invention relates to a multi-mechanism double-closed-loop master-slave synchronous control system of a tower crane, belonging to the technical field of tower crane control.
Background
Tower cranes, also known as tower cranes, originate in western europe. And the movable arm is arranged on the rotary crane at the upper part of the high-rise tower body. The working space is large, and the device is mainly used for vertical and horizontal conveying of materials and installation of building components in building construction. The device consists of a metal structure, a working mechanism and an electrical system. The metal structure comprises a tower body, a movable arm, a base and the like. The working mechanism has four parts of lifting, amplitude variation, rotation and walking. The electric system comprises a motor, a controller, a power distribution cabinet, a connecting circuit, a signal and lighting device and the like.
The application of tower cranes with the scale of more than kiloton is already common in the market. The power of a single-mechanism motor cannot meet the application requirement of the tower crane, and a large-tonnage tower crane often adopts a mode of combined work of a plurality of mechanisms. In a multi-mechanism working mode, the requirement on the synchronism precision of the work of multiple motors is extremely high, if the motors are asynchronous, the lifting hook is inclined, the service lives of the motors and a steel wire rope are influenced if the lifting hook is not synchronous, and the hoisting safety is influenced if the lifting hook is inclined, otherwise, the lifting hook is in danger of overturning. The existing multi-mechanism synchronous control mostly adopts a speed closed-loop control mode of motor or drum speed synchronization, cannot eliminate the accumulated deviation of the long-term operation drum position, lacks redundancy control, and has low precision and reliability.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides a multi-mechanism double-closed-loop master-slave synchronous control system of a tower crane.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a tower crane multi-mechanism double-closed-loop master-slave synchronous control system, which comprises:
a plurality of variable frequency driving devices controlled by a master and a slave are adopted, and each variable frequency driving device drives a winding drum to move through a driving motor based on a control signal;
the speed encoders are arranged at the positions of the motors, and feed back real-time speed signals to the corresponding variable-frequency driving devices after detecting the speeds of the motors, and the variable-frequency driving devices perform synchronous control on the speeds of the motors in real time based on the real-time speed signals;
and the position encoders are arranged at the positions of the winding drums and used for feeding back winding drum position signals to the controller after detecting the positions of the winding drums, and the position encoders are used for synchronously correcting the positions of the winding drums when responding to the exceeding of the deviation of the positions of the winding drums.
Furthermore, the variable frequency driving device comprises a main variable frequency driving device and a plurality of slave variable frequency driving devices, the control signals comprise a main control signal and slave control signals which have the same speed set value, the main control signal is output to the main variable frequency driving device by a controller, and the slave control signals are output to the slave variable frequency driving device by the main variable frequency driving device.
Furthermore, a shared control unit or optical fiber communication is adopted between the master variable-frequency driving device and the slave variable-frequency driving device for data communication.
Further, after receiving the real-time speed signal, the variable frequency driving device adjusts the speed of the motor based on the given speed value and the real-time speed signal, and the adjustment is finished until the given speed value is the same as the real-time speed signal.
Furthermore, when the frequency conversion driving device responds to the real-time speed signal and is smaller than a given speed value, the driving motor is driven to increase the speed.
Further, when the frequency conversion driving device responds to the real-time speed signal and is greater than a given speed value, the driving motor reduces the speed.
Further, after receiving the reel position signal, the controller adjusts the speed of the motor by adding a given speed to the corresponding variable-frequency driving device.
Further, after receiving the reel position signal, the controller does not perform synchronous correction of the reel position in response to the fact that the deviation of the reel position of the multiple mechanisms is smaller than a preset limit value.
Further, after receiving the reel position signal, the controller responds to the situation that the deviation of the reel positions of the multiple mechanisms is larger than a preset limit value, and then synchronous correction of the reel positions is carried out.
Further, the synchronous correction of the positions of the winding drums comprises correcting the positions of the winding drums to be within a preset deviation range by adjusting the speed of the motor, so that the positions of the winding drums of the multiple mechanisms are recovered to be synchronous.
Further, the controller continues the roll position synchronization correction process in response to the multi-mechanism roll detecting non-synchronization via the position encoder.
Further, the controller exits the roll position synchronization correction process after the multi-mechanism rolls are detected by the position encoder to determine synchronization.
Further, the controller responds to the received signals that the position of one winding drum lags behind the position of other winding drums by reducing the speeds of the motors corresponding to the other winding drums until the positions of the winding drums are synchronous.
Furthermore, the controller and the variable frequency driving device are connected through an external terminal or a communication bus to carry out data communication.
Further, the speed encoder is an incremental speed encoder, and the position encoder is an absolute value encoder.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a method and a system for controlling the multi-mechanism double-closed-loop master-slave synchronization of a tower crane, which adopt a master-slave control mode, and realize redundant double-closed-loop control of an inner-layer speed closed loop and an outer-layer position closed loop, wherein the master-slave mode and the speed closed loop can ensure high speed synchronization precision, the inner-layer speed closed loop is always effective, the outer-layer position closed loop is only effective when the position deviation exceeds the limit, the long-term accumulated deviation of the speed synchronization can be eliminated, the speed closed loop and the position closed loop control are redundancy control, any closed loop fails, and the other closed loop still has a synchronization control function.
Drawings
Fig. 1 is a protection block diagram of four-rising synchronization according to an embodiment of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
Example (b):
a tower crane multi-mechanism double-closed-loop master-slave synchronous control system refers to fig. 1, and the used equipment mainly comprises a PLC controller, a variable frequency driving device, a communication bus, an incremental encoder (speed encoder) and an absolute value encoder (position encoder), and the like, wherein:
a PLC controller: the system is used for carrying out bus communication (can also be connected through an external terminal) with the variable-frequency driving devices, issuing start-stop commands and speed setting, receiving reel position signals and carrying out speed regulation by adding a given speed to any variable-frequency driving device to realize position synchronization;
frequency conversion drive arrangement: the speed encoder is used for driving the motor, receiving a motor speed signal transmitted by the speed encoder, realizing speed closed-loop control, and simultaneously carrying out bus communication with other variable-frequency driving devices to realize master-slave control;
a speed encoder: the speed detection device is arranged at the motor and used for detecting the speed of the motor, feeding the speed back to the variable frequency driving device and forming an inner layer speed closed loop with the variable frequency driving device, wherein an incremental speed encoder is adopted for detecting the speed of the motor in the embodiment;
a position encoder: the device is arranged at a winding drum driven by a motor, and is used for detecting the position of the winding drum, feeding the position back to a PLC (programmable logic controller) and forming an outer layer position closed loop with the PLC;
communication bus: the controller is used for data communication between the controller and the variable frequency driving device and between the variable frequency driving device and the variable frequency driving device.
It should be noted that, master-slave control is performed between the variable frequency driving devices, one variable frequency driving device is used as a master variable frequency driving device, the other three variable frequency driving devices are slave variable frequency driving devices, external control signals input by the PLC controller are only connected with the master variable frequency driving device, the master variable frequency driving device sends control words and speed set values of the slave variable frequency driving devices to all the slave variable frequency driving devices, and start-stop commands and set speeds of the slave variable frequency driving devices are consistent with those of the master variable frequency driving devices. Bus communication is carried out between the variable frequency driving devices to realize master-slave control, and a shared control unit, optical fiber communication or other bus network communication modes can be adopted.
The PLC controller can be in bus communication with the variable-frequency driving device and can also be connected through an external terminal to issue a start-stop command and speed setting and receive a position signal of the winding drum, and the PLC controller can adjust the speed of any motor by adding a given speed to any variable-frequency driving device, so that the purpose of adjusting the position of the winding drum is achieved.
Inner layer speed closed loop and outer position closed loop constitute redundant double closed-loop control, and the double closed-loop mode is each other redundant to motor speed is the control means, uses the reel position as final control object, and when arbitrary closed-loop control became invalid, another closed-loop control was still effective, wherein:
the inner-layer speed closed loop is an inner-layer closed loop and is always effective, firstly, the given speeds of the main variable-frequency driving device and the slave variable-frequency driving device are the same, and secondly, when a real-time speed signal is smaller than the given speed value, the driving motor is driven to increase the speed through the respective speed closed loop of each variable-frequency driving device; when the real-time speed signal is larger than the given speed value, the driving motor reduces the speed, so that the actual speed of the motor is consistent with the given speed of the variable-frequency driving device, and the speed synchronization of the motors is achieved.
The outer layer position closed loop directly detects the position of a winding drum, when the position deviation of a multi-mechanism winding drum exceeds the limit, the position adjustment is started, in order to ensure the running safety of the tower crane, in order to avoid the position adjustment from being too frequent, when the position deviation of the multi-mechanism winding drum is smaller than the preset limit value, the multi-mechanism winding drum is considered to be synchronized, when the position deviation exceeds the limit, a PLC controller adds given speed to one or more variable frequency driving devices, the speed of any motor can be adjusted under the condition that the main given speed is the same, the motor corrects the position of the winding drum to be within the preset deviation range through a speed reducer, the position of the multi-mechanism winding drum is recovered to be synchronized, when the multi-mechanism winding drum is detected by an absolute value encoder, the position correction process is withdrawn after the synchronization is determined, the additional given speed of the variable frequency driving devices is cancelled, and then the position is fed back to the variable frequency driving devices to form a speed closed loop after the detection by an incremental encoder, and each variable frequency driving device ensures the speed synchronization of the motors of the multiple mechanisms through a speed closed loop. Wherein: the position adjusting principle is that when one of the mechanisms has position deviation lagging behind other mechanisms, the speed of other motors is reduced instead of being increased, so that position synchronization is realized, and the operation safety is guaranteed. The speed closed loop and the position closed loop are redundant in the embodiment, the motion accuracy of the lifting hook is improved, and the safety and reliability are good.
In the embodiment, the speed synchronization of a plurality of motors can be realized through master-slave control and speed closed loop of the multi-mechanism variable frequency driving device; after long-term operation, due to the existence of accumulated deviation, position deviation overrun can occur, although the speed is still synchronous, the accumulated deviation cannot be eliminated; through the position closed loop, a controller adds a given speed to one or more variable frequency driving devices, so that the speed of any motor is adjusted, and the position of the winding drum is corrected to be within a preset deviation range; after synchronization, the position adjustment is exited and the speed synchronization control is continued.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (15)

1. A tower machine multi-mechanism double-closed-loop master-slave synchronous control system is characterized by comprising:
a plurality of variable frequency driving devices controlled by a master and a slave are adopted, and each variable frequency driving device drives a winding drum to move through a driving motor based on a control signal;
the speed encoders are arranged at the positions of the motors, and feed back real-time speed signals to the corresponding variable-frequency driving devices after detecting the speeds of the motors, and the variable-frequency driving devices perform synchronous control on the speeds of the motors in real time based on the real-time speed signals;
and the position encoders are arranged at the positions of the winding drums and used for feeding back winding drum position signals to the controller after detecting the positions of the winding drums, and the position encoders are used for synchronously correcting the positions of the winding drums when responding to the exceeding of the deviation of the positions of the winding drums.
2. A tower crane multi-mechanism double-closed-loop master-slave synchronous control system as claimed in claim 1, wherein said variable frequency drive comprises a master variable frequency drive and a plurality of slave variable frequency drives, said control signals comprise master control signals and slave control signals containing the same speed set value, said master control signals are outputted from a controller to the master variable frequency drive, and said slave control signals are outputted from the master variable frequency drive to the slave variable frequency drives.
3. The system as claimed in claim 2, wherein the master and slave variable frequency drives are in data communication by a common control unit or optical fiber communication.
4. The system as claimed in claim 2, wherein the variable frequency drive receives the real-time speed signal and adjusts the speed of the motor based on the given speed value and the real-time speed signal until the given speed value is the same as the real-time speed signal.
5. The system as claimed in claim 4, wherein the variable frequency drive drives the motor to increase speed in response to a real-time speed signal being less than a given speed value.
6. The system as claimed in claim 4, wherein the variable frequency drive unit drives the motor to reduce the speed in response to the real-time speed signal being greater than a given speed value.
7. The system as claimed in claim 2, wherein the controller adjusts the speed of the motor by adding a predetermined speed to the corresponding variable frequency driving device after receiving the drum position signal.
8. The system as claimed in claim 7, wherein the controller receives the drum position signal and does not perform drum position synchronization correction in response to the deviation of the multi-mechanism drum position being less than a predetermined limit.
9. The system as claimed in claim 7, wherein the controller receives the drum position signal and corrects the drum position synchronously in response to the deviation of the drum position of the multiple mechanisms being greater than a predetermined limit.
10. The tower crane multi-mechanism double-closed-loop master-slave synchronization control system as claimed in claim 9, wherein the drum position synchronization correction comprises correcting the drum position to within a predetermined deviation range by adjusting the motor speed so that the multi-mechanism drum position is restored to synchronization.
11. The tower crane multi-mechanism double-closed-loop master-slave synchronization control system as claimed in claim 10, wherein the controller continues the drum position synchronization correction process in response to the multi-mechanism drums detecting non-synchronization via the position encoder.
12. The system as claimed in claim 10, wherein said controller is responsive to the multi-mechanism drums being detected by the position encoder to determine synchronization and then to exit the drum position synchronization correction process.
13. The system as claimed in claim 10, wherein the controller responds to the receipt of a signal that the position of one of the reels lags behind the position of the other reels by reducing the speed of the motors corresponding to the other reels until the position of the reels is synchronized.
14. The system as claimed in claim 2, wherein the controller and the variable frequency driving device are connected through external terminals or are in data communication through a communication bus.
15. The system as claimed in claim 1, wherein said speed encoder is an incremental speed encoder and said position encoder is an absolute value encoder.
CN202111390852.2A 2021-11-19 2021-11-19 Double-closed-loop master-slave synchronous control system for multiple mechanisms of tower crane Pending CN114084802A (en)

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CN202111390852.2A CN114084802A (en) 2021-11-19 2021-11-19 Double-closed-loop master-slave synchronous control system for multiple mechanisms of tower crane
PCT/CN2022/133027 WO2023088449A1 (en) 2021-11-19 2022-11-18 Multi-mechanism double-closed-loop master-slave synchronous control system for tower crane

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CN202111390852.2A CN114084802A (en) 2021-11-19 2021-11-19 Double-closed-loop master-slave synchronous control system for multiple mechanisms of tower crane

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WO2023088449A1 (en) * 2021-11-19 2023-05-25 徐州建机工程机械有限公司 Multi-mechanism double-closed-loop master-slave synchronous control system for tower crane

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