Drive control system, method for a crane, crane and medium

Abstract

The present application relates to the crane drive and control technical field, disclose the drive control system, method, crane and medium for crane, the system includes: power supply unit, rectifier unit, common DC bus, multiple drive units, brake unit and control unit;Wherein, one end of rectifier unit is connected with power supply unit, the other end is connected with common DC bus, for converting the alternating current output by power supply unit into direct current;Each drive unit is connected with common DC bus respectively, and each drive unit is parallelly connected with each other;Wherein, the drive unit is used for driving the corresponding actuator of crane;The control unit is respectively connected with rectifier unit, each drive unit and brake unit, for monitoring the bus voltage of common DC bus and the running state of each drive unit;At the same time, the feedback data of each actuator operation is acquired to calculate the synchronization error of each actuator, to correspond to the synchronization instruction issued to each drive unit, which can realize the synchronous operation of multiple mechanisms.

Description

Technical Field

[0001] This invention relates to the field of crane drive and control technology, and more specifically to a drive control system, method, crane, and medium for cranes. Background Technology

[0002] Cranes are machines used for vertical lifting or vertical lifting and horizontal movement of heavy objects. Ring rail cranes, due to their low ground pressure, large lifting torque, and ability to travel in a ring under load, have become key equipment for hoisting ultra-large components in nuclear power, petrochemical, wind power, and marine engineering fields. However, due to their large structural size, high drive power requirements, and stringent synchronization requirements of multiple actuators, traditional drive methods, mostly hydraulic drives and CAN (Controller Area Network) distributed communication control, are gradually revealing their insufficient adaptability. For example, early hydraulic medium leakage led to poor synchronization accuracy of multiple actuators; unbalanced flow rates in the large and small chambers of the cylinder and inconsistent leakage easily caused discontinuous movement and high heat loss. Distributed control often relies on traditional fieldbuses such as CAN, which have low transmission rates and large communication delays, making it difficult to meet the sub-millisecond synchronization requirements of multiple winches and multiple traveling mechanisms.

[0003] Therefore, existing technologies suffer from technical problems such as high drive energy consumption, insufficient synchronization accuracy of multiple mechanisms, poor system stability, and low level of intelligence. There is an urgent need for an integrated solution for crane drive and control to achieve regenerative energy sharing, sub-millisecond synchronization of multiple actuators, and global intelligent scheduling, while simplifying the system structure, reducing costs and maintenance difficulty, and thus meeting the high-precision, high-safety, and high-economic operation requirements of ultra-large hoisting projects. Summary of the Invention

[0004] This invention provides a drive control system, method, crane, and medium for cranes, to solve the problems of high drive energy consumption, poor synchronization accuracy, and low system reliability in the prior art, which make it difficult to meet the requirements of high synchronization accuracy, high operational safety, and high economic efficiency in crane operation.

[0005] In a first aspect, the present invention provides a drive control system for a crane, the system comprising: Power supply unit, rectifier unit, common DC bus, multiple drive units, braking unit and control unit; One end of the rectifier unit is connected to the power supply unit, and the other end is connected to the common DC bus, which is used to convert the AC power output by the power supply unit into DC power. Each drive unit is connected to a common DC bus, and the drive units are connected in parallel with each other; the drive unit is used to drive the corresponding actuator of the crane. The braking unit is connected in parallel to the common DC bus to consume excess regenerative energy; The control unit is communicatively connected to the rectifier unit, each drive unit, and the braking unit to monitor the bus voltage of the common DC bus and the operating status of each drive unit. In addition, it acquires feedback data from the operation of each actuator, calculates the synchronization error of each actuator based on the feedback data, and uses the synchronization error to correct the synchronization commands issued to each drive unit, so as to achieve synchronous operation of multiple mechanisms.

[0006] This invention relates to a drive control system for cranes. By enabling free energy flow among multiple mechanisms through a common DC bus, it maximizes the utilization of regenerative electrical energy and significantly improves energy efficiency. Furthermore, by utilizing real-time industrial Ethernet to acquire feedback data from each actuator, calculating synchronization errors, and dynamically correcting commands, it achieves sub-millisecond communication and sub-millimeter displacement synchronization, greatly enhancing the synchronization accuracy of multiple mechanisms. The integrated solution of the aforementioned common DC bus energy-sharing architecture and real-time Ethernet hierarchical synchronization control effectively solves the core pain points of existing cranes, such as high energy consumption, low synchronization accuracy, and poor reliability, meeting the operational requirements of cranes for high precision, high safety, and high economy.

[0007] In one alternative implementation, the control unit is connected via a real-time industrial Ethernet network, specifically a PROFINET network. The system also includes an auxiliary communication network connected to the PROFINET network, which includes at least one fieldbus or industrial communication protocol network for assisting the control unit in communicating with the operating handle, remote controller, and box-type transformer.

[0008] This invention constructs a hybrid communication architecture based on the PROFINET network as the main network and superimposed with a multi-protocol auxiliary communication network. While retaining the sub-millisecond real-time synchronization capability of the main network, it specifically solves the problems of poor compatibility, high cost, heavy load, and wide range of fault impact that exist in a single PROFINET network, thereby further improving the practicality, reliability and economy of the system.

[0009] In one optional implementation, the control unit includes a main controller and multiple drive controllers; wherein the main controller is used to perform global logic control, synchronous operation of multiple mechanisms, and fault handling; and the drive controllers are used to perform vector control and torque following of the corresponding drive units.

[0010] This invention constructs a two-level hierarchical control architecture with a centrally controlled main controller making global decisions and a distributed execution drive controller, achieving a reasonable division of labor and decoupling of control tasks. It fundamentally solves the core defects of traditional centralized control architecture, such as prominent computational bottlenecks, insufficient synchronization accuracy, and single-point failures affecting the overall system, providing a solid control foundation for the high-precision collaborative operation of multiple mechanisms in ultra-large ring rail cranes.

[0011] In one optional implementation, the control unit adopts a hierarchical synchronization control strategy, which includes a global synchronization strategy, a local load sharing strategy, and a compensation control strategy. Among them, the global synchronization strategy is based on the displacement and velocity feedback from each actuator, and adopts a cross-coupling synchronization algorithm to calculate the synchronization error of each actuator and correct the synchronization command of each drive unit according to the synchronization error, so as to achieve multi-mechanism displacement synchronization. The local load sharing strategy employs master-slave torque following control for multiple drive controllers within the same collaborative execution group. Any drive controller within the group is the master, and the remaining drive controllers are slaves. The slaves follow the master to execute closed-loop speed and torque control and compare the torque or current adjustment output commands of each motor within the group in real time to achieve a uniform distribution of load torque. The compensation control strategy introduces a preset compensation algorithm into the main controller, which corrects the synchronization command based on real-time load and operating speed to eliminate synchronization errors caused by differences in mechanical characteristics.

[0012] The global synchronization strategy proposed in this invention enables high-precision displacement coordination across mechanisms, while eliminating safety accidents such as component eccentric loading, boom twisting, and even overturning, significantly enhancing the system's anti-interference capability. The local load-sharing strategy achieves uniform distribution of load torque within the group, effectively improving system reliability and extending equipment lifespan. The compensation control strategy eliminates inherent mechanical errors, achieving precise synchronization under all working conditions. The synergistic effect of the above-mentioned hierarchical synchronization control strategies enables ultra-large ring rail cranes to complete lifting operations safely, efficiently, and accurately, thereby significantly improving equipment operating efficiency.

[0013] In one optional implementation, the power supply unit includes an input power supply, a central current collector, a prefabricated substation system, and a power distribution system; wherein the prefabricated substation system is used to convert the input power supply into drive power and control power. And / or, the rectifier unit adopts a dual redundant parallel configuration of the rectifier cabinet, which is a diode basic rectifier, a three-phase uncontrolled rectifier bridge, or a PWM controllable rectifier; And / or, the common DC bus adopts a low-impedance copper bus design; And / or, the actuators include hoisting mechanisms and slewing mechanisms; And / or, the braking unit includes a three-phase braking cabinet and a braking resistor.

[0014] In a second aspect, the present invention provides a drive control method for a crane, applied to a drive control system for a crane according to the first aspect above or any corresponding embodiment thereof, the method comprising: Monitor the bus voltage of the common DC bus and the operating status of each drive unit; Furthermore, feedback data from the operation of each actuator is acquired via real-time industrial Ethernet. Based on the feedback data, the synchronization error of each actuator is calculated, and the synchronization error is used to correct the synchronization commands issued to each drive unit, so as to achieve synchronous operation of multiple mechanisms.

[0015] This invention enables the free flow of energy among multiple mechanisms through a common DC bus, thereby maximizing the utilization of regenerative electrical energy and significantly improving energy efficiency. Simultaneously, it utilizes real-time industrial Ethernet to acquire feedback data from each actuator, calculate synchronization errors, and dynamically correct commands, achieving sub-millisecond communication and sub-millimeter displacement synchronization, greatly improving the synchronization accuracy of multiple mechanisms. This integrated drive and control solution effectively addresses the core pain points of existing cranes, such as high energy consumption, low synchronization accuracy, and poor reliability, meeting the demands for high precision, high safety, and high economy in crane operations.

[0016] In one alternative implementation, the drive control method for the crane further includes: Based on the displacement and velocity feedback from each actuator, the main controller uses a cross-coupling synchronization algorithm to calculate the synchronization error of each actuator and corrects the synchronization error before sending synchronization commands to each drive unit. The corresponding drive controller of each drive unit controls the operation of the corresponding actuator according to the corrected synchronization command to achieve multi-mechanism displacement synchronization. For multiple actuators that drive the same actuator, the drive controller of the corresponding drive unit of any actuator is used as the master, and the other drive controllers are used as slaves. The master sends torque or speed commands to the slaves so that the load torque of each drive unit is kept uniform. The main controller calculates the amount of synchronization error compensation caused by mechanical characteristics based on real-time load and operating speed through a preset compensation algorithm, and synchronizes the synchronization error compensation and synchronization error correction instructions based on the synchronization error compensation amount.

[0017] This invention clarifies the collaborative division of labor between the main controller and the drive controller, refines the execution logic of each level of control algorithm, and designs a three-level hierarchical synchronization control strategy of global displacement synchronization, local torque load sharing, and mechanical error compensation. It constructs a complete closed-loop control system from global to local, from electrical control to mechanical characteristic compensation, which completely solves the industry problems of "large displacement deviation between groups, uneven load distribution within groups, and inability to eliminate inherent mechanical errors" in the multi-mechanism collaborative operation of ultra-large ring rail cranes. It meets the high precision, high safety, and high economy requirements of ultra-large hoisting projects.

[0018] In one optional implementation, the drive control method for the crane further includes: when a fault is detected in any drive unit, the main controller disconnects the actuator corresponding to the faulty drive unit and controls the remaining actuators to operate safely or stop.

[0019] When a drive unit fails, the present invention can effectively handle the faulty equipment and prevent the fault from spreading through the hierarchical processing of the main controller, thereby maximizing the continuity and safety of the operation and reducing economic losses.

[0020] Thirdly, the present invention provides a crane, the crane including the drive control system for the crane described in the first aspect or any corresponding embodiment thereof.

[0021] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to perform the drive control method for a crane described in the second aspect or any corresponding embodiment thereof. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a structural block diagram of a drive control system for a crane according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the controller structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the main circuit topology of the entire machine; Figure 4 This is a schematic diagram of an Ethernet distributed control architecture; Figure 5 This is a schematic flowchart of a first method for driving control of a crane according to an embodiment of the present invention; Figure 6 This is a structural block diagram of a crane. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] A crane is a machine used for vertical lifting or vertical lifting and horizontal movement of heavy objects. The tonnage requirements for cranes vary depending on the working environment. For example, in nuclear power, petrochemical, wind power, and marine engineering fields, ultra-large tonnage ring rail cranes are often required for lifting operations. In practical applications, ring rail cranes have advantages such as low ground pressure, large lifting torque, and the ability to travel in a ring under load, making them key equipment for lifting ultra-large components in these fields. However, due to their large structural size, high drive power requirements, and stringent synchronization requirements for multiple actuators, existing drive and control methods are gradually revealing their insufficient adaptability.

[0026] Currently, the drive methods for ring track cranes are mainly divided into two categories: hydraulic drive and independent busbar electric drive. Hydraulic drive relies on hydraulic pumps and motors / cylinders to transmit power. While it offers high power density and smooth transmission, it suffers from problems such as poor synchronization accuracy of multiple actuators due to hydraulic fluid leakage, and inconsistent flow rates and leakage in the cylinder's large and small chambers, which can lead to discontinuous movement. Furthermore, the system experiences significant heat loss and requires high installed power; closed-loop systems necessitate additional oil replenishment and cooling systems, resulting in complex structures and substantial energy waste. In addition, high driving torque requires oversized or numerous reducers, raising the equipment's center of gravity, increasing structural bulk, and simultaneously increasing cost and maintenance difficulty. Moreover, the valve-controlled reversing impact and susceptibility to oil temperature in hydraulic systems make it difficult to meet the long-term, high-precision load-bearing requirements of ring track cranes.

[0027] Further analysis reveals that the independent bus electrical drive scheme uses multiple independent frequency converters to drive the motors to improve efficiency. However, each frequency converter is independently configured with rectifier and braking units, which means that regenerative energy cannot be shared. During descent or braking, energy can only be consumed through the braking resistor. In particular, simultaneous braking by multiple units can easily cause grid voltage fluctuations. In addition, the bus voltages are independent of each other and are greatly affected by input voltage fluctuations. The synchronization of multiple mechanisms during coordinated operation is poor, and the hardware redundancy is high. The input wiring, contactors, reactors and other components are repeatedly configured, which increases costs, installation space and failure points, making it difficult to ensure system stability.

[0028] Furthermore, in terms of control methods, early crane distributed control relied heavily on traditional fieldbuses such as CAN, but their low transmission rates and large communication delays made it difficult to meet the sub-millisecond synchronization requirements of multiple hoists and traveling mechanisms. Moreover, the strong closed nature of bus protocols and poor compatibility between devices from different manufacturers led to high system integration difficulties and easily resulted in "data silos," thus hindering global scheduling and remote monitoring.

[0029] Based on this, this embodiment proposes an improved scheme for crane drive and control, namely a drive control system and method for cranes, to solve the problems of high drive energy consumption, insufficient synchronization accuracy of multiple mechanisms, poor system stability, and low level of intelligence in the existing technology, thereby improving the operating efficiency of cranes.

[0030] This embodiment provides a drive control system for a crane. Figure 1 This is a structural block diagram of a drive control system for a crane according to an embodiment of the present invention, such as... Figure 1 As shown, the system includes a power supply unit 110, a rectifier unit 120, a common DC bus 130, multiple drive units 140, a braking unit 150, and a control unit 160. One end of the rectifier unit 120 is connected to the power supply unit 110, and the other end is connected to the common DC bus 130, used to convert the AC power output from the power supply unit 110 into DC power. Each drive unit 140 is connected to the common DC bus 130, and the drive units 140 are connected in parallel. The drive units 140 are used to drive the corresponding actuators of the crane. The braking units 150 are connected in parallel to the common DC bus 130 to consume excess regenerated energy. The control unit 160 is communicatively connected to the rectifier unit 120, each drive unit 140, and the braking unit 150 via a real-time industrial Ethernet connection, used to monitor the common DC bus 130. The system monitors the bus voltage of the 30 and the operating status of each drive unit 140; when any drive unit 140 is in a power generation state, the system controls the regenerative power generated by the drive unit 140 to be preferentially supplied to other drive units 140 in a motoring state through the common DC bus 130; when the bus voltage exceeds a preset threshold, the system controls the braking unit 150 to consume excess regenerative power to stabilize the bus voltage of the common DC bus 130; and it acquires feedback data of the operation of each actuator, calculates the synchronization error of each actuator based on the feedback data, and uses the synchronization error to correct the synchronization command issued to each drive unit 140 to achieve synchronous operation of multiple mechanisms.

[0031] It should be noted that in this embodiment, the power supply unit 110 is the system energy inlet and front-end power supply hub, used to convert external input power (such as high-voltage AC power input from an external 10KV industrial power grid or generator) and then input it into the subsequent rectifier unit 120. The rectifier unit 120 can convert the AC power output from the power supply unit 110 into stable DC power and then input it into the common DC bus 130 to realize the flow and sharing of system energy. The drive unit 140 inverts the DC power from the bus into three-phase AC power with adjustable frequency and voltage to drive the main hook, luffing, and circular walking actuators. At the same time, it supports energy flow, that is, when the mechanism is lowered or decelerated, the motor works in the generator state and can convert mechanical energy into electrical energy to feed back to the bus. The braking unit 150 automatically starts when the regenerated electrical energy cannot be completely absorbed internally and the voltage exceeds the preset threshold. For example, the braking resistor can be controlled by the three-phase braking cabinet to convert the excess electrical energy into heat energy for dissipation, thereby stabilizing the bus voltage within a safe range.

[0032] In this embodiment, the specific type of crane and the specific contents of each component of the system are not limited and can be adapted to actual needs. For example, in addition to ring rail cranes, it may also include ultra-large gantry cranes (equipped with multi-main hook synchronous lifting and multi-wheel synchronous traveling mechanism of the trolley, generating a large amount of regenerative energy during operation), large-tonnage crawler cranes (equipped with main hook, auxiliary hook, luffing, slewing and other actuators, often using double main hook lifting operations, with strict requirements for the synchronization accuracy and fault tolerance of multiple mechanisms), offshore wind power installation cranes (equipped with ultra-large tonnage main hook, luffing and slewing mechanisms, generating huge amounts of regenerative energy), etc.; this is only an example for illustration.

[0033] In this embodiment of the invention, the free flow of energy among multiple mechanisms is achieved through a common DC bus, thereby maximizing the utilization of regenerative electrical energy and significantly improving energy efficiency. Furthermore, by utilizing real-time industrial Ethernet to acquire feedback data from each actuator, calculating synchronization errors, and dynamically correcting commands, sub-millisecond-level communication and sub-millimeter-level displacement synchronization can be achieved, greatly improving the synchronization accuracy of multiple mechanisms. The integrated solution of the above-mentioned common DC bus energy sharing architecture and real-time Ethernet hierarchical synchronization control effectively solves the core pain points of existing cranes, such as high energy consumption, low synchronization accuracy, and poor reliability, and meets the high-precision, high-safety, and high-economic operation requirements of cranes.

[0034] In this embodiment, the power supply unit 110 includes an input power supply, a central current collector, a transformer substation system, and a power distribution system. The transformer substation system converts the input power supply into drive power and control power. It should be explained that the input power supply refers to the connection to the high-voltage industrial power grid of the factory / construction site, providing the machine with raw mains power. The central current collector ensures uninterrupted and uninterrupted electrical conduction between the rotating and stationary parts of the crane, allowing for continuous power supply during 360° rotation. The transformer substation system transforms the high-voltage input power supply (e.g., 10KV) into different low-voltage power supplies to power different devices (e.g., converting 10KV to 0.38KV to power the control unit; converting to 0.48KV to power the main circuit).

[0035] In this embodiment, the rectifier unit 120 adopts a dual-redundant parallel configuration of rectifier cabinets. The rectifier cabinets are diode basic rectifiers, three-phase uncontrolled rectifier bridges, or PWM controllable rectifiers. It should be explained that by using a dual-redundant configuration with two rectifier cabinets operating in parallel, when one rectifier cabinet fails, the system can automatically disconnect the faulty unit, and the other rectifier cabinet will operate at reduced capacity to maintain the system's basic operational capability. This completely avoids interruptions in hoisting operations due to rectifier unit failures, ensuring the safety of hoisting ultra-large tonnage components.

[0036] In this embodiment, the common DC bus 130 adopts a low-impedance copper bus design. It should be explained that the large cross-section, high-purity low-impedance copper bus design can control the bus impedance to below the milliohm level, effectively reducing heat loss during high current transmission and improving the energy utilization efficiency of the system.

[0037] In this embodiment, the actuator includes a hoisting mechanism and a slewing mechanism. It should be explained that the hoisting mechanism is responsible for the vertical lifting and lowering of the component (which may include a main hook hoist, a luffing hoist, a fast hook hoist, etc.), and the slewing mechanism (i.e., the circular traveling mechanism) is responsible for the horizontal circumferential movement of the component, which can meet the equipment's 360° circumferential movement operation requirements.

[0038] In this embodiment, the braking unit 150 includes a three-phase braking cabinet and a braking resistor. It should be explained that when the mechanism decelerates and lowers, generating excessive regenerative energy that causes the bus voltage to rise, the three-phase braking cabinet controls the braking resistor to engage, converting the excess energy into heat energy for consumption. This stabilizes the bus voltage within a safe operating range, effectively preventing overvoltage protection triggering and damage to the frequency converter, thus providing a reliable guarantee for the safe operation of the system.

[0039] In this embodiment, the real-time industrial Ethernet is a PROFINET network. The system also includes an auxiliary communication network connected to the PROFINET network. The auxiliary communication network includes at least one fieldbus or industrial communication protocol network for assisting the control unit in communicating with the operating handle, remote control, and box-type transformer.

[0040] It should be explained that the PROFINET network is a deterministic real-time communication protocol based on Industrial Ethernet. It includes multiple versions, such as the highest level IRT isochronous real-time version used in this system. The communication cycle is ≤1ms and the jitter is <1μs. It is the communication foundation for realizing sub-millisecond synchronous control of multiple mechanisms. It only needs to carry core high-priority services, such as multi-mechanism synchronous command issuance, drive unit vector control, encoder displacement / speed feedback, bus voltage monitoring, rectifier / braking unit control, and connect to the main controller, all drive controllers, absolute encoders and other core devices.

[0041] To further explain, the auxiliary communication network is specifically designed to carry non-real-time, low-priority services. Its core functions are to strip redundant traffic from the main network, ensure the real-time performance of the main network, reduce hardware costs, and achieve fault isolation. Its specific type is determined based on actual needs. For example, CANOPEN bus (Controller Area Network OPEN, which has strong anti-interference capabilities and good real-time performance, and can be used to connect operating handles, remote controls, and other operating devices), MODBUS-RTU protocol (a serial communication implementation of the Modbus protocol, which is low-cost and easy to deploy, and can be used to connect instrumentation devices such as box-type transformers, electricity meters, and temperature control devices), and EtherNet / IP (which can be used to connect auxiliary devices such as anemometers and cameras).

[0042] In this embodiment of the invention, by constructing a hybrid communication architecture based on the PROFINET network as the main network and superimposed with a multi-protocol auxiliary communication network, the sub-millisecond real-time synchronization capability of the main network can be retained, while specifically solving the problems of poor compatibility, high cost, heavy load, and wide range of fault impact of a single PROFINET network, thereby further improving the practicality, reliability and economy of the system.

[0043] In this embodiment, the control unit includes a main controller and multiple drive controllers; wherein, the main controller is used to perform global logic control, synchronous operation of multiple mechanisms, and fault handling; the drive controllers are used to perform vector control and torque following of the corresponding drive units.

[0044] It needs to be explained that the main controller undertakes the highest-level overall scheduling and complex calculation tasks for the entire system, such as global logic scheduling (i.e., receiving operation instructions and coordinating the overall machine operation process and the coordinated actions of each mechanism), multi-mechanism synchronous control (running global cross-coupling synchronization algorithms and mechanical error compensation algorithms, calculating synchronization errors and dynamically correcting issued instructions), global energy management (scheduling the priority sharing of regenerated energy from the common DC bus and controlling the braking unit to stabilize the bus voltage), and global fault handling (monitoring the operating status of all units and executing fault isolation or safe shutdown control). Each drive controller corresponds one-to-one with each drive unit, undertaking the low-level real-time control tasks of a single mechanism / single motor, such as precise motor drive (executing dual closed-loop vector control of motor speed loop and current loop to precisely adjust motor speed and output), local load sharing (executing master-slave torque following control within the same collaborative execution group to achieve uniform load distribution among multiple motors within the group), real-time status feedback (uploading operating parameters and status information such as motor current, torque, and speed to the main controller), and local fault protection (independently executing local protection such as overcurrent, overvoltage, and overheating to prevent fault propagation).

[0045] In this embodiment of the invention, a two-level hierarchical control architecture is constructed by building a global centralized decision-making main controller and superimposing a distributed execution drive controller. This achieves a reasonable division of labor and decoupling of control tasks, fundamentally solving the core defects of traditional centralized control architecture, such as prominent computational bottlenecks, insufficient synchronization accuracy, and single-point failures affecting the overall system. This provides a solid control foundation for the high-precision collaborative operation of multiple mechanisms in ultra-large ring rail cranes.

[0046] In this embodiment, the control unit adopts a hierarchical synchronization control strategy, which includes a global synchronization strategy, a local load-sharing strategy, and a compensation control strategy. Specifically, the global synchronization strategy involves the main controller calculating the synchronization error of each actuator based on the displacement and velocity feedback from each actuator using a cross-coupling synchronization algorithm. The synchronization command of each drive unit is then corrected according to the synchronization error to achieve multi-mechanism displacement synchronization.

[0047] It should be explained that by using a cross-coupling synchronization algorithm instead of the traditional master-slave or parallel synchronization algorithms, the displacement and speed errors of all actuators can be incorporated into a unified closed-loop calculation, achieving global cross-correction of errors rather than independent correction, thus completely eliminating the error accumulation problem of traditional algorithms. Simultaneously, combined with the sub-millisecond communication capabilities of the PROFINET network, the displacement synchronization accuracy of multi-hoisting and multi-ring traveling mechanisms can be controlled at the 0.1mm level, meeting the hoisting and alignment requirements of ultra-large precision components. Furthermore, when an actuator encounters sudden load fluctuations or external interference, the main controller can detect the synchronization error within 1ms and issue correction commands to all relevant mechanisms, achieving global coordinated adjustment and avoiding major safety accidents such as component overload, boom twisting, or even overturning caused by the amplification of deviations in a single mechanism.

[0048] In this embodiment, the local load sharing strategy employs master-slave torque following control for multiple drive controllers within the same collaborative execution group. Any drive controller within the group is the master, and the remaining drive controllers are slaves. The slaves follow the master to execute closed-loop speed and torque control and compare the torque or current adjustment output commands of each motor within the group in real time to achieve a uniform distribution of load torque.

[0049] It should be explained that, for the working condition where multiple motors in the same collaborative execution group drive the same load, a master-slave speed closed-loop and torque following control strategy is adopted. The slave motor follows the torque command output of the master motor in real time, rather than just following the speed command. This eliminates the problem of uneven load distribution caused by differences in motor characteristics and mechanical transmission clearances at the root, and can keep the load torque deviation of each motor in the same collaborative execution group at a low level.

[0050] In this embodiment, the compensation control strategy introduces a preset compensation algorithm into the main controller, and corrects the synchronization command based on real-time load and running speed to eliminate synchronization errors caused by differences in mechanical characteristics.

[0051] It should be explained that the specific content of the preset compensation algorithm can be adaptively adjusted according to actual needs. For example, preset algorithms such as mechanical backlash compensation and wire rope elastic elongation compensation can be introduced. The compensation amount is dynamically calculated based on real-time load, running speed and historical running data to actively correct the synchronization command, rather than passively waiting for the error to occur before adjusting. This can solve the defect of traditional synchronization algorithms that can only guarantee accuracy under specific loads and speeds. It can maintain stable synchronization accuracy under all working conditions such as no load, full load, acceleration, deceleration and constant speed. It is especially suitable for the high load and wide speed range operation characteristics of ultra-large ring rail cranes.

[0052] Furthermore, the three strategies described above in this embodiment are not simply a superposition of three independent algorithms, but rather form a complete closed-loop control system encompassing "global inter-group control, local intra-group control, and compensation control error control." Specifically, the global synchronization strategy ensures accurate relative positioning between different actuators, the local load-sharing strategy ensures reasonable load distribution within the same actuator, and the compensation control strategy eliminates inherent deviations caused by the mechanical system. The synergistic effect of these three strategies enables the ultra-large ring rail crane to safely, efficiently, and accurately complete the hoisting operations of ultra-large components, thereby significantly improving equipment operating efficiency.

[0053] In this embodiment, the control unit 160 can also be referred to as a controller. Figure 2 This is a schematic diagram of the controller structure according to an embodiment of the present invention. Figure 2 As shown, the controller includes one or more processors 210, memory 220, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise as required. The processors can process instructions executed within the controller, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple controllers can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 2 Take a processor 210 as an example.

[0054] Processor 210 may be a central processing unit, a network processor, or a combination thereof. Processor 210 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0055] The memory 220 stores instructions executable by at least one processor 210 to cause the at least one processor 210 to perform the method shown in the above embodiments.

[0056] The memory 220 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the controller. Furthermore, the memory 220 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 220 may optionally include memory remotely located relative to the processor 210, and these remote memories may be connected to the controller via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0057] The memory 220 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 220 may also include a combination of the above types of memory.

[0058] The controller also includes an input device 230 and an output device 240. The processor 210, memory 220, input device 230, and output device 240 can be connected via a bus or other means. Figure 2 Taking the example of a connection between China and Israel via a bus.

[0059] Input device 230 can receive input digital or character information, and generate signal inputs related to user settings and function control of the thermal power unit's operation control unit, such as a touch screen, keypad, mouse, trackpad, touchpad, indicator, one or more mouse buttons, trackball, joystick, etc. Output device 240 may include display devices, auxiliary lighting devices (e.g., LEDs), and haptic feedback devices (e.g., vibration motors). The aforementioned display devices include, but are not limited to, liquid crystal displays, light-emitting diodes, displays, and plasma displays. In some alternative embodiments, the display device may be a touch screen.

[0060] It should be noted that the control method for the crane drive control system described below is integrated into the main control unit of the crane drive control system in this embodiment. This enables the crane drive control system to integrate energy management, voltage stabilization control, and multi-mechanism synchronous control into the same control unit, avoiding coordination delays and data interaction errors between multiple independent control systems. This results in a faster system response and more coordinated operation. In addition, high-precision synchronous control significantly shortens the hoisting and alignment time of ultra-large components, while energy recovery and utilization reduce equipment heating and downtime cooling time, significantly improving overall operating efficiency. Furthermore, the above drive control scheme can be adapted to cranes of different tonnages and configurations, and is especially suitable for the multi-mechanism, high-load, and high-precision operation requirements of ultra-large ring rail cranes, possessing strong engineering practical value.

[0061] In one specific embodiment, taking a ring rail crane as an example, to address the technical problems of high drive energy consumption, insufficient synchronization accuracy of multiple mechanisms, poor system stability, and low level of intelligence in existing ring rail cranes, an integrated solution of common bus drive and Ethernet distributed control is provided. This solution achieves regenerative energy sharing, sub-millisecond synchronization of multiple actuators, and global intelligent scheduling, while simplifying the system structure, reducing costs and maintenance difficulty, and thus meeting the high precision, high safety, and high economy requirements of ultra-large hoisting projects. This embodiment adopts a common DC bus centralized drive architecture to solve the problems of main circuit drive instability and hardware redundancy, solves the problems of multi-mechanism synchronization and anti-interference through real-time industrial Ethernet and distributed control strategies, and achieves deep collaboration between drive and control by combining closed-loop feedback and intelligent algorithms.

[0062] It should be noted that the above solution mainly includes a common bus drive system architecture design, an Ethernet distributed control architecture design, and control strategies; among them, Figure 3 This is a schematic diagram of a common bus drive system architecture. It needs to be explained that... Figure 3 This fully demonstrates the entire process of electrical energy input from the external power grid to the final driving of various actuators, clearly illustrating the core architectural features of this embodiment: "dual redundant power supply, centralized rectification, shared DC bus energy, and centralized braking." As shown in the figure, the shared bus drive system consists of the following parts: Input power: Two high-voltage 10KV power input modes are available: mains power and generator set; the two independent power sources serve as backups for each other, and uninterrupted power supply is achieved through dual power switching, thus solving the safety hazard of power outages during ultra-large hoisting operations from the source; Central current collector: Provides 10KV high-voltage power to the entire unit; The main function of the prefabricated substation system is to transform the high voltage of 10KV to 0.48KV (main circuit drive power supply) and 0.38KV (control power supply). Power distribution system: Input power cabinet Q1, two sets of contactor cabinets K1 and K2; Rectification system: Rectifier cabinet 1 and rectifier cabinet 2 (diode basic rectification, three-phase uncontrolled rectifier bridge or PWM controllable rectifier can be selected according to actual conditions); the two sets of rectifier cabinets operate in parallel and serve as redundant backups for each other; DC bus system: 1 set of low-impedance common DC busbars; Main hook hoisting mechanism: N1 main hook inverter cabinets (N1≥2, matching the number of actuator motors); Luffing hoisting mechanism: N2 units of luffing inverter cabinet (N2≥2, matching the number of actuator motors); Quick hook hoisting mechanism: N3 quick hook inverter cabinets (N3≥2, matching the number of actuator motors); Rotary mechanism: N4 rotary inverter cabinets (N4≥2, matching the number of actuator motors); Braking mechanism: 1 set of three-phase braking cabinet and braking resistor cabinet R1 (this equipment is not required if there is a feedback grid rectifier unit). The backup mechanism, namely the backup inverter cabinet, consists of one hoist inverter cabinet and one rotary inverter cabinet. The rectifier system employs diode basic rectification, a three-phase uncontrolled rectifier bridge, or a PWM controllable rectifier, connected to the power grid, converting AC power into DC power input to a common DC bus, followed by a supporting capacitor for voltage regulation. Compared to a single speed control device that combines rectification and inversion, this significantly reduces redundant hardware and fault issues in the rectifier equipment. The common DC bus uses a low-impedance copper bus design, uniformly supplying power to all inverters and enabling energy sharing among multiple drive mechanisms. Each hoist inverter drives one motor, while the rotary inverter connects to multiple rotary motors. The hoist inverter uses a PG vector control mode, with multiple hoists operating synchronously in a master-slave mode, employing speed and torque-limited drive methods. The rotary inverter uses a PG vector speed control mode, supporting multiple rotary motors, each motor individually controlled. Thermal and overload protection signals are fed back to the control system to monitor the status of the rotary motor. Abnormal motors are promptly shut down, while normal motors continue to operate normally. The energy feedback / braking unit is connected in parallel to the common DC bus. During descent or braking, the regenerated energy from the motor is preferentially supplied to other motors. Excess energy can be fed back to the grid through the feedback unit. The bus voltage can also be monitored in real time; if it exceeds the limit, the three-phase braking cabinet braking unit is activated. The resistor consumes redundant energy, preventing overvoltage protection. Compared to energy storage units, which are complex, expensive, difficult to maintain, and have a high failure rate, the three-phase braking cabinet and braking resistor offer the following advantages: simple structure, low cost, simple control, fast response, high reliability, simple maintenance, and suitability for harsh environments. In addition, the rectifier system is equipped with an input reactor and an EMC filter to suppress grid harmonics and electromagnetic interference, thereby improving the quality of input power. The common DC bus is equipped with an energy storage capacitor bank to stabilize the bus voltage, absorb the inrush current during the start-up and shutdown of multiple mechanisms, and reduce voltage fluctuations. The inverter output is equipped with an output reactor to suppress high-frequency harmonic impacts from the motor and extend the motor insulation life. All drive units integrate temperature detection, overcurrent, overvoltage, and undervoltage protection modules and communicate with the main control system in real time.

[0063] In this embodiment, Figure 4This is a schematic diagram of an Ethernet distributed control architecture. As shown in the diagram, the entire communication network formed by this architecture, divided by control hierarchy, consists of a main control cabinet, a server cabinet, a main power supply cabinet, a transformer substation cabinet, and a driver's cab control cabinet. The main control cabinet (taking 4 main hook winches and 4 luffing winches as an example) consists of the following parts: 8 main hook winches (1-4#) with 8 motor inverters controlled by 2 CU320-2PN control units; 8 luffing winches (1-4#) with 8 motor inverters controlled by 2 CU320-2PN control units; 2 fast hook winches with 2 motor inverters + 2 backup inverters controlled by 1 CU320-2PN control unit; 2 BLM rectifier units and 1 braking unit controlled by 1 CU320-2PN control unit; 1-8# slewing inverters controlled by 2 CU320-2PN control units; and absolute encoders for the main hooks, luffing winches, and fast hook winches (1-9#), and a central controller CPU1515F-2PN. The PLC consists of two 16-port switches, communicating with the main PLC via PROFINET. The driver's cab comprises a 6-port switch, a Siemens HMI, and an ET200SP remote I / O device, connected to the main control cabinet via PROFINET communication lines. The ET200SP remote I / O device integrates a CAN communication protocol module, forming a communication network with the remote controller and left and right handles. The transformer substation communicates with the main control cabinet's CPU1515F-2PN PLC via a 485 MODBUS-RTU communication network. The main power supply cabinet is primarily composed of ET200SP remote I / O devices, which handle power distribution and external signal acquisition, communicating with the main unit via PROFINET.

[0064] To further explain, the distributed control system mainly consists of: a main control PLC, distributed I / O slave stations, a drive system control unit, detection signals, control handles, a remote control, and driver's cab button operation units. It utilizes a hybrid communication architecture based on the PROFINET real-time industrial Ethernet main network + CAN + 485 communication protocol auxiliary communication network. Compared to a pure PROFINET communication network, this hybrid communication network offers higher integration, compatibility with modules and mechanisms using various communication methods, and greater flexibility. The functions of each component of the above system are as follows: The main control PLC unit uses a Siemens high-performance S7-1500 safety-type PLC as the central processing unit. The main communication uses PROFINET communication as the main communication method for the whole machine, and the auxiliary communication module MODBUS-RTU collects high voltage, current and other protection data of the transformer cabinet. The central processing unit is the core of the system and is responsible for receiving operation commands (lifting, traveling, luffing), generating global synchronization reference commands, processing feedback data, and realizing global logic control and fault interlocking. Distributed I / O slave stations: configured according to the type of actuator (power cabinet slave, driver's cab slave, etc.). Each slave unit corresponds to a specific coordinating mechanism and is responsible for receiving master control commands, collecting local sensor data (encoder, tension sensor, limit switch), and executing the corresponding logic control. The drive unit, or inverter, has a built-in control chip and main drive inverter IGBT. It is responsible for receiving commands from the main control unit, realizing motor vector control, and providing feedback on the motor's operating status (speed, current, torque). Operating unit: cab I / O button commands and remote control commands; cab ET200SP slave station configuration 1 CAN communication protocol module to receive commands from left and right handles and remote control.

[0065] In this embodiment, the optimized design of the communication network includes the main communication adopting the PROFINET bus protocol, with a transmission rate of ≥100Mbps and a communication cycle of ≤1ms, to meet the low latency requirements of multi-mechanism synchronous control; in addition, the communication lines adopt shielded twisted pair or optical fiber, and surge protectors are configured at key nodes to improve the anti-electromagnetic interference capability and adapt to the harsh operating environment of the ring rail crane.

[0066] According to embodiments of the present invention, based on the drive control system mentioned in the above embodiments, a corresponding embodiment of a drive control method for a crane is also provided, applied to a drive control system for a crane. It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0067] This embodiment provides a drive control method for a crane, which is applied to a drive control system for a crane. Figure 5 This is a schematic flowchart of a first embodiment of a drive control method for a crane according to an embodiment of the present invention, as shown below. Figure 5 As shown, the process includes the following steps: Step S501: Monitor the bus voltage of the common DC bus and the operating status of each drive unit.

[0068] In this embodiment, the specific detection method for bus voltage and operating status can be adaptively determined according to actual needs. For example, the DC voltage at both ends of the common DC bus can be collected in real time by a voltage sensor and sent locally to the drive controller or directly uploaded to the main controller via a real-time industrial Ethernet. The main controller continuously samples and compares the voltage values ​​in real time to determine whether they exceed a preset threshold. Each drive unit has its own built-in current, temperature, and fault detection circuits to collect operating parameters such as motor current, output torque, operating speed, module temperature, and fault codes in real time. All drive units upload their own operating status, operating data, and fault information to the main controller in real time via PROFINET real-time industrial Ethernet. The main controller uniformly summarizes and diagnoses the operating conditions, abnormalities, and fault states of each drive unit in real time, realizing full-domain online monitoring.

[0069] Step S502: When any drive unit is in the power generation state, the regenerative power generated by the control drive unit is preferentially supplied to other drive units in the electric state through the common DC bus.

[0070] It should be noted that during crane hoist lowering (such as main hook lowering, luffing descent), mechanism deceleration, and slewing braking, the motor switches from passive drive to generator mode, and the corresponding drive unit enters the generator state to produce regenerative electrical energy. Relying on the bidirectional energy transmission characteristic of the common DC bus, the regenerative electrical energy is directly fed into the common DC bus without direct loss or waste. The system prioritizes distributing this part of the electrical energy to the electric drive unit that is currently working and consuming electricity for local consumption, so as to realize the mutual utilization of energy between mechanisms.

[0071] Step S503: When the bus voltage exceeds the preset threshold, the braking unit is controlled to consume excess regenerated energy to stabilize the bus voltage of the common DC bus.

[0072] It should be noted that when multiple mechanisms are simultaneously in the lowering and deceleration state, the total amount of regenerative energy fed back to the common DC bus exceeds the capacity that the drive unit can consume in the current electric state. This excess energy will cause the bus voltage to rise continuously. To prevent overvoltage damage to electrical equipment, in this embodiment, after the main controller detects that the bus voltage exceeds a set threshold, it immediately triggers the braking unit to operate, converting the excess regenerative energy into heat energy through the braking resistor, thereby stabilizing the bus voltage within a safe and permissible range. The value of the preset threshold can be determined based on actual needs.

[0073] Step S504: Obtain feedback data of each actuator's operation through real-time industrial Ethernet, calculate the synchronization error of each actuator based on the feedback data, and use the synchronization error to correct the synchronization command issued to each drive unit, so as to achieve synchronous operation of multiple mechanisms.

[0074] In this embodiment, this step aims to use real-time industrial Ethernet to collect high-speed, real-time operational feedback data such as position and speed of each crane actuator; the main controller compares the actual operating conditions of each mechanism, calculates the synchronization deviation between them, and then dynamically corrects the control commands sent to each drive unit based on the error, forcing each actuator to adjust its operating rhythm, and finally achieving synchronous operation of multiple mechanisms in terms of displacement and speed coordination.

[0075] The drive control method for cranes provided in this embodiment enables the free flow of energy among multiple mechanisms through a common DC bus, thereby maximizing the utilization of regenerative electrical energy and significantly improving energy efficiency. At the same time, it also uses real-time industrial Ethernet to acquire feedback data from each actuator, calculate synchronization error and dynamically correct commands, achieving sub-millisecond synchronization response, greatly improving the synchronization accuracy of multiple mechanisms, and meeting the high precision, high safety and high economy requirements of crane operation.

[0076] It should be noted that steps S501-S503 above belong to the energy management steps; step S504 is the synchronization control step; wherein, the synchronization control step further includes: Step a1: Based on the displacement and velocity feedback from each actuator, the main controller uses a cross-coupling synchronization algorithm to calculate the synchronization error of each actuator and corrects the synchronization error before sending synchronization commands to each drive unit. The corresponding drive controller of each drive unit controls the operation of the corresponding actuator according to the corrected synchronization command to achieve multi-mechanism displacement synchronization.

[0077] In this embodiment, this step aims to achieve high-precision cross-mechanism collaboration without error accumulation through global cross-coupling synchronous control.

[0078] Step a2: For multiple actuators that drive the same actuator, the drive controller of the corresponding drive unit of any actuator is used as the master, and the other drive controllers are used as slaves. The master sends torque or speed commands to the slaves so that the load torque of each drive unit is kept uniform.

[0079] In this embodiment, this step aims to achieve uniform load distribution within the same actuator through local master-slave torque load sharing control. This effectively avoids common faults such as partial motor overload burnout, gearbox uneven load wear, drive shaft breakage, and wire rope breakage due to uneven stress. Simultaneously, it eliminates mechanical vibration and noise caused by uneven load, significantly improving the overall machine's operational stability and extending equipment lifespan. Furthermore, this embodiment supports flexible configuration of any drive controller within the group as the master. When the original master fails, the system can automatically designate another normal drive controller within the group as the new master without requiring downtime for switching, ensuring the continuity of hoisting operations and avoiding the safety risks associated with suspending oversized components.

[0080] Step a3: The main controller calculates the compensation amount for the synchronization error caused by mechanical characteristics based on the real-time load and operating speed through a preset compensation algorithm, and synchronizes the synchronization error compensation amount and the synchronization error correction command based on the synchronization error compensation amount.

[0081] It should be noted that this step aims to overcome the limitations of electrical synchronization through dynamic compensation control of mechanical characteristics, achieving precise synchronization under all operating conditions. Specifically, by offsetting some machining and installation errors through electrical compensation, the manufacturing tolerances and installation accuracy requirements of the mechanical system can be appropriately reduced while ensuring synchronization accuracy, significantly lowering the production and manufacturing costs of the equipment.

[0082] Note: For a more detailed understanding of steps a1-a3 in this embodiment, please refer to the relevant content above. Further details will not be provided here.

[0083] In this embodiment of the invention, by clarifying the collaborative division of labor between the main controller and the drive controller, refining the execution logic of each level of control algorithm, and designing a three-level hierarchical synchronization control strategy of global displacement synchronization, local torque load sharing, and mechanical error compensation, a complete closed-loop control system from global to local and from electrical control to mechanical characteristic compensation is constructed. This completely solves the industry problem of "large displacement deviation between groups, uneven load distribution within groups, and inability to eliminate inherent mechanical errors" in the multi-mechanism collaborative operation of ultra-large ring rail cranes, and meets the high precision, high safety, and high economy requirements of ultra-large hoisting projects.

[0084] It should be noted that the drive control method for cranes in this embodiment further includes: when a fault is detected in any drive unit, the main controller disconnects the actuator corresponding to the faulty drive unit and controls the remaining actuators to operate safely or stop. Specifically, by the hierarchical processing of the main controller when a drive unit fails, not only is the faulty equipment effectively handled and the spread of the fault prevented, but the continuity and safety of operations are maximized, and economic losses are significantly reduced.

[0085] In one specific embodiment, see Figure 3 and Figure 4 Based on the structure of the common bus drive and Ethernet distributed control system, corresponding control strategies are also proposed, specifically including: 1. Common bus energy optimization control: Real-time monitoring of the common DC bus voltage and the operating status (motor / generator) of each inverter, and dynamic allocation of regenerative energy: When a certain mechanism (such as a descending hoist) is in generator mode, its regenerative energy is preferentially supplied to the mechanism in motor mode (such as traveling wheels and hoisting hoist) through the bus, realizing energy mutual feedback. 2. Bus voltage closed-loop control: In BLM diode rectification mode, the status of the CU320-2PN control unit is monitored in real time. The bus voltage is detected through its internal DRIVE-CLIQ communication. When the voltage is too high, the resistor after the three-phase brake cabinet inverter consumes braking energy to stabilize the bus voltage within the set range (taking 480V for the main circuit as an example, the DC bus is limited to 650V-750V). This avoids voltage fluctuations caused by sudden load changes and improves the synchronous stability of multiple mechanisms. In the mode of the rectifier unit with energy feedback unit, excess electrical energy is fed back to the grid to maintain the stability of the bus voltage. 3. Multi-mechanism hierarchical synchronous control, specifically including: 3.1 First-level synchronization (global synchronization): Based on the displacement and speed feedback of each mechanism (drum encoder / rope length sensor), the main control unit uses a cross-coupling synchronization algorithm to calculate the synchronization error of each mechanism and dynamically correct the slave control unit commands to ensure the displacement synchronization accuracy of multi-winch lifting / multi-walking wheel drive. When multiple winches are running synchronously, if a slight inconsistency in the rope length of one winch mechanism is detected, causing its inverter current to be too high or too low, the main control unit will reduce or increase its speed relative to maintain the same rope output as other winch mechanisms and keep its torque output within the error range. 3.2 Secondary Synchronization (Local Load Sharing): Within the same cooperative group (such as two motors of the same hoist or multiple wheel motors traveling on the same side), the slave control unit adopts master-slave + torque following control. One hoist with multiple motors uses any one of the motor inverters as the master, and the other motor inverters as slaves, following the master inverter to perform closed-loop control of speed and torque; compare the torque / current of each motor in real time, adjust the output command, and achieve uniform distribution of load torque; 3.3 Error Compensation Control: Mechanical backlash compensation and wire rope elastic elongation compensation algorithms are introduced. Based on real-time load and running speed, the synchronization command is dynamically corrected to eliminate synchronization errors caused by mechanical characteristics.

[0086] 4. Safety protection and fault handling strategies, specifically including: 4.1 Safety Protection Mechanism: The drive unit implements overcurrent, overload, and overheat protection, which can be transmitted to the central controller via communication; the external mechanisms on the hoisting mechanism, such as encoders, position switches, detection switches, and brake systems, can implement limit, rope slack, off-center load, and braking protection; the main control unit implements global emergency stop and synchronization deviation over-limit protection, and executes the "synchronous deceleration - torque holding - synchronous braking" process in case of failure to avoid structural impact; 4.2 Fault Diagnosis and Fault-Tolerant Control: The operating data of each unit is uploaded in real time through Ethernet and other auxiliary communication networks. The main control unit locates the fault based on the fault code and operating status. The rectifier and inverter of the whole system have redundancy considerations. When a single mechanism of the rectifier cabinet or inverter cabinet fails, the actuator is disconnected, and the remaining mechanisms are de-capacitated to maintain synchronous operation or safely shut down, thereby improving the system reliability.

[0087] In summary, the integrated solution of common bus drive and Ethernet distributed control proposed in this embodiment has the following advantages: 1. Significantly improved synchronization accuracy: Based on PROFINET bus, low-latency communication and precise clock synchronization, error compensation algorithm, multi-mechanism synchronization accuracy reaches sub-millimeter level, effectively avoiding risks such as off-center load, slack rope, and structural distortion; 2. Wide adaptability: It can be flexibly expanded to ring rail cranes of different tonnages and different numbers of actuators, and its application scenarios cover ultra-large lifting fields such as petrochemical, nuclear industry, wind power, and ports; 3. Enhanced system stability and compatibility: Common DC bus, simple hardware structure, reducing failure points; open Ethernet protocol improves equipment compatibility and reduces integration difficulty; 4. Simplified structure: The centralized rectification and common bus design reduce redundant hardware such as rectifier units and braking resistors.

[0088] This invention also provides a crane, such as... Figure 6 As shown, the crane includes a drive control system for the crane. For detailed descriptions, please refer to the above embodiments, which will not be repeated here.

[0089] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the drive control method for a crane shown in the above embodiments is implemented.

[0090] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A drive control system for a crane, characterized in that, The system includes: Power supply unit, rectifier unit, common DC bus, multiple drive units, braking unit and control unit; One end of the rectifier unit is connected to the power supply unit, and the other end is connected to the common DC bus, which is used to convert the AC power output by the power supply unit into DC power. Each drive unit is connected to the common DC bus, and the drive units are connected in parallel with each other; wherein, the drive unit is used to drive the corresponding actuator of the crane; The braking unit is connected in parallel to the common DC bus to consume excess regenerative energy; The control unit is communicatively connected to the rectifier unit, each drive unit, and the braking unit, and is used to monitor the bus voltage of the common DC bus and the operating status of each drive unit. In addition, the system acquires feedback data from the operation of each actuator, calculates the synchronization error of each actuator based on the feedback data, and uses the synchronization error to correct the synchronization commands issued to each drive unit, so as to achieve synchronous operation of multiple actuators.

2. The drive control system for a crane according to claim 1, characterized in that, The control unit is connected via a real-time industrial Ethernet network, which is a PROFINET network. The system also includes an auxiliary communication network connected to the PROFINET network. The auxiliary communication network includes at least one fieldbus or industrial communication protocol network to assist the control unit in communicating with the operating handle, remote control, and box transformer.

3. The drive control system for a crane according to claim 1, characterized in that, The control unit includes a main controller and multiple drive controllers; wherein, the main controller is used to perform global logic control, synchronous operation of multiple mechanisms, and fault handling; the drive controllers are used to perform vector control and torque following of the corresponding drive units.

4. The drive control system for a crane according to claim 3, characterized in that, The control unit adopts a hierarchical synchronization control strategy, which includes a global synchronization strategy, a local load sharing strategy, and a compensation control strategy. The global synchronization strategy involves the main controller using a cross-coupling synchronization algorithm based on the displacement and velocity feedback from each actuator to calculate the synchronization error of each actuator, and then correcting the synchronization instructions of each drive unit according to the synchronization error, so as to achieve multi-mechanism displacement synchronization. The local load sharing strategy involves multiple drive controllers within the same collaborative execution group employing master-slave torque following control. Any drive controller within the group is the master, and the remaining drive controllers are slaves. The slaves follow the master to execute closed-loop speed and torque control and compare the torque or current adjustment output commands of each motor within the group in real time to achieve a uniform distribution of load torque. The compensation control strategy introduces a preset compensation algorithm into the main controller, and corrects the synchronization command based on real-time load and operating speed to eliminate synchronization errors caused by differences in mechanical characteristics.

5. The drive control system for a crane according to claim 1, characterized in that, The power supply unit includes an input power supply, a central current collector, a prefabricated substation system, and a power distribution system; wherein, the prefabricated substation system is used to convert the input power supply into drive power supply and control power supply; And / or, the rectifier unit adopts a dual-redundant parallel configuration of the rectifier cabinet, wherein the rectifier cabinet is a diode basic rectifier, a three-phase uncontrollable rectifier bridge, or a PWM controllable rectifier; And / or, the common DC bus adopts a low-impedance copper bus design; And / or, the actuator includes a hoisting mechanism and a slewing mechanism; And / or, the braking unit includes a three-phase braking cabinet and a braking resistor.

6. A drive control method for a crane, applied to a drive control system for a crane as described in any one of claims 1 to 5, characterized in that, The method includes: Monitor the bus voltage of the common DC bus and the operating status of each drive unit; Furthermore, feedback data of each actuator's operation is acquired via real-time industrial Ethernet, the synchronization error of each actuator is calculated based on the feedback data, and the synchronization error is used to correct the synchronization commands issued to each drive unit, so as to achieve synchronous operation of multiple mechanisms.

7. The drive control method for a crane according to claim 6, characterized in that, The method further includes: The main controller calculates the synchronization error of each actuator based on the displacement and velocity feedback from each actuator using a cross-coupling synchronization algorithm, and corrects the synchronization error by sending synchronization commands to each drive unit. The corresponding drive controller of each drive unit controls the operation of the corresponding actuator according to the corrected synchronization command to achieve multi-mechanism displacement synchronization. For multiple actuators that drive the same actuator, the drive controller of the corresponding drive unit of any actuator is used as the master, and the other drive controllers are used as slaves. The master sends torque or speed commands to the slaves so that the load torque of each drive unit is kept uniform. The main controller calculates the amount of synchronization error compensation caused by mechanical characteristics based on real-time load and operating speed through a preset compensation algorithm, and corrects the synchronization command based on the amount of synchronization error compensation and the synchronization error.

8. The drive control method for a crane according to claim 6, characterized in that, The method further includes: when a fault is detected in any drive unit, the main controller disconnects the actuator corresponding to the faulty drive unit and controls the remaining actuators to operate safely or stop.

9. A crane, characterized in that, The crane includes a drive control system for the crane as described in any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the drive control method for a crane as described in any one of claims 6 to 8.

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