Remote control grab bucket control method and system of hook crane

Abstract

The invention relates to the field of grab bucket control, and discloses a remote control grab bucket control method and system of a hook type crane, which are used for providing a solution for accurate positioning and flexible control of the hook type crane. The remote control grab bucket control method of the hook type crane comprises the following steps: based on a target position input by an operator, generating a non-swing ideal track and a feedforward control instruction by applying a differential flatness theory, realizing prospective accurate positioning, estimating system total disturbance such as wind power and load change in real time through an extended state observer, generating a total disturbance observation value, and performing remote control on the grab bucket. Feedforward compensation calculation is carried out on the basis, an anti-disturbance compensation instruction is output, the contact state of the grab bucket and materials is monitored in real time, a compliance control instruction is generated through a fractional order impedance model, ideal compliance interaction is achieved, control modes are flexibly switched according to the contact state, and different instructions are fused. The grab bucket control precision, flexibility and safety are effectively improved, and the grab bucket control system is suitable for various hook type crane operation scenes.

Description

Technical Field

[0001] This invention relates to the field of grab bucket control, and more particularly to a remote control grab bucket control method and system for a hook crane. Background Technology

[0002] In modern industrial production and logistics, hook cranes play an irreplaceable role as a key material handling equipment. Especially in large-scale operations such as ports, mines, and steel plants, hook cranes undertake a large number of loading, unloading, and handling tasks, and their operating efficiency and safety directly affect the smoothness of the entire production process and economic benefits.

[0003] Traditional control methods primarily rely on operators on-site via wired control devices. This not only limits the operator's range of movement and increases labor intensity, but also poses a threat to the operator's personal safety in harsh environments (such as high temperatures, dust, and heights). To improve this situation, remote control technology is increasingly being applied to hook cranes. Operators can remotely control the crane's operation in a relatively safe and comfortable environment, greatly improving operational flexibility and safety.

[0004] In the operation of hook cranes, precise positioning and compliant control of the grab bucket are crucial. Precise positioning ensures that the grab bucket accurately grasps and places materials, improving operational efficiency; compliant control prevents material damage or equipment malfunction due to excessive impact when the grab bucket comes into contact with the material, while also improving operational stability and reliability. However, due to the strong coupling, nonlinearity, and time-varying characteristics of hook crane systems, and the influence of various external disturbances during operation, such as wind and load changes, precise positioning and compliant control of the grab bucket face numerous challenges.

[0005] Therefore, we propose a remote control method and system for the grab bucket of a hook crane to solve the above problems. Summary of the Invention

[0006] This invention provides a remote control method and system for the grab bucket of a hook crane, providing a solution for the precise positioning and smooth control of hook cranes.

[0007] The first aspect of this invention provides a remote-controlled grab control method for a hook crane. The method includes: online trajectory planning based on target position information input by the operator to generate a swing-free ideal trajectory and feedforward control commands; real-time estimation of the total system disturbance, including wind force, load changes, and unmodeled dynamic factors, to generate total disturbance observations; feedforward compensation calculation based on the feedforward control commands and the total disturbance observations to generate anti-disturbance compensation commands; monitoring the contact state between the grab and the material, and generating compliant control commands when contact or imminent contact is detected; and combining the feedforward control commands with the anti-disturbance compensation commands, or fusing the combined commands with the compliant control commands, based on the contact state determination result, to generate a final control command.

[0008] Optionally, in a first implementation of the first aspect of the present invention, the method includes: receiving target position coordinates input by an operator via a remote control terminal; using these target position coordinates and the current position coordinates of the grab bucket as the starting and ending points, planning a position trajectory curve to generate a spatial motion path for the grab bucket; performing time parameterization processing on the spatial motion path to generate a grab bucket spatial coordinate sequence, which constitutes a swing-free ideal trajectory; obtaining the velocity and acceleration parameters of the grab bucket at each point on the trajectory based on the swing-free ideal trajectory, and generating velocity and acceleration curves for the grab bucket motion; based on the dynamic model of the crane-grab bucket system, using the swing-free ideal trajectory, velocity curves, and acceleration curves as input, obtaining all state parameters of the system, and generating a complete system state description including the hook swing state and wire rope tension state; using the complete system state description as input, calculating inversely based on the system control model the control force required for the system to accurately track the swing-free ideal trajectory, and generating feedforward control commands.

[0009] Optionally, in a second implementation of the first aspect of the present invention, the method includes: real-time acquisition of the actual position signals of the crane's trolley and trolley traveling mechanisms, and filtering the actual position signals to generate filtered position signals; receiving the current control quantity of the feedforward control command as a control input, and simultaneously receiving the filtered position signals as a system output; simultaneously inputting the control input and the filtered position signals to an extended state observer, which reconstructs the state based on the deviation between the internally constructed system dynamics model and the actual output to generate an extended state vector; the extended state observer aggregates all uncertainties not included in the system model into a virtual disturbance state, and tracks the disturbance state in real time through a dynamic feedback mechanism to generate a total disturbance observation value.

[0010] Optionally, in a third implementation of the first aspect of the present invention, the method includes: receiving the current control quantity of the feedforward control command and simultaneously receiving the current disturbance estimate of the total disturbance observation, generating a control-disturbance data pair to be processed; performing time synchronization calibration on the control-disturbance data pair to eliminate the transmission delay difference between the control command and the disturbance observation, generating a synchronized feedforward control command and a total disturbance observation; inverting the synchronized total disturbance observation to generate a preliminary compensation signal that is opposite in direction and equal in magnitude to the total disturbance of the system; performing amplitude limiting and rate limiting processing on the preliminary compensation signal to generate a safety compensation signal; and superimposing the safety compensation signal with the synchronized feedforward control command to generate an anti-disturbance compensation command that can be directly applied to the actuator.

[0011] Optionally, in the fourth implementation of the first aspect of the present invention, the method includes: real-time acquisition of wire rope tension sensor signals and / or drive motor current signals; generating a contact state indicator signal based on these signals using a threshold judgment method or a state observer method; when the contact state indicator signal indicates a contact or imminent contact state, receiving the current position command of the ideal trajectory without swaying, and simultaneously receiving the real-time acquired or estimated actual contact force signal to generate a trajectory-force feedback data pair; inputting the trajectory-force feedback data pair into a fractional impedance model, which establishes a mathematical relationship between position deviation and contact force through a fractional differential operator to calculate and generate a desired compliant contact force; comparing the desired compliant contact force with the actual contact force signal, and calculating and generating a position adjustment command through a fractional impedance control algorithm; and outputting the position adjustment command as a compliant control command after smoothing filtering and amplitude limiting processing.

[0012] Optionally, in a fifth implementation of the first aspect of the present invention, the method includes: receiving the contact state flag signal; generating a mode selection instruction based on the state value of the signal, the instruction indicating that the system should currently operate in a free motion mode or an interactive operation mode; when the mode selection instruction indicates a free motion mode, superimposing a feedforward control instruction and an anti-disturbance compensation instruction to generate a preliminary control instruction; when the mode selection instruction indicates an interactive operation mode, fusing a compliant control instruction with the preliminary control instruction to generate a compliant enhanced control instruction; performing output limiting and rate limiting processing on the preliminary control instruction or the compliant enhanced control instruction to generate a safety control instruction; and processing the safety control instruction through a smooth transition algorithm and outputting it as a final control instruction.

[0013] Optionally, in the sixth implementation of the first aspect of the present invention, the method further includes: real-time monitoring of the operating parameters of each mechanism of the crane, including the travel speed of the trolley and crane, the lifting height, and the wire rope tension, to generate system operating status data; based on the system operating status data, performing status analysis and anomaly detection through a preset fault diagnosis rule base to generate a system health status assessment result; when the system health status assessment result indicates an abnormal operating condition, generating a degraded control strategy instruction according to the anomaly type and severity; and fusing the degraded control strategy instruction with the final control instruction to generate a safety enhancement control instruction.

[0014] A second aspect of the present invention provides a remote-controlled grab control system for a hook crane. The remote-controlled grab control system for the hook crane includes: a planning module for online trajectory planning based on target position information input by the operator, generating a swing-free ideal trajectory and feedforward control commands; a disturbance module for real-time estimation of the total system disturbance, including wind force, load changes, and unmodeled dynamic factors, generating total disturbance observations; a compensation module for performing feedforward compensation calculations based on the feedforward control commands and the total disturbance observations, generating anti-disturbance compensation commands; a monitoring module for monitoring the contact state between the grab and the material, generating compliant control commands when contact or imminent contact is detected; and an allocation module for combining the feedforward control commands with the anti-disturbance compensation commands, or fusing the combined commands with the compliant control commands, based on the contact state determination results, to generate final control commands.

[0015] The mechanism of this invention is as follows: by accurately describing the dynamics of the grab bucket-material interaction through fractional differential operators, a leap from traditional position control to intelligent force-position compliant control is achieved. The three models are interconnected and jointly realize the unity of precise positioning, active disturbance rejection and compliant operation, breaking through the limitations of traditional methods that rely on operator experience, PID control or machine learning, and providing higher-order deterministic control performance. Beneficial effects: Online trajectory planning using differential flatness theory can generate ideal trajectories without swaying. Compared with traditional trajectory planning methods, it fully considers the dynamic characteristics of the system, effectively avoids the swaying problem of the grab bucket during operation, greatly improves the positioning accuracy of the grab bucket, reduces positioning errors caused by swaying, and improves work efficiency and quality; By generating feedforward control commands, proactive control of the system's motion is achieved. These commands, calculated based on the ideal trajectory and the system's dynamics model, can provide the necessary control force to the system in advance, enabling the system to better track the ideal trajectory and enhancing its response speed and stability. The extended state observer is used to estimate the total disturbance of the system in real time, covering a variety of uncertainties such as wind force, load change and unmodeled dynamic factors. It can capture various disturbances in the system operation process in a timely and accurate manner, and provide a reliable basis for subsequent compensation control. Feedforward compensation calculations are performed based on the feedforward control commands and total disturbance observations to generate disturbance rejection compensation commands. By inverting the disturbance observations and superimposing them on the feedforward control commands, the impact of the total system disturbance can be quickly and effectively offset, enabling the system to maintain stable operation even in complex environments and improving the system's anti-interference capability and robustness. By acquiring the wire rope tension sensor signal and / or drive motor current signal in real time, and using the threshold judgment method or state observer method to generate contact state indicator signal, the contact state between the grab bucket and the material can be accurately perceived, including the free suspension state, the contact state, and the imminent contact state. Compliant control commands are generated based on a fractional impedance model, and a mathematical relationship between position deviation and contact force is established using a fractional differential operator. Compared with the traditional integer impedance model, the fractional model can more accurately describe the complex contact mechanics between the grab and the material, better simulate the compliant behavior in the actual contact process, and thus achieve more ideal compliant interactive operation, effectively avoiding problems such as material damage and equipment vibration. Based on the contact state assessment, feedforward control commands are selectively combined with anti-disturbance compensation commands, or the combined commands are integrated with compliant control commands, enabling flexible switching between free movement mode and interactive operation mode. Employing different control strategies in different modes better meets the needs of the grab bucket at different operational stages, improving the system's adaptability and flexibility. The system monitors the operating parameters of each mechanism of the crane in real time, performs status analysis and anomaly detection through a preset fault diagnosis rule base, generates degraded control strategy instructions when abnormal operating conditions occur, and outputs them after being integrated with the final control instructions. This enables timely detection and handling of system faults, and the implementation of corresponding degraded control measures to ensure that the system operates in a safe state. At the same time, it sends early warning information to the operator, thereby improving the safety and reliability of the system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an embodiment of the remote control grab bucket operation method for a hook-type crane according to the present invention; Figure 2 This is a schematic diagram of another embodiment of the remote control grab bucket operation method for a hook-type crane in this invention. Detailed Implementation

[0017] This invention provides a remote-controlled grab bucket control method and system for hook cranes, offering a solution for precise positioning and compliant control of hook cranes. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0018] For ease of understanding, the specific process of the embodiments of the present invention is described below. Please refer to [link / reference]. Figure 1 One embodiment of the remote control grab bucket operation method for a hook-type crane in this invention includes: 101. Based on the target position information input by the operator, online trajectory planning is performed using the differential flatness theory to generate an ideal trajectory without swaying and the corresponding feedforward control command; It is understood that the executing entity of this invention can be a remote control grab bucket control system for a hook crane, or it can be a terminal or a server; no specific limitation is made here. This embodiment of the invention will be described using a server as the executing entity as an example.

[0019] It should be noted that the target position coordinates input by the operator through the remote terminal are used as the starting and ending points of the target position coordinates and the current position coordinates of the grab bucket to plan a position trajectory curve that meets the condition of continuous smoothness, thereby generating the spatial motion path of the grab bucket. The spatial motion path is parameterized by time to generate a grab spatial coordinate sequence with timestamps, which constitutes an ideal trajectory without swaying. Based on the ideal trajectory without swaying, the velocity and acceleration parameters of the grab at each point on the trajectory are obtained by differential calculation, and the velocity and acceleration curves of the grab motion are generated. Based on the dynamic model of the crane-grab system, the ideal trajectory without swing, velocity curve and acceleration curve are taken as input, and all state parameters of the system are calculated through algebraic mapping relationship to generate a complete system state description including hook swing state and wire rope tension state. Using the complete system state description as input, the control force required for the system to accurately track the ideal trajectory without swaying is calculated in reverse according to the system control model, and a feedforward control command is generated. The feedforward control command is used in subsequent steps to combine with the anti-disturbance compensation command and act together on the actuator. 102. Estimate the total system disturbance in real time using an extended state observer. The total disturbance includes wind force, load changes and unmodeled dynamic factors, and generate total disturbance observations. It should be noted that the actual position signals of the crane's trolley and crane traveling mechanisms are collected in real time, and the actual position signals are filtered to generate filtered position signals. The system receives the current control quantity of the feedforward control command as the control input, and simultaneously receives the filtered position signal as the system output. The control input and the filtered position signal are simultaneously input to the extended state observer. The observer reconstructs the state by comparing the deviation between the internally constructed system dynamics model and the actual output, generating an extended state vector that includes the actual velocity and acceleration of the system. The extended state observer aggregates all uncertainties not included in the system model into a virtual disturbance state and tracks this disturbance state in real time through a dynamic feedback mechanism to generate a total disturbance observation value. The total disturbance observation value is used as the basis for calculating the anti-disturbance compensation command in subsequent steps. The total disturbance observations are output buffered and transmitted to ensure that they are synchronized with the corresponding feedforward control commands in time, providing real-time and accurate disturbance prediction data for subsequent feedforward compensation calculations. 103. Based on the feedforward control command and the total disturbance observation, perform feedforward compensation calculation and generate disturbance rejection compensation command; It should be noted that the current control quantity of the feedforward control command is received, and the current disturbance estimate of the total disturbance observation is also received to generate the control-disturbance data pair to be processed. Time synchronization calibration is performed on the control-disturbance data pair to eliminate the transmission delay difference between the control command and the disturbance observation, and to generate synchronized feedforward control command and total disturbance observation. The synchronized total disturbance observations are inverted to generate a preliminary compensation signal that is opposite in direction and equal in magnitude to the total disturbance of the system. The initial compensation signal is subjected to amplitude limiting and rate limiting processing to generate a safety compensation signal that meets the physical constraints of the actuator. The safety compensation signal is superimposed with the synchronized feedforward control command to generate an anti-disturbance compensation command that can be directly applied to the actuator. The anti-disturbance compensation command is then used in subsequent steps to merge with the compliant control command to form the final control command. 104. Monitor the contact status between the grab bucket and the material. When contact or imminent contact is detected, generate compliant control commands based on the fractional impedance model. It should be noted that the wire rope tension sensor signal and / or drive motor current signal are collected in real time. Based on these signals, a contact state indicator signal is generated by a threshold judgment method or a state observer method. This signal indicates that the grab bucket is in a free suspension state, a contact state, or an imminent contact state. When the contact status indicator signal indicates a contact or imminent contact state, it receives the current position command of the ideal trajectory without swaying, and at the same time receives the actual contact force signal acquired or estimated in real time, and generates a trajectory-force feedback data pair. The trajectory-force feedback data is input into a fractional impedance model, which establishes a mathematical relationship between position deviation and contact force through a fractional differential operator, and calculates and generates the desired compliant contact force. The desired compliant contact force is compared with the actual contact force signal, and a position adjustment command is generated by calculating the fractional impedance control algorithm. This command is used to correct the ideal trajectory without swaying. After the position adjustment command is smoothed and amplitude limited, the output is a compliant control command. In subsequent steps, the compliant control command is used to merge with the anti-disturbance compensation command to form the final control command, so as to realize compliant interactive operation between the grab and the material. 105. Based on the judgment of the contact state, selectively combine the feedforward control command with the anti-disturbance compensation command, or fuse the combined command with the compliant control command to generate the final control command and output it to the actuator to complete the precise positioning and compliant control of the grab.

[0020] It should be noted that the received contact status flag signal generates a mode selection instruction based on the status value of the signal. This instruction indicates whether the system should currently be operating in free motion mode or interactive operation mode. When the mode selection command indicates the free motion mode, the feedforward control command and the anti-disturbance compensation command are superimposed to generate the preliminary control command. When the mode selection command indicates the interactive operation mode, the compliant control command and the preliminary control command are fused and calculated to generate the compliant enhanced control command. The output amplitude and rate of the preliminary control command or the compliant enhanced control command are limited to generate a safety control command that meets the physical constraints of the actuator. After the safety control commands are processed by a smooth transition algorithm, they are output as final control commands to the crane's actuators, driving the trolley, hoisting mechanism to coordinate their movements and achieve precise positioning and smooth control of the grab bucket.

[0021] In this embodiment of the invention, the differential flatness theory is used for online trajectory planning, which can plan an ideal trajectory without swaying, effectively avoiding the swaying problem of the grab bucket during the movement, greatly improving the positioning accuracy of the grab bucket, and significantly reducing the positioning error compared with traditional methods; Based on the dynamic model of the crane-grab system, by inputting the ideal trajectory without swaying, velocity curve and acceleration curve, all state parameters of the system can be accurately calculated, the system's operating status can be fully grasped, and a solid foundation can be provided for precise control. By using an extended state observer to estimate the total system disturbance in real time, and aggregating uncertainties such as unmodeled dynamic factors into virtual disturbance states and tracking them in real time, the disturbance situation of the system can be obtained in a timely and accurate manner, providing a reliable basis for disturbance compensation. Feedforward compensation calculations are performed based on feedforward control commands and total disturbance observations to generate anti-disturbance compensation commands. These commands are then combined with the feedforward control commands to act on the actuators, effectively offsetting the impact of the total system disturbance on the grab's movement and enhancing the system's stability and anti-interference capabilities in complex environments. It can collect multiple signals in real time and generate contact status indicator signals through multiple methods to accurately determine the contact status between the grab and the material, providing timely and accurate information for compliant control; Based on the fractional impedance model, compliant control commands are generated. By establishing the mathematical relationship between position deviation and contact force through the fractional differential operator, the compliant interaction between the grab and the material can be simulated and realized more accurately, reducing contact impact and protecting materials and equipment. The system generates mode selection instructions based on contact status indicator signals, enabling it to flexibly switch between free movement mode and interactive operation mode. By employing corresponding control strategies in different modes, it ensures both efficient and accurate positioning during free movement and smooth control during interactive operation, thus improving the system's adaptability and practicality. During the generation of various control commands, the signals undergo multiple safety processing steps, such as time synchronization calibration, amplitude limiting, rate limiting, and smoothing filtering, to ensure that the generated control commands meet the physical constraints of the actuators, avoid damage to the equipment due to command anomalies, and ensure the safe and stable operation of the system. Another embodiment of the remote control grab bucket operation method for the hook crane in this invention includes 106, real-time monitoring of the operating parameters of each mechanism of the crane, including the travel speed of the trolley and the crane, the lifting height and the wire rope tension, and generating system operating status data; Based on system operation status data, status analysis and anomaly detection are performed through a pre-set fault diagnosis rule base to generate system health status assessment results; When the system health status assessment results indicate abnormal operating conditions, corresponding degradation control strategy instructions are generated according to the type and severity of the abnormality. The degradation control strategy instructions and the final control instructions are merged and processed to generate security-enhancing control instructions; The system outputs enhanced safety control commands to the actuators and sends early warning information to the operators, thereby ensuring safe operation and fault protection of the system.

[0022] The above describes the remote control method for the grab bucket of a hook crane in an embodiment of the present invention. The following describes the remote control system for the grab bucket of a hook crane in an embodiment of the present invention. Please refer to [link to relevant documentation]. Figure 2 An embodiment of the remote-controlled grab control system for a hook-type crane in this invention includes: a planning module 201, used to perform online trajectory planning based on target position information input by the operator, generating an ideal trajectory without swaying and feedforward control commands; a disturbance module 202, used to estimate the total system disturbance in real time, the total disturbance including wind force, load change and unmodeled dynamic factors, and generate total disturbance observations; a compensation module 203, used to perform feedforward compensation calculations based on the feedforward control commands and the total disturbance observations, generating anti-disturbance compensation commands; a monitoring module 204, used to monitor the contact state between the grab and the material, and generate compliant control commands when contact or imminent contact is detected; and an allocation module 205, used to combine the feedforward control commands with the anti-disturbance compensation commands, or to fuse the combined commands with the compliant control commands, based on the judgment result of the contact state, to generate final control commands.

[0023] In this embodiment of the invention, the planning module can perform online trajectory planning based on operator input, generating an ideal trajectory without swaying and feedforward control commands. This effectively reduces the swaying of the grab bucket during operation, improving the accuracy and stability of the grabbing operation. Compared with traditional crane control methods, it can move the grab bucket to the target position more quickly and accurately. The disturbance module can estimate the total system disturbance in real time, covering wind force, load changes, and unmodeled dynamic factors, and generate total disturbance observations. The compensation module performs feedforward compensation calculations based on this, generating anti-disturbance compensation commands, enabling the system to actively respond to various complex disturbances, ensuring that the grab bucket can maintain stable operation under complex working conditions, and improving... This enhances the system's reliability and adaptability. The monitoring module monitors the contact state between the grab bucket and the material, generating compliant control commands when contact or imminent contact is detected. This helps avoid rigid collisions during material grabbing, reducing damage to materials and equipment, extending equipment lifespan, and improving the safety of grabbing operations. The distribution module flexibly combines feedforward control commands with anti-disturbance compensation commands, or further integrates them with compliant control commands, based on the contact state judgment results, to generate the final control command. This comprehensively considers the control requirements under different working conditions, enabling the coordinated operation of multiple control strategies, optimizing the overall system performance, and improving the intelligence level of crane remote grab bucket operation. The present invention also provides a remote control grab bucket control device for a hook crane. The remote control grab bucket control device for a hook crane includes a memory and a processor. The memory stores computer-readable instructions. When the computer-readable instructions are executed by the processor, the processor performs the steps of the remote control grab bucket control method for the hook crane in the above embodiments.

[0024] The present invention also provides a computer-readable storage medium, which can be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium, wherein the computer-readable storage medium stores instructions that, when the instructions are executed on a computer, cause the computer to perform the steps of the remote control grab bucket operation method of the hook crane.

[0025] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0026] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0027] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A remote-controlled grab control method for a hook-type crane, characterized in that, The remote control method for operating the grab bucket of the hook-type crane includes: Based on the target position information input by the operator, online trajectory planning is performed to generate an ideal trajectory without swaying and feedforward control commands; The total system disturbance, including wind force, load change and unmodeled dynamic factors, is estimated in real time, and total disturbance observations are generated. Based on the feedforward control command and the total disturbance observation, feedforward compensation calculation is performed to generate an anti-disturbance compensation command; Monitor the contact status between the grab and the material, and generate compliant control commands when contact or imminent contact is detected; Based on the determination of the contact state, the feedforward control command is combined with the anti-disturbance compensation command, or the combined command is fused with the compliant control command to generate the final control command.

2. The remote control method for the grab bucket of a hook crane according to claim 1, characterized in that, include: The system receives the target position coordinates input by the operator via a remote control terminal. Using the target position coordinates and the current position coordinates of the grab bucket as the starting and ending points, it plans the position trajectory curve and generates the spatial motion path of the grab bucket. The spatial motion path is parameterized over time to generate a grab bucket spatial coordinate sequence, which constitutes an ideal trajectory without swaying. Based on the ideal trajectory without swaying, the velocity and acceleration parameters of the grab bucket at each point on the trajectory are obtained, and the velocity and acceleration curves of the grab bucket motion are generated. Based on the dynamic model of the crane-grab system, the ideal trajectory without swaying, velocity curve and acceleration curve are used as inputs to obtain all the state parameters of the system and generate a complete system state description including the hook swaying state and the wire rope tension state. Using the complete system state description as input, the control force required for the system to accurately track the ideal trajectory without oscillation is calculated in reverse according to the system control model, and feedforward control commands are generated.

3. The remote control method for the grab bucket of a hook-type crane according to claim 2, characterized in that, include: The actual position signals of the crane's trolley and crane traveling mechanisms are collected in real time, and the actual position signals are filtered to generate filtered position signals. The system receives the current control quantity of the feedforward control command as the control input, and simultaneously receives the filtered position signal as the system output. The control input and the filtered position signal are simultaneously input to the extended state observer. The observer reconstructs the state by comparing the deviation between the internally constructed system dynamics model and the actual output, and generates an extended state vector. The extended state observer aggregates all uncertainties not included in the system model into a virtual disturbance state, and tracks this disturbance state in real time through a dynamic feedback mechanism to generate a total disturbance observation value.

4. The remote control method for the grab bucket of a hook-type crane according to claim 3, characterized in that, include: The system receives the current control quantity of the feedforward control command and the current disturbance estimate of the total disturbance observation, and generates a control-disturbance data pair to be processed. Time synchronization calibration is performed on the control-disturbance data pair to eliminate the transmission delay difference between the control command and the disturbance observation, and to generate synchronized feedforward control command and total disturbance observation. The synchronized total disturbance observations are inverted to generate a preliminary compensation signal that is opposite in direction and equal in magnitude to the total disturbance of the system. The initial compensation signal is subjected to amplitude limiting and rate limiting processing to generate a safety compensation signal; The safety compensation signal is superimposed with the synchronized feedforward control command to generate an anti-disturbance compensation command that can be directly applied to the actuator.

5. The remote control method for the grab bucket of a hook-type crane according to claim 4, characterized in that, include: Real-time acquisition of wire rope tension sensor signals and / or drive motor current signals; based on these signals, a contact state indicator signal is generated using a threshold judgment method or a state observer method. When the contact status indicator signal indicates a contact or imminent contact state, the system receives the current position command of the non-swaying ideal trajectory and simultaneously receives the real-time acquired or estimated actual contact force signal to generate a trajectory-force feedback data pair. The trajectory-force feedback data is input into a fractional impedance model, which establishes a mathematical relationship between position deviation and contact force through a fractional differential operator, and calculates and generates the desired compliant contact force. The desired compliant contact force is compared with the actual contact force signal, and a position adjustment command is generated by calculating using a fractional impedance control algorithm. After the position adjustment command is smoothed and amplitude limited, the output is a compliant control command.

6. The remote control method for the grab bucket of a hook-type crane according to claim 5, characterized in that, include: Receive the contact status flag signal, and generate a mode selection instruction based on the status value of the signal. The instruction indicates that the system should currently be working in free motion mode or interactive operation mode. When the mode selection command indicates the free motion mode, the feedforward control command and the anti-disturbance compensation command are superimposed to generate the preliminary control command. When the mode selection instruction indicates the interactive operation mode, the compliant control instruction and the preliminary control instruction are fused and calculated to generate a compliant enhanced control instruction; The initial control command or compliant enhancement control command is subjected to output limiting and rate limiting processing to generate a safety control command; The safety control commands are processed by a smooth transition algorithm and then output as the final control commands.

7. The remote control method for the grab bucket of a hook crane according to claim 6, characterized in that, Also includes: Real-time monitoring of the operating parameters of each mechanism of the crane, including the travel speed of the trolley and crane, lifting height and wire rope tension, to generate system operating status data; Based on the system operation status data, status analysis and anomaly detection are performed through a preset fault diagnosis rule base to generate system health status assessment results. When the system health status assessment result indicates an abnormal operating condition, a degradation control strategy instruction is generated based on the type and severity of the abnormality. The degradation control strategy instructions are fused with the final control instructions to generate security enhancement control instructions.

8. A remote-controlled grab bucket control system for a hook-type crane, characterized in that, The remote control system for the grab bucket of the hook crane includes: The planning module is used to perform online trajectory planning based on the target position information input by the operator, and generate an ideal trajectory without swaying and feedforward control commands; The disturbance module is used to estimate the total system disturbance in real time, which includes wind force, load change and unmodeled dynamic factors, and generate total disturbance observations; The compensation module is used to perform feedforward compensation calculations based on the feedforward control command and the total disturbance observation value, and generate disturbance rejection compensation commands. The monitoring module is used to monitor the contact status between the grab and the material. When contact or imminent contact is detected, a compliant control command is generated. The allocation module is used to combine the feedforward control command with the anti-disturbance compensation command, or to fuse the combined command with the compliant control command, based on the judgment result of the contact state, to generate the final control command.

Images