Multi-axis coordinated motion control system and method for a unitized cargo door machine

Abstract

The present application relates to the technical field of automatic control of hoisting machinery, and particularly relates to a piece of miscellaneous cargo door machine multi-axis coordinated motion control system and method, comprising a device and a control device, the control device obtains a cargo transfer path and an angular displacement parameter to generate a discrete matrix and an eigenvalue through a data acquisition module; a continuous target displacement variable is generated by solving kinematics in combination with the size of the boom; and then a time division reference scale is used to perform calculus calculation to output a synchronous driving sequence; the present application generates a dynamic compensation torque in combination with lifting quality and environmental wind resistance, superimposes the driving sequence to form a control data stream, and drives precise synchronous operation of multiple components.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology for lifting machinery, and in particular to a multi-axis coordinated motion control system and method for a general cargo gantry crane. Background Technology

[0002] The general cargo gantry cranes deployed in port loading and unloading areas are special lifting machinery used for lifting and transferring loosely packaged goods. They are equipped with independent hoisting, luffing, and slewing mechanisms. Multi-axis cooperative motion control technology is responsible for coordinating the instruction signals output from the main control module's memory and synchronously distributing the execution instructions to each drive unit. The multi-signal distribution process directs the hoisting, luffing, and slewing mechanisms to operate simultaneously, thereby guiding the lifted load to complete a continuous displacement and transfer task in three-dimensional space.

[0003] Currently, gantry cranes generally adopt a general industrial control architecture as their core computing hub. This general industrial control system is primarily designed and developed to match standard factory assembly line scenarios, and the accompanying microcontroller employs a single-threaded sequential computation logic structure. The microcontroller calculates spatial motion state information sequentially along a fixed logic link, and processes lifting displacement, luffing displacement, and slewing displacement tasks serially. This serial data processing mechanism introduces an inherent instruction flow delay, meaning that the microprocessor can only distribute the motion control waveform to the servo motor units sequentially after completing all branch serial calculations.

[0004] When hoisting heavy, irregular cargo in the open environment of a port terminal, general industrial control architectures lack dynamic compensation algorithms suitable for suspended inertial loads and external wind resistance disturbances. Microprocessor processing of multi-axis linkage commands suffers from channel operation blockage, causing severe time phase dispersion in the receiving of drive commands by various actuators of the gantry crane. This results in the hoisting motor, luffing motor, and slewing motor failing to synchronously generate rotational torque at the same microsecond time point. For example, when the crane lifts heavy asymmetrical metal components and transfers them from the deep hold of a cargo ship to a container truck, continuous sea winds cause the metal components to sway randomly. The superimposed delays and misalignments in mechanism startup caused by control system operation blockages make it difficult for the crane to synchronously adjust the spatial attitude of the wire rope to correct force deviations. The discrete response of multi-axis actuators leads to severe spatial oscillations in the suspended state of heavy asymmetrical metal components, accelerating fatigue wear of transmission components and drastically increasing the probability of cargo impact and fall. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a multi-axis coordinated motion control system and method for a general cargo gantry crane. This invention solves the technical problem that the lack of dynamic compensation algorithms in the general control architecture and the computational blockage in processing multi-axis coordinated instructions cause the drive phase of each actuator of the gantry crane to become discrete, resulting in severe oscillation of the suspended load.

[0006] To solve the above-mentioned technical problems, the specific contents of the present invention are as follows: In a first aspect, the present invention provides a multi-axis cooperative motion control system for a general cargo door operator, comprising an equipment device and a control device that establishes a communication connection with the equipment device; The equipment includes a slewing transmission assembly, a luffing boom assembly, a hoisting transmission assembly, a wind speed sensor, a tension sensor, and a motor driver. The control device includes: The data acquisition module acquires the spatial transfer path coordinate sequence of the cargo, receives the absolute angular displacement parameters of the rotor output by the lifting transmission assembly, the luffing boom assembly and the slewing transmission assembly, and processes them to generate a discrete spatial node matrix and stable angular displacement characteristic values. The motion calculation module receives the discrete space node matrix and the stable angular displacement eigenvalues, obtains the geometric dimension parameters of the portal arm as constraint boundaries, and performs kinematic solution to generate continuous joint target displacement variables. The synchronous interpolation module receives the continuous joint target displacement variables, obtains the time segmentation reference scale, and uses the time segmentation reference scale to perform calculus discretization calculation on the continuous joint target displacement variables to output a synchronous drive sequence. The instruction distribution module receives the lifting mass characteristic data sent by the tension sensor and the environmental wind resistance characteristic data sent by the wind speed sensor, performs multiplication and addition operations to generate dynamic compensation torque parameters, superimposes the dynamic compensation torque parameters with the synchronous drive sequence to generate a dynamic compensation control data stream, and pushes the dynamic compensation control data stream to the motor driver to drive the hoisting transmission assembly, the luffing boom assembly and the slewing transmission assembly to operate synchronously.

[0007] Furthermore, in the multi-axis coordinated motion control system for a general cargo gantry crane described in this invention, the equipment further includes a gantry, a rotary transmission assembly disposed on the top of the gantry, a luffing boom assembly connected to the rotary transmission assembly via a first hinge shaft, a lifting transmission assembly disposed at the top of the luffing boom assembly and extending downward, a wind speed sensor distributed on the surface of the luffing boom assembly, and a tension sensor disposed below the lifting transmission assembly; The data acquisition module is used to parse and reconstruct the spatial transfer path coordinate sequence of the cargo into the discrete spatial node matrix, and to perform filtering and noise reduction operations on the rotor absolute angular displacement parameter to extract the stable angular displacement feature value. The motion calculation module is specifically used to: construct a forward kinematic polynomial equation by combining the discrete space node matrix, the stable angular displacement eigenvalue, and the geometric dimension parameters of the portal arm; perform differentiation on the forward kinematic polynomial equation to derive and output the theoretical joint angle value; calculate the deviation value between the theoretical joint angle value and the stable angular displacement eigenvalue; and start iterative calculation to generate the continuous joint target displacement variable when the deviation value is greater than a preset convergence threshold. The synchronous interpolation module is specifically used to: acquire a high-frequency clock pulse generated by a preset clock signal, configure the high-frequency clock pulse as a reference interpolation period as the time division reference scale, and use the reference interpolation period to perform calculus discretization calculation on the continuous joint target displacement variables to output the synchronous drive sequence; the instruction distribution module is specifically used to: perform multiplication and addition operations on the lifting mass characteristic data and the environmental wind resistance characteristic data to generate the dynamic compensation torque parameter, and perform control instruction word superposition operation on the dynamic compensation torque parameter and the synchronous drive sequence to generate the dynamic compensation control data stream.

[0008] Furthermore, in the multi-axis coordinated motion control system for a general merchandise door operator according to the present invention, the data acquisition module specifically includes: The coordinate extraction unit parses the spatial transfer path coordinate sequence of the goods and outputs Cartesian space coordinate point set information. The matrix transformation unit receives the Cartesian space coordinate point set information and uses the space coordinate transformation matrix to reconstruct the Cartesian space coordinate point set information into the discrete space node matrix. The filtering processing unit receives the rotor absolute angular displacement parameter, calls the Kalman filter algorithm to perform noise reduction operation on the rotor absolute angular displacement parameter, removes high-frequency disturbance signals, and extracts the stable angular displacement feature value.

[0009] Furthermore, in the multi-axis cooperative motion control system for a general merchandise gantry crane described in this invention, the motion calculation module includes: The equation building unit receives the discrete space node matrix and the stable angular displacement eigenvalues, and constructs the forward kinematic polynomial equations by combining the geometric parameters of the portal arm. The differentiation and inversion unit receives the forward kinematics polynomial equation, performs inverse Jacobian matrix differentiation and matrix inversion operations on the forward kinematics polynomial equation, and calculates and outputs the theoretical joint angle value.

[0010] Furthermore, in the multi-axis cooperative motion control system for a general merchandise gantry crane described in this invention, the motion calculation module further includes: The comparison and analysis unit receives the theoretical joint angle value and the stable angular displacement characteristic value, and uses a subtraction difference algorithm to calculate the deviation value between the theoretical joint angle value and the stable angular displacement characteristic value; The iterative solution unit receives the deviation value. When the deviation value is greater than the preset convergence threshold, it starts the Newton-Raphson solution algorithm to perform multiple rounds of iterative calculations and outputs the target displacement variable of the continuous joint.

[0011] Furthermore, in the multi-axis cooperative motion control system for a general merchandise door operator according to the present invention, the synchronous interpolation module includes: The period configuration unit receives the high-frequency clock pulse generated by the preset clock signal and configures the high-frequency clock pulse as the reference interpolation period at the microsecond level. The interpolation calculation unit receives the target displacement variables of the continuous joints and the reference interpolation period, calls a cubic B-spline function to perform discrete calculus calculations on the target displacement variables of the continuous joints at equal time intervals using the reference interpolation period, and outputs the incremental values ​​of the hoisting shaft position, the incremental value of the luffing shaft position, and the incremental value of the slewing shaft position.

[0012] Furthermore, in the multi-axis coordinated motion control system for a general merchandise gantry crane described in this invention, the synchronous interpolation module further includes: The tag attaching unit receives the incremental value of the hoisting shaft position, the incremental value of the luffing shaft position, and the incremental value of the slewing shaft position, and attaches a timestamp tag of the current clock cycle to the incremental value of the hoisting shaft position, the incremental value of the luffing shaft position, and the incremental value of the slewing shaft position to generate tagged incremental data; The cross-validation unit receives the stamped incremental data, performs timestamp cross-matching validation on the stamped incremental data, discards asynchronous incremental data with inconsistent timestamps, and extracts synchronous incremental data with successfully matched timestamps to output the synchronous driving sequence.

[0013] Furthermore, in the multi-axis cooperative motion control system for a general merchandise door operator according to the present invention, the instruction distribution module specifically includes: The analog-to-digital conversion unit converts the analog voltage output by the tension sensor into the lifting mass characteristic data, and converts the frequency pulses sent by the wind speed sensor into the environmental wind resistance characteristic data. The compensation calculation unit receives the lifting mass characteristic data and the environmental wind resistance characteristic data, substitutes the lifting mass characteristic data and the environmental wind resistance characteristic data into a preset nonlinear torque compensation equation, performs weighted multiplication and addition operations using preset aerodynamic coefficients and preset gravity distribution weighting coefficients, and outputs the dynamic compensation torque parameter.

[0014] Furthermore, in the multi-axis cooperative motion control system for a general merchandise gantry crane described in this invention, the instruction distribution module further includes: The instruction fusion unit receives the dynamic compensation torque parameter and the synchronous drive sequence, calls the bitwise OR operation to perform data bit logic matching, performs superposition operation on the dynamic compensation torque parameter and the synchronous drive sequence to generate the dynamic compensation control data stream; The addressing and writing unit receives the dynamic compensation control data stream, allocates a dedicated storage block in the preset internal storage array, and writes the dynamic compensation control data stream into the dedicated storage block. The periodic push unit reads the dynamic compensation control data stream inside the dedicated storage block according to a fixed clock sampling period, and pushes the read dynamic compensation control data stream to the motor driver. The signal analysis unit receives the dynamic compensation control data stream, unpacks and analyzes the dynamic compensation control data stream, and synchronously outputs a pulse width modulation electrical pulse waveform. The pulse width modulation electrical pulse waveform is then used to drive the hoisting transmission assembly, the luffing boom assembly, and the slewing transmission assembly to move.

[0015] Secondly, the present invention provides a multi-axis cooperative motion control method for a general cargo gantry crane, applied to a multi-axis cooperative motion control system for a general cargo gantry crane as described above, comprising: Step 1: Obtain the spatial transfer path coordinate sequence of the cargo, receive the rotor absolute angular displacement parameters output by the lifting transmission assembly, the luffing boom assembly and the slewing transmission assembly, and process them to generate a discrete spatial node matrix and stable angular displacement characteristic values. Step 2: Receive the discrete space node matrix and the stable angular displacement eigenvalues, obtain the portal arm geometric dimension parameters as constraint boundaries, and perform kinematic solution to generate continuous joint target displacement variables; Step 3: Receive the continuous joint target displacement variables, obtain the time segmentation reference scale, and use the time segmentation reference scale to perform calculus discretization calculation on the continuous joint target displacement variables to output a synchronous drive sequence; Step 4: Receive the lifting mass characteristic data sent by the tension sensor and the environmental wind resistance characteristic data sent by the wind speed sensor, perform multiplication and addition operations to generate dynamic compensation torque parameters, superimpose the dynamic compensation torque parameters with the synchronous drive sequence to generate a dynamic compensation control data stream, and push the dynamic compensation control data stream to the motor driver to drive the hoisting transmission assembly, the luffing boom assembly and the slewing transmission assembly to operate synchronously.

[0016] Beneficial effects of this invention: This invention solves the technical problem of the lack of dynamic compensation algorithms in general control architectures, and the resulting computational blockage when processing multi-axis collaborative commands, which leads to phase dispersion of the drive mechanisms of lifting machinery and causes severe oscillations of the suspended load. The system integrates dynamic compensation torque parameters with synchronous drive sequences to generate a high-precision dynamic compensation control data stream, directly driving the hoisting transmission assembly, luffing boom assembly, and slewing transmission assembly to operate synchronously at the same microsecond time point. The zero-phase time difference collaborative linkage action of this invention can continuously correct the wire rope stress deviation and spatial attitude, avoiding spatial oscillations of the suspended load caused by phase dispersion in multi-axis command execution, thereby ensuring the smooth landing of asymmetrical heavy loads (such as steel structural components). Attached Figure Description

[0017] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on the accompanying drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating a multi-axis coordinated motion control method for a general cargo gantry crane according to the present invention. Detailed Implementation

[0019] To make the technical solution of the present invention clearer, the present invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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.

[0020] In a first aspect, the present invention provides a multi-axis cooperative motion control system for a general cargo door operator, comprising an equipment device and a control device that establishes a communication connection with the equipment device; The equipment includes a slewing transmission assembly, a luffing boom assembly, a hoisting transmission assembly, a wind speed sensor, a tension sensor, and a motor driver. The control device includes: The data acquisition module acquires the spatial transfer path coordinate sequence of the cargo, receives the absolute angular displacement parameters of the rotor output by the lifting transmission assembly, the luffing boom assembly and the slewing transmission assembly, and processes them to generate a discrete spatial node matrix and stable angular displacement characteristic values. The motion calculation module receives the discrete space node matrix and the stable angular displacement eigenvalues, obtains the geometric dimension parameters of the portal arm as constraint boundaries, and performs kinematic solution to generate continuous joint target displacement variables. The synchronous interpolation module receives the continuous joint target displacement variables, obtains the time segmentation reference scale, and uses the time segmentation reference scale to perform calculus discretization calculation on the continuous joint target displacement variables to output a synchronous drive sequence. The instruction distribution module receives the lifting mass characteristic data sent by the tension sensor and the environmental wind resistance characteristic data sent by the wind speed sensor, performs multiplication and addition operations to generate dynamic compensation torque parameters, superimposes the dynamic compensation torque parameters with the synchronous drive sequence to generate a dynamic compensation control data stream, and pushes the dynamic compensation control data stream to the motor driver to drive the hoisting transmission assembly, the luffing boom assembly and the slewing transmission assembly to operate synchronously.

[0021] This invention provides a multi-axis coordinated motion control system for a general merchandise gantry crane, including a device and a control device that establishes a communication connection with the device.

[0022] The equipment includes a gantry, a slewing drive assembly mounted on top of the gantry, a luffing boom assembly connected to the slewing drive assembly via a first hinge shaft, a hoisting drive assembly located at the top of the luffing boom assembly and extending downwards, wind speed sensors distributed on the surface of the luffing boom assembly, a tension sensor located below the hoisting drive assembly, and a motor driver. In the specific structural configuration, the gantry serves as a load-bearing support base, and the slewing drive assembly is mounted on top of the gantry via a large slewing bearing, enabling 360-degree horizontal rotation. Simultaneously, the luffing boom assembly performs pitch movement via the first hinge shaft to change the working radius. The hoisting drive assembly includes a hoisting drum and a wire rope, responsible for the vertical lifting and lowering of the load. The wind speed sensor uses an ultrasonic anemometer to measure three-dimensional wind direction and speed; the tension sensor uses a pin-type strain gauge sensor to measure the force on the wire rope.

[0023] The control device includes a data acquisition module, a motion calculation module, a synchronous interpolation module, and a command distribution module. The data acquisition module analyzes and reconstructs the spatial transfer path coordinate sequence of the cargo into a discrete spatial node matrix, and performs filtering and noise reduction operations on the rotor's absolute angular displacement parameters to extract stable angular displacement characteristic values. The motion calculation module combines the discrete spatial node matrix, stable angular displacement characteristic values, and portal boom geometric parameters to construct a forward kinematic polynomial equation. Simultaneously, it performs differentiation operations on the forward kinematic polynomial equation to derive theoretical joint angle values. When the deviation value exceeds a preset convergence threshold, the motion calculation module initiates iterative calculations to generate continuous joint target displacement variables. The synchronous interpolation module acquires a high-frequency clock pulse generated from a preset clock signal, configures the high-frequency clock pulse as a reference interpolation period as a time division reference scale, and then uses the reference interpolation period to perform calculus discretization calculations on the continuous joint target displacement variables, outputting a synchronous drive sequence. The instruction distribution module performs multiplication and addition operations on the lifting mass characteristic data and environmental wind resistance characteristic data to generate dynamic compensation torque parameters. It then superimposes the dynamic compensation torque parameters with the synchronous drive sequence execution control instruction words to generate a dynamic compensation control data stream.

[0024] The data acquisition module is further subdivided into a coordinate extraction unit, a matrix transformation unit, and a filtering unit.

[0025] The coordinate extraction unit parses the spatial transfer path coordinate sequence of the goods, extracts the X-axis, Y-axis and Z-axis coordinate values ​​in the three-dimensional spatial coordinate system included in the spatial transfer path coordinate sequence, and then generates Cartesian spatial coordinate point set information.

[0026] The matrix transformation unit receives the Cartesian space coordinate point set information, introduces the homogeneous coordinate transformation matrix, and maps the Cartesian space coordinate point set information, including translation and rotation elements, to the base coordinate system of the device, reconstructing it into a discrete space node matrix.

[0027] Spatial coordinate transformation matrix equation:

[0028] In the formula, Represents a discrete space node matrix; Represents the spatial coordinate transformation matrix; It represents the information of the set of coordinate points in Cartesian space.

[0029] The filtering unit receives the rotor absolute angular displacement parameters sent by the absolute encoders in the hoisting mechanism, luffing mechanism, and slewing mechanism. The filtering unit calls the Kalman filter algorithm to establish the state prediction equation and the measurement update equation, and calculates the Kalman gain at the current moment; then, it performs optimal estimation of the rotor absolute angular displacement parameters by updating the covariance matrix, removes abnormal high-frequency disturbance signals caused by mechanical vibration, and extracts smooth and stable angular displacement feature values.

[0030] The input data for the Kalman filter algorithm consists of the rotor absolute angular displacement parameters, including high-frequency vibration interference, acquired by an absolute encoder. The output data consists of stable angular displacement characteristic values ​​after filtering out the interference. The intrinsic relationship between the input and output data lies in mapping the mechanical vibration amplitude parameters caused by structural elastic deformation and wind load during the lifting operation of the general cargo gantry crane to the characteristic elements of the measurement noise covariance matrix in the Kalman filter algorithm; and mapping the angular velocity state transition uncertainty parameters during the rotational transmission process of each mechanism to the characteristic elements of the process noise covariance matrix. The control device, combined with the dynamic operating characteristics of the crane mechanism, constructs state prediction equations and measurement update equations. This allows the input rotor absolute angular displacement parameters to adjust the Kalman gain by updating the covariance matrix, extracting and outputting stable angular displacement characteristic values ​​representing the true angular positions of each actuator and transmission component. This establishes a connection between the algorithm model and the crane machinery state assessment scenario.

[0031] Kalman filter state prediction equation:

[0032] In the formula, The predicted value of the rotor's absolute angular displacement parameter at the current moment; Represents the state transition matrix; The characteristic value representing the stable angular displacement at the previous moment; Represents the control input matrix; This represents the control input quantity.

[0033] Kalman filter measurement update equation:

[0034] In the formula, The Kalman gain represents the current time step. The prediction covariance matrix represents the current moment; Represents the measurement matrix; The transpose of the measurement matrix; This represents the measurement noise covariance matrix.

[0035] Kalman filter optimal estimation equation:

[0036] In the formula, This represents the stable angular displacement feature value extracted at the current moment; The predicted value of the rotor's absolute angular displacement parameter at the current moment; The Kalman gain represents the current time step. This represents the absolute angular displacement parameter of the rotor input at the current moment; Represents the measurement matrix; This represents the predicted value of the rotor's absolute angular displacement parameter at the current moment.

[0037] To achieve high-precision displacement conversion, the motion solution module includes an equation establishment unit, a differentiation and inversion unit, a comparison and analysis unit, and an iterative solution unit.

[0038] The equation-building unit receives the discrete space node matrix and stable angular displacement eigenvalues, extracts the pre-measured and stored portal boom geometric parameters such as link length and joint offset parameters, and uses the DH parameter method to construct the forward kinematic polynomial equations from the base to the end effector.

[0039] Forward kinematic polynomial equations:

[0040] In the formula, The transformation matrix represents the end effector relative to the base; The homogeneous transformation matrix representing the rotary transmission component; Represents the geometric parameters of the gantry boom associated with the rotary drive assembly; This represents the stable angular displacement characteristic value corresponding to the rotary transmission component; The homogeneous transformation matrix representing the luffing boom assembly; Represents the geometric dimensional parameters of the portal boom associated with the luffing boom assembly; This represents the characteristic value of the stable angular displacement corresponding to the luffing boom assembly. The homogeneous transformation matrix representing the hoisting transmission assembly; Represents the geometric parameters of the gantry boom associated with the hoisting drive assembly; This represents the characteristic value of the stable angular displacement corresponding to the hoisting transmission component.

[0041] The differentiation and inversion unit receives the forward kinematic polynomial equations and uses partial derivative operations to establish an inverse Jacobian matrix that includes the mapping relationship between linear velocity and angular velocity. Based on this, a pseudo-inverse operation is performed on the inverse Jacobian matrix to calculate and output the theoretical joint angle values ​​required to reach the target space node.

[0042] Inverse Jacobian derivative to derive the equation:

[0043] In the formula, The matrix representing the theoretical joint angle increment values; This represents the inverse Jacobian matrix corresponding to the forward kinematic polynomial equation; Represents the eigenvalue matrix of stable angular displacement; It represents the difference matrix between the discrete spatial node matrix and the current end-space pose.

[0044] The comparison and analysis unit receives the theoretical joint angle value and the stable angular displacement characteristic value, and uses the subtraction difference algorithm to calculate the difference between the theoretical joint angle value and the current actual stable angular displacement characteristic value to obtain the deviation value.

[0045] Subtraction difference algorithm equation:

[0046] In the formula, The numerical value representing the deviation between the theoretical joint angle value and the characteristic value of the stable angular displacement; This represents the calculated theoretical joint angle value. This represents the current actual stable angular displacement characteristic value.

[0047] The iterative solution unit receives the deviation value and sets the accuracy tolerance as the preset convergence threshold. When the deviation value is greater than the preset convergence threshold, the iterative solution unit starts the Newton-Raphson solution algorithm, which is based on the first-order Taylor expansion and performs multiple rounds of iterative calculations according to the set iteration step size. After iterative calculation, the deviation value converges to within the preset convergence threshold, and finally outputs a smooth and interference-free continuous joint target displacement variable.

[0048] The Newton-Raphson algorithm takes theoretical joint angle values ​​and deviation values ​​as input data, and outputs continuous joint target displacement variables that achieve a set accuracy. The intrinsic relationship between the input and output data lies in mapping the allowable pose error limit of the end-hook of the gantry crane at a 3D spatial node to a preset convergence threshold. The Newton-Raphson algorithm uses the gantry boom geometry as spatial topological constraint parameters, configures the constructed inverse Jacobian matrix as the gradient descent direction in the iterative optimization process, and uses the deviation values ​​as feedback parameters to adjust the iteration step size of each calculation. By nonlinearly mapping the target pose command in Cartesian space to the angle increment values ​​of each rotary joint of the gantry crane through the objective function, the input deviation values, after multiple rounds of iterative approximation calculations, output continuous joint target displacement variables that fully conform to the kinematic constraints of the gantry crane linkage mechanism, thus completing the specific integration of the motion calculation algorithm and the gantry crane spatial trajectory planning scenario.

[0049] Newton-Raphson cyclic iterative equation:

[0050] In the formula, This represents the continuous joint target displacement variable generated in the (n+1)th iteration; Represents the theoretical joint angle value input in the nth iteration; Represents the inverse Jacobian matrix; This represents the deviation between the theoretical joint angle value calculated in the nth iteration and the stable angular displacement characteristic value.

[0051] The synchronous interpolation module is divided into a period configuration unit, an interpolation calculation unit, a label attachment unit, and a cross-validation unit.

[0052] The period configuration unit receives the clock signal generated by the quartz crystal oscillator circuit, extracts the high-frequency clock pulses included in the clock signal, and precisely configures the high-frequency clock pulses into a microsecond-level reference interpolation period through a frequency divider circuit.

[0053] The interpolation calculation unit receives the continuous joint target displacement variables and the reference interpolation period, calls the cubic B-spline curve interpolation function, and uses the reference interpolation period as a parameter node to perform discrete calculus calculations on the continuous joint target displacement variables at equal time intervals.

[0054] cubic B-spline discretized differential equations:

[0055] In the formula, These represent the output increment values ​​for the hoisting shaft position, the luffing shaft position, and the slewing shaft position. Represents a time segmentation benchmark based on reference interpolation period normalization; Represents cubic B-spline basis functions; The coordinates of the control points representing the target displacement variables of the continuous joint; Represents the control point sequence index number.

[0056] After calculus calculation, the interpolation calculation unit synchronously outputs the incremental values ​​of the hoisting shaft position, the luffing shaft position, and the slewing shaft position within the same reference interpolation cycle interval, thereby ensuring that the three-axis displacements are continuous and without abrupt changes on the velocity and acceleration curves.

[0057] The tag attaching unit receives the incremental values ​​of the hoisting shaft position, the luffing shaft position, and the slewing shaft position. Using the unified global time base of the control system, it attaches a timestamp tag of the current clock cycle to the incremental values ​​of the hoisting shaft position, the luffing shaft position, and the slewing shaft position, and packages them to generate tagged incremental data.

[0058] The cross-validation unit receives stamped incremental data and performs timestamp cross-matching validation logic on it, comparing whether the timestamps of the three axial incremental data are completely consistent. If the timestamps are inconsistent, the cross-validation unit discards the corresponding asynchronous incremental data; if the timestamps are completely consistent, the cross-validation unit extracts the successfully matched synchronous incremental data, combines the bytes, and outputs a microsecond-level phase-aligned synchronous drive sequence.

[0059] The cross-validation unit receives time-stamped increments in the hoisting shaft, luffing shaft, and slewing shaft positions, and outputs a phase-aligned synchronous drive sequence. The inherent relationship between the input and output data lies in the system's mapping of high-frequency clock pulses from the control motherboard to a globally unified reference time stamp. The control device compares the reference time stamps carried by the three axial increments, ensuring that the discrete displacement commands output by spatial calculation are tightly bound to the microsecond-level control cycles of each independent actuator of the gantry crane. When the reference time stamps of the three transmission component command data perfectly match, a strong temporal correlation is established between the incremental data of each channel. Based on this, the control device combines the execution bytes of the time-stamped increments to generate a synchronous drive sequence, deeply integrating the multi-channel timing alignment algorithm with the synchronous anti-vibration drive scenario of multi-axis motors in crane machinery.

[0060] The instruction distribution module consists of an analog-to-digital conversion unit, a compensation calculation unit, an instruction fusion unit, an addressing and writing unit, a periodic push unit, and a signal parsing unit.

[0061] The analog-to-digital converter (ADC) acquires the analog voltage output from the tension sensor, and converts it into digital lifting mass characteristic data through sampling, holding, quantization, and encoding. At the same time, the ADC converts the frequency pulses sent by the wind speed sensor into digital environmental wind resistance characteristic data through a counter.

[0062] The compensation calculation unit receives lifting mass characteristic data and environmental wind resistance characteristic data, and substitutes these data into a preset nonlinear torque compensation equation. The nonlinear torque compensation equation calculates the wind resistance disturbance torque using a preset aerodynamic coefficient of the structural frontal area, and calculates the heavy-load inertial torque using a gravity distribution weighting coefficient. Nonlinear torque compensation equation:

[0063] In the formula, Represents the dynamic compensation torque parameter; This represents the preset gravity distribution weighting coefficient; This represents the lifting mass characteristic data sent by the tension sensor; Represents the gravitational acceleration constant; This represents the lever arm length corresponding to the luffing boom assembly. Represents the preset aerodynamic coefficient; Represents the air density constant; This represents the environmental wind resistance characteristics data sent by the wind speed sensor; Represents the windward area of ​​the structure; This represents the lever arm length corresponding to the point of action of wind resistance.

[0064] The compensation calculation unit integrates the two calculation data through weighted multiplication and addition operations, and outputs the dynamic compensation torque parameter.

[0065] The input data for the nonlinear torque compensation equation are the lifting mass characteristic data and the environmental wind resistance characteristic data, and the output data is the dynamic compensation torque parameter applied to the motor driver. The inherent relationship between the input and output data is as follows: mapping the windward cross-sectional projection area of ​​the luffing boom assembly and the suspended load under the current spatial posture of the general cargo gantry crane to the preset structural windward area aerodynamic coefficient; mapping the inertial force transmission ratio of the heavy cargo deviating from the line of gravity in the suspended and rotating state to the gravity distribution weight coefficient. The control device establishes a mathematical mapping relationship between environmental state parameters, load mass parameters, and motor compensation torque of each transmission mechanism through the nonlinear torque compensation equation. This allows the input lifting mass characteristic data and environmental wind resistance characteristic data to be transformed into dynamic compensation torque parameters to offset external random disturbances based on the force distribution model of the hoisting transmission assembly, luffing boom assembly, and slewing transmission assembly, realizing the integrated application of the torque compensation algorithm in heavy suspended load lifting scenarios.

[0066] The instruction fusion unit receives the dynamic compensation torque parameter and the synchronous drive sequence. At the data link layer, it calls the bitwise OR logic operation instruction to perform data bit logic matching and inserts the dynamic compensation torque parameter as an additional control word into the reserved data frame structure of the synchronous drive sequence. After the insertion is completed, the instruction fusion unit performs control instruction word superposition operation to generate a high-precision dynamic compensation control data stream that includes both position and torque control information.

[0067] The addressing and writing unit receives the dynamic compensation control data stream, delineates a dedicated storage block with special access permissions in the non-volatile memory array, and writes the dynamic compensation control data stream sequentially into the dedicated storage block.

[0068] The periodic push unit uses direct data access technology to independently read the dynamic compensation control data stream temporarily stored in the dedicated storage block according to a fixed clock sampling period, and pushes the read dynamic compensation control data stream to the motor driver through the industrial Ethernet bus.

[0069] The signal analysis unit receives the pushed dynamic compensation control data stream, performs frame header identification and checksum verification, and unpacks and analyzes the data stream. Subsequently, based on the parsed control commands, the signal analysis unit uses integrated logic gate circuits to synchronously output pulse-width modulated electrical pulse waveforms. The motor driver, including the insulated-gate bipolar transistor inverter bridge arm, performs on / off actions according to the pulse-width modulated electrical pulse waveform, converting DC power into three-phase AC power with adjustable frequency and voltage, ultimately driving the hoisting drive assembly, luffing boom assembly, and slewing drive assembly to perform zero-time-difference synchronous movement.

[0070] Secondly, please refer to Figure 1 The present invention provides a multi-axis cooperative motion control method for a general cargo gantry crane, which is applied to a multi-axis cooperative motion control system for a general cargo gantry crane as described above, comprising: Step 1: Obtain the spatial transfer path coordinate sequence of the cargo, receive the rotor absolute angular displacement parameters output by the lifting transmission assembly, the luffing boom assembly and the slewing transmission assembly, and process them to generate a discrete spatial node matrix and stable angular displacement characteristic values. Step 2: Receive the discrete space node matrix and the stable angular displacement eigenvalues, obtain the portal arm geometric dimension parameters as constraint boundaries, and perform kinematic solution to generate continuous joint target displacement variables; Step 3: Receive the continuous joint target displacement variables, obtain the time segmentation reference scale, and use the time segmentation reference scale to perform calculus discretization calculation on the continuous joint target displacement variables to output a synchronous drive sequence; Step 4: Receive the lifting mass characteristic data sent by the tension sensor and the environmental wind resistance characteristic data sent by the wind speed sensor, perform multiplication and addition operations to generate dynamic compensation torque parameters, superimpose the dynamic compensation torque parameters with the synchronous drive sequence to generate a dynamic compensation control data stream, and push the dynamic compensation control data stream to the motor driver to drive the hoisting transmission assembly, the luffing boom assembly and the slewing transmission assembly to operate synchronously.

[0071] In this embodiment of the invention: When performing loading and unloading operations on a 50-ton asymmetric heavy steel structure across the deep hold of a cargo ship to the truck position at an open port terminal, the control device acquires the spatial transfer path coordinate sequence to avoid obstacles in the cargo hold. Simultaneously, the control system receives the absolute angular displacement parameters of the rotor output from the hoisting drive assembly, the luffing boom assembly, and the slewing drive assembly, and then analyzes and generates a discrete spatial node matrix and stable angular displacement eigenvalues.

[0072] In constructing the forward kinematics polynomial equations, the computational unit establishes a local coordinate system from the gantry to the end hook using the link parameter method. The computational unit extracts the pre-calibrated and stored 30-meter boom link length, joint offset distance, and link torsion angle as geometric parameters of the gantry boom. Then, it substitutes the discrete spatial node matrix and stable angular displacement eigenvalues ​​into the forward kinematics polynomial equations, uses partial derivative operations to establish a mapping matrix, and performs differentiation to calculate the theoretical joint angle values ​​required to reach the target spatial node. When the deviation between the theoretical joint angle value and the actual angular displacement exceeds a preset convergence threshold, the computational unit initiates an iterative solution algorithm to calculate and output the continuous joint target displacement variables.

[0073] The control device extracts 1000-microsecond clock pulses generated by the internal clock generator of the control motherboard and configures these extracted clock pulses as a time-division reference scale. Using the set time-division reference scale, the interpolation module performs discrete calculus calculations on the continuous joint target displacement variables at equal time intervals, calculating and outputting a time-phase aligned synchronous drive sequence.

[0074] Under conditions of continuous sea winds at level 6 and asymmetric loads, the control system constructs a nonlinear torque compensation equation incorporating rigid-flexible coupling dynamics. The compensation calculation unit substitutes the 50-ton lifting mass characteristic data monitored by the tension sensor and the 12 m / s environmental wind resistance characteristic data collected by the wind speed sensor into the nonlinear torque compensation equation. The equation calculates the wind pressure disturbance torque using a preset aerodynamic coefficient of 1.2 for the structural windward area, and simultaneously calculates the heavy-load inertial swaying torque using a gravity distribution weighting coefficient of 0.8. The two torque data are then processed through weighted multiplication and addition operations, and integrated to output the dynamic compensation torque parameter.

[0075] The logic unit superimposes the dynamic compensation torque parameter with the synchronous drive sequence execution control command word to generate a dynamic compensation control data stream, which is then pushed to the motor driver. The motor driver parses the control data stream and outputs a pulse width modulated electrical pulse waveform, directly driving the hoisting transmission assembly, luffing boom assembly, and slewing transmission assembly to operate synchronously at the same microsecond time node. The coordinated linkage action with zero phase time difference in three-dimensional space can continuously correct the wire rope stress deviation and spatial attitude, avoid spatial oscillation of the suspended load caused by phase dispersion of multi-axis command execution, and ensure the smooth landing of asymmetric heavy steel structure components onto the truck platform.

Claims

1. A multi-axis cooperative motion control system for a general merchandise gantry crane, characterized in that, Includes equipment and control devices that establish a communication connection with the equipment; The equipment includes a slewing transmission assembly, a luffing boom assembly, a hoisting transmission assembly, a wind speed sensor, a tension sensor, and a motor driver. The control device includes: The data acquisition module acquires the spatial transfer path coordinate sequence of the cargo, receives the absolute angular displacement parameters of the rotor output by the lifting transmission assembly, the luffing boom assembly and the slewing transmission assembly, and processes them to generate a discrete spatial node matrix and stable angular displacement characteristic values. The motion calculation module receives the discrete space node matrix and the stable angular displacement eigenvalues, obtains the geometric dimension parameters of the portal arm as constraint boundaries, and performs kinematic solution to generate continuous joint target displacement variables. The synchronous interpolation module receives the continuous joint target displacement variables, obtains the time segmentation reference scale, and uses the time segmentation reference scale to perform calculus discretization calculation on the continuous joint target displacement variables to output a synchronous drive sequence. The instruction distribution module receives the lifting mass characteristic data sent by the tension sensor and the environmental wind resistance characteristic data sent by the wind speed sensor, performs multiplication and addition operations to generate dynamic compensation torque parameters, superimposes the dynamic compensation torque parameters with the synchronous drive sequence to generate a dynamic compensation control data stream, and pushes the dynamic compensation control data stream to the motor driver to drive the hoisting transmission assembly, the luffing boom assembly and the slewing transmission assembly to operate synchronously.

2. The multi-axis cooperative motion control system for a general merchandise gantry crane according to claim 1, characterized in that, The equipment also includes a gantry, the slewing drive assembly is disposed on the top of the gantry, the luffing boom assembly is connected to the slewing drive assembly via a first hinge shaft, the hoisting drive assembly is disposed on the top of the luffing boom assembly and extends downward, the wind speed sensor is distributed on the surface of the luffing boom assembly, and the tension sensor is disposed below the hoisting drive assembly. The data acquisition module is used to parse and reconstruct the spatial transfer path coordinate sequence of the cargo into the discrete spatial node matrix, and to perform filtering and noise reduction operations on the rotor absolute angular displacement parameter to extract the stable angular displacement feature value. The motion calculation module is specifically used to: construct a forward kinematic polynomial equation by combining the discrete space node matrix, the stable angular displacement eigenvalue, and the geometric dimension parameters of the portal arm; perform differentiation on the forward kinematic polynomial equation to derive and output the theoretical joint angle value; calculate the deviation value between the theoretical joint angle value and the stable angular displacement eigenvalue; and start iterative calculation to generate the continuous joint target displacement variable when the deviation value is greater than a preset convergence threshold. The synchronous interpolation module is specifically used to: acquire a high-frequency clock pulse generated by a preset clock signal, configure the high-frequency clock pulse as a reference interpolation period as the time division reference scale, and use the reference interpolation period to perform calculus discretization calculation on the continuous joint target displacement variables to output the synchronous drive sequence; the instruction distribution module is specifically used to: perform multiplication and addition operations on the lifting mass characteristic data and the environmental wind resistance characteristic data to generate the dynamic compensation torque parameter, and perform control instruction word superposition operation on the dynamic compensation torque parameter and the synchronous drive sequence to generate the dynamic compensation control data stream.

3. The multi-axis cooperative motion control system for a general merchandise gantry crane according to claim 2, characterized in that, The data acquisition module specifically includes: The coordinate extraction unit parses the spatial transfer path coordinate sequence of the goods and outputs Cartesian space coordinate point set information. The matrix transformation unit receives the Cartesian space coordinate point set information and uses the space coordinate transformation matrix to reconstruct the Cartesian space coordinate point set information into the discrete space node matrix. The filtering processing unit receives the rotor absolute angular displacement parameter, calls the Kalman filter algorithm to perform noise reduction operation on the rotor absolute angular displacement parameter, removes high-frequency disturbance signals, and extracts the stable angular displacement feature value.

4. The multi-axis cooperative motion control system for a general merchandise gantry crane according to claim 3, characterized in that, The motion calculation module includes: The equation building unit receives the discrete space node matrix and the stable angular displacement eigenvalues, and constructs the forward kinematic polynomial equations by combining the geometric parameters of the portal arm. The differentiation and inversion unit receives the forward kinematics polynomial equation, performs inverse Jacobian matrix differentiation and matrix inversion operations on the forward kinematics polynomial equation, and calculates and outputs the theoretical joint angle value.

5. The multi-axis cooperative motion control system for a general merchandise gantry crane according to claim 4, characterized in that, The motion calculation module also includes: The comparison and analysis unit receives the theoretical joint angle value and the stable angular displacement characteristic value, and uses a subtraction difference algorithm to calculate the deviation value between the theoretical joint angle value and the stable angular displacement characteristic value; The iterative solution unit receives the deviation value. When the deviation value is greater than the preset convergence threshold, it starts the Newton-Raphson solution algorithm to perform multiple rounds of iterative calculations and outputs the target displacement variable of the continuous joint.

6. The multi-axis cooperative motion control system for a general merchandise gantry crane according to claim 5, characterized in that, The synchronous interpolation module includes: The period configuration unit receives the high-frequency clock pulse generated by the preset clock signal and configures the high-frequency clock pulse as the reference interpolation period at the microsecond level. The interpolation calculation unit receives the target displacement variables of the continuous joints and the reference interpolation period, calls a cubic B-spline function to perform discrete calculus calculations on the target displacement variables of the continuous joints at equal time intervals using the reference interpolation period, and outputs the incremental values ​​of the hoisting shaft position, the incremental value of the luffing shaft position, and the incremental value of the slewing shaft position.

7. A multi-axis cooperative motion control system for a general merchandise gantry crane according to claim 6, characterized in that, The synchronous interpolation module also includes: The tag attaching unit receives the incremental value of the hoisting shaft position, the incremental value of the luffing shaft position, and the incremental value of the slewing shaft position, and attaches a timestamp tag of the current clock cycle to the incremental value of the hoisting shaft position, the incremental value of the luffing shaft position, and the incremental value of the slewing shaft position to generate tagged incremental data; The cross-validation unit receives the stamped incremental data, performs timestamp cross-matching validation on the stamped incremental data, discards asynchronous incremental data with inconsistent timestamps, and extracts synchronous incremental data with successfully matched timestamps to output the synchronous driving sequence.

8. The multi-axis cooperative motion control system for a general merchandise gantry crane according to claim 7, characterized in that, The instruction distribution module specifically includes: The analog-to-digital conversion unit converts the analog voltage output by the tension sensor into the lifting mass characteristic data, and converts the frequency pulses sent by the wind speed sensor into the environmental wind resistance characteristic data. The compensation calculation unit receives the lifting mass characteristic data and the environmental wind resistance characteristic data, substitutes the lifting mass characteristic data and the environmental wind resistance characteristic data into a preset nonlinear torque compensation equation, performs weighted multiplication and addition operations using preset aerodynamic coefficients and preset gravity distribution weighting coefficients, and outputs the dynamic compensation torque parameter.

9. A multi-axis cooperative motion control system for a general merchandise gantry crane according to claim 8, characterized in that, The instruction distribution module also includes: The instruction fusion unit receives the dynamic compensation torque parameter and the synchronous drive sequence, calls the bitwise OR operation to perform data bit logic matching, performs superposition operation on the dynamic compensation torque parameter and the synchronous drive sequence to generate the dynamic compensation control data stream; The addressing and writing unit receives the dynamic compensation control data stream, allocates a dedicated storage block in the preset internal storage array, and writes the dynamic compensation control data stream into the dedicated storage block. The periodic push unit reads the dynamic compensation control data stream inside the dedicated storage block according to a fixed clock sampling period, and pushes the read dynamic compensation control data stream to the motor driver. The signal analysis unit receives the dynamic compensation control data stream, unpacks and analyzes the dynamic compensation control data stream, and synchronously outputs a pulse width modulation electrical pulse waveform. The pulse width modulation electrical pulse waveform is then used to drive the hoisting transmission assembly, the luffing boom assembly, and the slewing transmission assembly to move.

10. A multi-axis cooperative motion control method for a general cargo gantry crane, applied to a multi-axis cooperative motion control system for a general cargo gantry crane as described in any one of claims 1 to 9, characterized in that, include: Step 1: Obtain the spatial transfer path coordinate sequence of the cargo, receive the rotor absolute angular displacement parameters output by the lifting transmission assembly, the luffing boom assembly and the slewing transmission assembly, and process them to generate a discrete spatial node matrix and stable angular displacement characteristic values. Step 2: Receive the discrete space node matrix and the stable angular displacement eigenvalues, obtain the portal arm geometric dimension parameters as constraint boundaries, and perform kinematic solution to generate continuous joint target displacement variables; Step 3: Receive the continuous joint target displacement variables, obtain the time segmentation reference scale, and use the time segmentation reference scale to perform calculus discretization calculation on the continuous joint target displacement variables to output a synchronous drive sequence; Step 4: Receive the lifting mass characteristic data sent by the tension sensor and the environmental wind resistance characteristic data sent by the wind speed sensor, perform multiplication and addition operations to generate dynamic compensation torque parameters, superimpose the dynamic compensation torque parameters with the synchronous drive sequence to generate a dynamic compensation control data stream, and push the dynamic compensation control data stream to the motor driver to drive the hoisting transmission assembly, the luffing boom assembly and the slewing transmission assembly to operate synchronously.

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