A gantry crane automatic deviation correction method based on multi-motor cross coupling

Abstract

The application discloses a gantry crane automatic deviation correction method based on multi-motor cross coupling, which replaces mechanical hard synchronization and one-way master-slave following through master-slave cross coupling bidirectional compensation and digital twin virtual shaft soft synchronization, and actively cooperates instead of passively follows two sides of the motor, so that even if unilateral load mutation or skidding occurs, the other side can actively compensate, the synchronization accuracy is significantly improved, and the root cause of rail biting is fundamentally eliminated; the digital twin virtual shaft model provides an ideal synchronization reference for the two sides of the motor, can eliminate the relative deviation of the two sides, can eliminate the tracking error of each side relative to the ideal track, realizes true track synchronization instead of simple speed synchronization, and ensures stability through frequency fine adjustment when a small deviation occurs and ensures rapidity through torque compensation when a large deviation occurs, two modes are smoothly switched, and the contradiction that a traditional single frequency adjustment is slow in response and single torque control is large in impact is solved.

Description

Technical Field

[0001] This invention belongs to the field of automatic control technology for heavy lifting machinery, and relates to an automatic correction method for gantry crane trolley based on multi-motor cross-coupling. Background Technology

[0002] Gantry crane trolley traveling mechanisms typically employ a dual-side drive system, meaning each side of the trolley is equipped with an independent traveling motor and reduction gear transmission mechanism. Due to the characteristics of gantry cranes, such as large spans, low horizontal stiffness, uneven loads on both sides, track installation errors, and uneven road surfaces, the traveling distance on both sides of the trolley is prone to deviation during operation. This leads to severe friction between the wheel flanges and the sides of the track, a phenomenon known as "rail biting." Rail biting not only accelerates wear on the wheels and rails, reducing equipment lifespan, but can also, in severe cases, cause derailment accidents, threatening safe production.

[0003] Existing gantry crane trolley correction technologies mostly employ single-side following or simple frequency adjustment, i.e., fixing one side as the reference and passively following the other side. Essentially, this is still a one-way master-slave control. When slippage or sudden load changes occur on the reference side, the following side cannot actively compensate, resulting in poor anti-disturbance capability and difficulty in guaranteeing synchronization accuracy. Secondly, existing solutions only compare the difference in actual travel distance between the two sides, lacking an ideal virtual synchronization reference. This makes it impossible to assess the tracking error of each side relative to the ideal trajectory, leading to both sides potentially deviating from the ideal path simultaneously without being detected. Furthermore, existing solutions mostly use single frequency adjustment or single torque control. The former has a slow response when there is a large deviation, while the latter has a large impact when there is a small deviation, making it impossible to balance correction response speed and operational stability.

[0004] Furthermore, the dynamic characteristics of the mechanical system of the gantry crane vary significantly under different working conditions, such as high speed under no-load, low speed under heavy load, and frequent start-stop. Fixed correction parameters can easily cause overshoot oscillations at high speeds and sluggish response at low speeds, making it difficult to adapt across the entire speed range.

[0005] Therefore, there is an urgent need for an automatic gantry crane trolley correction technology that can achieve active coordination between the two motors, have an ideal virtual synchronization reference, support smooth correction in both speed and torque modes, and adapt to different operating speeds. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, this invention provides an automatic correction method for gantry crane trolley based on multi-motor cross-coupling.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: An automatic trolley alignment correction method for gantry cranes based on multi-motor cross-coupling includes the following steps: S1. Configure speed observers in the driving motors on both sides of the trolley to establish a master-slave cross-coupling model. The master shaft deviation signal of the master-slave cross-coupling model is coupled to the slave shaft control loop, and the slave shaft deviation signal is simultaneously coupled to the master shaft control loop, forming a bidirectional cross compensation. S2. Based on the mechanical structure parameters of the gantry crane trolley, establish a digital twin virtual axis model, input the actual position signals fed back by the encoders on both sides into the virtual axis model, calculate the deviation between the actual position on both sides and the ideal position of the virtual axis, as well as the relative deviation between the two sides, and generate cross-coupled correction control quantity. S3. When the deviation on both sides exceeds the preset threshold, adjust the output frequency or output torque of the inverters on both sides. S4. Dynamically adjust the response frequency and gain parameters of the correction control loop according to the current moving speed of the trolley; S5. Secondary detection and verification are performed through the encoder and position detection device. When the trolley moves to the preset reference position, the encoder is automatically reset. The current value of the encoder is compared and calibrated with the absolute position value of the position detection device to eliminate the cumulative error caused by wheel slippage. S6. Implement operation command issuance and operation status monitoring through industrial touch screen.

[0008] Furthermore, the speed observer in step S1 uses an extended Kalman filter or sliding mode observer algorithm to estimate the actual speed of the motor in real time based on the motor current and voltage signals.

[0009] Furthermore, the master-slave cross-coupling model described in step S1 includes a velocity difference proportional integral term and a position difference proportional term. Both velocity loops receive the cross-coupling compensation amount to achieve bidirectional active synchronization.

[0010] Furthermore, in step S2, the digital twin virtual axis model uses the average value of the motor commands on both sides as the ideal input and outputs the ideal position and ideal speed; the deviation includes the tracking error of each side relative to the virtual axis and the relative deviation between the two sides.

[0011] Furthermore, in step S3, when the relative deviation between the two sides does not exceed the first threshold, the frequency fine-tuning mode is adopted, and only the output frequency of the inverter is adjusted; when the relative deviation between the two sides exceeds the first threshold, the torque compensation mode is switched to output a short-term torque compensation amount to the lagging motor, and after the deviation falls back to below the first threshold, the frequency fine-tuning mode is smoothly transitioned back.

[0012] Furthermore, in step S4, the running speed of the trolley is divided into low-speed, medium-speed and high-speed segments, with each segment corresponding to different proportional gain, integral gain and filtering time constant of the correction loop.

[0013] Furthermore, in step S5, the position detection device uses an absolute encoder or a laser rangefinder sensor, which is installed at the end of the trolley to directly measure the absolute displacement of the trolley relative to the track reference; the secondary detection and verification uses encoder incremental detection and position detection device verification, and an early warning is triggered when the difference between the two exceeds the fault tolerance threshold.

[0014] Furthermore, step S5 also includes automatic encoder reset: recording the deviation data during each reset, updating the slippage compensation coefficient through iterative learning, and using iterative learning for slippage pre-compensation in subsequent operation.

[0015] Furthermore, it also includes a flange spacing auxiliary detection step: distance measuring sensors are installed at the front and rear travel wheels of the outriggers on both sides of the trolley to detect the distance between the travel wheel flanges and the track in real time; when the distance between any flange and the track is detected to be less than the minimum allowable distance, the anti-rail-biting control is activated first, the normal correction program is temporarily interrupted, and an emergency speed adjustment command is generated according to the trolley's travel direction to make the outriggers on both sides move in the direction of increasing the flange spacing until the flange spacing is restored to the theoretical clearance range, and then the normal cross-coupling correction control is restored.

[0016] Furthermore, the preset threshold adopts a three-level threshold control: the first level threshold is the normal allowable deviation range, and no correction control is performed within this range; the second level threshold is the automatic correction start threshold, and automatic correction control is started when the deviation exceeds this range; the third level threshold is the dangerous shutdown threshold, and the entire machine stops running and an alarm signal is issued when the deviation exceeds this range.

[0017] In summary, the advantages of this invention are: This invention replaces mechanical hard synchronization and unidirectional master-slave following with master-slave cross-coupling bidirectional compensation and digital twin virtual axis soft synchronization. The two motors actively cooperate instead of passively following. Even if a sudden load change or slippage occurs on one side, the other side can actively compensate, significantly improving synchronization accuracy and fundamentally eliminating the root cause of track wear.

[0018] The digital twin virtual axis model provides an ideal synchronization reference for the motors on both sides. It can not only eliminate the relative deviation between the two sides, but also eliminate the tracking error of each side relative to the ideal trajectory, thus achieving true trajectory synchronization, rather than simple speed synchronization.

[0019] When the deviation is small, frequency fine-tuning ensures stability, while torque compensation ensures speed when the deviation is large. The two modes can be switched smoothly, which solves the contradiction of slow response of traditional single frequency adjustment and large impact of single torque control.

[0020] The adaptive correction frequency algorithm enables the correction parameters to be automatically adjusted according to the speed of the trolley, which solves the contradiction between high-speed overshoot and low-speed sluggishness, and adapts to various working conditions such as high speed under no-load, low speed under heavy load, and frequent start-stop of gantry cranes.

[0021] The encoder, combined with the secondary detection architecture of absolute position detection, automatic reset logic, and adaptive correction of slippage coefficient, can automatically identify and eliminate the cumulative error caused by wheel slippage, ensuring that the position synchronization accuracy of the trolley does not drift after long-term operation.

[0022] The flange spacing auxiliary detection mechanism prioritizes anti-rail biting. When the flange spacing is too small, anti-rail biting control is executed first to avoid mechanical squeezing caused by improper correction control, thus achieving coordination and unity between correction and anti-rail biting. Attached Figure Description

[0023] Figure 1 This is a flowchart of the automatic correction method for gantry crane trolley based on multi-motor cross-coupling according to the present invention.

[0024] Figure 2 This is an architecture diagram of an automatic trolley correction system for gantry cranes based on multi-motor cross-coupling. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0026] This invention provides an automatic gantry crane trolley correction method based on multi-motor cross-coupling. The gantry crane trolley is equipped with independent travel motor drive systems on both sides, each drive system including a travel motor, a reducer, a frequency converter, and an encoder. The method includes the following steps: S1: Establish a master-slave cross-coupling control architecture Speed ​​observers are configured in the drive motors on both sides of the trolley to establish a master-slave cross-coupling model. The motors on both sides are defined as master shaft motors and slave shaft motors. Speed ​​observers are built into the frequency converters on both sides. The speed observers on both sides collect the actual speed signals of their respective motors in real time and calculate the speed difference and position difference between the two sides.

[0027] The spindle speed loop receives the master speed command and the slave cross-coupling compensation amount, and outputs the master spindle torque command; the slave speed loop receives the master speed command and the master spindle cross-coupling compensation amount, and outputs the slave spindle torque command. The cross-coupling controller input is the actual spindle speed. Actual speed of the shaft actual position of the spindle From the actual position of the shaft .

[0028] The cross-coupling control law is designed as follows: in, The cross-coupling speed compensation is superimposed on the speed loop commands on both sides; This is the cross-coupling torque compensation amount, used for torque compensation mode under large deviations; For speed proportional gain, For velocity integral gain, For position scaling gain, For position feedforward gain, This is the velocity differential gain. In this embodiment, =2.5, =0.8, =1.2, =5.0, =0.5, and the above parameters can be adjusted online on the touch screen.

[0029] The cross-coupling model introduces a dual-sided error feedback channel: the master spindle deviation signal is coupled to the slave spindle control loop, and the slave spindle deviation signal is simultaneously coupled to the master spindle control loop, forming a bidirectional cross-compensation mechanism to replace the traditional unidirectional master-slave following mode. Both motors actively adjust their outputs based on the other's deviation, rather than passively following on one side.

[0030] S2: Construct a digital twin virtual axis model for real-time correction calculations. A digital twin virtual axis model of the gantry crane traveling mechanism is constructed. The virtual axis model is based on the mechanical structural parameters (wheel track, track gauge, reduction ratio, wheel diameter) and kinematic equations of the gantry crane trolley, and establishes a virtual synchronous axis under an ideal and unbiased state.

[0031] The actual position signals from the encoders on both sides are input into the virtual axis model. The deviation between the actual positions on both sides and the ideal position of the virtual axis (tracking error), as well as the relative deviation between the two sides (synchronization error), are calculated in real time. Real-time correction calculations are performed based on the digital twin model to generate cross-coupled correction control quantities, replacing the traditional mechanical synchronization algorithm. The correction control quantities consist of two parts: tracking error compensation to eliminate deviations on each side relative to the ideal trajectory; and relative deviation compensation to eliminate asynchrony between the two sides.

[0032] Specifically, the mechanical structure parameters of the trolley are entered through the Weintek touch screen: wheel diameter D, reducer reduction ratio i, and encoder resolution N.

[0033] Establish the kinematic equations for the virtual axis: The relationship between the motor speed n (rpm) and the wheel linear velocity v (m / min) is as follows: The relationship between encoder pulse count C and travel distance s (mm) is as follows: .

[0034] The virtual axis model uses the average value of the commands from both motors as the ideal input. Let the command issued by the main controller for the left side be... The instructions on the right are Then the ideal velocity of the virtual axis Ideal location Through the The points are obtained through integration.

[0035] The actual positions of both sides , Ideal position of virtual axis The comparison yields the tracking error on the left side. Right-side tracking error and the relative deviation between the two sides .

[0036] The total corrective control quantity U is generated by superimposing the tracking error compensation and the relative deviation compensation: in To track the error compensation coefficient, This is the relative deviation proportionality coefficient. This is the integral coefficient for the relative deviation.

[0037] S3: Adaptive correction control output When the deviation between the two sides exceeds a preset threshold, the output frequency or output torque of the inverters on both sides is automatically adjusted to achieve smooth correction. The correction control adopts a speed-torque dual-mode switching strategy. Under small deviation conditions: the frequency fine-tuning mode is preferred. Speed ​​difference compensation is achieved by adjusting the output frequency of the frequency converter to ensure stable operation and avoid the impact of frequent torque fluctuations on the mechanical transmission chain. Under conditions of large deviation: Switch to torque compensation mode to quickly suppress the expansion of deviation through short-term torque adjustment, and then smoothly transition to frequency fine-tuning mode to balance the speed of correction response and the stability of operation.

[0038] Specifically, by setting a mode switching threshold When the relative deviation between the two sides ≤ When using the frequency fine-tuning mode, only the inverter output frequency is adjusted, and the frequency adjustment amount is... ,in =0.2Hz / mm. In this mode, the motor output torque remains stable, and the deviation is naturally eliminated only by the speed difference, resulting in minimal mechanical shock.

[0039] When the relative deviation of the two sides When switching to torque compensation mode, a short-term torque compensation amount is output to the lagging motor. 15% of rated torque, duration 500 ms, causing the lagging side to accelerate instantaneously, rapidly reducing the deviation. Wait for the deviation to return to... ≤ Then, the frequency fine-tuning mode is smoothly transitioned back to the S-curve with a transition time of 200ms.

[0040] S4: Adaptive adjustment of correction frequency An adaptive correction frequency algorithm is introduced to dynamically adjust the response frequency and gain parameters of the correction control loop based on the current moving speed of the trolley. A piecewise mapping relationship is established between the trolley's running speed and the correction parameters: High-speed operation: Reduce correction gain and increase filtering depth to prevent correction overshoot and oscillation at high speeds; Low-speed operation segment: Increase the correction gain and shorten the response cycle to ensure the correction sensitivity and speed at low speeds; Speed ​​switching segment: Use a smooth transition function (such as linear interpolation or S-curve) to avoid system shocks caused by parameter jumps.

[0041] Specifically, the parameter mapping relationships of the adaptive correction frequency algorithm include: For a gantry crane with a rated speed of 30 m / min, the trolley travel speed is divided into three ranges: Low speed range: 0≤v<5m / min (heavy load start / precision positioning conditions) Medium speed range: 5≤v<15m / min (normal operating conditions) High-speed section: 15≤v≤30m / min (unloaded high-speed operation condition) When the speed crosses the interval boundary, linear interpolation is used to achieve a smooth transition: in , This is the boundary value between adjacent speed segments. , To ensure the corresponding gain, parameters change continuously, avoiding sudden fluctuations.

[0042] S5: Encoder Automatic Reset and Secondary Detection Verification A secondary detection and verification mechanism is configured using an encoder and a position detection device. The position detection device includes an absolute encoder or a laser rangefinder sensor installed at the end of the trolley, used to directly detect the absolute travel distance of the trolley relative to the track.

[0043] The secondary detection and verification mechanism includes: the main detection channel consists of a left incremental encoder and a right incremental encoder, providing real-time feedback on the rotational speed and position of the motor shafts on both sides, offering fast response and high accuracy; the verification channel uses a laser rangefinder sensor, directly measuring the absolute displacement of the trolley, unaffected by slippage. During normal operation, the incremental encoder is the primary sensor, performing position calculations every 10ms; every 100ms, the encoder-calculated position is compared with the laser rangefinder value. If the difference exceeds 20mm, a verification anomaly warning is triggered, and the main controller automatically increases the correction gain for conservative control.

[0044] The flange spacing auxiliary detection includes: four laser rangefinders respectively detecting the distance between the wheel flange and the track at the left front, left rear, right front, and right rear ends, denoted as . , , , Theoretical gap Minimum allowable spacing .

[0045] When any ≤ Immediately trigger the anti-rail-biting interrupt: suspend the normal cross-coupling correction program; determine the trolley's direction of travel; if the trolley is traveling to the left and the left-side clearance is too small, temporarily reduce the frequency of the left-side inverter by 2Hz, causing the left side to decelerate and the right side to accelerate relatively, causing the trolley to shift to the right as a whole, increasing the left-side clearance; wait until all... > Afterwards, normal cross-coupling correction control is restored.

[0046] This mechanism prioritizes the safety of the wheel flange spacing to prevent wheel flanges from squeezing against the track due to improper control during the correction process.

[0047] An automatic encoder reset logic is established: When the trolley reaches a preset reference position (such as the track end limit point, intermediate calibration mark point, or the corresponding position of the limit detection block), the encoder is automatically reset. The current encoder value is compared and calibrated with the absolute position value of the position detection device to automatically eliminate the accumulated error caused by wheel slippage. During operation at non-reference points, a fusion strategy is adopted, with encoder incremental detection as the primary method and position detection device verification as a secondary method. When the difference between the two exceeds the fault tolerance threshold, an early warning is triggered and adaptive error compensation is initiated.

[0048] Furthermore, the automatic reset logic also includes adaptive correction of the slippage coefficient: recording the deviation data during each reset, updating the slippage compensation coefficient through iterative learning, and using iterative learning for slippage pre-compensation in subsequent operation.

[0049] Specifically, the complete process of the encoder automatic reset logic includes: Metal induction plates are installed at both ends and the middle of the track (e.g., 50m from the middle of the track) as reference marks, and proximity switches are installed at the ends of the trolley as positioning detection sensors. The distance between adjacent reference points is no more than 100m to ensure that the cumulative error is not too large.

[0050] When the trolley passes the reference point, the positioning detection sensor generates a rising edge signal, triggering a reset interrupt. The main controller performs the following operations: Read the current absolute position value of the laser rangefinder sensor ; Read the current calculation position of the left incremental encoder The current calculated position of the right incremental encoder. ; Calculate the deviation: ; If | If |≤100 mm (normal cumulative error range), then the encoder's current value will be forcibly corrected to Complete the reset; If | If the deviation exceeds 100 mm (abnormal deviation), a slippage alarm will be triggered, prompting manual inspection. No forced reset will be performed.

[0051] After the reset is completed, the main controller records the reset deviation data of the last 10 resets and calculates the average deviation. Update the slippage compensation coefficient: in This is the learning rate. This coefficient is used for slippage pre-compensation in subsequent operation: in normal correction calculations, the encoder feedback value is multiplied by (1+ Corrections are made to mitigate the effects of slippage in advance.

[0052] S6: Human-Computer Interaction and Monitoring The Weintek 10-inch industrial touchscreen enables the issuance of operation commands and monitoring of operational status. The touchscreen communicates with the inverters on both sides and the main controller, displaying real-time motor speeds, position deviations, correction amounts, virtual axis status, and alarm information. Operators can manually set correction parameters, start and stop correction functions, and view historical deviation curves and slippage cumulative error trends via the touchscreen.

[0053] Furthermore, the present invention also includes a flange spacing auxiliary detection step: distance sensors are installed at the front and rear ends of the traveling wheels on both sides of the trolley to detect the distance between the traveling wheel flanges and the track in real time. When any flange spacing is detected to be less than the minimum allowable spacing, anti-rail-biting control is initiated first: the normal correction procedure is temporarily interrupted, and an emergency speed adjustment command is generated according to the trolley's direction of travel, causing the two outriggers to move in the direction of increasing flange spacing until the flange spacing is restored to the theoretical clearance range, and then normal cross-coupling correction control is resumed. This mechanism prioritizes anti-rail-biting to avoid flange-track squeezing due to improper control during the correction process.

[0054] Furthermore, this invention employs a three-level threshold control strategy: within the first-level threshold (normal allowable deviation), no correction is performed to reduce unnecessary control actions; within the second-level threshold (automatic correction activation), automatic correction is activated; outside the third-level threshold (dangerous shutdown), the entire machine stops and an alarm is triggered. Each threshold is set proportionally based on the gantry crane span value, balancing safety and control accuracy.

[0055] The present invention also provides an automatic gantry crane trolley correction system for implementing the above method, including a main controller, a left-side drive subsystem, a right-side drive subsystem, an absolute position detection device, a wheel flange distance detection device, and a human-machine interface terminal.

[0056] The main controller uses a PLC or industrial motion controller and is responsible for running the digital twin virtual axis model, cross-coupled correction algorithm, and adaptive parameter adjustment algorithm. The left-side drive subsystem includes a left-side travel motor, a left-side reducer, a left-side frequency converter, and a left-side incremental encoder; The right-side drive subsystem includes a right-side travel motor, a right-side reducer, a right-side frequency converter, and a right-side incremental encoder; The absolute position detection device is installed on the end beam of the trolley and uses an absolute encoder or laser rangefinder to directly measure the absolute displacement of the trolley relative to the track reference. The wheel flange spacing detection device includes four laser rangefinders, which are respectively installed on the outer side of the wheel box of the front traveling wheel of the left outrigger, the rear traveling wheel of the left outrigger, the front traveling wheel of the right outrigger, and the rear traveling wheel of the right outrigger, to detect the distance between the wheel flange of each traveling wheel and the side of the track in real time. The human-machine interface terminal uses a Weintek 10-inch industrial touch screen and communicates with the main controller via Ethernet; It also includes a communication network, in which the main controller is connected to the frequency converters on both sides via a bus, with a communication cycle of no more than 10ms, to ensure the real-time performance of the correction control.

[0057] The complete control process for automatic deviation correction of the gantry crane trolley in this embodiment is as follows: After the system is powered on and initialized, mechanical parameters, correction parameters, and slippage coefficients are loaded. The operator selects "automatic correction mode" or "manual mode" via the Weintek touchscreen. If manual mode is selected, the manual control process is executed; if automatic mode is selected, the main controller obtains the calculated positions of the left and right sides in real time through the left and right incremental encoders, and simultaneously obtains the absolute position verification value through the laser rangefinder.

[0058] The main controller prioritizes determining whether the wheel flange spacing is abnormal. If any wheel flange spacing is less than the minimum allowable spacing, it immediately initiates anti-rail-wearing emergency control, temporarily interrupts the normal correction procedure, adjusts the speeds on both sides according to the trolley's direction of travel to restore the spacing, and then resumes normal cross-coupling correction control.

[0059] If the wheel flange spacing is normal, the digital twin virtual axis model calculates the ideal position, and then calculates the tracking error and relative deviation. The main controller determines whether the relative deviation exceeds the third-level threshold (dangerous shutdown threshold). If so, it shuts down and alarms; if not, it continues to determine whether it exceeds the second-level threshold (automatic correction start threshold).

[0060] If the deviation is within the second-level threshold, the correction is considered complete, and the current operating state is maintained, continuing the loop detection. If the deviation exceeds the second-level threshold, correction control is initiated: first, the current speed range (low / medium / high speed) is determined, and the corresponding adaptive correction parameters are loaded; then, the cross-coupled controller calculates the correction control quantity; next, it is determined whether the deviation exceeds the mode switching threshold, and either the frequency fine-tuning mode or the torque compensation mode is selected; finally, the control quantity is output to the frequency converters on both sides to adjust the motor operating state.

[0061] During operation, if the trolley is detected to have passed the reference point, the encoder is automatically reset and the slippage coefficient is corrected. The entire process is executed in a loop until the automatic correction function is turned off.

[0062] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

Claims

1. A method for automatic trolley deviation correction of a gantry crane based on multi-motor cross-coupling, characterized in that, Includes the following steps: S1. Configure speed observers in the driving motors on both sides of the trolley to establish a master-slave cross-coupling model. The master shaft deviation signal of the master-slave cross-coupling model is coupled to the slave shaft control loop, and the slave shaft deviation signal is simultaneously coupled to the master shaft control loop, forming a bidirectional cross compensation. S2. Based on the mechanical structure parameters of the gantry crane trolley, establish a digital twin virtual axis model, input the actual position signals fed back by the encoders on both sides into the virtual axis model, calculate the deviation between the actual position on both sides and the ideal position of the virtual axis, as well as the relative deviation between the two sides, and generate cross-coupled correction control quantity. S3. When the deviation on both sides exceeds the preset threshold, adjust the output frequency or output torque of the inverters on both sides. S4. Dynamically adjust the response frequency and gain parameters of the correction control loop according to the current moving speed of the trolley; S5. Secondary detection and verification are performed through the encoder and position detection device. When the trolley moves to the preset reference position, the encoder is automatically reset. The current value of the encoder is compared and calibrated with the absolute position value of the position detection device to eliminate the cumulative error caused by wheel slippage. S6. Implement operation command issuance and operation status monitoring through industrial touch screen.

2. The automatic correction method for gantry crane trolley based on multi-motor cross-coupling as described in claim 1, characterized in that, The speed observer in step S1 uses an extended Kalman filter or sliding mode observer algorithm to estimate the actual speed of the motor in real time based on the motor current and voltage signals.

3. The automatic correction method for gantry crane trolley based on multi-motor cross-coupling as described in claim 2, characterized in that, The master-slave cross-coupling model described in step S1 includes a velocity difference proportional integral term and a position difference proportional term. Both velocity loops receive the cross-coupling compensation amount to achieve bidirectional active synchronization.

4. The automatic correction method for gantry crane trolley based on multi-motor cross-coupling as described in claim 1, characterized in that, In step S2, the digital twin virtual axis model uses the average value of the motor commands on both sides as the ideal input and outputs the ideal position and ideal speed; the deviation includes the tracking error of each side relative to the virtual axis and the relative deviation between the two sides.

5. The automatic correction method for gantry crane trolley based on multi-motor cross-coupling as described in claim 1, characterized in that, In step S3, when the relative deviation between the two sides does not exceed the first threshold, the frequency fine-tuning mode is adopted, and only the output frequency of the inverter is adjusted; when the relative deviation between the two sides exceeds the first threshold, the torque compensation mode is switched to output a short-term torque compensation amount to the lagging motor, and after the deviation falls back to below the first threshold, the frequency fine-tuning mode is smoothly transitioned back.

6. The automatic correction method for gantry crane trolley based on multi-motor cross-coupling according to claim 1, characterized in that, In step S4, the running speed of the trolley is divided into low-speed, medium-speed and high-speed segments, with each segment corresponding to different proportional gain, integral gain and filtering time constant of the correction loop.

7. The automatic correction method for gantry crane trolley based on multi-motor cross-coupling according to claim 1, characterized in that, In step S5, the position detection device uses an absolute encoder or a laser rangefinder sensor, which is installed at the end of the trolley to directly measure the absolute displacement of the trolley relative to the track reference. The secondary detection and verification uses encoder incremental detection and position detection device verification. When the difference between the two exceeds the fault tolerance threshold, an early warning is triggered.

8. The automatic correction method for gantry crane trolley based on multi-motor cross-coupling according to claim 7, characterized in that, Step S5 also includes automatic encoder reset: recording the deviation data during each reset, updating the slippage compensation coefficient through iterative learning, and using iterative learning for slippage pre-compensation in subsequent operation.

9. The automatic correction method for gantry crane trolley based on multi-motor cross-coupling according to claim 1, characterized in that, It also includes a flange spacing auxiliary detection step: distance measuring sensors are installed at the front and rear travel wheels of the outriggers on both sides of the trolley to detect the distance between the travel wheel flange and the track in real time; when the distance between any flange and the track is detected to be less than the minimum allowable distance, the anti-rail biting control is activated first, the normal correction program is temporarily interrupted, and an emergency speed adjustment command is generated according to the direction of travel of the trolley to make the outriggers on both sides move in the direction of increasing the flange spacing until the flange spacing is restored to the theoretical clearance range, and then the normal cross-coupling correction control is restored.

10. The automatic correction method for gantry crane trolley based on multi-motor cross-coupling according to claim 1, characterized in that, The preset threshold adopts a three-level threshold control: the first level threshold is the normal allowable deviation range, and no correction control is performed when the deviation is within this range; the second level threshold is the automatic correction start threshold, and automatic correction control is started when the deviation exceeds this range; the third level threshold is the dangerous shutdown threshold, and the whole machine stops running and an alarm signal is issued when the deviation exceeds this range.

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