A double-drive gantry deviation correction method based on motor torque feedback

Abstract

This invention relates to the field of motion control technology for gantry cranes, and discloses a method for correcting the alignment of a dual-drive gantry crane based on motor torque feedback. This method acquires the torque feedback signals of the left and right drive motors during the operation of the dual-drive gantry crane, filters them, and calculates the torque difference signal. The torque difference signal is then frequency-divided to obtain a static component related to horizontality and a dynamic component related to parallelism. A total adjustment amount in the left-right direction is generated based on the parallelism-related dynamic component, and a total adjustment amount in the up-down direction is generated based on the horizontality-related static component. The total adjustment amounts in the left-right and up-down directions are then differentially distributed to the left and right ends of the first drive shaft, the left and right ends of the second drive shaft, and the right ends of the second drive shaft, driving the corresponding electric cylinder adjustment components to perform the alignment correction. This invention achieves adaptive alignment correction of the horizontality and parallelism of a dual-drive gantry crane without the need for additional position or horizontality sensors.

Description

Technical Field

[0001] This invention relates to the field of motion control technology for gantry equipment, specifically a dual-drive gantry correction method based on motor torque feedback. Background Technology

[0002] To enable large-format, long-stroke operations, equipment such as laser welding, CNC machining, and automated inspection typically employs a dual-drive gantry structure. A dual-drive gantry structure generally includes a first and second drive shaft arranged parallel to each other. The gantry beam spans across the first and second drive shafts and is driven by two drive motors. To ensure the attitude stability and trajectory accuracy of the gantry beam during movement, existing technologies typically employ master-slave synchronous control, electronic gear synchronous control, electronic cam synchronous control, proportional-integral-derivative synchronous error compensation control, or cross-coupling control. Some solutions also collect the position or horizontal status of the two drive shafts by installing optical scales, magnetic scales, laser interferometers, or electronic levels, and then generate correction amounts based on position or attitude deviations.

[0003] However, existing dual-drive gantry milling correction methods generally rely on position detection signals or external attitude detection signals, resulting in complex hardware layouts. They are also sensitive to installation benchmarks, environmental cleanliness, and on-site vibrations. Over long-term operation, sensor drift, contamination, loosening, or damage can easily lead to a decrease in correction accuracy. Furthermore, in laser welding rooms, low-frequency vibrations generated by auxiliary equipment such as exhaust fans and cooling water circulating pumps are transmitted to the gantry bed through the foundation, causing disturbances with inconsistent amplitude or phase at both ends of the gantry beam. Traditional correction methods based on position synchronization errors struggle to directly identify horizontal and parallelism deviations from changes in drive load, leading to delayed correction response and increased on-site debugging and maintenance costs. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a dual-drive gantry correction method based on motor torque feedback, which solves the problems of existing dual-drive gantry correction methods relying on external position or attitude detection devices, having complex hardware installation, and being difficult to identify horizontal and parallelism deviations using drive load information.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a dual-drive gantry correction method based on motor torque feedback, comprising: The torque feedback signals of the left and right drive motors during the operation of the dual-drive gantry are acquired, and the torque feedback signals are filtered to obtain the filtered torque of the left motor and the filtered torque of the right motor. The torque difference signal is calculated based on the left motor filter torque and the right motor filter torque; The torque difference signal is divided by frequency to obtain the static component related to levelness and the dynamic component related to parallelism; The total adjustment amount in the left and right directions is generated based on the parallelism-related dynamic components, and the total adjustment amount in the up and down directions is generated based on the horizontality-related static components. The total adjustment amount in the left and right directions and the total adjustment amount in the up and down directions are allocated to the four endpoints to generate the left and right correction amount and the up and down correction amount for each endpoint. The corresponding electric cylinder adjustment component is driven to perform correction based on the left and right correction amount and the up and down correction amount of each endpoint; The four endpoints are the left end of the first drive shaft, the right end of the first drive shaft, the left end of the second drive shaft, and the right end of the second drive shaft.

[0006] Preferably, the steps for obtaining the left motor filtering torque and the right motor filtering torque include: The real-time output torque of the left drive motor and the real-time output torque of the right drive motor are read within the same sampling period. The real-time output torque of the left drive motor and the real-time output torque of the right drive motor are respectively subjected to low-pass filtering to remove high-frequency sampling noise; The filtered left drive motor torque is used as the left motor filtered torque, and the filtered right drive motor torque is used as the right motor filtered torque.

[0007] Preferably, the step of frequency division and separation of the torque difference signal includes: The frequency division parameters are determined based on the operating speed and sampling period of the dual-drive gantry. The torque difference signal is extracted at low frequencies using the frequency division parameters to obtain the levelness-related static component. The remaining component after deducting the horizontality-related static component from the torque difference signal is taken as the parallelism-related dynamic component.

[0008] Preferably, the steps of generating the total adjustment amount in the left-right direction and the total adjustment amount in the up-down direction include: The parallelism-related dynamic components are subjected to proportional differential processing to generate the total left-right adjustment amount used to adjust the parallelism between the first drive shaft and the second drive shaft. The horizontality-related static components are subjected to proportional-integral processing to generate the total vertical adjustment amount used to adjust the horizontality of the first and second drive shafts.

[0009] Preferably, the control parameters for the proportional-derivative (PD) and proportional-integral (PI) processing are obtained through adaptive tuning, which includes: Within a continuous control window, the peak-to-peak value, rate of change, and convergence speed of the parallelism-related dynamic components are statistically analyzed, and the proportional coefficient and derivative coefficient of the proportional-derivative processing are adjusted based on the statistical results. Within the continuous control window, the mean offset and duration of the levelness-related static components are statistically analyzed, and the proportional coefficient and integral coefficient of the proportional-integral processing are adjusted based on the statistical results.

[0010] Preferably, the step of allocating the total left-right adjustment and the total up-down adjustment to the four endpoints includes: Under the preset endpoint coordinate system, the total adjustment amount in the left and right directions is distributed to the four endpoints according to the differential relationship that the left and right ends are opposite and the endpoints on the same side are in the same direction, so as to obtain the left and right correction amount of each endpoint; In the preset endpoint coordinate system, the total vertical adjustment is distributed to the four endpoints according to the differential relationship of the left and right ends being opposite and the same-side endpoints being in the same direction, so as to obtain the vertical correction amount of each endpoint.

[0011] Preferably, the electric cylinder adjustment assembly is disposed at the four endpoints, and the electric cylinder adjustment assembly includes a lifting servo electric cylinder, an adjusting servo electric cylinder, a slide rail slider, and a drive shaft mounting plate; The lifting servo electric cylinder drives the drive shaft mounting plate to move in the vertical direction according to the vertical correction amount of each endpoint. The adjusting servo electric cylinder drives the drive shaft mounting plate to move in the left and right direction according to the left and right correction amount of each endpoint.

[0012] Preferably, before driving the corresponding electric cylinder adjustment component to perform correction, it further includes: Displacement limiting processing is applied to the left and right correction amounts and the up and down correction amounts of each endpoint, respectively. The slope of the left and right correction amount and the up and down correction amount of each endpoint after the amplitude limit are subjected to slope limiting processing to generate a smooth correction command; The corresponding electric cylinder adjustment component is driven to perform correction according to the smooth correction command.

[0013] Preferably, the method further includes a security protection step: Monitor the amplitude and duration of the torque difference signal; If the amplitude of the torque difference signal exceeds the fault threshold and the duration exceeds the fault duration, then the left and right correction amounts of each endpoint and the up and down correction amounts of each endpoint are locked, the dual-drive gantry is controlled to stop smoothly and an alarm signal is output.

[0014] This invention also provides a dual-drive gantry correction system based on motor torque feedback, used to execute the aforementioned dual-drive gantry correction method based on motor torque feedback, the system comprising: The torque acquisition module is used to acquire the torque feedback signals of the left drive motor and the right drive motor during the operation of the dual-drive gantry, and to obtain the filtered torque of the left motor and the filtered torque of the right motor. The torque difference calculation module is used to calculate the torque difference signal based on the left motor filter torque and the right motor filter torque; The frequency division and separation module is used to divide and separate the torque difference signal to obtain the horizontality-related static component and the parallelism-related dynamic component. The total adjustment amount generation module is used to generate the total adjustment amount in the left and right directions based on the parallelism-related dynamic components, and to generate the total adjustment amount in the up and down directions based on the horizontality-related static components. The endpoint correction amount allocation module is used to allocate the total adjustment amount in the left and right directions and the total adjustment amount in the up and down directions to the four endpoints, and generate the left and right correction amount and the up and down correction amount of each endpoint. The electric cylinder actuation module is used to drive the corresponding electric cylinder adjustment component to perform correction based on the left and right correction amount and the up and down correction amount of each endpoint.

[0015] This invention provides a dual-drive gantry correction method based on motor torque feedback. It has the following beneficial effects: 1. This invention calculates the torque difference signal by collecting the torque feedback signals of the left and right drive motors, and makes correction judgments based on the torque difference signal. It does not require the additional installation of grating rulers, magnetic grating rulers, laser interferometers or electronic levels. It can directly use the existing torque feedback information of the servo drive system to obtain the load asymmetry state of the dual-drive gantry, reduce the installation, calibration and maintenance requirements of external detection devices, reduce hardware costs and on-site debugging difficulty, and reduce the risk of correction failure caused by contamination, drift or loosening of external sensors.

[0016] 2. This invention performs frequency division and separation on the torque difference signal to obtain the static component related to horizontality and the dynamic component related to parallelism, and generates the total adjustment amount in the vertical direction and the total adjustment amount in the horizontal direction respectively. It can decouple the slow off-center load caused by horizontality deviation and the dynamic torsion caused by parallelism deviation, avoid the mixed compensation of different error sources, and improve the pertinence of the correction control. It is especially suitable for dual-drive gantry working conditions with low-frequency vibration in the machine room and inconsistent disturbances at both ends of the crossbeam.

[0017] 3. The present invention distributes the total adjustment amount in the left and right directions and the total adjustment amount in the up and down directions according to the differential relationship to the left end of the first drive shaft, the right end of the first drive shaft, the left end of the second drive shaft and the right end of the second drive shaft, so that the four endpoints can form a coordinated fine adjustment, which can correct the parallelism between the first drive shaft and the second drive shaft, as well as the horizontality between the first drive shaft and the second drive shaft, thereby improving the stability of the gantry beam's motion posture and the consistency of the welding trajectory.

[0018] 4. This invention adjusts the control parameters of proportional derivative processing and proportional integral processing through adaptive tuning. It can change the correction response according to the degree of change of the parallelism-related dynamic component and the degree of continuous off-center load of the horizontality-related static component. This enables the dual-drive gantry to maintain a stable correction effect under no-load, full-load, different running speeds, mechanical wear or changes in guide rail lubrication conditions, and reduces the need for repeated manual parameter tuning.

[0019] 5. Before the electric cylinder adjustment component performs correction, the present invention limits the displacement amplitude and slope of the left and right correction amount and the up and down correction amount of each endpoint. When the torque difference signal exceeds the fault threshold and the duration exceeds the fault duration, the fine adjustment output is locked, the vehicle stops smoothly and an alarm is triggered. This can prevent over-adjustment, mechanical collision limit and structural torsion of the gantry beam, and improve the safety and reliability of the dual-drive gantry correction process. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the dual-drive gantry of the present invention; Figure 2 This is a schematic diagram of the electric cylinder adjustment assembly of the present invention; Figure 3 This is a flowchart of the dual-drive gantry correction method based on motor torque feedback of the present invention; Figure 4 This is a flowchart of the torque differential frequency separation and adjustment quantity generation process of the present invention; Figure 5 This is a block diagram of the dual-drive gantry correction system of the present invention.

[0021] The components include: 1. Gantry column; 2. First drive shaft; 3. Second drive shaft; 4. Gantry beam; 5. Lifting servo cylinder; 6. Mechanism assembly; 7. Slide rail slider; 8. Drive shaft mounting plate; 9. Adjusting servo cylinder; 10. Cylinder adjustment mounting plate. Detailed Implementation

[0022] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0023] This embodiment provides a method for correcting the alignment of a dual-drive gantry crane based on motor torque feedback, applicable to dual-drive gantry crane equipment. (Refer to...) Figure 1 The dual-drive gantry equipment includes a gantry column 1, a first drive shaft 2, a second drive shaft 3, a gantry beam 4, an electric cylinder adjustment assembly, a left drive motor, a right drive motor, a controller, and a servo driver.

[0024] The first drive shaft 2 and the second drive shaft 3 are arranged parallel to each other. The gantry beam 4 spans across the first drive shaft 2 and the second drive shaft 3. The left drive motor and the right drive motor jointly drive the gantry beam 4 to move along the first drive shaft 2 and the second drive shaft 3. The servo driver is connected to the left drive motor and the right drive motor to acquire the real-time torque feedback signals of the left drive motor and send the torque feedback signals to the controller. The controller is used to calculate the correction amount based on the torque feedback signals and control the corresponding electric cylinder adjustment component to perform the correction action.

[0025] Electric cylinder adjustment assemblies are respectively installed at both ends of the first drive shaft 2 and both ends of the second drive shaft 3. (Refer to...) Figure 2 The electric cylinder adjustment assembly includes a lifting servo cylinder 5, a mechanism assembly 6, a slide rail slider 7, a drive shaft mounting plate 8, an adjustment servo cylinder 9, and an electric cylinder adjustment mounting plate 10. The lifting servo cylinder 5 is mounted on the electric cylinder adjustment mounting plate 10 and connected to the drive shaft mounting plate 8 via the mechanism assembly 6, used to drive the drive shaft mounting plate 8 to move vertically. The adjustment servo cylinder 9 is mounted on the electric cylinder adjustment mounting plate 10 and is connected to the drive shaft mounting plate 8, used to drive the drive shaft mounting plate 8 to move horizontally. The slide rail slider 7 is located between the drive shaft mounting plate 8 and the electric cylinder adjustment mounting plate 10, used to guide the movement direction of the drive shaft mounting plate 8, ensuring stable fine-tuning of the drive shaft mounting plate 8 under the drive of the lifting servo cylinder 5 or the adjustment servo cylinder 9.

[0026] For ease of description, the left end of the first drive shaft 2 is defined as the first endpoint A, the right end of the first drive shaft 2 is defined as the second endpoint B, the left end of the second drive shaft 3 is defined as the third endpoint C, and the right end of the second drive shaft 3 is defined as the fourth endpoint D. Each of the first endpoint A, second endpoint B, third endpoint C, and fourth endpoint D corresponds to an electric cylinder adjustment assembly. The vertical direction is defined as the Z-axis, with the vertical adjustment amount denoted as ΔZ, and upward as the positive direction. The horizontal direction is defined as the Y-axis, which is a horizontal direction perpendicular to the axes of the first drive shaft 2 and the second drive shaft 3, with the horizontal adjustment amount denoted as ΔY. For the first endpoint A and the second endpoint B on the first drive shaft 2, the positive direction of ΔY is the direction away from the second drive shaft 3; for the third endpoint C and the fourth endpoint D on the second drive shaft 3, the positive direction of ΔY is the direction away from the first drive shaft 2. In other words, the positive direction of ΔY for each endpoint is the direction that increases the distance between the first drive shaft 2 and the second drive shaft 3.

[0027] Reference Figure 3 The method in this embodiment includes the following steps: S100: The controller obtains the torque feedback signals of the left and right drive motors through the servo driver, and filters the torque feedback signals to obtain the filtered torque of the left motor and the filtered torque of the right motor.

[0028] Specifically, during the operation of the dual-drive gantry milling machine, the servo driver reads the output torque of the left drive motor and the output torque of the right drive motor in real time. Since the output torque contains high-frequency sampling noise and electrical disturbances, the controller performs low-pass filtering on the output torque of the left drive motor and the output torque of the right drive motor respectively to remove high-frequency components that do not reflect mechanical installation deviations, thus obtaining the filtered torque of the left motor and the filtered torque of the right motor.

[0029] S200: The controller calculates the torque difference signal based on the left motor filter torque and the right motor filter torque.

[0030] At time t, let the filtering torque of the left motor be... The right motor's filtering torque is The torque difference signal is The torque difference signal is then calculated using the following formula: ; in, This represents the torque difference signal at time t. This represents the filtering torque of the left motor at time t. This represents the filtering torque of the right motor at time t.

[0031] When the first drive shaft 2 and the second drive shaft 3 are not parallel, not horizontal, or have inconsistent coupling with external low-frequency vibrations, the additional resistance on both sides of the gantry beam 4 is different, resulting in a difference in the output torque of the left drive motor and the right drive motor. Therefore, this embodiment uses the torque difference signal to characterize the asymmetric state of the additional resistance torque during the operation of the dual-drive gantry equipment.

[0032] The S300 controller performs frequency division and separation on the torque difference signal to obtain the static component related to levelness and the dynamic component related to parallelism.

[0033] Specifically, refer to Figure 4 When there is a parallelism deviation between the first drive shaft 2 and the second drive shaft 3, the gantry beam 4 will be subject to a torsional constraint that changes with its position during movement. This torsional constraint causes the torque difference signal to exhibit a rapid change characteristic related to the movement speed and position, thus mainly manifesting as a parallelism-related dynamic component. When there is a horizontality deviation between the first drive shaft 2 and the second drive shaft 3, one side will bear a large gravity component or frictional load for a long time. This load changes slowly over time, thus mainly manifesting as a horizontality-related static component.

[0034] This embodiment uses a first-order low-pass filter to extract the horizontality-related static component from the torque difference signal. The horizontality-related static component satisfies the following formula: ; in, This represents the time constant of a first-order low-pass filter. This represents the static component related to the levelness at time t. This represents the torque difference signal at time t. The time constant τ is selected based on the frequency bandwidth of the gantry beam 4, so that the first-order low-pass filter can retain the slow-changing component caused by the horizontality deviation and suppress the faster-changing component caused by the parallelism deviation.

[0035] Furthermore, based on the torque difference signal and the static component related to levelness, the dynamic component related to parallelism is obtained: ; in, This represents the parallelism-related dynamic component at time t. Through the aforementioned frequency division and separation, the controller can decouple the levelness deviation information and parallelism deviation information in the same torque difference signal, avoiding the mixing of the two geometric deviations into the same correction command.

[0036] S400: The controller generates the total adjustment amount in the left and right directions based on the parallelism-related dynamic components, and generates the total adjustment amount in the up and down directions based on the horizontality-related static components.

[0037] Specifically, the total left-right adjustment is used to adjust the parallelism between the first drive shaft 2 and the second drive shaft 3. Because the torque asymmetry caused by parallelism deviation changes rapidly, this embodiment performs proportional-derivative processing on the parallelism-related dynamic components to quickly suppress the dynamic torsion of the gantry beam 4 during movement. Let the total left-right adjustment be denoted as... The total adjustment amount in the left and right directions is generated according to the following formula: ; in, This represents the total adjustment in the left and right directions at time t. This indicates the proportionality coefficient in the left-right direction. Indicates the differential coefficients in the left and right directions. This represents the parallelism-related dynamic component at time t.

[0038] The total vertical adjustment is used to adjust the levelness of the first drive shaft 2 and the second drive shaft 3. Since levelness deviation is mainly manifested as static or quasi-static off-center loading, this embodiment performs proportional-integral processing on the relevant static components of levelness. The proportional term is used to respond to the current off-center loading, and the integral term is used to eliminate long-standing static deviations. The total vertical adjustment is denoted as... The total adjustment amount in the vertical direction is generated according to the following formula: ; in, This represents the total vertical adjustment at time t. This indicates the scaling factor in the vertical direction. Indicates the integral coefficient in the up and down directions. Let T represent the static component of the level at time t, and let T represent the integral variable.

[0039] Preferably, the integral coefficient in the vertical direction is adaptively enhanced according to the degree of off-center loading: ; in, Represents the basic integral coefficient. This represents the adaptive adjustment factor for the levelness integral coefficient. This indicates the rated torque of the beam drive motor. Basic integral coefficient. and adaptive adjustment factor All of these can be determined through prototype testing before shipment.

[0040] When the absolute value of the static component related to the level is large, the integral coefficient in the vertical direction increases, which makes the total adjustment in the vertical direction converge faster; when the absolute value of the static component related to the level decreases, the integral coefficient in the vertical direction decreases, which prevents the electric cylinder adjustment component from over-adjusting.

[0041] Furthermore, the left-right proportional coefficient and differential coefficients in the left and right directions It can adaptively tune based on the changes in the torque difference signal within a continuous control window. When the torque difference signal changes drastically, the controller increases the proportional coefficient in the left and right directions. This improves the response speed to dynamic torsional skew; when an overshoot oscillation trend occurs during adjustment, the controller reduces the differential coefficients in the left and right directions. Alternatively, reduce the adjustment step size in the left and right directions to make the correction process more stable.

[0042] S500: The controller distributes the total adjustment amount in the left and right directions and the total adjustment amount in the up and down directions to the first endpoint A, the second endpoint B, the third endpoint C, and the fourth endpoint D, generating the left and right correction amount and the up and down correction amount for each endpoint.

[0043] Specifically, this embodiment employs a four-end differential distribution method, allocating the total adjustment amount in the left-right direction and the total adjustment amount in the up-down direction to the first endpoint A, the second endpoint B, the third endpoint C, and the fourth endpoint D, respectively. This four-end differential distribution method enables the first drive shaft 2 and the second drive shaft 3 to complete parallelism correction and levelness correction while maintaining the overall support relationship.

[0044] For the total adjustment in the left and right directions, let the left and right correction amount of the first endpoint A be denoted as . The left and right correction amounts of the second endpoint B are The left and right correction amounts of the third endpoint C are The left and right correction amounts of the fourth endpoint D are The differential distribution relationship in the left and right directions is as follows: ; ; ; ; in, This represents the total left-right adjustment at time t. Through the above allocation, the left and right endpoints form opposite adjustments, while the endpoints on the same side operate according to the same rules, thereby changing the relative parallel state between the first drive shaft 2 and the second drive shaft 3.

[0045] For the total vertical adjustment, let the vertical correction amount of the first endpoint A be denoted as . The vertical correction amount of the second endpoint B is The vertical correction amount of the third endpoint C is The vertical correction amount of the fourth endpoint D is The differential distribution relationship in the vertical direction is as follows: ; ; ; ; in, This represents the total vertical adjustment at time t. Through the above allocation, the first drive shaft 2 and the second drive shaft 3 form opposite vertical fine adjustments at their left and right ends, thereby correcting the horizontal mounting state of the first drive shaft 2 and the second drive shaft 3.

[0046] S600: The controller controls the corresponding electric cylinder adjustment component to perform correction based on the left and right correction amount and the up and down correction amount of each endpoint.

[0047] Specifically, the controller converts the vertical correction amounts corresponding to the first endpoint A, the second endpoint B, the third endpoint C, and the fourth endpoint D into position commands for the corresponding lifting servo cylinder 5, and converts the horizontal correction amounts corresponding to the first endpoint A, the second endpoint B, the third endpoint C, and the fourth endpoint D into position commands for the corresponding adjusting servo cylinder 9.

[0048] The lifting servo cylinder 5 moves the drive shaft mounting plate 8 vertically according to the position command, causing fine vertical adjustments to the corresponding ends of the first drive shaft 2 or the second drive shaft 3. The adjusting servo cylinder 9 moves the drive shaft mounting plate 8 horizontally according to the position command, causing fine horizontal adjustments to the corresponding ends of the first drive shaft 2 or the second drive shaft 3. The slide rail slider 7 guides the drive shaft mounting plate 8 during the adjustment process to prevent it from swaying or jamming.

[0049] After the electric cylinder adjustment component completes one correction action, the controller continues to collect the torque feedback signals of the left and right drive motors through the servo driver, and recalculates the torque difference signal to form a closed-loop correction process of torque feedback, frequency division separation, total adjustment generation, four-terminal differential distribution and electric cylinder execution.

[0050] The S700 controller provides displacement limiting and safety protection for the left and right corrections and the up and down corrections at each endpoint.

[0051] To prevent mechanical interference or impact caused by over-adjustment, the controller performs displacement limiting on the left-right correction and the up-down correction of each endpoint. Let endpoint i be any one of A, B, C, or D, then the following condition is met: ; ; in, This represents the left and right correction amount at the i-th endpoint. This represents the vertical correction amount at the i-th endpoint. This indicates the maximum allowable adjustment range in the left and right directions. This indicates the maximum permissible adjustment range in the vertical direction. The maximum permissible adjustment range in the horizontal direction and the maximum permissible adjustment range in the vertical direction are set according to the adjustment stroke of the electric cylinder adjustment assembly, the mechanical clearance, and the permissible tilt angle of the first drive shaft 2 and the second drive shaft 3.

[0052] Furthermore, the controller continuously monitors the absolute value of the torque difference signal. When Exceeding the fault threshold If the fault persists for more than the preset fault duration, the controller determines that the dual-drive gantry equipment is at risk of jamming, collision, or abnormal off-center loading. At this time, the controller locks the left-right and up-down correction values ​​of the first endpoint A, second endpoint B, third endpoint C, and fourth endpoint D, stops outputting new fine-tuning commands, controls the dual-drive gantry equipment to stop smoothly, and outputs an alarm signal. The fault threshold is specified in the original text. The settings are based on the equipment's rated torque, maximum torque fluctuation under normal operating conditions, and safety margin.

[0053] Through the above implementation method, this embodiment does not require additional optical grating rulers, magnetic grating rulers, laser interferometers or electronic levels. It can identify the horizontal and parallelism deviations during the operation of the dual-drive gantry equipment by using the torque feedback signals of the left and right drive motors. The adaptive correction is completed by the electric cylinder adjustment components set at the four ends. Example 2

[0054] Reference Figure 5This embodiment provides a dual-drive gantry correction system based on motor torque feedback, used to execute the dual-drive gantry correction method based on motor torque feedback in Embodiment 1. The system includes a torque acquisition module, a torque difference calculation module, a frequency division and separation module, a total adjustment amount generation module, an endpoint correction amount allocation module, an electric cylinder execution module, and a safety protection module.

[0055] The torque acquisition module is used to acquire the torque feedback signals of the left drive motor and the right drive motor through the servo driver, and to filter the torque feedback signals to obtain the filtered torque of the left motor and the filtered torque of the right motor.

[0056] The torque difference calculation module is used to calculate the torque difference signal based on the filtered torque of the left motor and the filtered torque of the right motor. The frequency division and separation module is used to perform frequency division and separation on the torque difference signal to obtain the static component related to levelness and the dynamic component related to parallelism.

[0057] The total adjustment generation module generates the total adjustment in the left and right directions based on the parallelism-related dynamic components, and generates the total adjustment in the up and down directions based on the horizontality-related static components. The endpoint correction allocation module allocates the total adjustment in the left and right directions and the total adjustment in the up and down directions to the first endpoint A, the second endpoint B, the third endpoint C, and the fourth endpoint D, generating the left and right correction and the up and down correction for each endpoint.

[0058] The electric cylinder actuation module controls the corresponding electric cylinder adjustment component to perform correction based on the left-right and up-down correction amounts at each endpoint. Specifically, the lifting servo electric cylinder 5 in the electric cylinder adjustment component performs up-down correction, and the adjusting servo electric cylinder 9 performs left-right correction. The safety protection module limits the displacement of the left-right and up-down correction amounts at each endpoint. When the torque difference signal exceeds the fault threshold and the duration exceeds the preset fault duration, the module locks the fine-tuning output, controls the dual-drive gantry equipment to stop smoothly, and outputs an alarm signal.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual-drive gantry correction method based on motor torque feedback, characterized in that, include: The torque feedback signals of the left and right drive motors during the operation of the dual-drive gantry are acquired, and the torque feedback signals are filtered to obtain the filtered torque of the left motor and the filtered torque of the right motor. The torque difference signal is calculated based on the left motor filter torque and the right motor filter torque; The torque difference signal is divided by frequency to obtain the static component related to levelness and the dynamic component related to parallelism; The total adjustment amount in the left and right directions is generated based on the parallelism-related dynamic components, and the total adjustment amount in the up and down directions is generated based on the horizontality-related static components. The total adjustment amount in the left and right directions and the total adjustment amount in the up and down directions are allocated to the four endpoints to generate the left and right correction amount and the up and down correction amount for each endpoint. The corresponding electric cylinder adjustment component is driven to perform correction based on the left and right correction amount and the up and down correction amount of each endpoint; The four endpoints are the left end of the first drive shaft, the right end of the first drive shaft, the left end of the second drive shaft, and the right end of the second drive shaft.

2. The dual-drive gantry correction method based on motor torque feedback according to claim 1, characterized in that, The steps for obtaining the left motor filtering torque and the right motor filtering torque include: The real-time output torque of the left drive motor and the real-time output torque of the right drive motor are read within the same sampling period. The real-time output torque of the left drive motor and the real-time output torque of the right drive motor are respectively subjected to low-pass filtering to remove high-frequency sampling noise; The filtered left drive motor torque is used as the left motor filtered torque, and the filtered right drive motor torque is used as the right motor filtered torque.

3. The dual-drive gantry correction method based on motor torque feedback according to claim 1, characterized in that, The steps for frequency division and separation of the torque difference signal include: The frequency division parameters are determined based on the operating speed and sampling period of the dual-drive gantry. The torque difference signal is extracted at low frequencies using the frequency division parameters to obtain the levelness-related static component. The remaining component after deducting the horizontality-related static component from the torque difference signal is taken as the parallelism-related dynamic component.

4. The dual-drive gantry correction method based on motor torque feedback according to claim 1, characterized in that, The steps for generating the total adjustment amount in the left-right direction and the total adjustment amount in the up-down direction include: The parallelism-related dynamic components are subjected to proportional differential processing to generate the total left-right adjustment amount used to adjust the parallelism between the first drive shaft and the second drive shaft. The horizontality-related static components are subjected to proportional-integral processing to generate the total vertical adjustment amount used to adjust the horizontality of the first and second drive shafts.

5. The dual-drive gantry correction method based on motor torque feedback according to claim 4, characterized in that, The control parameters for the proportional-derivative (PD) and proportional-integral (PI) processing are obtained through adaptive tuning, which includes: Within a continuous control window, the peak-to-peak value, rate of change, and convergence speed of the parallelism-related dynamic components are statistically analyzed, and the proportional coefficient and derivative coefficient of the proportional-derivative processing are adjusted based on the statistical results. Within the continuous control window, the mean offset and duration of the levelness-related static components are statistically analyzed, and the proportional coefficient and integral coefficient of the proportional-integral processing are adjusted based on the statistical results.

6. The dual-drive gantry correction method based on motor torque feedback according to claim 1, characterized in that, The step of distributing the total left-right adjustment and the total up-down adjustment to the four endpoints includes: Under the preset endpoint coordinate system, the total adjustment amount in the left and right directions is distributed to the four endpoints according to the differential relationship that the left and right ends are opposite and the endpoints on the same side are in the same direction, so as to obtain the left and right correction amount of each endpoint; In the preset endpoint coordinate system, the total vertical adjustment is distributed to the four endpoints according to the differential relationship of the left and right ends being opposite and the same-side endpoints being in the same direction, so as to obtain the vertical correction amount of each endpoint.

7. The dual-drive gantry correction method based on motor torque feedback according to claim 1, characterized in that, The electric cylinder adjustment assembly is located at the four endpoints, and the electric cylinder adjustment assembly includes a lifting servo electric cylinder, an adjusting servo electric cylinder, a slide rail slider, and a drive shaft mounting plate. The lifting servo electric cylinder drives the drive shaft mounting plate to move in the vertical direction according to the vertical correction amount of each endpoint. The adjusting servo electric cylinder drives the drive shaft mounting plate to move in the left and right direction according to the left and right correction amount of each endpoint.

8. The dual-drive gantry correction method based on motor torque feedback according to claim 1, characterized in that, Before driving the corresponding electric cylinder adjustment component to perform correction, it also includes: Displacement limiting processing is applied to the left and right correction amounts and the up and down correction amounts of each endpoint, respectively. The slope of the left and right correction amount and the up and down correction amount of each endpoint after the amplitude limit are subjected to slope limiting processing to generate a smooth correction command; The corresponding electric cylinder adjustment component is driven to perform correction according to the smooth correction command.

9. The dual-drive gantry correction method based on motor torque feedback according to claim 1, characterized in that, The method also includes security protection steps: Monitor the amplitude and duration of the torque difference signal; If the amplitude of the torque difference signal exceeds the fault threshold and the duration exceeds the fault duration, then the left and right correction amounts of each endpoint and the up and down correction amounts of each endpoint are locked, the dual-drive gantry is controlled to stop smoothly and an alarm signal is output.

10. A dual-drive gantry correction system based on motor torque feedback, characterized in that, The system is used to execute the dual-drive gantry correction method based on motor torque feedback as described in any one of claims 1 to 9, the system comprising: The torque acquisition module is used to acquire the torque feedback signals of the left drive motor and the right drive motor during the operation of the dual-drive gantry, and to obtain the filtered torque of the left motor and the filtered torque of the right motor. The torque difference calculation module is used to calculate the torque difference signal based on the left motor filter torque and the right motor filter torque; The frequency division and separation module is used to divide and separate the torque difference signal to obtain the horizontality-related static component and the parallelism-related dynamic component. The total adjustment amount generation module is used to generate the total adjustment amount in the left and right directions based on the parallelism-related dynamic components, and to generate the total adjustment amount in the up and down directions based on the horizontality-related static components. The endpoint correction amount allocation module is used to allocate the total adjustment amount in the left and right directions and the total adjustment amount in the up and down directions to the four endpoints, and generate the left and right correction amount and the up and down correction amount of each endpoint. The electric cylinder actuation module is used to drive the corresponding electric cylinder adjustment component to perform correction based on the left and right correction amount and the up and down correction amount of each endpoint.

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