A portable pipe cutting rolling support leveling control system

Abstract

This invention discloses a portable pipe cutting rolling support leveling control system, specifically relating to the field of cutting limit leveling control. It addresses the problems of fluctuating cutting gaps between the nozzle and the pipe surface, torch collisions, and cut offsets caused by pipe eccentricity, weld protrusions, and uneven support during existing portable pipe cutting processes. By collecting roller contact force signals and pipe rotation angle signals, a circumferential contact force distribution sequence is constructed. Based on the calibration mapping relationship between contact force and roller indentation depth, the radial runout curve of the pipe support section is reconstructed. After extracting the pipe eccentricity vector, the support leg is driven to perform reverse differential telescopic compensation. Simultaneously, a leading angle value is generated by combining the pipe rotation angular velocity and the response time of the torch limit follower unit. This pre-aiming compensation is performed on the radial undulations of the pipe surface about to enter the cutting area, preventing limit roughness and lag during the cutting process and achieving dynamic and stable control of the cutting.

Description

Technical Field

[0001] This invention relates to the field of cutting limit leveling control technology, and more specifically, to a portable pipe cutting rolling support leveling control system. Background Technology

[0002] When performing on-site rotary cutting operations on pipes of different diameters, existing portable pipe cutting equipment typically uses rollers to support the rotation of the pipe body and completes the cutting along the circumference of the pipe body using a cutting torch. However, the pipes to be cut in reality generally have issues such as ellipticity deviation, weld protrusion, local deformation, support tilt, and clamping eccentricity. During the continuous rotation of the pipe body, the radial position of the pipe surface relative to the cutting torch will constantly change, causing the cutting gap between the nozzle and the pipe surface to fluctuate continuously.

[0003] When the cutting gap is too small, the nozzle is prone to colliding with the pipe surface, causing nozzle wear, kerf deviation, or even torch jamming. When the cutting gap is too large, it leads to heat dispersion, incomplete cutting, increased slag buildup, and decreased cut quality. Therefore, in portable pipe cutting scenarios, torch limit control directly affects cutting stability and accuracy.

[0004] Most existing solutions use fixed limit spacing or manual adjustment, which makes it difficult to adapt to the radial runout of the pipe surface in real time during pipe rotation. Especially in large-diameter pipes, pipes with irregular welds, and uneven ground conditions, the support eccentricity and pipe surface runout will further amplify the radial fluctuation of the cutting torch, resulting in obvious limit lag problems in the cutting process, making it difficult to ensure that the cutting nozzle and the pipe surface always maintain a stable cutting gap. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, embodiments of the present invention provide a portable pipe cutting rolling support leveling control system to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A portable pipe cutting rolling support leveling control system includes:

[0008] The signal acquisition module is used to acquire contact force signals through the circumferentially distributed thin-film pressure detection unit embedded in each set of rollers when a cutting command is received, and to simultaneously acquire the tube rotation angle signal.

[0009] The fluctuation calculation module is used to calculate the steady-state load mean value of the collected contact force signal when the cumulative rotation angle reaches a full revolution, determine the support load bias term, subtract the support load bias term from the contact force signal, and obtain the pipe surface profile force fluctuation sequence.

[0010] The eccentricity calculation module is used to reconstruct the radial runout curve of the support section based on the pipe surface profile force fluctuation sequence, according to the calibration mapping relationship between the contact force and the roller indentation depth within the preset elastic deformation range and the roller radius, and to extract the eccentricity vector of the geometric center of the radial runout curve deviating from the support rotation reference axis through circle fitting.

[0011] The telescopic adjustment module is used to decompose the eccentric vector into the displacement components of each leg, and drive each leg to perform reverse differential telescopic adjustment of the support reference plane based on the displacement components.

[0012] The limit compensation module is used to calculate the radial undulation of the pipe surface that is about to reach the cutting point by using the radial runout curve and the advance angular displacement added to the current angular position of the cutting torch, after the support reference plane adjustment is completed, and to generate the cutting limit compensation amount.

[0013] The limit adjustment module is used to take the cutting limit compensation amount as the radial position offset command of the cutting torch, drive the cutting torch limit follower unit to move the cutting nozzle radially by the cutting limit compensation amount. When the rotation angle reaches a whole circle again, the signal acquisition module, fluctuation calculation module, eccentricity calculation module, telescopic adjustment module and limit compensation module are repeatedly executed to form a closed loop control.

[0014] As a further aspect of the present invention, the signal acquisition module specifically includes acquiring contact force signals and simultaneously acquiring pipe rotation angle signals, including:

[0015] During the pipe cutting and rotation process, a low-pass filter is applied to the output signal of each pressure detection unit to obtain a filtered contact force signal;

[0016] The filtered contact force signal is compared with the reference contact force of the corresponding roller under no-load conditions to identify the sampling point where the roller and the pipe surface are in a non-contact state, and the corresponding filtered contact force signal is set to zero.

[0017] The rotation angle signal of the pipe body is collected, and the roller and circumferential angle position corresponding to each sampling point are extracted. The filtered contact force signals of each roller after being zeroed are arranged in order of circumferential angle position to generate a circumferential contact force distribution sequence synchronized with the rotation angle.

[0018] As a further aspect of the present invention, the wave calculation module specifically includes obtaining the pipe surface profile force wave sequence as follows:

[0019] When the cumulative rotation angle reaches a full circle, the circumferential contact force distribution sequence is divided into a set number of sectors according to the circumferential angle position, and the average contact force of each sector is calculated as the steady-state reference load.

[0020] Based on the installation angle position of each roller in the circumferential direction of the tube body section, the geometric distribution coefficient of the support load corresponding to each roller is set;

[0021] Multiply the steady-state reference load by the geometric distribution coefficient of the support load corresponding to each roller to obtain the support load bias term corresponding to each roller. Subtract the corresponding support load bias term point by point from the filtered contact force signal of each roller. Then, splice the contact force fluctuation components after subtraction in circumferential angle position order to obtain the pipe surface profile force fluctuation sequence.

[0022] As a further aspect of the present invention, the extraction of the eccentricity vector from the geometric center of the radial runout curve deviating from the support rotation reference axis in the eccentricity calculation module specifically includes:

[0023] Input the force values ​​of each sampling point in the pipe surface profile force fluctuation sequence into the preset contact force and indentation depth calibration mapping table one by one, look up the table to obtain the roller indentation depth value corresponding to each sampling point, and superimpose the roller indentation depth value with the roller radius to obtain the pipe surface contact radius corresponding to each sampling point.

[0024] Based on the circumferential angular position and contact polar diameter of each sampling point, a discrete contour point set of the pipe support section in the polar coordinate system is constructed, and least squares circle fitting is performed on the discrete contour point set.

[0025] The vector difference between the fitted circle center coordinates and the support rotation reference axis coordinates is used as the eccentric vector, and the support rotation reference axis is the theoretical rotation center axis enclosed by the installation centers of each roller.

[0026] As a further aspect of the present invention, the telescopic adjustment module, specifically including driving each leg to perform differential telescopic extension and retraction based on displacement components, includes:

[0027] When decomposing the eccentric vector, the installation position vector of each leg relative to the rotation reference axis of the support in the support reference plane is obtained. The support compensation displacement is constructed with the eccentric vector, and the compensation projection in the direction corresponding to the installation position vector of each leg is solved to obtain the displacement components of each leg.

[0028] The displacement components of each leg are inverted to generate a reverse displacement command for each leg. The reverse displacement command is then sent synchronously to the telescopic actuators corresponding to each leg to drive each leg to perform reverse differential telescopic extension and retraction.

[0029] As a further aspect of the present invention, the generation of the cutting limit compensation amount in the limit compensation module specifically includes:

[0030] The current angular velocity of the pipe is obtained by performing time differentiation on the pipe rotation angle signal;

[0031] Obtain the current circumferential angular position of the cutting torch, and calculate the corresponding lead angle value based on the current angular velocity of the tube body and the response time required for the cutting torch limit follower unit to complete one limit adjustment.

[0032] The circumferential angle position is added to the lead angle value to obtain the aiming angle position, and the contour point corresponding to the aiming angle position is located on the radial runout curve to extract the corresponding polar radius value.

[0033] The difference between the extreme diameter value and the fitting radius corresponding to the fitting circle center is used to obtain the radial undulation of the pipe surface at the pre-aiming angle position. The set cutting gap between the nozzle and the pipe surface is corrected based on the radial undulation of the pipe surface to generate the cutting limit compensation amount.

[0034] As a further aspect of the present invention, in the limit adjustment module, the cutting torch limit follow-up unit drives the cutting nozzle to move radially, and the cutting limit compensation amount specifically includes:

[0035] Obtain the current radial position of the torch limit follower unit, and superimpose the cutting limit compensation amount with the current radial position to obtain the target radial position;

[0036] Calculate the difference between the target radial position and the current radial position, and use it as the radial displacement step.

[0037] The radial displacement step and the lead of the torch limit follower unit are converted into the number of driving pulses. The number of driving pulses drives the torch limit follower unit to move the cutting nozzle radially until it reaches the target radial position.

[0038] The technical effects and advantages of the portable pipe cutting rolling support leveling control system of the present invention are as follows:

[0039] This invention acquires pipe contact force signals in real time during roller support and constructs a circumferential contact force distribution sequence by combining pipe rotation angle information. After separating the support load offset term, a pipe surface profile force fluctuation sequence reflecting the true undulation of the pipe surface is obtained. Furthermore, the radial runout curve of the pipe support section is reconstructed based on the calibration mapping relationship between contact force and roller indentation depth, enabling real-time identification of pipe eccentricity and local profile changes. By extracting the eccentric vector of the radial runout curve's geometric center deviating from the support rotation reference axis, reverse differential expansion and contraction compensation is performed on each support leg, reducing the accumulation of support offset during pipe rotation. Simultaneously, this invention dynamically generates a lead angle value based on the current pipe rotation angular velocity and the response time of the torch limit follower unit, pre-planning the pipe surface profile about to enter the cutting area, and correcting the cutting gap between the nozzle and the pipe surface in real time based on the pre-planning results. This reduces problems such as nozzle collision, cut offset, and incomplete cutting, improving cutting stability and cut consistency during portable pipe cutting. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of a portable pipe cutting rolling support leveling control system according to the present invention. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] Example 1

[0043] Figure 1 The present invention discloses a portable pipe cutting rolling support leveling control system, comprising:

[0044] The signal acquisition module is used to acquire contact force signals through the circumferentially distributed thin-film pressure detection unit embedded in each set of rollers when a cutting command is received, and to simultaneously acquire the tube rotation angle signal.

[0045] The fluctuation calculation module is used to calculate the steady-state load mean value of the collected contact force signal when the cumulative rotation angle reaches a full revolution, determine the support load bias term, subtract the support load bias term from the contact force signal, and obtain the pipe surface profile force fluctuation sequence.

[0046] The eccentricity calculation module is used to reconstruct the radial runout curve of the support section based on the pipe surface profile force fluctuation sequence, according to the calibration mapping relationship between the contact force and the roller indentation depth within the preset elastic deformation range and the roller radius, and to extract the eccentricity vector of the geometric center of the radial runout curve deviating from the support rotation reference axis through circle fitting.

[0047] The telescopic adjustment module is used to decompose the eccentric vector into the displacement components of each leg, and drive each leg to perform reverse differential telescopic adjustment of the support reference plane based on the displacement components.

[0048] The limit compensation module is used to calculate the radial undulation of the pipe surface that is about to reach the cutting point by using the radial runout curve and the advance angular displacement added to the current angular position of the cutting torch, after the support reference plane adjustment is completed, and to generate the cutting limit compensation amount.

[0049] The limit adjustment module is used to take the cutting limit compensation amount as the radial position offset command of the cutting torch, drive the cutting torch limit follower unit to move the cutting nozzle radially by the cutting limit compensation amount. When the rotation angle reaches a whole circle again, the signal acquisition module, fluctuation calculation module, eccentricity calculation module, telescopic adjustment module and limit compensation module are repeatedly executed to form a closed loop control.

[0050] The signal acquisition module acquires contact force signals and simultaneously acquires pipe rotation angle signals.

[0051] A thin-film pressure detection unit is embedded circumferentially inside each roller of the portable rolling support. Each roller has an independent signal output channel, and a rotating conductive slip ring is installed inside the roller shaft to ensure stable transmission of the pressure detection unit's output signal during continuous roller rotation. After the tube is placed on the roller, the actively driven roller drives the tube to rotate continuously, maintaining continuous rolling contact between the roller and the tube surface. Due to vibrations from the drive motor, impacts from roller bearing clearances, localized weld tapping, and periodic shaking caused by uneven ground during on-site cutting, the pressure detection unit's output signal will contain numerous transient spikes. Therefore, low-pass filtering is performed on the original contact force signal during the acquisition phase. A fixed-length sliding window is used for smoothing filtering. The length of the sliding window is set based on both the tube's rotation speed and the sampling frequency. For example, when the tube's rotation speed is 18 revolutions per minute and the pressure detection unit's sampling frequency is 1000 times per second, 25 consecutive sampling points are used as a filtering window. The sampled values ​​within the window are then averaged and smoothed to obtain the filtered contact force signal at the corresponding moment. The window length is pre-calibrated based on the width of the roller contact area and the roller speed. When the window length is less than 10 sampling points, the weld impact peak cannot be effectively suppressed. When the window length exceeds 40 sampling points, the local contour change will be over-smoothed. Therefore, in this embodiment, 20 to 30 sampling points are used as the effective filtering window range.

[0052] Before the equipment is put into cutting, a no-load reference calibration process is performed. This involves keeping the rollers rotating continuously without placing the pipe body on them, and collecting the output values ​​of each pressure detection unit under no-load conditions. The stable average value of the samples over 5 consecutive seconds is used as the no-load reference contact force for the corresponding roller. Due to manufacturing errors in the internal membrane pressure detection units of different rollers, a separate no-load reference value is established for each roller, instead of using a uniform fixed threshold. During the actual cutting process, when there is local elliptical deformation, weld protrusion, or support eccentricity in the pipe body, some rollers will briefly detach from the pipe surface during the rotation cycle, causing the contact force to drop rapidly at the corresponding moment. To avoid misidentifying the detached state as a pipe surface depression, the filtered contact force signal is compared with the no-load reference contact force of the corresponding roller in each sampling cycle. When three consecutive sampling points are close to the no-load reference contact force, it is determined that the current roller is in a non-contact state with the pipe surface, and the filtered contact force signal of the corresponding sampling point is directly set to zero. The number of consecutive sampling points is set according to the sampling frequency. For example, when the sampling frequency is 1000 times per second, three consecutive sampling points correspond to a continuous detachment state of 3 milliseconds, which can effectively eliminate misjudgments caused by single-point vibration interference. After zeroing, the original circumferential angle position information is retained, and only the corresponding contact force value is set to zero.

[0053] A rotary encoder is installed at the end of the active drive roller shaft. The encoder output pulse signal changes synchronously with the rotation of the drive roller, and the current circumferential angular position of the pipe is calculated by accumulating the number of encoder pulses. Since the pipe and the active drive roller are driven by friction, the relationship between the roller outer diameter and the pipe rotation speed is calibrated during the equipment installation phase to establish the correspondence between the roller rotation angle and the actual circumferential angle of the pipe. During sampling, the encoder angle value corresponding to the current output moment of each pressure detection unit is synchronously written into the sampling record, so that each filtered contact force signal corresponds to a unique circumferential angular position. Subsequently, the circumferential angular positions are arranged in order from 0 degrees to 360 degrees, and the contact force sampling values ​​from different rollers are uniformly mapped to the same circumferential coordinate system. When multiple rollers are in contact at the same circumferential angular position, the sampling value with the larger contact force amplitude is retained first to reduce the contact instability caused by the edge contact area. For angular gaps caused by the removal of zero values, the zero value position is retained and no interpolation is performed to fill them. This ensures that the features of local out-of-round or suspended areas are truly preserved during the subsequent contour reconstruction process, and finally forms a circumferential contact force distribution sequence that corresponds to the rotation angle of the tube.

[0054] The fluctuation calculation module obtains the pipe surface profile force fluctuation sequence.

[0055] After the tube rotates a full revolution, the rotary encoder corresponding to the active drive roller outputs the complete circumferential angle information. At this point, the current circumferential contact force distribution sequence is divided into multiple continuous sectors according to the circumferential angle position. Instead of using a fixed single-point averaging method, segmented statistical processing is performed based on the contact coverage range of the roller in the circumferential direction. For example, in a tube cutting scenario with an outer diameter of 800 mm, the complete circumference is divided into thirty-six sectors, each corresponding to a ten-degree range, thus ensuring that local weld protrusions and tube out-of-roundness areas are not directly canceled out by the full circumferential average. The number of sectors is pre-calibrated based on the roller contact width and the cutting tube diameter. For example, when the sector angle is greater than twenty degrees, abrupt changes in the local contour are easily smoothed by averaging; when the sector angle is less than five degrees, the instantaneous disturbances caused by roller vibration increase significantly. Therefore, eight to twelve degrees are used as the single sector coverage range. After segmentation, all effective contact force samples within each sector are statistically analyzed. Zero-value samples within the same sector are not included in the mean calculation; only samples maintaining contact are averaged to avoid the negative impact of localized voiding on steady-state load estimation. After obtaining the mean contact force for each sector, the mean is defined as the steady-state reference load for the corresponding circumferential region. This steady-state reference load does not represent the actual weight distribution of the pipe body, but rather characterizes the long-term stable contact level of each circumferential region under the current support condition. Subsequently, a geometrical distribution coefficient for the support load is established based on the installation angle position of each roller in the circumferential direction of the pipe cross-section. During implementation, a circumferential coordinate system is established with the support rotation reference axis as the center, and the included angle position of each roller's installation center in the circumferential direction is input into a pre-established geometrical distribution table. The geometrical distribution table is calibrated during equipment assembly; that is, under the static placement state of a standard circular pipe, the long-term stable contact force of each roller is collected, and the geometrical distribution coefficient of the support load for the corresponding roller is determined based on the proportion of each roller's stable contact force to the total stable contact force of all rollers. For example, the main load-bearing roller located below the support has a support geometric distribution coefficient of 0.34, while the auxiliary rollers located on the side have support geometric distribution coefficients of 0.18 and 0.16, respectively. The coefficients for the remaining rollers are determined based on their actual installation angles and calibration results. The support geometric distribution coefficients for each roller are fixed and stored after the equipment is installed, and are only recalibrated after the roller installation positions are readjusted or the rollers are replaced.

[0056] After obtaining the steady-state reference load for each sector, the corresponding steady-state reference load value is read according to the circumferential sector to which the current sampling point belongs. This value is then multiplied by the geometric distribution coefficient of the support load of the roller corresponding to the current sampling point to calculate the corresponding support load bias term. The support load bias term characterizes the basic contact level of the roller within the corresponding circumferential region under long-term stable support conditions. Therefore, real-time transient vibration and local contour abrupt changes are not introduced during the calculation process, thus avoiding the incorrect inclusion of true contour information such as weld protrusions and local pits into the steady-state baseline. Subsequently, the support load bias term is subtracted point-by-point from the filtered contact force signal of the corresponding roller at the current moment to obtain the contact force fluctuation component of the corresponding sampling point. If a negative value is obtained after subtraction, the negative value is retained without absolute value correction to truly preserve the contact weakening characteristics corresponding to the local pitted area. For example, when a local pit exists on a certain section of the pipe surface, the corresponding roller contact force is lower than the current steady-state support level. In this case, the subtraction results in a negative fluctuation, thus reflecting the true contour pitting trend in the subsequent radial runout curve reconstruction process. For empty sampling points that have already undergone zeroing, the zero value is maintained and the process proceeds directly to the subsequent stitching process. After calculating the contact force fluctuation components corresponding to each roller, the sampling points are stitched sequentially according to their corresponding circumferential angle positions. During the stitching process, sampling points from different rollers but located in adjacent circumferential regions are sorted according to angular continuity, and the synchronization deviation between rollers is corrected based on the sampling timestamp. For overlapping circumferential angle positions, sampling points with longer contact durations are preferentially selected as the effective fluctuation values ​​for the current angle position, thereby reducing profile jumps caused by unstable contact at the roller edges. Finally, a pipe surface profile force fluctuation sequence covering the entire circumferential range is formed, where each sampling point corresponds to a unique circumferential angle position and a corresponding contact force fluctuation amount.

[0057] In the eccentricity calculation module, the eccentricity vector of the radial runout curve's geometric center deviating from the support's rotation reference axis is extracted.

[0058] After the equipment is assembled, the roller contact indentation calibration process is performed. A standard round tube with the same material and wall thickness as the actual cutting scenario is used as the calibration tube. The standard round tube is placed on the rolling support, and the standard round tube is continuously rotated at a constant speed by an active drive roller. During the calibration process, the contact pressure between the roller and the tube surface is gradually changed by adjusting the support loading components. At the same time, a dial indicator is used to measure the actual indentation depth of the roller surface relative to the outer surface of the standard round tube, and the actual indentation depth value corresponding to different contact force states is recorded. To avoid the influence of material elastic rebound on the calibration results, each set of contact force is applied and the contact is maintained for more than 8 seconds until the contact state between the roller and the tube surface stabilizes before the indentation depth is read. For the same contact force value, the loading measurement is repeated five times, and the stable average value of the five measurement results is taken as the indentation depth value corresponding to the current contact force. After completing the measurement of all contact force ranges, a corresponding calibration mapping table between contact force and indentation depth is established and stored in the equipment. The pipe surface profile force fluctuation sequence itself represents the fluctuation amount after deducting the support load bias term. A historical calibration mapping method is used to directly establish the correspondence between the fluctuating contact force and the actual indentation change, thus avoiding the problem of theoretical contact model inaccuracies caused by roller material aging, differences in pipe surface roughness, and local weld hardness variations. During actual cutting, the fluctuating contact force value corresponding to each sampling point in the pipe surface profile force fluctuation sequence is entered into the calibration mapping table one by one for lookup matching, and the corresponding indentation depth value is read. If the current fluctuating contact force is between two historical calibration points, linear interpolation is performed based on the depth change trend between adjacent calibration points to obtain the indentation depth value corresponding to the current sampling point. For example, when the fluctuating contact force is between 120 N and 140 N, and the corresponding historical calibration indentation depths are 0.21 mm and 0.26 mm respectively, the current indentation depth value is calculated according to the current position ratio. Subsequently, the roller radius and the corresponding indentation depth value are superimposed to obtain the pipe surface contact radius corresponding to the current sampling point. The contact radius here does not represent the actual physical radius of the pipe, but rather the position of the equivalent contact radius corresponding to the compression change of the roller contact under the current roller contact state.

[0059] After obtaining the contact radius corresponding to all sampling points, the circumferential angle position output by the active drive roller encoder is used as the polar coordinate angle value, and the corresponding contact radius is used as the polar coordinate radius value. All sampling points are mapped to the same polar coordinate system to form a discrete profile point set of the pipe support section. The center of the support installation reference platform is used as the origin of the plane coordinate system, and the geometric center axis formed by the theoretical connection of each roller installation center is used as the support rotation reference axis. During the equipment assembly stage, the spatial position of each roller installation shaft center in the support reference plane is first measured. Then, the theoretical rotation center corresponding to all roller installation centers is obtained by circle fitting. The center axis passing through the theoretical rotation center and perpendicular to the support reference plane is used as the support rotation reference axis. Since this axis comes from the geometric layout of the roller installation structure itself, it serves as the fixed geometric reference axis of the entire equipment. After completing the construction of the discrete profile point set, least squares circle fitting is performed on all profile points. During the fitting process, the distance deviation from each discrete profile point to the current fitting circle boundary is calculated sequentially, and the position of the fitting circle center and the fitting radius are continuously adjusted to minimize the sum of squares of the distance deviations of all profile points. To avoid excessive traction of the circular fitting results by local weld protrusions, the range of extreme diameter changes corresponding to all contour points is statistically analyzed before fitting. Contour points whose abrupt changes within a continuous angular range exceed 1.8 times the average extreme diameter change are marked as local abrupt change points. During the fitting process, the weight of the corresponding contour points is reduced, thereby ensuring that the fitted circle center is closer to the overall rotation center of the pipe. After fitting, the planar coordinates of the fitted circle center in the support reference plane are read, and the planar displacement difference between the fitted circle center coordinates and the plane center coordinates corresponding to the rotation reference axis of the support is calculated. This displacement difference is defined as the eccentric vector, which contains both the offset direction and offset distance information.

[0060] In the telescopic adjustment module, each leg is driven to perform differential telescopic extension and retraction based on displacement components.

[0061] After the rolling support is assembled, a reference plane coordinate system is established. The upper surface of the support mounting base plate is used as the support reference plane, and the intersection of the support rotation reference axis and the support reference plane is used as the origin of the plane coordinates. The support rotation reference axis is the theoretical rotation center axis enclosed by the mounting centers of all rollers. That is, during the equipment assembly stage, after measuring the center positions of all roller mounting axes, the theoretical rotation center corresponding to all roller mounting centers is obtained through circle fitting. Then, the axis passing through the theoretical rotation center and perpendicular to the support reference plane is used as the support rotation reference axis. Subsequently, the coordinates of the intersection point of the extension center axis of each leg and the support reference plane are measured respectively, and the line connecting the intersection point and the origin of the plane corresponding to the support rotation reference axis is defined as the installation position vector of the corresponding leg. For example, in a three-leg support structure, the three legs are located at different circumferential positions within the support reference plane, and the installation position vector of each leg represents the planar direction and distance from the support rotation center to the corresponding leg installation position. Since the installation positions of each outrigger remain fixed after the equipment is assembled, the vectors of each installation position are measured and stored once during the equipment calibration phase. During actual operation, after the radial runout curve is fitted to obtain the eccentric vector, the plane offset direction corresponding to the eccentric vector is used as the current support compensation direction. The eccentric vector is then mapped to the direction corresponding to the installation position vector of each outrigger, and a directional compensation relationship is established based on the spatial distribution of each outrigger in the circumferential direction of the support. For example, when the eccentric direction is towards the area where a certain outrigger is located, the compensation projection amount corresponding to that outrigger increases, while the compensation projection amount corresponding to the outrigger located in the opposite eccentric direction area decreases. The compensation projection amount is calculated based on the angle between the eccentric direction and the corresponding outrigger installation position vector, thus ensuring that the extension / retraction adjustment direction of each outrigger is consistent with the current eccentric direction. For outriggers with an angle close to 90 degrees, their corresponding compensation projection amount automatically decreases to avoid ineffective outriggers participating in overcompensation. Finally, the displacement components corresponding to each outrigger are obtained, and each displacement component simultaneously includes the required adjustment direction and adjustment stroke of the corresponding outrigger.

[0062] After obtaining the displacement components corresponding to all outriggers, the direction of each displacement component is reversed to generate the corresponding reverse displacement command for each outrigger. Direction reversal means making the outrigger adjustment direction opposite to the current eccentricity direction. That is, when the eccentricity vector points to the right side of the support, the outrigger in the right region retracts, and the outrigger in the left region extends, thereby reducing the current eccentricity through support posture adjustment. Each outrigger has an independent telescopic actuator, such as a lead screw lifting structure. During control, the current telescopic position of each outrigger is first read and compared with the compensation stroke corresponding to the target displacement component to generate the target telescopic position for the corresponding outrigger. Subsequently, the corresponding compensation stroke is converted into the number of motor pulses based on the lead screw lead. For example, when the lead screw lead is 4 mm per revolution and the motor encoder outputs 2000 pulses per revolution, when the target compensation stroke is 0.8 mm, 400 drive pulses are output. The drive pulses for each outrigger are sent synchronously, enabling all outriggers to perform differential telescopic movements simultaneously, avoiding additional transient skew of the support reference plane during the sequential adjustment of the outriggers. To avoid abrupt changes in the tube's contact state due to excessively rapid adjustments of local outriggers, the contact force changes of the corresponding rollers are continuously monitored during outrigger movement. When the rate of change of contact force on any roller exceeds the pre-calibrated stable range, the drive speed of the corresponding outrigger is reduced until the roller contact state stabilizes again, at which point the remaining compensation stroke continues. After all outrigger compensation actions are completed, the current circumferential contact force distribution sequence is re-acquired and the eccentricity vector is recalculated. When the length of the eccentricity vector drops below 15% of the initial eccentricity, the differential compensation of the current outrigger cycle ends.

[0063] The limit compensation module generates the cutting limit compensation amount.

[0064] The angle values ​​of two adjacent sampling times are continuously read at a fixed sampling period, and the change in angle per unit time is calculated to obtain the current rotational angular velocity of the tube. To avoid angular velocity fluctuations caused by instantaneous jitter, a smoothing process using a moving average of five consecutive sampling periods is adopted during the angular velocity calculation to obtain the current stable rotational angular velocity. Subsequently, the current circumferential angular position of the torch is obtained. A fixed angular relationship is established between the torch mounting base and the rotation reference axis of the support, and the current circumferential position of the torch is read by the angle marker installed on the torch support arm. The torch limiting follow-up unit is a radial following adjustment component installed on the torch support mechanism, including, for example, a radial guide rail, a ball screw, a secondary guide slider, a reduction drive motor, and a stroke feedback encoder. The torch mounting base is fixed on the guide rail slider. After the reduction drive motor drives the ball screw to rotate, it drives the guide rail slider to perform reciprocating movement along the radial direction of the tube, thereby adjusting the cutting gap between the nozzle and the tube surface. Since there is a fixed mechanical response time from receiving the position adjustment command to completing the target displacement, a dynamic response calibration process is performed after the equipment is assembled. Different amplitude radial displacement commands are input to the torch limit follower unit. The total time required from the issuance of the drive pulse to the actual arrival of the cutting nozzle at the target position is recorded, and the corresponding average response time is calculated. For example, when the cutting nozzle moves 1.2 mm, the corresponding average response time is 0.18 seconds, and when it moves 2.5 mm, the corresponding average response time is 0.24 seconds. A calibration relationship table between radial displacement and response time is then established. During actual operation, based on the expected adjustment stroke corresponding to the current cutting limit compensation amount, the corresponding response time is read from the calibration relationship table, and the current tube rotation angular velocity is multiplied by the response time to obtain the current lead angle value. This lead angle value is used to characterize the expected circumferential angle range of the tube body during the period when the torch limit follower unit completes the current position adjustment.

[0065] After obtaining the current lead angle value, the current circumferential angle position of the torch is accumulated with the lead angle value to obtain the pre-aiming angle position. When the accumulated result exceeds 360 degrees, 360 degrees is automatically subtracted and remapped to the current circumferential range, thus ensuring that the pre-aiming angle position is always within the complete circumferential angle range. Subsequently, the contour point corresponding to the current pre-aiming angle position is found on the previously constructed radial runout curve. Since the sampling points in the radial runout curve are discretely distributed, when the pre-aiming angle position is between two sampling points, the extreme diameter values ​​corresponding to the two adjacent sampling points are read, and linear interpolation is performed according to the angle interval to obtain the actual extreme diameter value corresponding to the current pre-aiming angle position. After completing the extreme diameter reading, the current extreme diameter value is compared with the fitting radius corresponding to the fitting circle center. The difference between the two is defined as the radial undulation of the pipe surface at the current pre-aiming angle position. Among them, when the extreme diameter value is greater than the fitting radius, it indicates that there is an outward convex contour in the current area; when the extreme diameter value is less than the fitting radius, it indicates that there is a local depression in the current area. Subsequently, the pre-set cutting gap between the nozzle and the pipe surface is dynamically corrected based on the current radial undulation of the pipe surface. Before cutting, a standard cutting gap is preset according to the pipe diameter, wall thickness, and nozzle model. For example, in the scenario of cutting a carbon steel pipe with a wall thickness of 12 mm, the standard cutting gap is set to 3 mm. When the radial undulation of the pipe surface corresponding to the aiming angle position is positive, the feed amount of the nozzle towards the pipe body is reduced accordingly; when the radial undulation is negative, the feed amount of the nozzle towards the pipe body is increased accordingly. Finally, the corrected gap adjustment amount is defined as the current cutting limit compensation amount.

[0066] In the limit adjustment module, the torch limit follow-up unit drives the nozzle to move radially to compensate for the cutting limit.

[0067] The radial distance between the nozzle tip and the support rotation reference axis is used as the current radial position, and a zero-position calibration process is performed after the equipment assembly is completed. The calculated cutting limit compensation amount is superimposed with the current radial position to obtain the target radial position. The cutting limit compensation amount here includes both the current radial undulation change of the pipe surface and the advance compensation amount calculated based on the dynamic aiming angle position. Therefore, the target radial position corresponds to the actual radial position that the nozzle should reach in the future, not the current instantaneous position. Subsequently, the difference between the target radial position and the current radial position is read, and this difference is defined as the radial displacement step that the cutting torch needs to perform at the current time. When the target radial position is greater than the current radial position, it is determined that the nozzle needs to move away from the pipe body; when the target radial position is less than the current radial position, it is determined that the nozzle needs to move closer to the pipe body. In order to avoid sudden changes in the target position due to local weld protrusions, a displacement change rate constraint is added in the radial displacement step calculation process, that is, the displacement step change between two consecutive control cycles does not exceed 1.5 times the displacement step of the previous cycle. For example, if the radial displacement step in the previous cycle was 0.4 mm, then the maximum allowable displacement step in the current cycle will not exceed 0.6 mm, thus avoiding guide rail impact or nozzle oscillation caused by the torch limit follower unit's instantaneous large adjustment. If multiple consecutive cycles adjust in the same direction, the cumulative displacement trend is retained, and direction reset is not performed.

[0068] The system reads the lead parameters of the ball screw or other similar drive connection device. For example, one revolution of the screw corresponds to a 4 mm radial movement of the cutting torch. Simultaneously, it reads the pulse resolution of the drive motor encoder, for example, 2000 pulses per revolution of the drive motor. Then, it calculates the corresponding number of drive pulses based on the current radial displacement step. For example, if the current radial displacement step is 0.8 mm, then 0.2 revolutions of the ball screw corresponds to 400 drive pulses. After calculation, it sends the corresponding number of pulse control signals to the drive motor, driving the ball screw to perform the corresponding radial displacement adjustment. During torch movement, the system reads the position feedback value output by the linear encoder in real time and continuously compares the remaining deviation between the current actual position and the target radial position. When the remaining deviation is less than 0.05 mm, the current cycle of drive pulse output is stopped to prevent the torch from continuing to overshoot due to inertia. For cases where the radial displacement direction frequently reverses, the number of displacement direction changes within three consecutive control cycles is counted. When the number of changes reaches more than two, the current drive speed is reduced to 70% of the rated drive speed to reduce guide rail vibration and nozzle oscillation. After completing the radial adjustment for the current cycle, the active drive roller continues to rotate the tube. When the cumulative angle of the rotary encoder reaches a full revolution again, a new circumferential contact force distribution sequence is acquired, and the support load offset term separation, radial runout curve reconstruction, eccentric vector extraction, outrigger differential compensation, and dynamic pre-aiming limit compensation are executed again. Since each round of compensation is recalculated based on the latest circumferential profile state, a complete closed-loop leveling and cutting limit control process is formed during the continuous rotation of the tube, thereby ensuring that a stable cutting gap is always maintained between the nozzle and the tube surface.

[0069] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0070] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0071] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0072] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0073] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0074] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0075] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0076] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0077] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A portable pipe cutting rolling support leveling control system, characterized in that, include: The signal acquisition module is used to acquire contact force signals through the circumferentially distributed thin-film pressure detection unit embedded in each set of rollers when a cutting command is received, and to simultaneously acquire the tube rotation angle signal. The fluctuation calculation module is used to calculate the steady-state load mean value of the collected contact force signal when the cumulative rotation angle reaches a full revolution, determine the support load bias term, subtract the support load bias term from the contact force signal, and obtain the pipe surface profile force fluctuation sequence. The eccentricity calculation module is used to reconstruct the radial runout curve of the support section based on the pipe surface profile force fluctuation sequence, according to the calibration mapping relationship between the contact force and the roller indentation depth within the preset elastic deformation range and the roller radius, and to extract the eccentricity vector of the geometric center of the radial runout curve deviating from the support rotation reference axis through circle fitting. The telescopic adjustment module is used to decompose the eccentric vector into the displacement components of each leg, and drive each leg to perform reverse differential telescopic adjustment of the support reference plane based on the displacement components. The limit compensation module is used to calculate the radial undulation of the pipe surface that is about to reach the cutting point by using the radial runout curve and the advance angular displacement added to the current angular position of the cutting torch, after the support reference plane adjustment is completed, and to generate the cutting limit compensation amount. The limit adjustment module is used to take the cutting limit compensation amount as the radial position offset command of the cutting torch, drive the cutting torch limit follower unit to move the cutting nozzle radially by the cutting limit compensation amount. When the rotation angle reaches a whole circle again, the signal acquisition module, fluctuation calculation module, eccentricity calculation module, telescopic adjustment module and limit compensation module are repeatedly executed to form a closed loop control.

2. The portable pipe cutting rolling support leveling control system according to claim 1, characterized in that, The signal acquisition module acquires contact force signals and simultaneously acquires pipe rotation angle signals, specifically including: During the pipe cutting and rotation process, a low-pass filter is applied to the output signal of each pressure detection unit to obtain a filtered contact force signal; The filtered contact force signal is compared with the reference contact force of the corresponding roller under no-load conditions to identify the sampling point where the roller and the pipe surface are in a non-contact state, and the corresponding filtered contact force signal is set to zero. The rotation angle signal of the pipe body is collected, and the roller and circumferential angle position corresponding to each sampling point are extracted. The filtered contact force signals of each roller after being zeroed are arranged in order of circumferential angle position to generate a circumferential contact force distribution sequence synchronized with the rotation angle.

3. The portable pipe cutting rolling support leveling control system according to claim 2, characterized in that, The fluctuation calculation module specifically includes obtaining the pipe surface profile force fluctuation sequence, which includes: When the cumulative rotation angle reaches a full circle, the circumferential contact force distribution sequence is divided into a set number of sectors according to the circumferential angle position, and the average contact force of each sector is calculated as the steady-state reference load. Based on the installation angle position of each roller in the circumferential direction of the tube body section, the geometric distribution coefficient of the support load corresponding to each roller is set; Multiply the steady-state reference load by the geometric distribution coefficient of the support load corresponding to each roller to obtain the support load bias term corresponding to each roller. Subtract the corresponding support load bias term point by point from the filtered contact force signal of each roller. Then, splice the contact force fluctuation components after subtraction in circumferential angle position order to obtain the pipe surface profile force fluctuation sequence.

4. The portable pipe cutting rolling support leveling control system according to claim 1, characterized in that, In the eccentricity calculation module, extracting the eccentricity vector of the radial runout curve's geometric center deviating from the support's rotation reference axis specifically includes: Input the force values ​​of each sampling point in the pipe surface profile force fluctuation sequence into the preset contact force and indentation depth calibration mapping table one by one, look up the table to obtain the roller indentation depth value corresponding to each sampling point, and superimpose the roller indentation depth value with the roller radius to obtain the pipe surface contact radius corresponding to each sampling point. Based on the circumferential angular position and contact polar diameter of each sampling point, a discrete contour point set of the pipe support section in the polar coordinate system is constructed, and least squares circle fitting is performed on the discrete contour point set. The vector difference between the fitted circle center coordinates and the support rotation reference axis coordinates is used as the eccentric vector, and the support rotation reference axis is the theoretical rotation center axis enclosed by the installation centers of each roller.

5. A portable pipe cutting rolling support leveling control system according to claim 1, characterized in that, The telescopic adjustment module specifically includes driving each outrigger to perform differential telescopic movement based on displacement components, including: When decomposing the eccentric vector, the installation position vector of each leg relative to the rotation reference axis of the support in the support reference plane is obtained. The support compensation displacement is constructed with the eccentric vector, and the compensation projection in the direction corresponding to the installation position vector of each leg is solved to obtain the displacement components of each leg. The displacement components of each leg are inverted to generate a reverse displacement command for each leg. The reverse displacement command is then sent synchronously to the telescopic actuators corresponding to each leg to drive each leg to perform reverse differential telescopic extension and retraction.

6. The portable pipe cutting rolling support leveling control system according to claim 1, characterized in that, The limit compensation module generates the cutting limit compensation amount specifically including: The current angular velocity of the pipe is obtained by performing time differentiation on the pipe rotation angle signal; Obtain the current circumferential angular position of the cutting torch, and calculate the corresponding lead angle value based on the current angular velocity of the tube body and the response time required for the cutting torch limit follower unit to complete one limit adjustment. The circumferential angle position is added to the lead angle value to obtain the aiming angle position, and the contour point corresponding to the aiming angle position is located on the radial runout curve to extract the corresponding polar radius value. The difference between the extreme diameter value and the fitting radius corresponding to the fitting circle center is used to obtain the radial undulation of the pipe surface at the pre-aiming angle position. The set cutting gap between the nozzle and the pipe surface is corrected based on the radial undulation of the pipe surface to generate the cutting limit compensation amount.

7. The portable pipe cutting rolling support leveling control system according to claim 1, characterized in that, In the limit adjustment module, the cutting torch limit follow-up unit drives the cutting nozzle to move radially, and the cutting limit compensation amount specifically includes: Obtain the current radial position of the torch limit follower unit, and superimpose the cutting limit compensation amount with the current radial position to obtain the target radial position; Calculate the difference between the target radial position and the current radial position, and use it as the radial displacement step. The radial displacement step and the lead of the torch limit follower unit are converted into the number of driving pulses. The number of driving pulses drives the torch limit follower unit to move the cutting nozzle radially until it reaches the target radial position.

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