Automatic production control method and system for bottom web steel reinforcement framework

Abstract

The invention relates to the technical field of steel reinforcement framework production, in particular to an automatic production control method and system for a bottom web steel reinforcement framework. According to the invention, the predicted duration of the corresponding transfer is obtained based on the first speed and the moving track length, the predicted duration of the corresponding traction is obtained based on the second speed and the to-be-moved amount, and the first speed or the second speed is iteratively adjusted according to the difference between the two predicted durations. Synchronously executing a transfer instruction and a traction instruction when the absolute value of the difference value is not reduced any more after multiple times of continuous adjustment; therefore, time asynchronization of transferring and traction actions is eliminated, the U-shaped steel bar unit and the longitudinal steel bar bundle can reach a target welding position at the same time, and inaccurate positioning or welding dislocation caused by time difference is avoided.

Description

Technical Field

[0001] This invention relates to the field of steel reinforcement cage production technology, specifically to an automatic production control method and system for bottom and web steel reinforcement cages. Background Technology

[0002] In the automated production process of the bottom web reinforcement cage, discretely manufactured U-shaped steel bar units are typically assembled and welded with continuously pulled longitudinal steel bar bundles. The U-shaped steel bar units must be positioned sequentially according to the structural design order, and the longitudinal steel bar bundles must be simultaneously pulled to their corresponding welding points.

[0003] In existing technologies, the transfer of U-shaped steel bar units and the traction of longitudinal steel bar bundles are usually controlled as two independent motion processes. There is a lack of time-coordinated control for the transfer and traction. The arrival time of the U-shaped steel bar units and longitudinal steel bar bundles at the target welding position often deviates, resulting in inaccurate positioning or welding misalignment, which affects welding quality and production efficiency.

[0004] Secondly, due to the deviation between the actual storage position and the theoretical position of the U-shaped steel bar unit, the longitudinal steel bar bundle will shift in position due to elastic recoil after the traction stops, which will also cause positioning deviation and affect the welding quality.

[0005] Meanwhile, during continuous assembly, the actual position deviation of the previous welding point was not fed back in time and used to correct the target position of the next cycle, resulting in error accumulation, which in turn affected the overall dimensional accuracy of the bottom web reinforcement cage. Summary of the Invention

[0006] The purpose of this invention is to overcome the defects of the prior art and solve the problem of inaccurate positioning caused by the lack of timing coordination between the transfer of U-shaped steel bar units and the traction of longitudinal steel bar bundles, storage position deviation, elastic retraction, and error accumulation.

[0007] The technical solution adopted by the present invention to solve its technical problem is: an automatic production control method for bottom web reinforcement cage, including the following steps: determining its storage position according to the current U-shaped reinforcement unit sequence number; calculating the displacement to be made according to the position of the front end of the longitudinal reinforcement bundle and the target welding position.

[0008] Based on the storage location and the target welding location, a transfer command containing the movement trajectory and the first velocity is generated; based on the amount of displacement to be generated, a traction command containing the axial displacement and the second velocity is generated.

[0009] Based on the first velocity and the length of the trajectory, and the second velocity and the displacement to be determined, the corresponding estimated durations are calculated.

[0010] The first or second speed is adjusted based on the difference between the two estimated durations. When the absolute value of the difference no longer decreases after at least three consecutive adjustments, the transfer command and traction command are executed synchronously based on the first and second speeds at this time.

[0011] During execution, when the real-time position of the U-shaped steel bar unit and the longitudinal steel bar bundle are within the target accuracy range for at least three consecutive sampling cycles, the positioning is determined to be complete and welding is performed.

[0012] After welding is completed, update the sequence number and determine the target welding position for the next cycle based on the actual welding position.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention obtains the expected duration of the corresponding transfer based on the first speed and the length of the moving trajectory, and obtains the expected duration of the corresponding traction based on the second speed and the displacement to be moved. The first speed or the second speed is iteratively adjusted according to the difference between the two expected durations, and the transfer command and traction command are executed synchronously when the absolute value of the difference no longer decreases after multiple consecutive adjustments. This eliminates the time asynchrony between the transfer and traction actions, so that the U-shaped steel bar unit and the longitudinal steel bar bundle can arrive at the target welding position at the same time, avoiding inaccurate positioning or welding misalignment caused by time difference.

[0014] 2. The present invention determines the storage position based on the current sequential numbering of the U-shaped steel bar unit and the standard work station spacing, thereby eliminating the initial storage position deviation. At the same time, the displacement to be obtained is obtained by superimposing the straight-line distance between the current position of the longitudinal steel bar bundle front end and the target alignment point, which compensates for the position deviation of the longitudinal steel bar bundle caused by elastic recoil after the traction stops.

[0015] 3. After the positioning is determined, the present invention uses the actual welding position as the benchmark to determine the target welding position for the next cycle, so that the welding point position can be corrected in real time during continuous assembly, reducing error accumulation and thus improving the overall dimensional accuracy of the bottom web reinforcement cage. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the control method of the present invention.

[0018] Figure 2 This is a schematic diagram of the system module connections of the present invention.

[0019] Figure 3 This is a schematic diagram of the process for obtaining the first speed and movement trajectory according to the present invention.

[0020] Figure 4 This is a schematic diagram of the process for obtaining axial displacement and second velocity according to the present invention.

[0021] Figure 5 This is a partial structural diagram of the U-shaped steel bar unit and longitudinal steel bar bundle after welding.

[0022] In the diagram: 1. U-shaped steel bar unit; 2. Longitudinal steel bar bundle. Detailed Implementation

[0023] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. Furthermore, it should be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale.

[0024] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

[0025] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] The following describes in detail, with reference to the accompanying drawings, a specific scheme for an automatic production control method for the bottom and web reinforcement cage provided by the present invention.

[0028] Please see Figure 1 The diagram shows a flowchart of an automatic production control method for bottom web reinforcement cage provided by the present invention, which specifically includes the following steps: Step S1, determining the storage location of the U-shaped reinforcement unit and calculating the displacement of the longitudinal reinforcement bundle.

[0029] The process of determining the storage location is as follows: Based on the geometric feature that the U-shaped steel reinforcement units in the bottom web structure are arranged sequentially along the transverse direction, they are numbered sequentially according to their arrangement order in the bottom web structure. Starting from the initial placement point of the first U-shaped steel reinforcement unit, the fixed spacing is accumulated one by one along the transverse direction of the bottom web.

[0030] Each additional number represents a shift of one standard workstation spacing from the actual placement position of the previous U-shaped rebar unit towards the next workstation. The resulting position is the storage location of the current U-shaped rebar unit.

[0031] In this invention, the fixed spacing is the theoretical center-to-center distance in the design drawings of the bottom web reinforcement cage. The standard work station spacing can be set to be equal to the fixed spacing.

[0032] If the actual outer width deviation of the current batch of U-shaped steel bar units exceeds ±2mm, the absolute value of the actual outer width deviation can be added to or subtracted from the current fixed spacing to obtain the final fixed spacing, in order to avoid error accumulation.

[0033] The calculation process for the displacement of the longitudinal steel bar bundle is as follows: First, the actual position of the front end of the longitudinal steel bar bundle can be obtained by a high-precision laser rangefinder sensor installed on the outlet side of the traction mechanism.

[0034] Simultaneously, based on the design drawings of the bottom web reinforcement cage, the design distance between adjacent welding points, i.e., the longitudinal pitch, is obtained. The sequential number of the current U-shaped reinforcement unit is read, and the welding position corresponding to the first U-shaped reinforcement unit is taken as the origin of the longitudinal coordinate. The current sequential number is subtracted by one and then multiplied by the longitudinal pitch. The resulting value is the coordinate of the current target welding position in the longitudinal direction of the bottom web, which is the longitudinal reference position.

[0035] Due to measurement and installation deviations, the longitudinal reference position may not be exactly located on the axis of the longitudinal reinforcement bundle. Therefore, it is necessary to project the longitudinal reference position onto its axis along the extension direction of the longitudinal reinforcement bundle to obtain the target alignment point.

[0036] Then, the straight-line distance between the current position of the front end of the longitudinal steel bar bundle and the target alignment point is calculated. Since the longitudinal steel bar bundle will have a positional deviation at the target alignment point due to elastic recoil after traction stops, the straight-line distance is superimposed with the compensation amount to obtain the displacement of the longitudinal steel bar bundle in order to compensate for this positional deviation.

[0037] The process for determining the compensation amount can be as follows: During the trial production stage, a one-dimensional coordinate system is established with the far end fixed point of the longitudinal steel bar bundle as the origin and the direction of the steel bar bundle axis pointing towards the traction mechanism. The front end of the steel bar bundle is pulled to different coordinate points, and the actual distance between the clamping point of the traction mechanism and the far end fixed point is measured as the tensile length at the stop. Then, the steel bar bundle is released to a free and relaxed state, and the actual distance between the clamping point and the far end fixed point is measured as the free length. The difference between the tensile length at the stop and the free length is taken as the compensation amount at that coordinate point, and finally, a correspondence table between the coordinate points and the compensation amounts is obtained.

[0038] In actual production, the corresponding compensation amount is determined by consulting a lookup table based on the coordinates of the current target alignment point. For example, a partial lookup table is shown in Table 1 below.

[0039]

[0040] In a preferred embodiment of the present invention, when the coordinates of the target alignment point are between two adjacent coordinate points in the corresponding table, the corresponding compensation amount is calculated using linear interpolation. The specific calculation process is prior art and will not be described in detail here.

[0041] Step S2: Generate a transfer command containing the movement trajectory and the first velocity, and a traction command containing the axial displacement and the second velocity.

[0042] Please see Figure 3 In step S20, the first speed and movement trajectory are obtained based on the storage location and the target welding location.

[0043] Specifically, starting from the current storage location of the U-shaped rebar unit and ending at the target welding location of the current cycle, a collision-free spatial path from the starting point to the ending point is planned using the RRT algorithm. The spatial path consists of a series of waypoints. The specific planning process is existing technology and will not be elaborated here.

[0044] Next, along the directions of each independent drive axis of the transfer mechanism, the spatial path is decomposed into corresponding axial motion components. Here, the drive axis direction refers to the independent motion direction of the transfer mechanism. For example, the drive axis directions of a three-axis robot are the mutually orthogonal linear motion directions of the X, Y, and Z axes.

[0045] The decomposition process involves calculating the coordinates of each path point on each drive axis using an inverse kinematics algorithm. The specific calculation process is existing technology and will not be elaborated upon here.

[0046] For a given drive shaft, the displacement between adjacent path points is the difference between the coordinates of the next point and the coordinates of the previous point. The calculated displacements are arranged in chronological order to form a displacement sequence, and the algebraic sum of all displacements is the axial motion component of the drive shaft.

[0047] Then, in order to coordinate the movement of each drive shaft, it is necessary to determine the minimum time required for each drive shaft to complete its axial movement component independently, based on the displacement length of each axial motion component and the corresponding drive shaft's maximum allowable acceleration and maximum allowable speed. The maximum allowable acceleration and maximum allowable speed can be obtained from the equipment's technical manual.

[0048] The minimum time calculation process is as follows: calculate the total displacement required for the drive shaft to accelerate from rest to the maximum allowable speed and then decelerate back to rest at the maximum allowable acceleration, and record it as the shortest displacement.

[0049] If the displacement length is greater than the shortest displacement, it indicates that the displacement length is long enough, and the drive shaft can go through three stages: acceleration, constant speed and deceleration. The minimum time consumed is the sum of the acceleration time, constant speed time and deceleration time.

[0050] If the displacement length is less than or equal to the shortest displacement, it indicates that the displacement length is too short, and the drive shaft cannot accelerate to the maximum allowable speed. The motion process only includes acceleration and deceleration phases. In this case, the drive shaft accelerates from rest at the maximum allowable acceleration, and immediately switches to uniform deceleration at the maximum allowable acceleration until it stops before reaching the midpoint of the path. The time taken is the minimum time consumption.

[0051] After obtaining the minimum time, take the maximum value among all the minimum times as the benchmark operation cycle of the transfer mechanism.

[0052] Subsequently, the benchmark work cycle is used as a unified completion benchmark. Based on the initial speed on which the lowest time corresponding to each drive shaft is based, acceleration, constant speed and deceleration phases are assigned to it according to the following allocation rules.

[0053] The allocation rule is as follows: the acceleration phase and deceleration phase of each drive shaft are set to have equal time, and both are driven by the maximum allowable acceleration.

[0054] 1) When the displacement length is greater than the shortest displacement, the acceleration, constant speed, and deceleration phases are allocated. The acceleration and deceleration times are obtained by dividing the maximum allowable speed (i.e., the initial speed) by the maximum allowable acceleration. The displacement in the acceleration phase is equal to the square of the maximum allowable speed divided by twice the maximum allowable acceleration. The displacement in the deceleration phase is equal to the displacement in the acceleration phase. The displacement in the constant speed phase is the displacement length minus twice the displacement in the acceleration phase.

[0055] 2) When the displacement length is less than or equal to the shortest displacement, only acceleration and deceleration phases are allocated. The displacement of both the acceleration and deceleration phases is half of the displacement length. The acceleration time can be obtained by removing the acceleration phase position and taking the square root of the maximum allowable acceleration. The deceleration time is equal to the acceleration time. The peak velocity (i.e., the initial velocity) that can be achieved in the acceleration phase is obtained by multiplying the maximum allowable acceleration by the acceleration time.

[0056] Considering that each drive shaft must complete its movement within a unified baseline working cycle, the speed during the constant speed phase is adjusted so that each drive shaft completes its corresponding axial motion component within the baseline working cycle.

[0057] Step S200: Adjust the speed during the constant speed phase.

[0058] The specific process is as follows: When the drive shaft is assigned acceleration, constant speed, and deceleration phases, the sum of the acceleration time, constant speed time, and deceleration time is used as the estimated total time required for the drive shaft to complete the corresponding axial motion component. The constant speed time is obtained by removing the constant speed phase position and calculating the maximum permissible speed.

[0059] When the drive shaft is only assigned acceleration and deceleration phases, the sum of the deceleration time and acceleration time is used as the estimated total time required for the drive shaft to complete the corresponding axial motion component.

[0060] Then, the time deviation between the estimated total time and the baseline operation cycle is multiplied by a preset adjustment factor to obtain the adjustment amount.

[0061] The preset adjustment factor can be determined based on the response speed of the drive axis servo system. For example, when the response speed is less than 10 milliseconds, the preset adjustment factor can be 0.8; when the response speed is greater than 30 milliseconds, the preset adjustment factor can be 0.3. And when the response speed is between 10 milliseconds and 30 milliseconds, the preset adjustment factor can be 0.5.

[0062] If the estimated total time is less than the baseline operation cycle, the speed of the constant speed phase needs to be increased by the adjustment amount. The speed of the current constant speed phase is increased by the adjustment amount, but the final speed does not exceed the maximum allowable speed.

[0063] If the estimated total time is greater than the baseline operation cycle, the speed of the constant speed phase needs to be reduced by the adjustment amount, and the speed of the current constant speed phase should be reduced by the adjustment amount.

[0064] Recalculate the actual total motion time based on the adjusted speed, and repeat the adjustment steps until the actual total motion time equals the baseline operation cycle.

[0065] If the speed in the constant speed phase is adjusted to zero, and the actual total motion time is still greater than the benchmark operation cycle, it indicates that adjusting the speed in the constant speed phase alone cannot meet the requirement of making the actual total motion time equal to the benchmark operation cycle. In this case, the constant speed phase is canceled, and the peak speed adjustment phase begins.

[0066] The peak speed adjustment phase is as follows: taking the current peak speed when the constant speed phase speed is adjusted to zero as the initial value, multiplying the deviation between the current actual total motion time and the benchmark operation cycle by the peak speed adjustment coefficient to obtain the peak speed adjustment amount for this iteration, and subtracting the peak speed adjustment amount from the current peak speed to obtain the new peak speed. If the new peak speed is lower than the minimum allowable speed of the transfer mechanism, the minimum allowable speed is used as the peak speed, and a warning is issued that the transfer cannot be completed within the benchmark operation cycle; otherwise, the iteration continues until the actual total motion time equals the benchmark operation cycle.

[0067] The peak speed adjustment coefficient can be determined based on the ratio of the corresponding displacement length to the shortest displacement. When the ratio is less than or equal to 1.2, it indicates that the change in peak speed has a relatively large impact on the actual total motion time, and the peak speed adjustment coefficient can be taken as 0.2. When the ratio is greater than or equal to 2.5, it indicates that the change in peak speed has a relatively small impact on the actual total motion time, and the peak speed adjustment coefficient can be taken as 0.4. When the ratio is between 1.2 and 2.5, the peak speed adjustment coefficient can be taken as 0.3.

[0068] After completing step S200, the maximum value among the peak motion speeds of all adjusted drive shafts is taken as the first speed. The first speed characterizes the overall speed level of the transfer motion, facilitating speed coordination with the traction motion.

[0069] Here, for a drive shaft that includes a constant speed phase, the peak speed is the adjusted constant speed phase speed; for a drive shaft that only includes acceleration / deceleration phases, the peak speed is the maximum speed that can be reached during the acceleration phase.

[0070] Finally, the displacement sequences of each drive shaft are synchronously sampled using a unified time reference to obtain the position coordinates of each drive shaft at each moment. Then, based on the orthogonal or non-orthogonal geometric relationship of each drive shaft in three-dimensional space, the obtained position coordinates are combined in time order to form a continuous spatial position sequence, which is used as the movement trajectory.

[0071] Please see Figure 4 Step S21: Obtain the axial displacement and second velocity based on the displacement to be determined.

[0072] Specifically, the displacement to be moved is taken as the total stroke that the traction mechanism needs to move along its own axis, i.e., the axial displacement.

[0073] Next, based on the axial displacement and the maximum permissible acceleration and maximum permissible speed of the traction mechanism, the speed mode adopted by the traction mechanism to complete the axial displacement is determined. The maximum permissible acceleration and maximum permissible speed can be obtained from the equipment technical manual.

[0074] The speed mode determination process is as follows: calculate the total displacement of the traction mechanism from rest to the maximum allowable speed and then decelerates back to rest at the maximum allowable acceleration, and take it as the minimum displacement.

[0075] If the axial displacement is less than or equal to the minimum displacement, it indicates that the displacement is short and the traction mechanism may not be able to accelerate to the maximum allowable speed before it needs to start decelerating. Therefore, the speed mode is determined to include only the acceleration and deceleration motion phases.

[0076] If the axial displacement is greater than the minimum displacement, the velocity mode is determined to include acceleration, constant speed and deceleration motion stages.

[0077] Then, taking the benchmark work cycle as the uniform execution time of the traction action, and based on the uniform execution time and axial displacement, the motion timing parameters that satisfy the total time consumption equal to the benchmark work cycle under the determined speed mode are obtained through kinematic calculations.

[0078] The specific calculation process is as follows: when the velocity mode includes acceleration, constant speed, and deceleration phases, solve for the peak velocity. The equation is as follows: .

[0079] Where S is the axial displacement (in millimeters); T is the baseline operating cycle (in seconds); and a is the maximum permissible acceleration of the traction mechanism (in millimeters per second). 2 ).

[0080] Subsequently, the peak speed is divided by the maximum permissible acceleration to obtain the time of the acceleration phase, and the time of the deceleration phase is equal to the time of the acceleration phase. At the same time, twice the time of the acceleration phase is subtracted from the baseline operating cycle to obtain the time of the constant speed phase.

[0081] When the velocity mode only includes acceleration and constant velocity phases, first calculate the theoretical acceleration required to complete the axial displacement in the reference operation cycle according to the following equation. The equation takes the following specific form: .

[0082] Where S is the axial displacement (unit: millimeters); T is the reference working cycle (unit: seconds).

[0083] like If ≤a, then remove twice the axial position based on the baseline operating cycle to obtain the peak speed. The time for both the deceleration phase and the acceleration phase is half of the baseline operating cycle.

[0084] like If >a, it indicates that even with maximum acceleration, axial displacement cannot be completed within the baseline operating cycle. In this case, the baseline operating cycle needs to be readjusted or an error warning needs to be issued.

[0085] The peak speed, the time of the deceleration phase, and the time of the acceleration phase, or the peak speed, the time of the deceleration phase, the time of the acceleration phase, and the time of the uniform motion phase obtained from the above calculations, constitute the motion timing parameters.

[0086] Finally, the velocity value is extracted from the motion timing parameters as the second velocity. Specifically, if there is a uniform motion phase, the velocity of the uniform motion phase is taken as the second velocity; if there is no uniform motion phase, the corresponding calculated peak velocity is taken as the second velocity.

[0087] Step S3: Calculate the estimated duration and adjust the iteration speed.

[0088] Specifically, the estimated duration is first calculated based on the first velocity and the length of the trajectory, and the second velocity and the displacement to be determined.

[0089] To ensure that the transfer and traction actions end simultaneously and the welding position is synchronized, the first speed or the second speed is iteratively adjusted based on the difference between the two expected durations.

[0090] The iterative adjustment process is as follows: the difference between the two estimated durations is taken as the synchronization time difference, and multiplied by the preset proportional coefficient to obtain the adjustment range.

[0091] The preset scaling factor can be determined based on the ratio between the two initial estimated duration values. When the ratio is greater than 1.5, the preset scaling factor can be 0.15. When the ratio is not greater than 1.5, the preset scaling factor can be 0.25 to speed up the adjustment process.

[0092] If the synchronization time difference is greater than zero, it indicates that the transfer is slow. In this case, keep the first speed unchanged and subtract the adjustment range from the second speed to obtain the adjusted second speed. However, it is necessary to ensure that the adjusted second speed is greater than or equal to the minimum permissible speed of the traction mechanism.

[0093] If the synchronization time difference is less than zero, it indicates that the traction is slow. In this case, keep the second speed unchanged and subtract the adjustment range from the first speed to obtain the adjusted first speed. However, it is necessary to ensure that the adjusted first speed is greater than or equal to the minimum allowable speed of the transfer mechanism.

[0094] If the synchronization time difference is zero, proceed directly to step S4 without further iterative adjustments.

[0095] After each speed adjustment, the corresponding estimated duration and synchronization time difference are recalculated; the adjustment steps are repeated until the absolute value of the synchronization time difference calculated multiple times no longer decreases. At this point, the first and second speeds determined after the adjustment are used as the execution speed parameters in the transfer command and traction command, respectively, and the transfer command and traction command are executed simultaneously under the same start signal.

[0096] Furthermore, the rule for determining when the absolute value of the synchronization time difference no longer decreases is as follows: Let the absolute value of the synchronization time difference obtained in the current k-th iteration be Δ. When Δ ≤Δ It appears three times consecutively, and the Δ value in the third occurrence... Δ at the first time When the difference is less than the convergence threshold, it is determined that the absolute value of the synchronization time difference no longer decreases.

[0097] The convergence threshold is typically set to one-thousandth to one-hundredth of the baseline operation cycle to ensure synchronization accuracy and avoid infinite loops in the iteration process due to computational noise. In this invention, the convergence threshold is preferably five-thousandths of the baseline operation cycle.

[0098] Furthermore, if the absolute value of the synchronization time difference in 10 consecutive iterations is greater than the previous value, the convergence threshold will be increased to 1.5 times the current value to relax the convergence condition; if the absolute value of the synchronization time difference in 20 consecutive iterations decreases by less than one ten-thousandth of the baseline operation cycle, the convergence threshold will be reduced to 0.5 times the current value to narrow the convergence condition.

[0099] In this invention, the number of consecutive times required to determine that the absolute value of the synchronization time difference no longer decreases can also be determined based on the intensity of electromagnetic interference at the site; when the intensity of electromagnetic interference is lower than 3 volts / meter, take 3 consecutive times; when the intensity of electromagnetic interference is higher than 10 volts / meter, take 4 consecutive times; and for other electromagnetic interference intensities, maintain 3 consecutive times.

[0100] Step S4: During execution, monitor the real-time position of the U-shaped steel bar unit and the distance between the target welding position and the target position to determine whether the positioning is complete.

[0101] Specifically, during the execution of transfer and traction commands, the real-time positions of the U-shaped steel bar unit and the longitudinal steel bar bundle can be obtained in real time by a vision sensor or laser tracker installed on the end effector of the transfer mechanism, and a position encoder installed near the clamping point of the traction mechanism, and the straight-line distance between the real-time positions of the U-shaped steel bar unit and the longitudinal steel bar bundle and the target welding position can be calculated respectively.

[0102] When the straight-line distances between the two objects fall within the target accuracy range for at least three consecutive sampling periods, the positioning is considered complete and welding is performed.

[0103] Among them, if the effective value of the vibration acceleration measured by the on-site acceleration sensor is greater than 2 m / s 2 The sampling period can be increased to up to four consecutive periods to prevent misjudgment; if the effective value of vibration acceleration is less than 0.5 m / s². 2 The sampling period can be reduced to two consecutive sampling periods to improve the efficiency of judgment; for other effective values ​​of vibration acceleration, at least three consecutive sampling periods are maintained.

[0104] The target accuracy range can be set to 1.5 times the absolute value of the rebar diameter tolerance to ensure physical contact and successful welding of the rebar. The rebar diameter tolerance can be determined according to national standards or the company's internal control standards.

[0105] Please see Figure 5 Step S5: After welding is completed, update the sequence number and determine the target welding position for the next cycle.

[0106] After welding, the U-shaped steel bar unit 1 and the longitudinal steel bar bundle 2 are as follows: Figure 5 As shown. After welding is completed, the sequence number of the current U-shaped steel bar unit is incremented by one, and used as the sequence number of the next U-shaped steel bar unit.

[0107] Meanwhile, considering that the welding point is usually located at the intersection of the end of the U-shaped rebar unit and the longitudinal rebar bundle, the real-time position of the welding end of the U-shaped rebar unit and the real-time position of the front end of the longitudinal rebar bundle, recorded at the time of positioning completion, are extracted, and the midpoint between the two is calculated as the actual welding position for this operation.

[0108] Then, taking the actual welding position as a reference, along the transverse arrangement direction of the bottom web structure, increase forward by one standard work station spacing, and the resulting position is the target welding position for the next cycle.

[0109] Please see Figure 2 An automatic production control system for bottom web reinforcement cage includes: a position calculation module for determining the storage position of the current U-shaped reinforcement unit; and a module for calculating the displacement to be performed based on the position of the front end of the longitudinal reinforcement bundle and the target welding position.

[0110] The instruction generation module is used to generate a transfer instruction containing a movement trajectory and a first velocity based on the storage location and the target welding position; and to generate a traction instruction containing axial displacement and a second velocity based on the displacement to be generated.

[0111] The timing synchronization module is used to calculate the corresponding estimated duration based on the first speed and the length of the moving trajectory, and the second speed and the displacement to be moved.

[0112] The speed coordination module is used to iteratively adjust the first speed or the second speed based on the difference between the two estimated durations. When the absolute value of the difference no longer decreases after at least three consecutive adjustments, the transfer command and traction command are executed synchronously based on the first speed and the second speed at this time.

[0113] The positioning determination module is used to determine that the positioning is complete and to perform welding when the distance between the real-time position of the U-shaped steel bar unit and the longitudinal steel bar bundle and the target welding position falls within the target accuracy range for at least three consecutive sampling cycles.

[0114] The status update module is used to update the sequence number and determine the target welding position for the next cycle after welding is completed.

[0115] 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 implementations should not be considered beyond the scope of this invention.

[0116] In addition, the functional modules in the various embodiments of the present invention 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.

[0117] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0118] Finally, 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. An automatic production control method for bottom and web reinforcement cages, characterized in that, include: Determine the storage location of the current U-shaped steel bar unit according to its sequential numbering; calculate the displacement to be made based on the position of the front end of the longitudinal steel bar bundle and the target welding position. Based on the storage location and the target welding location, a transfer command containing the movement trajectory and the first velocity is generated; based on the amount of displacement to be generated, a traction command containing the axial displacement and the second velocity is generated. Based on the first velocity and the length of the trajectory, and the second velocity and the displacement to be determined, the corresponding estimated durations are calculated respectively. The first or second speed is iteratively adjusted based on the difference between the two estimated durations. When the absolute value of the difference no longer decreases after at least three consecutive adjustments, the transfer command and traction command are executed synchronously based on the first and second speeds at this time. During execution, when the real-time position of the U-shaped steel bar unit and the distance between the target welding position and the target welding position both fall within the target accuracy range for at least three consecutive sampling cycles, the positioning is determined to be complete and welding is performed. After welding is completed, update the sequence number and determine the target welding position for the next cycle based on the actual welding position.

2. The automatic production control method for the bottom web reinforcement cage according to claim 1, characterized in that, The process of determining the storage location is as follows: The U-shaped steel bar units are numbered sequentially according to their arrangement order in the bottom web structure. Based on the number, starting from the initial placement point of the first U-shaped steel bar unit, the fixed spacing is added one by one along the transverse direction of the bottom web. Each time a number is added, that is, based on the actual placement position of the previous U-shaped steel bar unit, it is shifted one standard work position spacing in the direction of the next work position. The resulting position is the storage position of the current U-shaped steel bar unit.

3. The automatic production control method for the bottom web reinforcement cage according to claim 1, characterized in that, The calculation process for the displacement is as follows: Obtain the actual position of the front end of the longitudinal reinforcement bundle, and at the same time determine the coordinates of the target welding position in the longitudinal direction of the bottom web in the current cycle, as the longitudinal reference position; Project the longitudinal reference position along the extension direction of the longitudinal steel bar bundle onto its axis to obtain the target alignment point; Calculate the straight-line distance between the current position of the front end of the longitudinal reinforcement bundle and the target alignment point, and superimpose the compensation amount used to characterize the positional deviation of the longitudinal reinforcement bundle at the target alignment point due to elastic recoil, to obtain the displacement amount of the longitudinal reinforcement bundle.

4. The automatic production control method for the bottom web reinforcement cage according to claim 1, characterized in that, The process of obtaining the first velocity and the trajectory is as follows: Starting from the current storage location of the U-shaped rebar unit, and ending at the target welding location of the current cycle; The spatial path from the starting point to the end point is decomposed into corresponding axial motion components along the directions of each independent drive shaft of the transfer mechanism. Based on the displacement length of each axial motion component and the maximum allowable acceleration and maximum allowable speed of the corresponding drive shaft, calculate the minimum time required for the drive shaft to complete the axial motion component independently. Take the maximum value among all the lowest time consumption as the benchmark operation cycle of the transfer mechanism; The benchmark work cycle is used as a unified completion benchmark. Based on the initial speed on which the minimum time corresponding to each drive shaft is based, acceleration, constant speed and deceleration phases are allocated to it. And adjust the speed during the constant speed phase so that each drive shaft completes the corresponding axial motion component within the reference working cycle; Take the maximum value among the peak motion speeds of all adjusted drive shafts as the first speed; The displacement sequences of each drive shaft are synchronously superimposed according to their spatial directional relationship to synthesize a continuous spatial position sequence as the movement trajectory.

5. The automatic production control method for the bottom web reinforcement cage according to claim 4, characterized in that, The process of adjusting the speed during the constant speed phase is as follows: Based on the acceleration during the acceleration and deceleration phases and the velocity during the constant velocity phase, the estimated total time required for the drive shaft to complete the corresponding axial motion component is calculated. Multiply the time deviation between the estimated total time and the baseline operation cycle by a preset adjustment factor to obtain the adjustment amount; If the estimated total time is less than the baseline operation cycle, the speed of the constant speed phase will be increased by the adjustment amount. If the estimated total time is greater than the baseline operation cycle, the speed of the constant speed phase will be reduced by the adjustment amount. Recalculate the actual total motion time based on the adjusted speed, and repeat the adjustment steps until the actual total motion time equals the baseline operation cycle.

6. The automatic production control method for the bottom web reinforcement cage according to claim 4, characterized in that, The process of obtaining the axial displacement and the second velocity is as follows: The displacement to be moved is taken as the total stroke that the traction mechanism needs to move along its own axis, i.e., the axial displacement. Based on the axial displacement and the maximum allowable acceleration and maximum allowable speed of the traction mechanism, determine the speed mode adopted by the traction mechanism to complete the axial displacement; Using the benchmark work cycle as the uniform execution time of the traction action, and based on the uniform execution time and axial displacement, kinematic calculations are used to obtain the motion timing parameters that satisfy the total time consumption equal to the benchmark work cycle under the determined speed mode. The velocity during the uniform motion phase is extracted from the motion time sequence parameters as the second velocity. If there is no uniform motion phase, the peak velocity is extracted as the second velocity.

7. The automatic production control method for the bottom web reinforcement cage according to claim 6, characterized in that, The process of determining the speed mode is as follows: The total displacement of the traction mechanism, which accelerates from rest to the maximum permissible speed and then decelerates back to rest at the maximum permissible acceleration, is calculated as the minimum displacement. If the axial displacement is greater than the minimum displacement, the determined velocity pattern includes acceleration, constant speed and deceleration phases; otherwise, the determined velocity pattern only includes acceleration and deceleration phases.

8. The automatic production control method for the bottom web reinforcement cage according to claim 1, characterized in that, The process of iteratively adjusting the first or second speed is as follows: The difference between the two estimated durations is used as the synchronization time difference, and multiplied by a preset proportional coefficient to obtain the adjustment range; If the synchronization time difference is greater than zero, the first speed remains unchanged, and the second speed is reduced by the adjustment range; the adjusted second speed is greater than or equal to the minimum permissible speed of the traction mechanism. If the synchronization time difference is less than zero, the second speed remains unchanged, and the first speed is reduced by the adjustment range; the adjusted first speed is greater than or equal to the minimum permissible speed of the transfer mechanism. After each speed adjustment, the corresponding estimated duration and synchronization time difference are recalculated. Repeat the adjustment steps until the absolute value of the synchronization time difference calculated for at least three consecutive times no longer decreases, and the difference between the absolute value of the synchronization time difference of the third time and the absolute value of the synchronization time difference of the first time is less than the preset convergence threshold, then terminate the iteration.

9. The automatic production control method for the bottom web reinforcement cage according to claim 1, characterized in that, The process of updating the sequence number and determining the target welding position for the next cycle is as follows: Increment the sequence number of the current U-shaped steel bar unit by one, and use it as the sequence number of the next U-shaped steel bar unit; Extract the real-time position of the welded end of the U-shaped steel bar unit and the real-time position of the front end of the longitudinal steel bar bundle recorded at the same time as the positioning is determined, and calculate the midpoint of the two as the actual welding position. Based on the actual welding position, proceed forward by one standard work station spacing along the transverse arrangement direction of the bottom web structure. The resulting position is the target welding position for the next cycle.

10. An automatic production control system for bottom and web reinforcement cages, characterized in that, include: The position calculation module is used to determine the storage location of the current U-shaped rebar unit; and to calculate the displacement to be made based on the position of the front end of the longitudinal rebar bundle and the target welding position. The instruction generation module is used to generate a transfer instruction containing a movement trajectory and a first velocity based on the storage location and the target welding position; and to generate a traction instruction containing axial displacement and a second velocity based on the displacement amount to be generated. The timing synchronization module is used to calculate the corresponding estimated duration based on the first speed and the length of the movement trajectory, and the second speed and the displacement to be made. The speed coordination module is used to iteratively adjust the first speed or the second speed based on the difference between the two estimated durations. When the absolute value of the difference no longer decreases after at least three consecutive adjustments, the transfer command and traction command are executed synchronously based on the first speed and the second speed at this time. The positioning determination module is used to determine that the positioning is complete and to perform welding when the distance between the real-time position of the U-shaped steel bar unit and the longitudinal steel bar bundle and the target welding position falls within the target accuracy range for at least three consecutive sampling cycles. The status update module is used to update the sequence number and determine the target welding position for the next cycle after welding is completed.

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