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CN-122007558-A - Double-wire feeding system and push-pull wire compensation control method thereof

CN122007558ACN 122007558 ACN122007558 ACN 122007558ACN-122007558-A

Abstract

The invention belongs to the technical field of automatic welding, and provides a double wire feeding system and a push-pull wire compensation control method thereof, wherein the system is powered on and then controls a front wire feeder to stop and a rear wire feeder to start, so as to calibrate an absolute zero point of a buffer; the real-time position of the buffer is acquired, the position difference delta X between the buffer and the absolute zero is calculated, the difference delta X is added into the buffer position parameter to refresh the state of the device, a safety interval [ -delta, +delta ] associated with the absolute zero is preset, when delta X is in the safety interval, the PID controller does not interfere with the speed of the wire feeder, when delta X exceeds the safety interval, the basic compensation speed value is calculated based on PID closed loop control, and the final speed compensation value is generated by combining the control gain factor and the damping factor to act on the speed regulation of the post wire feeder. The invention can make the wire feeding operation speeds of the front wire feeder and the rear wire feeder reach the same speed, effectively inhibit the oscillation of the small-stroke buffer structure and improve the stability and precision of wire feeding.

Inventors

  • ZOU YONGSONG

Assignees

  • 无锡超强伟业科技有限公司
  • 无锡弘德科技有限公司

Dates

Publication Date
20260512
Application Date
20260203

Claims (10)

  1. 1. The push-pull wire compensation control method of the double wire feeding system is characterized by comprising the following steps of: (1) After the system is electrified, controlling the front wire feeder to stop, and the rear wire feeder to start, driving the photoelectric sensor of the buffer to move relative to the grating, triggering the grating to limit, controlling the rear wire feeder to reversely move to 1/2 of the maximum running range, and calibrating the position of the corresponding grating of the photoelectric sensor as the absolute zero point of the buffer position; (2) In normal operation of the system, collecting the real-time position of the buffer, calculating the position difference delta X between the buffer and the absolute zero, and adding the difference into the buffer position parameter to refresh the state of the device; (3) Presetting a safety interval [ -delta, +delta ] associated with an absolute zero, wherein the safety interval allows the sliding block of the buffer to freely wave; (4) When the delta X is in a safety interval, the output of the PID controller is cleared without intervention of the speed of the wire feeder, when the delta X exceeds the safety interval, PID closed-loop control is started, a basic compensation speed value is calculated, a final speed compensation value is generated by combining a control gain factor and a damping factor, and the speed compensation value is acted on the speed regulation of the post wire feeder after calibration.
  2. 2. The method according to claim 1, wherein in step (2), it is detected whether the buffer position exceeds the maximum stroke, whether the limit is triggered during normal operation or whether the instantaneous moving speed exceeds the threshold, and if so, it is determined that the buffer state is an abnormal state, and the scram process is performed.
  3. 3. The method according to claim 1, wherein in the step (3), the setting conditions of the safety interval [ - δ, +δ ] include: 1) The value of delta is larger than the comprehensive fluctuation amplitude caused by the inherent noise level of the system; 2) The range of the safety interval is larger than the fluctuation range of the position of the sliding block caused by the tension tolerance of the wire feeding process; 3) The range of the safety interval is smaller than the difference between the grating range and the system compensation adjustment limit.
  4. 4. The method for controlling push-pull wire compensation of a dual wire feeding system according to claim 3, wherein the calculation mode of the fluctuation range of the position of the sliding block is x=Δt/k, wherein Δt is the tiny fluctuation range of the wire tension allowed according to the process requirement, and k is the elastic coefficient of the spring in the buffer; the calculation mode of the compensation adjustment limit of the system is S=v.t, wherein v is the maximum movement speed of the system allowing the sliding block to slide, and t is the compensation period of the system.
  5. 5. The method of controlling push-pull wire compensation of a dual wire feed system according to claim 1, wherein in step (4), the basic compensation speed value is calculated by the following method: V=Kp×ΔX+Ki×∫ΔXdt+Kd×d(ΔX)/dt wherein V is a basic compensation speed value, kp is a proportional gain, ki is an integral gain, and Kd is a differential gain.
  6. 6. The method for controlling push-pull wire compensation of a dual wire feeding system according to claim 5, wherein the integral term in the PID closed loop control adopts a limiting process, and when the integral value exceeds the maximum integral limiting, the integral value is gradually attenuated according to the percentage coefficient of the current integral value, so as to prevent overshoot.
  7. 7. The method for controlling push-pull wire compensation of a dual wire feeding system according to claim 1, wherein in step (4), the control gain factor is updated according to the degree of positional deviation of the buffer slider, and specifically comprises: The gain factor is not changed to be the initial gain when the deviation distance is within the allowable safety interval, the gain factor is increased to perform medium compensation intervention when the deviation distance exceeds the safety interval range and is in the warning zone, and the maximum gain factor is used to perform strong compensation intervention when the deviation distance exceeds the warning zone range and is in the critical zone.
  8. 8. The method for controlling push-pull wire compensation of a dual wire feeding system according to claim 1, wherein in the step (4), the damping factor is updated according to a matching relationship between an actual running direction and a deviation direction of the buffer slider, and the method specifically comprises: When the actual running direction and the deviation direction of the sliding block are inconsistent, the damping factor is reduced, and the convergence of the sliding block is accelerated.
  9. 9. A dual wire feed system comprising a processor and a memory storing a computer program, the processor implementing the method of any of claims 1-8 when executing the computer program.
  10. 10. The dual wire feed system of claim 9, further comprising a front wire feeder, a buffer, and a rear wire feeder connected in sequence by a wire feed tube; The buffer comprises a sliding rail, a sliding block, springs, photoelectric sensors and a grating, wherein the sliding block is slidably arranged on the sliding rail, the springs are respectively arranged at two ends of the sliding block, the photoelectric sensors are fixed on the side face of the sliding block and are slidably arranged relative to the grating, and limiting holes are respectively formed in the two ends of the grating.

Description

Double-wire feeding system and push-pull wire compensation control method thereof Technical Field The invention belongs to the technical field of automatic welding, and particularly relates to a double wire feeding system and a push-pull wire compensation control method thereof. Background In modern manufacturing industry, laser welding is used as a core connection process, and is widely applied to the fields of automobiles, ships and the like, and the quality and efficiency of the welding process directly determine the product performance and the enterprise competitiveness. With the transition of manufacturing industry to intelligent, manual welding is difficult to meet the production requirements of high precision and high efficiency, and an automatic welding technology becomes a mainstream development direction. In order to meet the long-distance wire feeding requirement of a welding robot under a complex working condition, a double wire feeding system framework of a front wire feeding machine, a buffer device and a rear wire feeding machine is generally adopted. The welding wire sequentially passes through the front wire feeder, the buffer device and the rear wire feeder, and tension fluctuation caused by inconsistent front and rear wire feeding speeds is absorbed through the buffer device, so that the problems of clamping, wire piling or breakage and the like of the welding wire in a wire feeding pipe are avoided. In the prior art, for example, chinese patent application No. CN200580002742.7 discloses a welding wire storage device, in which a buffer structure (core wire storage) is shaped like a half moon, and after a speed difference occurs between front and rear wire feeding, a closed loop control logic is adopted to correct the wire feeding speed. However, in order to meet the industrial requirement, the flexibility of the mechanical arm needs to be ensured, the device is oversized, the existing requirement is not met, and the buffer device needs to be smaller in size design. However, the small-size buffer structure needs to take the problem of buffer stroke into consideration, because there is not enough buffer stroke, the buffer internal oscillation problem caused by environmental interference occupies a part of buffer stroke, such as motor noise, the comprehensive fluctuation amplitude of the slider position signal caused by photoelectric sensor measurement error, mechanical transmission clearance and the like can all cause buffer balance point oscillation problem, if the movable part for recording the buffer stroke is adjusted immediately when the buffer device is active, the buffer internal oscillation problem caused by environmental interference is not considered, the buffer can be caused to have an over-adjustment condition, and long-time operation can cause the reset unbalance of the buffer internal reset part, so that the device compensation precision is reduced. Therefore, there is a need for an intelligent compensation control method suitable for a small-stroke buffer structure, which can realize high-precision and high-reliability cooperative control of push-pull wires while suppressing system oscillation. Disclosure of Invention The invention aims to overcome the existing defects, and provides a double wire feeding system and a push-pull wire compensation control method thereof, so that the wire feeding operation speeds of a front wire feeding machine and a rear wire feeding machine can be quickly consistent in a small-amplitude buffer structure, thereby meeting the welding work requirements of stable wire feeding and back drawing, and effectively inhibiting the vibration of the wire feeding system near a balance point, so as to meet the welding work requirements of high-stability wire feeding and back drawing. In order to solve the technical problems, the invention provides the following technical scheme: The first object of the present invention is to provide a push-pull wire compensation control method of a double wire feeding system, comprising the following steps: (1) After the system is electrified, controlling the front wire feeder to stop, and the rear wire feeder to start, driving the photoelectric sensor of the buffer to move relative to the grating, triggering the grating to limit, controlling the rear wire feeder to reversely move to 1/2 of the maximum running range, and calibrating the position of the corresponding grating of the photoelectric sensor as the absolute zero point of the buffer position; (2) In normal operation of the system, collecting the real-time position of the buffer, calculating the position difference delta X between the buffer and the absolute zero, and adding the difference into the buffer position parameter to refresh the state of the device; (3) Presetting a safety interval [ -delta, +delta ] associated with an absolute zero, wherein the safety interval allows the sliding block of the buffer to freely wave; (4) When the delta X is in a safety interv