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CN-121972775-A - Full-automatic intelligent stud welding system

CN121972775ACN 121972775 ACN121972775 ACN 121972775ACN-121972775-A

Abstract

The invention discloses a full-automatic intelligent stud welding system, and relates to the technical field of automatic welding equipment. The system comprises a crawler-type mobile chassis, a multi-axis mechanical arm, a welding pin welding execution assembly, a welding pin automatic feeding system, an integrated motion control device and a welding power supply device. The integrated motion control device cooperatively controls chassis movement and mechanical arm gesture based on a coupling kinematics model, adopts a rough and fine coupling positioning strategy, and eliminates chassis parking errors by utilizing a visual sensing module and an inverse kinematics solver. The system is also configured with a dynamic follow-up welding algorithm that enables relatively stationary welding in a continuously moving state by generating a compensating motion vector that is opposite to the chassis dragging motion. In addition, the system integrates dynamic collision detection and closed loop feeding timing control logic based on motor current monitoring. The invention effectively solves the problems of low positioning precision and poor operation efficiency in the welding of large-scale workpieces, and realizes high-precision automatic operation in complex environments.

Inventors

  • ZHOU WEIDONG

Assignees

  • 固安县鑫盛达建筑钢制品有限公司

Dates

Publication Date
20260505
Application Date
20260317

Claims (10)

  1. 1. Full-automatic intelligent double-screw bolt welding system, its characterized in that includes: The welding machine comprises a crawler-type mobile chassis (10), a multi-axis mechanical arm (20), a welding pin welding execution assembly (30), a welding pin automatic feeding system (40), an integrated motion control device (50), a welding power supply device (60) and a vehicle-mounted power supply module (70); The welding nail welding execution assembly (30) is arranged at the tail end flange of the multi-axis mechanical arm (20), the automatic feeding system (40) for welding nails is arranged on the crawler-type movable chassis (10) and is communicated with the welding nail welding execution assembly (30) through a flexible nail conveying pipe; The integrated motion control device (50) is respectively in communication connection with a chassis driving motor of the crawler-type mobile chassis (10) and a joint servo motor of the multi-axis mechanical arm (20) through an industrial real-time bus, and the integrated motion control device (50) is electrically connected with the welding nail automatic feeding system (40) and the welding power supply device (60) through an I/O interface; The integrated motion control device (50) is configured to cooperatively control the movement of the crawler-type mobile chassis (10) and the posture adjustment of the multi-axis mechanical arm (20) by using a coupling kinematics model of the crawler-type mobile chassis (10) and the multi-axis mechanical arm (20) based on a multi-body dynamics principle, and control the welding nail automatic feeding system (40) and the welding nail welding execution assembly (30) to finish the conveying and welding operation of welding nails. The vehicle-mounted power supply module (70) is used for providing direct-current power for the whole system.
  2. 2. The fully automatic intelligent stud welding system according to claim 1, wherein the coordinated movement between the tracked mobile chassis (10) and the multi-axis robotic arm (20) is based on the following coupling control logic: the integrated motion control device (50) establishes a chassis coordinate system and a mechanical arm base coordinate system and stores a chassis-mechanical arm transformation matrix; The integrated motion control device (50) maps the angular speeds of driving wheels at the left side and the right side of the crawler-type mobile chassis (10) into chassis motion vectors according to a differential kinematics equation; the integrated motion control device (50) constructs a generalized jacobian matrix comprising the crawler-type mobile chassis (10) and the multi-axis mechanical arm (20), and calculates the absolute speed of the welding executing assembly (30) under a world coordinate system into vector superposition of the chassis dragging motion speed and the mechanical arm relative motion speed; When the target weld point is outside of a single working range of the multi-axis robotic arm (20), the integrated motion control device (50) assigns a desired tip speed vector to the chassis motion vector and the joint angular velocity vector of the multi-axis robotic arm (20).
  3. 3. The full-automatic intelligent stud welding system of claim 1, wherein the welding stud welding execution assembly (30) comprises a welding gun dedicated to welding studs, a vision sensing module, and a laser ranging sensor; An automatic clamping chuck, a floating buffer mechanism and an electromagnetic lifting mechanism are arranged in the welding gun special for welding nails and are used for clamping the welding nails and executing lifting and upsetting actions required by welding; the visual sensing module is relatively and fixedly connected with the welding gun special for the welding nail, and a hand-eye calibration transformation matrix calibrated in advance is arranged between the optical center of the visual sensing module and the central axis of the welding gun special for the welding nail; the integrated motion control device (50) is configured to perform visual servo closed loop correction by controlling the visual sensing module to acquire a workpiece image, extracting feature pixel coordinates of a welding target point, calculating a pixel deviation vector between the feature pixel coordinates and pre-stored image bulls-eye coordinates, and converting the pixel deviation vector into an end correction velocity vector of the multi-axis robotic arm (20) using an image jacobian.
  4. 4. The fully automatic intelligent stud welding system according to claim 1, wherein the integrated motion control device (50) is operated with a coarse-fine coupling positioning control strategy, the strategy comprising: the global path planning module is used for generating a global driving path according to the welding task; The coarse positioning navigation module is used for controlling the crawler-type mobile chassis (10) to move along the global driving path and controlling the crawler-type mobile chassis (10) to be braked and locked when the Euclidean distance between the crawler-type mobile chassis and a target welding point is smaller than a preset coarse positioning judgment threshold value; And the fine positioning compensation module is used for calculating an actual position deviation vector of the target point under an end effector coordinate system by utilizing the visual sensing module after coarse positioning is finished, keeping the crawler-type movable chassis (10) stationary if the module length of the actual position deviation vector is smaller than or equal to a preset mechanical arm singular boundary threshold value, and calculating joint angle compensation quantity by using an inverse kinematics solver of the multi-axis mechanical arm (20) so as to eliminate the actual position deviation vector.
  5. 5. The fully automatic intelligent stud welding system of claim 4, wherein the fine positioning compensation module is further configured to handle large deviation situations: And if the modulus of the actual position deviation vector is larger than the singular boundary threshold of the mechanical arm, the fine positioning compensation module sends a repositioning instruction to the coarse positioning navigation module, and drives the crawler-type mobile chassis (10) to carry out secondary pose adjustment until the target point falls into the smart working space of the multi-axis mechanical arm (20).
  6. 6. The fully automatic intelligent stud welding system according to claim 1, wherein the integrated motion control device (50) is further configured with a dynamic follow welding algorithm for welding while the crawler-type mobile chassis (10) remains continuously moving; The dynamic follow-up welding algorithm comprises real-time motion compensation logic, wherein the integrated motion control device (50) reads the current motion velocity vector of the crawler-type mobile chassis (10) in real time, and generates a target joint angular velocity vector of the multi-axis mechanical arm (20) according to a differential kinematics equation, so that the welding nail welding execution assembly (30) generates compensation motion with opposite and equal magnitude to the traction motion direction of the crawler-type mobile chassis (10), and the tool center point is kept stationary relative to the surface of a workpiece.
  7. 7. The fully automatic intelligent stud welding system of claim 6, wherein the dynamic follow welding algorithm further comprises time safety verification logic: The integrated motion control device (50) predicts the residual time required by the operation interval of the multi-axis mechanical arm (20) to be moved out of the welding point according to the current speed of the crawler-type movable chassis (10), and allows the welding action to be triggered only when the residual time is larger than the sum of the standard welding cycle time and the safety margin time of the single welding pin.
  8. 8. The fully automatic intelligent stud welding system of claim 1, wherein the stud automatic feeding system (40) includes a vibratory screening tray, a linear alignment rail, a T-shaped split reversing mechanism, and a flexible stud tube; The integrated motion control device (50) performs welding nail feeding time sequence control, when a feeding request is received and a feeding condition is detected to be provided at the tail end of the straight line whole row track, the T-shaped feeding reversing mechanism is controlled to push a single welding nail into the emission cavity to form airtight closure, then a high-voltage pulse electromagnetic valve is controlled to be opened, and the welding nail is pneumatically conveyed to the welding nail welding execution assembly (30) through the flexible nail conveying pipe by using compressed air.
  9. 9. The fully automatic intelligent stud welding system according to claim 8, wherein the integrated motion control device (50) performs a conveyance timer based fault diagnosis: The integrated motion control device (50) starts a conveying timer when opening the high-voltage pulse electromagnetic valve, monitors signals of an annular metal sensor arranged at the middle section of the flexible nail conveying pipe, and judges that conveying jamming faults occur and outputs alarm signals if the count value of the conveying timer exceeds a preset maximum transmission timeout threshold value and a trigger signal is not detected.
  10. 10. The fully automatic intelligent stud welding system according to claim 1, wherein the integrated motion control device (50) includes a safety monitoring module that performs current monitoring based kinetic collision detection: The safety monitoring module acquires real-time current values of motors of the crawler-type mobile chassis (10) and the multi-axis mechanical arm (20) in real time, calculates a rated current value in combination with a theoretical torque model, calculates an equivalent external torque interference value according to a difference value between the real-time current value and the rated current value and a motor torque constant, and if the equivalent external torque interference value is larger than a preset collision protection threshold value, the integrated motion control device (50) cuts off power supply of the motors and controls the band-type brake mechanism to lock.

Description

Full-automatic intelligent stud welding system Technical Field The invention relates to the technical field of automatic welding equipment, in particular to a full-automatic intelligent stud welding system. Background Stud welding is a fastening connection process for instantaneously welding a metal stud to the surface of a workpiece in an arc discharge or energy storage discharge mode. The process has the characteristics of high welding strength, small heat affected zone, high construction efficiency and the like, is widely applied to the fields of steel structure building, bridge engineering, ship manufacturing, heavy equipment manufacturing and the like, and is mainly used for installing shear nails, heat preservation nails or various fixed supporting pieces. When stud welding operation is carried out on a large-scale steel structure plane or a large-span workpiece, the traditional mode mainly relies on manual handheld welding guns to carry out point-by-point welding, so that the labor intensity is high, and the efficiency is limited by the physical strength of operators. To improve the level of automation, attempts have been made in the industry to employ mobile welding robot systems, which are typically constructed with a mobile carrier (e.g., wheeled or tracked chassis) carrying a multi-degree of freedom robotic arm and a welding actuator. In the operation process, the movable carrier is responsible for conveying the mechanical arm to a rough operation area, and then the mechanical arm performs posture adjustment in a local range and performs welding action, so that the covering operation of a large workpiece is realized. However, the existing movable stud welding equipment faces the problem that positioning accuracy is difficult to meet process requirements in practical application. Because the movable carrier is limited by the ground flatness, the mechanical transmission clearance or the physical characteristics of the travelling mechanism, the self parking positioning precision is generally low, and the millimeter positioning requirement required by stud welding is difficult to directly reach. When the moving carrier stops after reaching the target station, a non-negligible positional deviation or attitude inclination is often generated, which directly causes the reference coordinate system of the mechanical arm fixed thereon to deviate. The existing control system generally regards a mobile carrier and a mechanical arm as two independent motion units to perform step control, and lacks an effective system-level error sensing and linkage compensation mechanism, so that when the chassis parking error exceeds a single fault tolerance range of the mechanical arm, a terminal welding gun cannot accurately align with a preset welding point, welding nails are easily caused to be deviated, the positions of the welding nails are out of tolerance and even the welding is failed, and the quality stability of automatic welding of large-scale complex components is seriously influenced. Disclosure of Invention The invention aims to solve the technical problems of low automation degree, high positioning precision, high interference by a moving platform, low welding efficiency and the like in the existing welding operation of large-sized workpiece studs. The first aspect of the invention provides a full-automatic intelligent stud welding system. The system comprises a crawler-type mobile chassis, a multi-axis mechanical arm, a welding pin welding execution assembly, a welding pin automatic feeding system, an integrated motion control device and a welding power supply device. The welding pin automatic feeding system is arranged on the crawler-type movable chassis and is communicated with the welding pin welding executing assembly through a flexible pin conveying pipe, and the integrated motion control device is respectively in communication connection with a chassis driving motor of the crawler-type movable chassis and a joint servo motor of the multi-axis mechanical arm through an industrial real-time bus and is electrically connected with the welding pin automatic feeding system and the welding power supply device through an input/output interface. The integrated motion control device is configured to cooperatively control the movement of the crawler-type movable chassis and the posture adjustment of the multi-axis mechanical arm by using a coupling kinematics model of the crawler-type movable chassis and the multi-axis mechanical arm, and control the welding nail automatic feeding system and the welding nail welding execution assembly to finish the conveying and welding operation of welding nails. The second aspect of the invention provides a multi-body cooperative motion control method based on the system. The coordinated control of the mobile base and the operating arm is realized by establishing a system coordinate tether comprising a world coordinate system, a chassis coordinate system, a mechanical arm base c