Automatic joint laser tracking system for longitudinal seam welding

Automatic joint laser tracking system for longitudinal seam welding Automatic joint laser tracking system for longitudinal seam welding

The system has been designed for automatic tracking the V-groove joints without filling or with partial filling after welding pass during arc or submerged arc welding. The system consists of two basic part: laser sensor (LS) with microprocessor control and communication module (CM).

The laser sensor provides contactless measuring of lateral and vertical butt-joint center shifting and data transfer to communication module through RS-422 interface. Laser sensor is also equipped with TV-out for visual tracking of the system operation. The main functions of communication module are: laser sensor data receive, forming the signals of lateral and vertical welding head position correction, tracking system tuning, coordination with welding mill main controller, operator pendant and external computer for service parametrization and tracking system setting.

Tracking system is integrated into existing welding mill equipment. The sensor TV-out is connected to the existing remote viewing display. The communication module is facilitated with required interface, digital and/or analogue inputs and outputs for interaction with welding mill and operator pendant (the list of required signals is additionally coordinated with the Customer depending on welding mill type).

The tracking system is based on modern industrial-purpose electronic components and print-boards assuring advanced reliability of the supplied equipment.  

Tracking system main advantages

· high sensitivity to the groove depth due to larger triangulation angle provides the reliable butt-joint tracking for thin-wall pipes welding;

· no Windows operation system;

· the system loading time is less then 3-4 seconds upon actuation;

· no computer in the scope of tracking system;

· transformer feed and signal circuits galvanic isolation is installed directly in the sensor block, allowing to eliminate the electromagnetic fields influence on the welding cables;

· interchangeable sensor blocks and communication modules decrease the spare parts expenses;

· simple maintainable cables;

· TV-out giving the view of the tracking process to the welding operator;

· available information оn actual groove width (no preliminary entry required) and edges excess in real time mode;

· unique optical path helps eliminate the glares and extraneous lights influence on the tracking process;

· the protective classes have standard diameter of 20 and 30 mm and can be easily replaced in just a few minutes.



Lateral and vertical butt-joint center tracking accuracy, mm

± 0.5


Laser sensor operation area in cross direction, mm

± 30


Laser sensor operation area in vertical direction, mm

± 25


Nominal distance between sensor and pipe, mm



Minimum permissible groove residual depth, mm



Max. communication line length between laser sensor and communication module, m



Output TV-signal standard



System feeding

24 В


Working power, Wt, max



Sensor galvanic isolation breakdown voltage, kW, max



Laser sensor IP protection class



Sensor operating temperature °С