A control unit and method for a joining system having at least one joining station, which is designed to join at least one first joining element to a workpiece, determines actual data with respect to a first joining element joined to a current workpiece by the joining station. The control unit and method determine, in accordance with the actual data, a subsequent control instruction for the joining station for joining a first joining element to a subsequent workpiece.

A method for joining joining elements to components, in particular for stud welding, comprises the steps of: providing a joining element having a first joining surface, and providing a component having a second joining surface; preparing the first or the second joining surface, wherein the preparation step includes detecting the state of the first or the second joining surface; joining the joining element to the component. The preparation step uses least one of the following detection methods: (i) an electrical contact resistance measurement, (ii) an electrical conductivity measurement, (iii) a fluorescence measurement, and (iv) a laser measurement.

A drawn arc welding system includes a weld gun having a stepper motor, a power inverter module configured to receive a single-phase power input and output welding power to the weld gun, and a control module having a stepper motor driver, a user interface, and a controller in communication with the stepper motor driver, the user interface, and the power inverter module. The controller is configured to receive a current for the welding power from the user interface, and instruct the power inverter module to output the current to the weld gun.

A method and apparatus for teaching a programmed controlled robot at least one of two set up position coordinates by use of a tool having a first surface aligned with the end of a stud welding gun collet when the tool is mounted in the collet, a second surface on the tool spaced from the first surface by a predetermined set up distance. A probe carried by the stud welding engagable with the second surface on the tool to establish a predetermined set up distance. A third surface on the tool spaced from the first surface and engagable with a work piece to establish a minimum stud-welding gun set up dimension. The coordinates of the stud-welding gun when the third surface is engaged with the work piece are transmitted to a robot control program to establish the predetermined stud weld gun travel distance dimension.

In one aspect, there is disclosed a drawn arc fastener welding process that includes the steps of providing a fastener positioned in a welding tool, providing a weld control, providing a work piece, contacting the fastener against the work piece, energizing a pilot current, lifting the fastener from the work piece and drawing a pilot arc, energizing a main arc for a predetermined duration, short circuiting the fastener relative to the work piece, cyclically redrawing an arc and short circuiting the fastener relative to the work piece at least one additional cycle, dynamically sensing an arc voltage and calculating a derivative signal of the voltage over time for each drawn arc and short circuit of the cycle wherein a position and motion of the fastener relative to the work piece is controlled and the energizing of the arc is controlled, and plunging the fastener into the work piece forming a weld.

A portable drawn arc stud welder apparatus with a lithium ferrophosphate (LFP) battery and stud weld battery control system (SWBCS) is provided for welding a stud onto a workpiece. The portable drawn arc stud welder apparatus includes a housing, an LFP battery disposed in the housing and including a plurality of LFP battery cells, a weld stud gun configured to hold a stud and is electrically connected to the LFP battery for receiving energy from the LFP battery to pass a current through the stud and the workpiece to form a weldment. The SWBCS is disposed in the housing and electrically connected to the LFP battery of the portable drawn arc stud welder apparatus. The SWBCS includes a computer, a memory, and instructions therein to implement control and monitoring of the operation of the portable drawn arc stud welder apparatus.

A device and a method for position measurement for welding guns, wherein based on the inductance of the coil, which changes depending on the insertion depth of the welding stud into a solenoid coil, it is inferred how far the welding stud is inserted into the solenoid in order to allow conclusions to be drawn concerning a proper arrangement of the welding stud relative to the workpiece.