Stitch & Multipass Welding

Built stitch welding (alternating weld beads and gaps along a path) and multipass welding (multiple offset passes over the same joint for thick materials) — two advanced welding modes requiring C++ trajectory segmentation, arc path linearization, and a per-pass offset system with configurable work angles, push angles, and position offsets.

Implemented stitch welding — alternating weld beads and gaps along a trajectory path for aesthetic or structural applications. Built a TrajectorySegmenter C++ service that takes a continuous weld trajectory and segments it into equal-length beads with configurable gap spacing. The Python layer linearizes arc paths (converting curved waypoints into dense linear approximations) before passing them to the C++ segmenter. During execution, the executive interpreter enables the torch for bead segments and disables it for gaps, producing evenly spaced stitch patterns along the weld path.

Built a complete multipass welding system for thick materials (structural steel, pressure vessels) that require multiple weld passes to fill a joint. Each pass has independent position offsets (start and end), work angle adjustments, and push angle modifications — allowing the robot to lay successive beads at different positions and orientations within the groove. Pass direction handling ensures correct bead ordering. The system supports global procedures — save and reload multipass configurations as reusable templates across different programs and workpieces.

Both features required tight integration across the stack: the Vue.js tablet UI provides operator controls for bead length, gap length, pass count, and per-pass offsets. The Python executive interpreter manages the welding state machine (torch on/off, recipe switching between passes). The C++ EtherCAT master executes the segmented trajectories at 1kHz with live speed control. A MultipassModal Vue component provides the operator interface for configuring and previewing multipass parameters before execution.