📋 Case Study

Welding Robot Cell Collision-Free Path Synthesis for Automotive Body-in-White

Interference between dual-arm robots and fixture-mounted part carriers during simultaneous weld passes

🏗️ Project Overview

Tier-1 supplier welding 12-kW laser seams on aluminum chassis at BMW Plant Leipzig

🎯 Challenge

Interference between dual-arm robots and fixture-mounted part carriers during simultaneous weld passes

🔧 Design Approach

Hybrid RRT*-CHOMP planner with occupancy grid mapping updated via PLC-triggered vision snapshots; synchronized multi-robot coordination using ROS 2 Time-Sensitive Networking (TSN)

📐 Design Diagram

AI-generated project design illustration

📐 Key Calculations

Minimum Safe Separation Distance

d_min = v_rel × t_response + d_buffer

Result: 142 mm

Ensures collision avoidance under 12ms network latency

Weld Seam Timing Tolerance

Δt ≤ (v_weld × Δx)/v_weld

Result: ±8 ms

Prevents thermal distortion from unsynchronized passes

📊 Results

Zero unplanned stops for 18 months, 99.2% first-pass weld quality, 3.1s cycle time reduction

💡 Lessons Learned

• •Occupancy grid resolution must match fixture repeatability (±0.1mm)
• •TSN synchronization eliminates temporal drift in multi-robot coordination

✅ Key Takeaways

• 1Occupancy grid resolution must match fixture repeatability (±0.1mm)
• 2TSN synchronization eliminates temporal drift in multi-robot coordination