Tunnel & Underground Mapping

Inertial Navigation for Tunnel Construction & Mapping

Tunnel construction and underground surveying present some of the most challenging navigation problems in engineering. With no GPS availability, confined spaces, metallic interference, and the need for millimeter-level accuracy, Tunnel Boring Machines (TBMs) and survey crews demand specialized inertial navigation solutions.

TBM Guidance Systems

Modern tunnel boring machines require continuous, real-time knowledge of their position and orientation to stay on the designed alignment. An Inertial Navigation System (INS) provides the core position and attitude reference for automated TBM guidance.

• Continuous Positioning: Track TBM position along the tunnel axis continuously, without stopping for survey measurements
• Attitude Monitoring: Real-time pitch, roll, and yaw data for steering corrections
• Productivity Gains: Reduce downtime from traditional survey methods, increasing advance rates
• Integration: Combine with total station and laser-based systems for hybrid guidance

Underground 3D Mapping & Surveying

Mobile mapping systems mounted on rail carts, utility vehicles, or handheld platforms use INS to georeference LiDAR and camera data in GPS-denied underground environments. When combined with SLAM algorithms, the INS provides the initial pose and constrains drift, enabling accurate 3D point cloud generation.

Key Technical Requirements

• Heading Accuracy: Critical for maintaining tunnel alignment over kilometers of excavation
• Shock & Vibration Resistance: Withstand the harsh mechanical environment of TBM operations
• Temperature Stability: Consistent performance across the wide temperature range of underground environments
• Long-Duration Stability: Low drift over extended boring cycles between survey updates

Product Solutions

GyroNavi provides a range of FOG-based and MEMS-based INS products for tunnel and underground applications. Our systems are proven in major infrastructure projects including metro tunnels, highway tunnels, and hydropower headrace tunnels.

• FOG-INS for high-accuracy TBM guidance requiring the lowest drift
• MEMS-INS for cost-sensitive applications with shorter drift-free requirements
• Custom integration with existing TBM control and survey systems