1. Why is under-bridge positioning difficult?
The under-bridge environment has three major difficulties: first, no satellite signal, so GNSS cannot be relied on; second, dim light with weak visual features; third, complex structures and dense occlusion, where conventional positioning algorithms easily drift. Together these cause traditional drones to easily lose control in under-bridge operations.
2. How does RIEJIAN solve it?
RIEJIAN does not rely on satellite navigation. It uses a self-developed vision + sensor fusion positioning solution that matches the bridge’s real structural features in real time. The system is trained on massive real-scene samples of box girders and bridge undersides, giving it strong anti-interference capability that adapts to dark, structurally dense and texture-complex extreme environments, maintaining centimeter-level stable flight.
3. Special capability in low-light environments
| Environment | Capability |
|---|---|
| Zero satellite | Vision + sensor fusion positioning, no GPS reliance |
| Low-light / dark | Real-scene sample training, drift-free positioning |
| Complex occlusion | Structural feature matching, strong anti-interference |
4. Applicable conditions and scenarios
- Closed box girders, deep girder soffit inspection
- Under-bridge operations on long-span bridges
- Low-clearance ramp bridges, overpasses
- Inspection of bridge structures inside tunnels
5. Notes
In extreme low-illumination conditions, it is recommended to combine supplementary lighting (such as RIEJIAN inspection equipment’s automatic fill light) to improve imaging quality, ensuring both imaging and positioning stability.