1. What are the project phases?
An inspection project has three phases: the modeling phase completes the 3D model within hours using oblique photography and generates inspection routes (one-time baseline work); the collection phase has the drone fly automatically along routes — a 500m-class bridge generates about 100GB of data and over ten thousand photos; the office phase has AI automatically screen and detect defects, map them onto the 3D model and output the report, followed by manual review.
2. Time comparison by phase
| Phase | Traditional method | Drone + AI method |
|---|---|---|
| 3D modeling | Days to weeks | Hours |
| Data collection | Multiple days with inspection vehicle | Automatic flight along routes |
| Defect screening | Manual photo-by-photo review | AI auto detection + manual review |
3. Factors affecting the cycle
Bridge length and structural complexity, inspection scope (whether it includes the girder soffit), accuracy requirements, and restricted-area access all affect the schedule; special structures (cable-stayed, suspension) and high-precision re-capture require additional evaluation.
4. Applicable conditions and scenarios
- Routine bridges delivered quickly via standardized workflow
- Special bridge types and complex sites require schedule evaluation
- Specific scheduling is confirmed by the project plan
5. Notes
The first inspection includes modeling and route planning (one-time baseline work); subsequent inspections directly reuse them, resulting in shorter cycles.