When millennia-old cultural relics meet automated black technology, what new possibilities for conservation could emerge? Chengdu Miji Technology has the answer — deeply integrating robotic-arm automation systems with terahertz nondestructive testing technology to equip heritage conservation with a “precision navigation system,” allowing long-slumbering historical sites to safely “tell” their past empowered by technology!
In the field of cultural heritage conservation, “precision” and “non-destructiveness” have always been core principles. Take the Kizil Grottoes as an example — this cultural treasure house embodying the essence of Kucha Buddhist art has its Cave 161 murals covered by a soot layer for a thousand years. Traditional manual inspection is not only inefficient but may also inadvertently touch the fragile mural surface due to operational errors. Although standalone terahertz testing can penetrate the covering layer, it struggles to achieve precise scanning in complex scenarios such as grotto domes and curved surfaces. Chengdu Miji Technology identified the industry pain points and innovatively developed a robotic-arm automated terahertz nondestructive testing solution, perfectly solving the dual challenges of “complex-scenario adaptability” and “high-precision detection.”
The core of this solution lies in turning the robotic arm into a “precision executor” of terahertz inspection: through a pre-planned grid path algorithm, the robotic arm can carry the terahertz time-domain spectrometer probe and move evenly across the mural surface, achieving automated area scanning with millimeter-level spacing, completely eliminating the subjective deviations of manual operation. Facing varying ceiling heights and uneven mural surfaces inside the grottoes, the robotic arm, with multi-axis coordination and real-time position calibration, can flexibly adjust scanning angles and distances, ensuring the probe always maintains a safe distance from the mural, thus avoiding contact damage while guaranteeing signal stability at every sampling point.
Even more noteworthy is the innovative “multi-technology synergy” design: the robotic arm not only carries terahertz equipment but also simultaneously integrates an X-ray fluorescence spectrometer (XRF) and a structured-light 3D scanner. In practice at Kizil Cave 161, the robotic arm first obtains the three-dimensional surface data of the mural through structured-light scanning, providing spatial coordinate references for terahertz and XRF inspection. It then coordinates with the terahertz device to penetrate the soot layer and capture time-domain signals from the pigment layer. Finally, it uses XRF to analyze the elemental composition of the pigments — the three sets of data are integrated through automated algorithms to form a complete inspection chain of “structure + composition + imaging.”
Relying on this system, the team successfully achieved a technological breakthrough: for a 50 × 70 cm² soot-covered mural area in Cave 161, the robotic arm completed the entire workflow of multimodal coarse scanning and fine scanning, improving efficiency by more than three times compared with traditional manual inspection. Through terahertz signal denoising and peak-finding algorithm processing, the reflection peaks of air/soot layer and soot layer/pigment layer were clearly identified. Combined with XRF elemental distribution data, details such as the divine figure’s halo and belt were accurately reconstructed, and even the distribution characteristics of pigments like cinnabar (Hg) and atacamite (Cu) were restored. The reconstructed image achieved a plane resolution of 1 mm and a depth resolution of 10 μm.
Chengdu Miji Technology’s robotic-arm automated terahertz solution is not only suitable for grotto murals but can also be flexibly adapted to various cultural relic inspection scenarios such as painted pottery, stone statues, and ancient book bindings. When facing the fine decorative patterns on pottery surfaces, the robotic arm can perform micron-level scanning; for the curved structures of large statues, the multi-axis coordination ensures inspection without blind spots. The standardized path-planning algorithms and data processing modules further endow the solution with strong industry reusability, providing a replicable technical template for the conservation of sites like the Dunhuang and Maijishan grottoes.
From “manual groping” to “automated precision inspection,” Chengdu Miji Technology has redefined the efficiency and accuracy of nondestructive testing for cultural relics through the innovative integration of robotic arms and terahertz technology. In the future, we will continue to optimize equipment miniaturization and algorithm intelligence, making automated black technology a “reliable partner” in cultural heritage conservation, safeguarding the thousand-year elegance of every cultural heritage site!
Source: Official website of Chengdu Miji Technology Co., Ltd. View original text