Les commentaires sont clos.

Post-doc in Computer Vision for soil characterization in tunnel construction

5 Septembre 2022

Catégorie : Post-doctorant

The objectives of this post-doc position are to develop a machine-learning based computer vision system that analyses the videos captured from one or several cameras installed at a tunnel boring machine and filming the excavated material on the conveyor belt in order to estimate different geophysical properties and decide on the possible reuse of the material.



In recent years, the issue of resource efficiency has also become increasingly important in construction engineering, as soil and rock account for more than 50% of mineral construction waste. Tunnel projects play a special role in this regard, as large quantities are generated at specific times and places. Due to the high degree of mechanisation and the associated advantages in terms of construction performance and safety at work, almost the half of tunnels is built with Tunnel Boring Machines (TBM). For documentation and control of the construction process, these are equipped with various sensor systems that provide comprehensive data sets. But in this area, modern data-driven processes have not yet found a wide application.

This 24-month post-doc position is funded by the French-German ANR project REMATCH. The overall objective of this project is to use the data sets from TBMs, with the help of AI methods, to enhance the recycling of the large quantities of tunnel excavation material. In this regard, an innovative real-time measurement system for material characterisation is to be developed which gives decision support on the question if soil is “usable” or “not usable” for other purposes and thus has to be disposed of in a landfill. This system will base on several approaches using AI methods: firstly, on image recognition of excavated material, secondly, on intelligent data processing of TBM data, and, thirdly, on a knowledge database.



The objectives of this post-doc position are to develop a computer vision system that analyses the videos captured from one or several cameras installed at the TBM and filming the excavated material on the conveyor belt. In order to decide on the possible reuse of the material, different geophysical properties needs to be estimated from visual features extracted in real-time from the video stream(s) coming from RGB cameras. This is challenging due to the mediocre acquisition conditions under low lighting and fast motion inducing some motion blur. More specifically, after some preprocessing, a first step is to develop a machine learning solution based on appropriate CNN models that are trained for either classification and/or regression tasks in a supervised manner. Different models should be designed, implemented and evaluated in terms of robustness and precision.

To go further, novel innovative neural network-based architectures and weakly supervised learning schemes should be proposed to learn a latent representation that reflects the meaningful similarities of relevant soil characteristics. Then, potentially other physical properties should be incorporated more explicitely into this semantic latent representation (either via a specific CNN or autoencoder-type model) to make the learnt features and models more explainable. After evalating these models, they should be appropriately integrated with other AI models that are not based on images but on TBM sensor data.



The position is in the IMAGINE team of the LIRIS laboratory in Lyon (Campus La Doua) under the supervision of Catherine Pothier and Stefan Duffner. The funding is for 24 months. Additional teaching activities may be conducted at INSA Lyon if the candidate desires to.



Stefan Duffner
Catherine Pothier