spectral measurement
SCANS: A Soft Gripper with Curvature and Spectroscopy Sensors for In-Hand Material Differentiation
Hanson, Nathaniel, Allison, Austin, DiMarzio, Charles, Padır, Taşkın, Dorsey, Kristen L.
We introduce the soft curvature and spectroscopy (SCANS) system: a versatile, electronics-free, fluidically actuated soft manipulator capable of assessing the spectral properties of objects either in hand or through pre-touch caging. This platform offers a wider spectral sensing capability than previous soft robotic counterparts. We perform a material analysis to explore optimal soft substrates for spectral sensing, and evaluate both pre-touch and in-hand performance. Experiments demonstrate explainable, statistical separation across diverse object classes and sizes (metal, wood, plastic, organic, paper, foam), with large spectral angle differences between items. Through linear discriminant analysis, we show that sensitivity in the near-infrared wavelengths is critical to distinguishing visually similar objects. These capabilities advance the potential of optics as a multi-functional sensory modality for soft robots. The complete parts list, assembly guidelines, and processing code for the SCANS gripper are accessible at: https://parses-lab.github.io/scans/.
Collision-Aware Traversability Analysis for Autonomous Vehicles in the Context of Agricultural Robotics
Philippe, Florian, Laconte, Johann, Lapray, Pierre-Jean, Spisser, Matthias, Lauffenburger, Jean-Philippe
In this paper, we introduce a novel method for safe navigation in agricultural robotics. As global environmental challenges intensify, robotics offers a powerful solution to reduce chemical usage while meeting the increasing demands for food production. However, significant challenges remain in ensuring the autonomy and resilience of robots operating in unstructured agricultural environments. Obstacles such as crops and tall grass, which are deformable, must be identified as safely traversable, compared to rigid obstacles. To address this, we propose a new traversability analysis method based on a 3D spectral map reconstructed using a LIDAR and a multispectral camera. This approach enables the robot to distinguish between safe and unsafe collisions with deformable obstacles. We perform a comprehensive evaluation of multispectral metrics for vegetation detection and incorporate these metrics into an augmented environmental map. Utilizing this map, we compute a physics-based traversability metric that accounts for the robot's weight and size, ensuring safe navigation over deformable obstacles.
Classification of Household Materials via Spectroscopy
Erickson, Zackory, Luskey, Nathan, Chernova, Sonia, Kemp, Charles C.
Abstract-- Recognizing an object's material can inform a robot on how hard it may grasp the object during manipulation, or if the object may be safely heated up. To estimate an object's material during manipulation, many prior works have explored the use of haptic sensing. In this paper, we explore a technique for robots to estimate the materials of objects using spectroscopy. We demonstrate that spectrometers provide several benefits for material recognition, including fast sensing times and accurate measurements with low noise. Furthermore, spectrometers do not require direct contact with an object. To illustrate this, we collected a dataset of spectral measurements from two commercially available spectrometers during which a robotic platform interacted with 50 distinct objects, and we show that a residual neural network can accurately analyze these measurements. Due to the low variance in consecutive spectral measurements, our model achieved a material classification accuracy of 97.7% when given only one spectral sample per object. Similar to prior works with haptic sensors, we found that generalizing material recognition to new objects posed a greater challenge, for which we achieved an accuracy of 81.4% via leave-one-object-out cross-validation. From this work, we find that spectroscopy poses a promising approach for further research in material classification during robotic manipulation.