GG-LLM: Geometrically Grounding Large Language Models for Zero-shot Human Activity Forecasting in Human-Aware Task Planning

A robot in a human-centric environment needs to account for the human's intent and future motion in its task and motion planning to ensure safe and effective operation. This requires symbolic reasoning about probable future actions and the ability to tie these actions to specific locations in the physical environment. While one can train behavioral models capable of predicting human motion from past activities, this approach requires large amounts of data to achieve acceptable long-horizon predictions. More importantly, the resulting models are constrained to specific data formats and modalities. Moreover, connecting predictions from such models to the environment at hand to ensure the applicability of these predictions is an unsolved problem. We present a system that utilizes a Large Language Model (LLM) to infer a human's next actions from a range of modalities without fine-tuning. A novel aspect of our system that is critical to robotics applications is that it links the predicted actions to specific locations in a semantic map of the environment. Our method leverages the fact that LLMs, trained on a vast corpus of text describing typical human behaviors, encode substantial world knowledge, including probable sequences of human actions and activities. We demonstrate how these localized activity predictions can be incorporated in a human-aware task planner for an assistive robot to reduce the occurrences of undesirable human-robot interactions by 29.2% on average

Towards force-correlated ultrasound volume elastography

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.Cataloged from PDF version of thesis.Includes bibliographical references (pages 58-67).This thesis proposes three ultrasound-based methods that enable quantification of tissue and organ properties with potential applications as non-invasive, image-based biomarkers: force-controlled elasticity quantification for the identification of strain hardening; registration and segmentation of B-mode images to measure organ volumes; and force-correlated three-dimensional elasticity maps. In order to allow for the simultaneous collection of tissue elasticity and compressive force, a shear wave elasticity enabled ultrasound probe was integrated with a load cell which measured the sonographer-applied preload. The device was used to demonstrate the strong preload dependence of elasticity in ex-vivo bovine liver, illustrating the importance of accounting for preload when using elastography to assess tissue health. Finally, this device enables the quantification of strain hardening as an additional metric for tissue health. The capability organ volume measurements through freehand ultrasound imaging was demonstrated in a clinical study in which kidney volumes were obtained from ultrasound sweeps and compared to ground truth data from CT scans. While the technology needs to be refined to achieve better agreement between the measured volumes, the initial results of this ongoing study allowed for the identification of an ideal acquisition strategy. These findings will inform future data collection to achieve an improved accuracy. The acquisition of three-dimensional force-correlated elasticity maps was demonstrated on a phantom with the successful detection of a high-stiffness lesion embedded in bulk material. The presented technology has the potential to be a quantitative replacement for manual palpation. Given further refinement, this technology could be used to replace needle biopsy in various diseases in which progression correlates with tissue stiffness, such as thyroid nodules or liver fibrosis and cirrhosis. Our method, unlike the inherently localized needle biopsy, allows for the assessment of tissue over a broad volume, potentially improving reliability and repeatability in diagnosing and staging diffuse diseases.by Moritz Alexander Graule.S.M

Novel High Pressure Hexagonal Osb2 By Mechanochemistry

Hexagonal OsB2, a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB2 begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB2 crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB2 phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from -225 °C to 1050 °C. The hexagonal OsB2 powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB 2 at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods. © 2014 Elsevier Inc

Shipboard design and fabrication of custom 3D-printed soft robotic manipulators for the investigation of delicate deep-sea organisms.

Soft robotics is an emerging technology that has shown considerable promise in deep-sea marine biological applications. It is particularly useful in facilitating delicate interactions with fragile marine organisms. This study describes the shipboard design, 3D printing and integration of custom soft robotic manipulators for investigating and interacting with deep-sea organisms. Soft robotics manipulators were tested down to 2224m via a Remotely-Operated Vehicle (ROV) in the Phoenix Islands Protected Area (PIPA) and facilitated the study of a diverse suite of soft-bodied and fragile marine life. Instantaneous feedback from the ROV pilots and biologists allowed for rapid re-design, such as adding "fingernails", and re-fabrication of soft manipulators at sea. These were then used to successfully grasp fragile deep-sea animals, such as goniasterids and holothurians, which have historically been difficult to collect undamaged via rigid mechanical arms and suction samplers. As scientific expeditions to remote parts of the world are costly and lengthy to plan, on-the-fly soft robot actuator printing offers a real-time solution to better understand and interact with delicate deep-sea environments, soft-bodied, brittle, and otherwise fragile organisms. This also offers a less invasive means of interacting with slow-growing deep marine organisms, some of which can be up to 18,000 years old

Various types of grasping and comparison with a human hand.

<p>A & C: A power grasp allows to pick up large objects. B & D: Pinch grasp allows more dexterity to pick up small objects.</p

Examples of grasping sea cucumber (Holothuria).

<p>A: On a sandy substrate (depth: 2224m). B: On a rocky substrate (depth: 1282m).</p