Dan Negruţ
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View article: Data‐Driven Bulldozer Blade Control for Autonomous Terrain Leveling
Data‐Driven Bulldozer Blade Control for Autonomous Terrain Leveling Open
Autonomous leveling of granular materials is a ubiquitous yet challenging operationin automated construction due to the complex physics governing the soil–tool interaction. This paper outlines a simulation‐driven framework for optimizing l…
View article: FNODE: Flow-Matching for data-driven simulation of constrained multibody systems
FNODE: Flow-Matching for data-driven simulation of constrained multibody systems Open
Data-driven modeling of constrained multibody systems faces two persistent challenges: high computational cost and limited long-term prediction accuracy. To address these issues, we introduce the Flow-Matching Neural Ordinary Differential …
View article: ChronoLLM: Customizing Language Models for Physics-Based Simulation Code Generation
ChronoLLM: Customizing Language Models for Physics-Based Simulation Code Generation Open
This contribution is concerned with the following issue: can pretrained large language models (LLMs) be refined and customized to the point where they become virtual assistants helping experts with the effective use of a simulation tool? I…
View article: A Physics-Based Continuum Model for Versatile, Scalable, and Fast Terramechanics Simulation
A Physics-Based Continuum Model for Versatile, Scalable, and Fast Terramechanics Simulation Open
This paper discusses Chrono's Continuous Representation Model (called herein Chrono::CRM), a general-purpose, scalable, and efficient simulation solution for terramechanics problems. Built on Chrono's Smoothed Particle Hydrodynamics (SPH) …
View article: Designing a Conditional Obstacle Avoidance for Tracked Vehicles Using Project Chrono
Designing a Conditional Obstacle Avoidance for Tracked Vehicles Using Project Chrono Open
The objectives of this study are to: 1) create simulation pipelines for the development of autonomous operation algorithms for tracked vehicles; and 2) design autonomous operation algorithms using these simulation pipelines. The focus of t…
View article: Chrono::Electronics: An Open-Source Simulation Package for Complex Electro-Mechanical Problems
Chrono::Electronics: An Open-Source Simulation Package for Complex Electro-Mechanical Problems Open
The growing relevance of mechatronic applications -- whose hallmark is a strong coupling between mechanical and electrical domains -- has led to renewed interest in the high-fidelity and expeditious simulation of electro-mechanical systems…
View article: A Study Demonstrating That Using Gravitational Offset to Prepare Extraterrestrial Mobility Missions Is Misleading
A Study Demonstrating That Using Gravitational Offset to Prepare Extraterrestrial Mobility Missions Is Misleading Open
Recently, there has been a surge of international interest in extraterrestrial exploration targeting the Moon, Mars, the moons of Mars, and various asteroids. This contribution discusses how current state‐of‐the‐art Earth‐based testing for…
View article: An analysis of the Yutu lunar rover’s mobility performance using a multibody dynamics framework and a physics-based terramechanics model
An analysis of the Yutu lunar rover’s mobility performance using a multibody dynamics framework and a physics-based terramechanics model Open
The interaction between wheels and soil has a significant impact on the dynamics of extraterrestrial vehicles in terrame-chanics applications. With very few exceptions, the mobility analysis of extraterrestrial rovers has been carried out …
View article: ChronoLLM: A Framework for Customizing Large Language Model for Digital Twins generalization based on PyChrono
ChronoLLM: A Framework for Customizing Large Language Model for Digital Twins generalization based on PyChrono Open
Recently, the integration of advanced simulation technologies with artificial intelligence (AI) is revolutionizing science and engineering research. ChronoLlama introduces a novel framework that customizes the open-source LLMs, specificall…
View article: Instance Performance Difference: A Metric to Measure the Sim-To-Real Gap in Camera Simulation
Instance Performance Difference: A Metric to Measure the Sim-To-Real Gap in Camera Simulation Open
In this contribution, we introduce the concept of Instance Performance Difference (IPD), a metric designed to measure the gap in performance that a robotics perception task experiences when working with real vs. synthetic pictures. By pair…
View article: A physics-based sensor simulation environment for lunar ground operations
A physics-based sensor simulation environment for lunar ground operations Open
This contribution reports on a software framework that uses physically-based rendering to simulate camera operation in lunar conditions. The focus is on generating synthetic images qualitatively similar to those produced by an actual camer…
View article: Enhancing Autonomous Navigation by Imaging Hidden Objects using Single-Photon LiDAR
Enhancing Autonomous Navigation by Imaging Hidden Objects using Single-Photon LiDAR Open
Robust autonomous navigation in environments with limited visibility remains a critical challenge in robotics. We present a novel approach that leverages Non-Line-of-Sight (NLOS) sensing using single-photon LiDAR to improve visibility and …
View article: SimBench: A Rule-Based Multi-Turn Interaction Benchmark for Evaluating an LLM's Ability to Generate Digital Twins
SimBench: A Rule-Based Multi-Turn Interaction Benchmark for Evaluating an LLM's Ability to Generate Digital Twins Open
We introduce SimBench, a benchmark designed to evaluate the proficiency of student large language models (S-LLMs) in generating digital twins (DTs) that can be used in simulators for virtual testing. Given a collection of S-LLMs, this benc…
View article: Using high-fidelity discrete element simulation to calibrate an expeditious terramechanics model in a multibody dynamics framework
Using high-fidelity discrete element simulation to calibrate an expeditious terramechanics model in a multibody dynamics framework Open
The wheel-soil interaction has great impact on the dynamics of off-road vehicles in terramechanics applications. The Soil Contact Model (SCM), which anchors an empirical method to characterize the frictional contact between a wheel and soi…
View article: Using high-fidelity discrete element simulation to calibrate an expeditious terramechanics model in a multibody dynamics framework
Using high-fidelity discrete element simulation to calibrate an expeditious terramechanics model in a multibody dynamics framework Open
The wheel-soil interaction has great impact on the dynamics of off-road vehicles in terramechanics applications. The Soil Contact Model (SCM), which anchors an empirical method to characterize the frictional contact between a wheel and soi…
View article: A Library of Lower Fidelity Dynamics Models (LFDMs) ForOn-Road Vehicle Dynamics Targeting Faster Than Real-TimeApplications
A Library of Lower Fidelity Dynamics Models (LFDMs) ForOn-Road Vehicle Dynamics Targeting Faster Than Real-TimeApplications Open
Unjhawala et al., (2024). A Library of Lower Fidelity Dynamics Models (LFDMs) For On-Road Vehicle Dynamics Targeting Faster Than Real-Time Applications. Journal of Open Source Software, 9(99), 6548, https://doi.org/10.21105/joss.06548
View article: MBD-NODE: Physics-informed data-driven modeling and simulation of constrained multibody systems
MBD-NODE: Physics-informed data-driven modeling and simulation of constrained multibody systems Open
We describe a framework that can integrate prior physical information, e.g., the presence of kinematic constraints, to support data-driven simulation in multi-body dynamics. Unlike other approaches, e.g., Fully-connected Neural Network (FC…
View article: Using physics-based simulation towards eliminating empiricism in extraterrestrial terramechanics applications
Using physics-based simulation towards eliminating empiricism in extraterrestrial terramechanics applications Open
Recently, there has been a surge of international interest in extraterrestrial exploration targeting the Moon, Mars, the moons of Mars, and various asteroids. This contribution discusses how current state-of-the-art Earth-based testing for…
View article: Human-Machine Interaction in Automated Vehicles: Reducing Voluntary Driver Intervention
Human-Machine Interaction in Automated Vehicles: Reducing Voluntary Driver Intervention Open
This paper develops a novel car-following control method to reduce voluntary driver interventions and improve traffic stability in Automated Vehicles (AVs). Through a combination of experimental and empirical analysis, we show how voluntar…
View article: Chrono DEM-Engine: A Discrete Element Method dual-GPU simulator with customizable contact forces and element shape
Chrono DEM-Engine: A Discrete Element Method dual-GPU simulator with customizable contact forces and element shape Open
This paper introduces DEM-Engine, a new submodule of Project Chrono, that is designed to carry out Discrete Element Method (DEM) simulations. Based on spherical primitive shapes, DEM-Engine can simulate polydisperse granular materials and …
View article: A Study on the Use of Simulation in Synthesizing Path-Following Control Policies for Autonomous Ground Robots
A Study on the Use of Simulation in Synthesizing Path-Following Control Policies for Autonomous Ground Robots Open
We report results obtained and insights gained while answering the following question: how effective is it to use a simulator to establish path following control policies for an autonomous ground robot? While the quality of the simulator c…
View article: Quantifying the Sim2real Gap for GPS and IMU Sensors
Quantifying the Sim2real Gap for GPS and IMU Sensors Open
Simulation can and should play a critical role in the development and testing of algorithms for autonomous agents. What might reduce its impact is the ``sim2real'' gap -- the algorithm response differs between operation in simulated versus…
View article: An Expeditious and Expressive Vehicle Dynamics Model for Applications in Controls and Reinforcement Learning
An Expeditious and Expressive Vehicle Dynamics Model for Applications in Controls and Reinforcement Learning Open
We present a Vehicle Model (VM) that has 17 degrees of freedom and includes nonlinear tire and powertrain subsystems. Implemented as a relatively small piece of C++ code, the model runs vehicle dynamics 2000 times faster than real time at …
View article: Calibration of an expeditious terramechanics model using a higher‐fidelity model, Bayesian inference, and a virtual bevameter test
Calibration of an expeditious terramechanics model using a higher‐fidelity model, Bayesian inference, and a virtual bevameter test Open
The soil contact model (SCM) is widely used in practice for off‐road wheeled vehicle mobility studies when simulation speed is important and highly accurate results are not a main concern. In practice, the SCM parameters are obtained via a…
View article: Chrono DEM-Engine: A Discrete Element Method dual-GPU simulator with customizable contact forces and element shape
Chrono DEM-Engine: A Discrete Element Method dual-GPU simulator with customizable contact forces and element shape Open
This paper introduces DEM-Engine, a new submodule of Project Chrono, that is designed to carry out Discrete Element Method (DEM) simulations. Based on spherical primitive shapes, DEM-Engine can simulate polydisperse granular materials and …
View article: POLAR-Sim: Augmenting NASA's POLAR Dataset for Data-Driven Lunar Perception and Rover Simulation
POLAR-Sim: Augmenting NASA's POLAR Dataset for Data-Driven Lunar Perception and Rover Simulation Open
NASA's POLAR dataset contains approximately 2,600 pairs of high dynamic range stereo photos captured across 13 varied terrain scenarios, including areas with sparse or dense rock distributions, craters, and rocks of different sizes. The pu…
View article: Zero-Shot Policy Transferability for the Control of a Scale Autonomous Vehicle
Zero-Shot Policy Transferability for the Control of a Scale Autonomous Vehicle Open
We report on a study that employs an in-house developed simulation infrastructure to accomplish zero shot policy transferability for a control policy associated with a scale autonomous vehicle. We focus on implementing policies that requir…