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Brian Williams

16 accepted papers

2025

Safe Multi-Agent Navigation Guided by Goal-Conditioned Safe Reinforcement Learning

ICRA 2025

Safe navigation is essential for autonomous systems operating in hazardous environments. Traditional planning methods are effective for solving long-horizon tasks but depend on the availability of a graph representation with prede-fined distance metrics. In contrast, safe Reinforcement Learning (RL)

Cited by 5SourcecodeScholar
2024

Multi-Agent Vulcan: An Information-Driven Multi-Agent Path Finding Approach

IROS 2024poster

Scientists often search for phenomenon of interest while exploring new environments. Autonomous vehicles are deployed to explore such areas where human-operated vehicles would be costly or dangerous. Online control of autonomous vehicles for information-gathering is called adaptive sampling and can…

Cited by 0SourcecodeScholar
2023

Motion Planning Under Uncertainty with Complex Agents and Environments via Hybrid Search (Extended Abstract)

IJCAI 2023poster

As autonomous systems tackle more real-world situations, mission success oftentimes cannot be guaranteed and the planner must reason about the probability of failure. Unfortunately, computing a trajectory that satisfies mission goals while constraining the probability of failure is difficult becaus…

Cited by 0SourcePDFScholar
2023

Non-Gaussian Uncertainty Minimization Based Control of Stochastic Nonlinear Robotic Systems

IROS 2023poster

In this paper, we consider the closed-loop control problem of nonlinear robotic systems in the presence of probabilistic uncertainties and disturbances. More precisely, we design a state feedback controller that minimizes deviations of the states of the system from the nominal state trajectories due…

Cited by 1SourceScholar
2023

Real-Time Tube-Based Non-Gaussian Risk Bounded Motion Planning for Stochastic Nonlinear Systems in Uncertain Environments via Motion Primitives

IROS 2023poster

We consider the motion planning problem for stochastic nonlinear systems in uncertain environments. More precisely, in this problem the robot has stochastic nonlinear dynamics and uncertain initial locations, and the environment contains multiple dynamic uncertain obstacles. Obstacles can be of arbi…

Cited by 2SourceScholar
2022

Non-Gaussian Risk Bounded Trajectory Optimization for Stochastic Nonlinear Systems in Uncertain Environments

ICRA 2022poster

We address the risk bounded trajectory optimization problem of stochastic nonlinear robotic systems. More precisely, we consider the motion planning problem in which the robot has stochastic nonlinear dynamics and uncertain initial locations, and the environment contains multiple dynamic uncertain o…

Cited by 37SourcecodeScholar
2020

Fast Risk Assessment for Autonomous Vehicles Using Learned Models of Agent Futures

RSS 2020poster

This paper presents fast non-sampling based methods to assess the risk of trajectories for autonomous vehicles when probabilistic predictions of other agents’ futures are generated by deep neural networks (DNNs). The presented methods address a wide range of representations for uncertain predictions…

2020

Provably Safe Trajectory Optimization in the Presence of Uncertain Convex Obstacles

IROS 2020poster

Real-world environments are inherently uncertain, and to operate safely in these environments robots must be able to plan around this uncertainty. In the context of motion planning, we desire systems that can maintain an acceptable level of safety as the robot moves, even when the exact locations of…

Cited by 17SourceScholar
2020

QSRNet: Estimating Qualitative Spatial Representations from RGB-D Images

IROS 2020poster

Humans perceive and describe their surroundings with qualitative statements (e.g., "Alice's hand is in contact with a bottle."), rather than quantitative values (e.g., 6-D poses of Alice's hand and a bottle). Qualitative spatial representation (QSR) is a framework that represents the spatial informa…

Cited by 3SourceScholar
2019

Chance Constrained Motion Planning for High-Dimensional Robots

ICRA 2019poster

This paper introduces Probabilistic Chekov (p-Chekov), a chance-constrained motion planning system that can be applied to high degree-of-freedom (DOF) robots under motion uncertainty and imperfect state information. Given process and observation noise models, it can find feasible trajectories which…

Cited by 42SourceScholar
2019

Improving Incremental Planning Performance through Overlapping Replanning and Execution

ICRA 2019poster

Deployment of motion planning algorithms in practical applications has lagged due to their slow speed in reacting to disturbances. We believe that the best way to address this is to reuse learned planning and control information across queries. In previous work, we introduced Chekov, a reactive, int…

Cited by 2SourceScholar
2019

Risk Contours Map for Risk Bounded Motion Planning under Perception Uncertainties

RSS 2019poster

In this paper, we introduce 'risk contours map' that contains the risk information of different regions in uncertain environments. Risk is defined as the probability of collision of robots with obstacles in presence of probabilistic uncertainties in location, size, and geometry of obstacles. We use…

Cited by 53SourcePDFScholar
2018

Improving Trajectory Optimization Using a Roadmap Framework

IROS 2018poster

We present an evaluation of several representative sampling-based and optimization-based motion planners, and then introduce an integrated motion planning system which incorporates recent advances in trajectory optimization into a sparse roadmap framework. Through experiments in 4 common application…

Cited by 24SourceScholar