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Brett T. Lopez

13 accepted papers

2025

Submodular Optimization for Keyframe Selection & Usage in SLAM

ICRA 2025

Keyframes are LiDAR scans saved for future reference in Simultaneous Localization And Mapping (SLAM), but despite their central importance most algorithms leave choices of which scans to save and how to use them to wasteful heuristics. This work proposes two novel keyframe selection strategies for l

Cited by 6SourceScholar
2023

Direct LiDAR-Inertial Odometry: Lightweight LIO with Continuous-Time Motion Correction

ICRA 2023poster

Aggressive motions from agile flights or traversing irregular terrain induce motion distortion in LiDAR scans that can degrade state estimation and mapping. Some methods exist to mitigate this effect, but they are still too simplistic or computationally costly for resource-constrained mobile robots.…

Cited by 111SourcecodeScholar
2023

Joint On-Manifold Gravity and Accelerometer Intrinsics Estimation for Inertially Aligned Mapping

IROS 2023poster

Aligning a robot's trajectory or map to the inertial frame is a critical capability that is often difficult to do accurately even though inertial measurement units (IMUs) can observe absolute roll and pitch with respect to gravity. Accelerometer biases and scale factor errors from the IMU's initial…

Cited by 5SourceScholar
2022

Direct LiDAR Odometry: Fast Localization With Dense Point Clouds

RA-L 2022

Field robotics in perceptually-challenging environments require fast and accurate state estimation, but modern LiDAR sensors quickly overwhelm current odometry algorithms. To this end, this letter presents a lightweight frontend LiDAR odometry solution with consistent and accurate localization for c

Cited by 178SourcecodeScholar
2021

Unsupervised Monocular Depth Learning with Integrated Intrinsics and Spatio-Temporal Constraints

IROS 2021poster

Monocular depth inference has gained tremendous attention from researchers in recent years and remains as a promising replacement for expensive time-of-flight sensors, but issues with scale acquisition and implementation overhead still plague these systems. To this end, this work presents an unsuper…

Cited by 6SourceScholar
2020

Dynamic Landing of an Autonomous Quadrotor on a Moving Platform in Turbulent Wind Conditions

ICRA 2020poster

Autonomous landing on a moving platform presents unique challenges for multirotor vehicles, including the need to accurately localize the platform, fast trajectory planning, and precise/robust control. Previous works studied this problem but most lack explicit consideration of the wind disturbance,…

Cited by 98SourceScholar
2019

FASTER: Fast and Safe Trajectory Planner for Flights in Unknown Environments

IROS 2019poster

High-speed trajectory planning through unknown environments requires algorithmic techniques that enable fast reaction times while maintaining safety as new information about the operating environment is obtained. The requirement of computational tractability typically leads to optimization problems…

Cited by 221SourceScholar
2019

Real-Time Planning with Multi-Fidelity Models for Agile Flights in Unknown Environments

ICRA 2019poster

Autonomous navigation through unknown environments is a challenging task that entails real-time localization, perception, planning, and control. UAVs with this capability have begun to emerge in the literature with advances in lightweight sensing and computing. Although the planning methodologies va…

Cited by 50SourceScholar
2017

Semantic-level decentralized multi-robot decision-making using probabilistic macro-observations

ICRA 2017poster

Robust environment perception is essential for decision-making on robots operating in complex domains. Intelligent task execution requires principled treatment of uncertainty sources in a robot's observation model. This is important not only for low-level observations (e.g., accelerom-eter data), bu…

Cited by 10SourceScholar