Arrow Research search

Author name cluster

Mikel Luján

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

9 papers
2 author rows

Possible papers

9

IROS Conference 2025 Conference Paper

NGD-SLAM: Towards Real-Time Dynamic SLAM without GPU

  • Yuhao Zhang
  • Mihai Bujanca
  • Mikel Luján

Many existing visual SLAM methods can achieve high localization accuracy in dynamic environments by leveraging deep learning to mask moving objects. However, these methods incur significant computational overhead as the camera tracking needs to wait for the deep neural network to generate mask at each frame, and they typically require GPUs for realtime operation, which restricts their practicality in real-world robotic applications. Therefore, this paper proposes a real-time dynamic SLAM system that runs exclusively on a CPU. Our approach incorporates a mask propagation mechanism that decouples camera tracking and deep learning-based masking for each frame. We also introduce a hybrid tracking strategy that integrates ORB features with optical flow methods, enhancing both robustness and efficiency by selectively allocating computational resources to input frames. Compared to previous methods, our system maintains high localization accuracy in dynamic environments while achieving a tracking frame rate of 60 FPS on a laptop CPU. These results demonstrate the feasibility of utilizing deep learning for dynamic SLAM without GPU support. Since most existing dynamic SLAM systems are not open-source, we make our code publicly available at: https://github.com/yuhaozhang7/NGD-SLAM

Details

IROS Conference 2024 Conference Paper

A Framework for Reproducible Benchmarking and Performance Diagnosis of SLAM Systems

  • Nikola Radulov
  • Yuhao Zhang
  • Mihai Bujanca
  • Ruiqi Ye
  • Mikel Luján

We propose SLAMFuse, an open-source SLAM benchmarking framework that provides consistent cross-platform environments for evaluating multi-modal SLAM algorithms, along with tools for data fuzzing, failure detection, and diagnosis across different datasets. Our framework introduces a fuzzing mechanism to test the resilience of SLAM algorithms against dataset perturbations. This enables the assessment of pose estimation accuracy under varying conditions and identifies critical perturbation thresholds. SLAMFuse improves diagnostics with failure detection and analysis tools, examining algorithm behaviour against dataset characteristics. SLAMFuse uses Docker to ensure reproducible testing conditions across diverse datasets and systems by streamlining dependency management. Emphasizing the importance of reproducibility and introducing advanced tools for algorithm evaluation and performance diagnosis, our work sets a new precedent for reliable benchmarking of SLAM systems. We provide ready-to-use docker compatible versions of the algorithms and datasets used in the experiments, together with guidelines for integrating and benchmarking new algorithms. Code is available at https://github.com/nikolaradulov/slamfuse

Details

JMLR Journal 2023 Journal Article

A Unified Theory of Diversity in Ensemble Learning

  • Danny Wood
  • Tingting Mu
  • Andrew M. Webb
  • Henry W. J. Reeve
  • Mikel Luján
  • Gavin Brown

We present a theory of ensemble diversity, explaining the nature of diversity for a wide range of supervised learning scenarios. This challenge has been referred to as the “holy grail” of ensemble learning, an open research issue for over 30 years. Our framework reveals that diversity is in fact a hidden dimension in the bias-variance decomposition of the ensemble loss. We prove a family of exact bias-variance-diversity decompositions, for a wide range of losses in both regression and classification, e.g., squared, cross-entropy, and Poisson losses. For losses where an additive bias-variance decomposition is not available (e.g., 0/1 loss) we present an alternative approach: quantifying the effects of diversity, which turn out to be dependent on the label distribution. Overall, we argue that diversity is a measure of model fit, in precisely the same sense as bias and variance, but accounting for statistical dependencies between ensemble members. Thus, we should not be ‘maximising diversity’ as so many works aim to do---instead, we have a bias/variance/diversity trade-off to manage. [abs] [ pdf ][ bib ] [ code ] &copy JMLR 2023. ( edit, beta )

PDF Details

IROS Conference 2022 Conference Paper

ACEFusion - Accelerated and Energy-Efficient Semantic 3D Reconstruction of Dynamic Scenes

  • Mihai Bujanca
  • Barry Lennox
  • Mikel Luján

ACEFusion is the first 3D reconstruction system able to capture the geometry and semantics of dynamic scenes using an RGB-D camera in real-time on a robotic computing platform. Harnessing the hardware accelerators of an Nvidia Jetson AGX Xavier, the system uses heterogeneous computing to achieve 30 FPS under a 30W power budget. Using a data-parallel design, we perform most image computation on the dedicated hardware accelerators, freeing the general purpose cores and GPU to process 3D geometry. To further increase efficiency, we employ a hybrid geometry representation with octrees for static-semantic reconstruction and surfels for dynamic reconstruction. ACEFusion achieves competitive results on standard benchmarks while efficiently performing a more complex overall task than existing SLAM techniques. Figure. 1 shows the output of our system on a dynamic sequence.

Details

IROS Conference 2021 Conference Paper

Robust SLAM Systems: Are We There Yet?

  • Mihai Bujanca
  • Xuesong Shi
  • Matthew Spear
  • Pengpeng Zhao 0005
  • Barry Lennox
  • Mikel Luján

Progress in the last decade has brought about significant improvements in the accuracy and speed of SLAM systems, broadening their mapping capabilities. Despite these advancements, long-term operation remains a major challenge, primarily due to the wide spectrum of perturbations robotic systems may encounter. Increasing the robustness of SLAM algorithms is an ongoing effort, however it usually addresses a specific perturbation. Generalisation of robustness across a large variety of challenging scenarios is not well-studied nor understood. This paper presents a systematic evaluation of the robustness of open-source state-of-the-art SLAM algorithms with respect to challenging conditions such as fast motion, non-uniform illumination, and dynamic scenes. The experiments are performed with perturbations present both independently of each other, as well as in combination in long-term deployment settings in unconstrained environments (lifelong operation). The detailed results (approx. 20, 000 experiments) along with comprehensive documentation of the benchmarking tool for integrating new datasets and evaluating SLAM algorithms not studied in this work are available at https://robustslam.github.io/evaluation.

Details

ICRA Conference 2019 Conference Paper

SLAMBench 3. 0: Systematic Automated Reproducible Evaluation of SLAM Systems for Robot Vision Challenges and Scene Understanding

  • Mihai Bujanca
  • Paul Gafton
  • Sajad Saeedi 0001
  • Andy Nisbet
  • Bruno Bodin
  • Michael F. P. O'Boyle
  • Andrew J. Davison
  • Paul H. J. Kelly

As the SLAM research area matures and the number of SLAM systems available increases, the need for frameworks that can objectively evaluate them against prior work grows. This new version of SLAMBench moves beyond traditional visual SLAM, and provides new support for scene understanding and non-rigid environments (dynamic SLAM). More concretely for dynamic SLAM, SLAMBench 3. 0 includes the first publicly available implementation of DynamicFusion, along with an evaluation infrastructure. In addition, we include two SLAM systems (one dense, one sparse) augmented with convolutional neural networks for scene understanding, together with datasets and appropriate metrics. Through a series of use-cases, we demonstrate the newly incorporated algorithms, visulation aids and metrics (6 new metrics, 4 new datasets and 5 new algorithms).

Details

ICRA Conference 2018 Conference Paper

SLAMBench2: Multi-Objective Head-to-Head Benchmarking for Visual SLAM

  • Bruno Bodin
  • Harry Wagstaff
  • Sajad Saeedi 0001
  • Luigi Nardi
  • Emanuele Vespa
  • John Mawer
  • Andy Nisbet
  • Mikel Luján

SLAM is becoming a key component of robotics and augmented reality (AR) systems. While a large number of SLAM algorithms have been presented, there has been little effort to unify the interface of such algorithms, or to perform a holistic comparison of their capabilities. This is a problem since different SLAM applications can have different functional and non-functional requirements. For example, a mobile phone-based AR application has a tight energy budget, while a UAV navigation system usually requires high accuracy. SLAMBench2 is a benchmarking framework to evaluate existing and future SLAM systems, both open and close source, over an extensible list of datasets, while using a comparable and clearly specified list of performance metrics. A wide variety of existing SLAM algorithms and datasets is supported, e. g. ElasticFusion, InfiniTAM, ORB-SLAM2, OKVIS, and integrating new ones is straightforward and clearly specified by the framework. SLAMBench2 is a publicly-available software framework which represents a starting point for quantitative, comparable and val-idatable experimental research to investigate trade-offs across SLAM systems.

Details

ICRA Conference 2015 Conference Paper

Introducing SLAMBench, a performance and accuracy benchmarking methodology for SLAM

  • Luigi Nardi
  • Bruno Bodin
  • M. Zeeshan Zia
  • John Mawer
  • Andy Nisbet
  • Paul H. J. Kelly
  • Andrew J. Davison
  • Mikel Luján

Real-time dense computer vision and SLAM offer great potential for a new level of scene modelling, tracking and real environmental interaction for many types of robot, but their high computational requirements mean that use on mass market embedded platforms is challenging. Meanwhile, trends in low-cost, low-power processing are towards massive parallelism and heterogeneity, making it difficult for robotics and vision researchers to implement their algorithms in a performance-portable way. In this paper we introduce SLAMBench, a publicly-available software framework which represents a starting point for quantitative, comparable and validatable experimental research to investigate trade-offs in performance, accuracy and energy consumption of a dense RGB-D SLAM system. SLAMBench provides a KinectFusion implementation in C++, OpenMP, OpenCL and CUDA, and harnesses the ICL-NUIM dataset of synthetic RGB-D sequences with trajectory and scene ground truth for reliable accuracy comparison of different implementation and algorithms. We present an analysis and breakdown of the constituent algorithmic elements of KinectFusion, and experimentally investigate their execution time on a variety of multicore and GPU-accelerated platforms. For a popular embedded platform, we also present an analysis of energy efficiency for different configuration alternatives.

Details

JMLR Journal 2012 Journal Article

Conditional Likelihood Maximisation: A Unifying Framework for Information Theoretic Feature Selection

  • Gavin Brown
  • Adam Pocock
  • Ming-Jie Zhao
  • Mikel Luján

We present a unifying framework for information theoretic feature selection, bringing almost two decades of research on heuristic filter criteria under a single theoretical interpretation. This is in response to the question: "what are the implicit statistical assumptions of feature selection criteria based on mutual information?". To answer this, we adopt a different strategy than is usual in the feature selection literature-instead of trying to define a criterion, we derive one, directly from a clearly specified objective function: the conditional likelihood of the training labels. While many hand-designed heuristic criteria try to optimize a definition of feature 'relevancy' and 'redundancy', our approach leads to a probabilistic framework which naturally incorporates these concepts. As a result we can unify the numerous criteria published over the last two decades, and show them to be low-order approximations to the exact (but intractable) optimisation problem. The primary contribution is to show that common heuristics for information based feature selection (including Markov Blanket algorithms as a special case) are approximate iterative maximisers of the conditional likelihood. A large empirical study provides strong evidence to favour certain classes of criteria, in particular those that balance the relative size of the relevancy/redundancy terms. Overall we conclude that the JMI criterion (Yang and Moody, 1999; Meyer et al., 2008) provides the best tradeoff in terms of accuracy, stability, and flexibility with small data samples. [abs] [ pdf ][ bib ] &copy JMLR 2012. ( edit, beta )

PDF Details