publications
Publication and Theses
2024
- CoRL
Sparsh: Self-supervised touch representations for vision-based tactile sensingCarolina Higuera*, Akash Sharma*, Chaithanya Krishna Bodduluri, Taosha Fan, Mrinal Kalakrishnan, Michael Kaess, Byron Boots, Mike Lambeta, Tingfan Wu, and Mustafa MukadamIn 8th Annual Conference on Robot Learning, 2024In this work, we introduce general purpose touch representations for the increasingly accessible class of vision-based tactile sensors. Such sensors have led to many recent advances in robot manipulation as they markedly complement vision, yet solutions today often rely on task and sensor specific handcrafted perception models. Collecting real data at scale with task centric ground truth labels, like contact forces and slip, is a challenge further compounded by sensors of various form factor differing in aspects like lighting and gel markings. To tackle this we turn to self-supervised learning (SSL) that has demonstrated remarkable performance in computer vision. We present Sparsh, a family of SSL models that can support various vision-based tactile sensors, alleviating the need for custom labels through pre-training on 460k+ tactile images with masking and self-distillation in pixel and latent spaces. We also build TacBench, to facilitate standardized benchmarking across sensors and models, comprising of six tasks ranging from comprehending tactile properties to enabling physical perception and manipulation planning. In evaluations, we find that SSL pre-training for touch representation outperforms task and sensor-specific end-to-end training by 95.1% on average over TacBench, and Sparsh (DINO) Sparsh (IJEPA) are the most competitive, indicating the merits of learning in latent space for tactile images.
2023
- Neural Radiance Field with LiDAR mapsIn Proceedings of the IEEE/CVF International Conference on Computer Vision, ICCV, Oct 2023
We address outdoor Neural Radiance Fields (NeRF) with LiDAR maps. Existing NeRF methods usually require specially collected hypersampled source views and do not perform well with the open source camera-LiDAR datasets - significantly limiting the approach’s practical utility. In this paper, we demonstrate an approach that allows for these datasets to be utilized for high quality neural renderings. Our design leverages 1) LiDAR sensors for strong 3D geometry priors that significantly improve the ray sampling locality, and 2) Conditional Adversarial Networks (cGANs) to recover image details since aggregating embeddings from imperfect LiDAR maps causes artifacts in the synthesized images. Our experiments show that while NeRF baselines produce either noisy or blurry results on Argoverse 2, the images synthesized by our system not only outperform baselines in image quality metrics under both clean and noisy conditions, but also obtain closer Detectron2 results to the ground truth images. Furthermore, to show the substantial applicability of our system, we demonstrate that our system can be used in data augmentation for training a pose regression network and multi-season view synthesis. Our dataset and code will be released.
2022
- Learned Depth Estimation of 3D Imaging Radar for Indoor MappingIn Proc. IEEE/RSJ Intl. Conf. on Intelligent Robots and Systems, IROS, Oct 2022
3D imaging radar offers robust perception capability through visually demanding environments due to the unique penetrative and reflective properties of millimeter waves (mmWave). Current approaches for 3D perception with imaging radar require knowledge of environment geometry, accumulation of data from multiple frames for perception, or access to between-frame motion. Imaging radar presents an additional difficulty due to the complexity of its data representation. To address these issues, and make imaging radar easier to use for downstream robotics tasks, we propose a learning-based method that regresses radar measurements into cylindrical depth maps using LiDAR supervision. Due to the limitation of the regression formulation, directions where the radar beam could not reach will still generate a valid depth. To address this issue, our method additionally learns a 3D filter to remove those pixels. Experiments show that our system generates visually accurate depth estimation. Furthermore, we confirm the overall ability to generalize in the indoor scene using the estimated depth for probabilistic occupancy mapping with ground truth trajectory.
2021
- Compositional and Scalable Object SLAMAkash Sharma, Wei Dong, and Michael KaessIn Proc. IEEE Intl. Conf. on Robotics and Automation, ICRA, May 2021
We present a fast, scalable, and accurate Simultaneous Localization and Mapping (SLAM) system that represents indoor scenes as a graph of objects. Leveraging the observation that artificial environments are structured and occupied by recognizable objects, we show that a compositional and scalable object mapping formulation is amenable to a robust SLAM solution for drift-free large-scale indoor reconstruction. To achieve this , we propose a novel semantically assisted data association strategy that results in unambiguous persistent object landmarks and a 2.5D compositional rendering method that enables reliable frame-to-model RGB-D tracking. Consequently, we deliver an optimized online implementation that can run at near frame rate with a single graphics card, and provide a comprehensive evaluation against state-of-the-art baselines. An open-source implementation will be provided at https://github.com/rpl-cmu/object-slam.
- M.S.
