A Fast Global Method Combined with Local Features for 6D Object Pose Estimation

The next generation of service robots is to offer services relying heavily on visually guided manipulation, besides navigation, such services as errand, logistics, appliance, home keeping, etc. For the successful introduction of these services, it is critical to establish the consumer-level dependability in 3D object recognition and pose estimation in a natural setting where a large variation of environment, e.g., perspective, texture, form factor, illumination, occlusion, etc., is common. To address this problem, we propose an approach of the two-layered particle filter to the dependability in 3D object recognition and pose estimation. In the upper layer, a set of object pose candidates is identified and maintained in the search space as a set of super-particles, each of which is assigned a probability of the true pose and evolved in time along with the accumulation of further evidences. To define the object pose candidates, first, we acquire initially weak evidences quickly and interpret them in terms of possible object poses in space. These interpretations serve as the region of interest for detailed investigation by which the pose probabilities are computed for individual interpretations based on the likelihood and unlikelihood of various features available in the corresponding regions of interest. During the process of probability computation, we select the object pose candidates to be used as super-particles in the upper layer. In the lower level, the pose uncertainties associated with the individual candidates are represented as particles that are subject to the propagation in time. Finally, the experimental results support the strength of the proposed approach in the real environment in terms of its dependability in 3D object recognition and pose estimation.

Six degrees-of-freedom (6D) object pose estimation plays an important role in pattern recognition of fields such as robotics and augmented reality. However, there are issues with low accuracy and real-time performance of 6D object pose estimation in complex scenes. To address these challenges, in this article, RFF-PoseNet (a 6D object pose estimation network based on robust feature fusion) is proposed for complex scenes. Firstly, a more lightweight Ghost module is used to replace the convolutional blocks in the feature extraction network. Then, a pyramid pooling module is added to the semantic label branch of PoseCNN to fuse the features of different pooling layers and enhance the network’s ability to capture information about objects in complex scenes and the correlations between contextual information. Finally, a pose regression and optimization module is utilized to further improve object pose estimation in complex scenes. Simulation experiments conducted on the YCB-Video and Occlusion LineMOD datasets show that the RFF-PoseNet algorithm can strengthen the correlation of features between different levels and the recognition ability of unclear targets, thereby achieving excellent accuracy and real-time performance, as well as strong robustness.

6D pose estimation is an important branch in the field of vision measurement, and is widely used in the fields of robotics, autonomous driving and reality augmentation. The latest research trend in 6D pose estimation is to train a deep neural network to directly predict the 2D projection position of the 3D keypoint from the image, establish the corresponding relationship, and finally use the perspective-n-point (PnP) algorithm to perform pose estimation. The current challenge of pose estimation is that when objects are textureless, occluded or scene-clutterd, the detection accuracy is reduced, and most of the existing algorithm models are large and cannot accommodate real-time requirements. In this paper, we introduce a densely connected feature pyramid network (DFPN) that can efficiently integrate and utilize features. We combine the cross-stage partial network (CSPNet) with DFPN to design a new network for 6D pose estimation, DFPN-6D, a new approach for 6D object pose estimation. DFPN-6D can efficiently and accurately handle objects with textureless, occluded and scene clutter and estimate their full 6D poses in a single shot. Furthermore, we propose a new confidence calculation method and loss function for object pose estimation, which can fully consider spatial information. Finally, we propose a novel augmentation method for direct 6D pose estimation approaches to improve performance and generalization ability in the case of occlusion, which is called 6D augmentation. Our approach achieves a new state-of-the-art accuracy of 98.06 and 87.09 in terms of the ADD(-S) metric on the Linemod dataset and Occluded-Linemod dataset, and our method also achieves the best result in terms of the different metric on the MULT-I dataset, BIN-P dataset and T-LESS dataset, respectively, while still running end-to-end at over 65 FPS. The experimental results demonstrate that our algorithm is robust to textureless materials and occlusion while running more efficiently than other methods. We also deploy our proposed method to a real robot to grasp and manipulate objects based on the estimated pose.

3D object pose estimation by using a depth sensor is one of the important tasks in activities by robots. To reduce the pose ambiguity of an estimated object pose, several methods for multiple viewpoint pose estimation have been proposed. However, these methods need to select the viewpoints carefully to obtain better results. If the pose of the target object is ambiguous from the current observation, we could not decide where we should move the sensor to set as the next viewpoint. In this paper, we propose a best next viewpoint recommendation method by minimizing the pose ambiguity of the object by making use of the current pose estimation result as a latent variable. We evaluated viewpoints recommended by the proposed method and confirmed that it helps us to gain better pose estimation results than several comparative methods on a synthetic dataset.

The 6D pose estimation of objects plays a crucial role in robot sorting technology. To simultaneously improve the accuracy and efficiency of pose estimation during the grasping process, this study proposes an innovative deep learning pose estimation method based on PVN3D. Specifically, this study deeply optimized the backbone network of the image extraction model, using dense connections and learnable grouped convolutions to improve model accuracy and reduce model complexity. At the same time, the core idea of convolutional neural networks is integrated into the point cloud feature extraction process, which uses dynamic convolution techniques to process point cloud features, making the processing of point cloud data more efficient and flexible. In addition, by introducing a parameter-free attention mechanism, the accuracy of the model has been further improved. Through extensive experimental verification on the publicly available LineMOD, YCB video datasets and other three core datasets under the BOP benchmark, the method proposed in this paper demonstrates significant advantages in both computational efficiency and estimation accuracy. It not only significantly improves the accuracy of pose estimation but also significantly enhances real-time performance.

With the continuous development of computer technology and deep learning, object detection technology has received great attention in recent years. Especially on the problem of 3D object detection in AR field, a variety of novel algorithms are in bloom. However, these algorithms are either low precision or slow speed. Therefore, we propose an object detection and pose estimation method for AR Application, which is a model for 6D pose estimation of 3D object based on 2D object detection. In our model, we firstly input the 2D projection image of the 3D model into the improved RetinaNet model, and detect the coordinates of the vertex and center point of the object on the image. Then the coordinates on the image and the coordinates on the CAD are matched by point matching. Then, the EPnP improved by Perspective-n-Point (PnP) algorithm is used to complete the pose estimation of 3D object. Finally, we test the performance of our algorithm. The results show that our accuracy has reached the average level of the mainstream algorithms.KeywordsPose estimationObject detectionDeep learningConvolutional neural network

In this work, a visual object detection and localization workflow integrated into a robotic platform is presented for the 6D pose estimation of objects with challenging characteristics in terms of weak texture, surface properties and symmetries. The workflow is used as part of a module for object pose estimation deployed to a mobile robotic platform that exploits the Robot Operating System (ROS) as middleware. The objects of interest aim to support robot grasping in the context of human–robot collaboration during car door assembly in industrial manufacturing environments. In addition to the special object properties, these environments are inherently characterised by cluttered background and unfavorable illumination conditions. For the purpose of this specific application, two different datasets were collected and annotated for training a learning-based method that extracts the object pose from a single frame. The first dataset was acquired in controlled laboratory conditions and the second in the actual indoor industrial environment. Different models were trained based on the individual datasets and a combination of them were further evaluated in a number of test sequences from the actual industrial environment. The qualitative and quantitative results demonstrate the potential of the presented method in relevant industrial applications.

Joint object recognition and pose estimation using multiple-anchor triplet learning of canonical plane

This paper presents a probabilistic object recognition and pose estimation method using multiple interpretation generation in cluttered indoor environments. How to handle pose ambiguity and uncertainty is the main challenge in most recognition systems. In order to solve this problem, we approach it in a probabilistic manner. First, given a three-dimensional (3D) polyhedral object model, the parallel and perpendicular line pairs, which are detected from stereo images and 3D point clouds, generate pose hypotheses as multiple interpretations, with ambiguity from partial occlusion and fragmentation of 3D lines especially taken into account. Different from the previous methods, each pose interpretation is represented as a region instead of a point in pose space reflecting the measurement uncertainty. Then, for each pose interpretation, more features around the estimated pose are further utilized as additional evidence for computing the probability using the Bayesian principle in terms of likelihood and unlikelihood. Finally, fusion strategy is applied to the top ranked interpretations with high probabilities, which are further verified and refined to give a more accurate pose estimation in real time. The experimental results show the performance and potential of the proposed approach in real cluttered domestic environments.

Object 6D pose estimation is an important research topic in the field of computer vision due to its wide application requirements and the challenges brought by complexity and changes in the real-world. We think fully exploring the characteristics of spatial relationship between points will help to improve the pose estimation performance, especially in the scenes of background clutter and partial occlusion. But this information was usually ignored in previous work using RGB image or RGB-D data. In this paper, we propose a framework for 6D pose estimation from RGB-D data based on spatial structure characteristics of 3D keypoints. We adopt point-wise dense feature embedding to vote for 3D keypoints, which makes full use of the structure information of the rigid body. After the direction vectors pointing to the keypoints are predicted by CNN, we use RANSAC voting to calculate the coordinate of the 3D keypoints, then the pose transformation can be easily obtained by the least square method. In addition, a spatial dimension sampling strategy for points is employed, which makes the method achieve excellent performance on small training sets. The proposed method is verified on two benchmark datasets, LINEMOD and OCCLUSION LINEMOD. The experimental results show that our method outperforms the state-of-the-art approaches, achieves ADD(-S) accuracy of 98.7% on LINEMOD dataset and 52.6% on OCCLUSION LINEMOD dataset in real-time.

Currently, many methods of object pose estimation use images or point clouds alone for pose estimation. This leads to their inability to accurately estimate the object pose in the case of occlusion and poor illumination. Second, these models have large parameters and cannot be deployed on mobile devices. Therefore, we propose a lightweight two-terminal feature fusion network, which can effectively use images and point clouds for accurate object pose estimation. First, Pointno problemNet network is used to extract point cloud features. Then the extracted point cloud features are combined with the images at pixel level and the features are extracted by CNN. Secondly, the extracted image features are combined with the point cloud point by point. Then feature extraction is performed on it using the improved PointNet++ network. Finally, a set of center point features are obtained and pose estimation is performed for each feature. The pose with the highest confidence is selected as the final result. Furthermore, we apply depthwise separable convolutions to reduce the amount of model parameters. Experiments show that the proposed method exhibits better performance on Linemod and Occlusion Linemod datasets. Furthermore, the model parameters are small, and it is robust in occlusion and low-light situations.

This work focuses on the problem of 6D pose estimation for novel objects when a reference 3D model or posed reference images are not available. While existing methods can estimate the precise 6D pose of objects, they heavily rely on curated CAD models or reference images, the preparation of which is a time-consuming and labor-intensive process. Moreover, in real-world scenarios, 3D models or reference images may not be available in advance and instant robot reaction is desired. In this work, we propose a novel framework named HIPPo, which eliminates the need for curated CAD models and reference images by harnessing image-to-3D priors from Diffusion Models, enabling model-free zero-shot 6D pose estimation. Specifically, we construct HIPPo Dreamer, a rapid image-to-mesh model built on a multiview Diffusion Model and a 3D reconstruction foundation model. Our HIPPo Dreamer can generate a 3D mesh of any unseen objects from a single glance in just a few seconds. Then, as more observations are acquired, we propose to continuously refine the diffusion prior mesh model by joint optimization of object geometry and appearance. This is achieved by a measurement-guided scheme that gradually replaces the plausible diffusion priors with more reliable online observations. Consequently, HIPPo can instantly estimate and track the 6D pose of a novel object and maintain a complete mesh for immediate robotic applications. Thorough experiments on various benchmarks show that HIPPo outperforms state-of-the-art methods in 6D object pose estimation when prior reference images are limited.

Bin-picking is a practical and challenging robotic manipulation task, where accurate 6D pose estimation plays a pivotal role. The workpieces in bin-picking are typically texture-less and randomly stacked in a bin, which poses a significant challenge to 6D pose estimation. Existing solutions are typically learning-based methods, which require object-specific training. Their efficiency of practical deployment for novel workpieces is highly limited by data collection and model retraining. Zero-shot 6D pose estimation is a potential approach to address the issue of deployment efficiency. Nevertheless, existing zero-shot 6D pose estimation methods are designed to leverage feature matching to establish point-to-point correspondences for pose estimation, which is less effective for workpieces with textureless appearances and ambiguous local regions. In this paper, we propose ZeroBP, a zero-shot pose estimation frame-work designed specifically for the bin-picking task. ZeroBP learns Position-Aware Correspondence (PAC) between the scene instance and its CAD model, leveraging both local features and global positions to resolve the mismatch issue caused by ambiguous regions with similar shapes and appearances. Extensive experiments on the ROBI dataset demonstrate that ZeroBP outperforms state-of-the-art zero-shot pose estimation methods, achieving an improvement of 9.1 % in average recall of correct poses.

Purpose Accurate 6D object pose estimation is essential for various robotic tasks. Uncertain pose estimates can lead to task failures; however, a certain degree of error in the pose estimates is often acceptable. This paper aims to enable the robots to make informed decisions by quantifying errors in the object pose estimate and acceptable errors for task success. Design/methodology/approach In this paper, the authors introduce a framework for evaluating robotic task success under object pose uncertainty, representing both the estimated error space of the object pose and the acceptable error space for task success using multi-modal non-parametric probability distributions. The proposed framework pre-computes the acceptable error space for task success using dynamic simulations and subsequently integrates the pre-computed acceptable error space over the estimated error space of the object pose to predict the likelihood of the task succes. Findings The authors evaluated the proposed framework on two mobile manipulation tasks. Their results show that by representing the estimated and the acceptable error space using multi-modal non-parametric distributions, the authors achieve higher task success rates and fewer failures. Research limitations/implications Their proposed framework is generic and can be applied to a wide range of robotic tasks requiring object pose estimation. Hence, given the recent advancements in object pose uncertainty estimation and dynamic simulations, the proposed framework, in conjunction with these advancements, has the potential to enable robots to make reliable and informed decisions under pose uncertainty. Originality/value Unlike related works that model both acceptable error space and estimated error space using parametric uni-modal distributions, the authors model them as multi-modal distributions which is often the case in the real world.

Enabling robots to automatically locate and pick up randomly placed and oriented objects from a bin is an important challenge in factory automation, replacing tedious and heavy manual labor. A system should be able to recognize and locate objects with a predefined shape and estimate the position with the precision necessary for a gripping robot to pick it up. We describe a system that consists of a structured light instrument for capturing 3D data and a robust approach for object location and pose estimation. The method does not depend on segmentation of range images, but instead searches through pairs of 2D manifolds to localize candidates for object match. This leads to an algorithm that is not very sensitive to scene complexity or the number of objects in the scene. Furthermore, the strategy for candidate search is easily reconfigurable to arbitrary objects. Experiments reported in this paper show the utility of the method on a general random bin picking problem, in this paper exemplified by localization of car parts with random position and orientation. Full pose estimation is done in less than 380 ms per image. We believe that the method is applicable for a wide range of industrial automation problems where precise localization of 3D objects in a scene is needed.