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Segmenting 3D objects from a set of disordered point cloud is always one challenge work in Bin-pi cking systems. In this paper, an easy and valid algorithm is proposed to solve this problem. The point data set obtained from a low-cost depth camera, RealSense, can be quickly filtered to be a much clean compact one, significantly saving the computing resources. The filtered points set is next divided...
Point-cloud is a widely used representation for objects and scenes. It generally consists of a large amount of 3D coordinates of points describing reflective surfaces. A subtle problem is that the number of points is usually so large that real-time transmission and efficient storage is not feasible. In this work, we propose to use 3D Discrete Cosine Transform (3D-DCT) to compress these two typical...
This paper aims at realizing high precision control of a 3 degrees of freedom (DOFs) exoskeleton robot for space teleoperation, using virtual decomposition control (VDC), while strictly ensuring global stability. Based on the VDC approach, firstly, the entire system is virtually decomposed into several subsystems. Secondly, kinematics and dynamics of each subsystem are analyzed and the control equations...
In this paper, we propose an efficient terrain meshing method based on discrete point cloud, which is based on the existing meshing method of 3D reconstruction. Our meshing method uses the DTM (Delaunay Triangle Mesh) as a criterion to establish vertex constraints and evaluation functions. We start from a seed triangle and use the growing method to extend the outer-edge of each triangle until all...
This paper presents a path planning framework for low-cost mobile robots, which mainly includes three parts: map-processing, collision avoidance and wall following. We change the point cloud maps provided by SLAM to grid maps and filter redundant points in the map-processing procedure. An improved A-star based path planning method and the collision avoidance framework are proposed subsequently. Finally,...
For an unmanned marine vehicles, the calculations of its resistance under the water and hydrodynamic coefficients are necessary and important work. For the complexity of the fluid around autonomous underwater vehicles(AUV), the kinematic and dynamic model of underwater vehicles are highly nonlinear and coupled so that the hydrodynamic performance are hardly to be obtained. With the help of computational...
Although there are a large number of autonomous robot platforms for ground contact and flying robots, this has not been the case for underwater robotic platforms. This is not due to the lack of interesting applications in the shallow underwater domain (50m depth), but rather due to the relative cost of building such platforms. This has recently changed with the development of inexpensive thrusters...
Scene management technology is one of the key technologies of virtual reality and visualization. In this paper, we propose a new method based on adaptive binary tree (ABT) and scene graph, which is used to improve the real-time rendering of indoor and outdoor objects and enhance the organization efficiency of scenes structure. The generation algorithm of adaptive binary tree, the scoring standard...
A novel model of heterogeneous multiple dynamic agent systems is established, which describes the chasing process between a group of agents and their quarries. In the model, the group is modeled based on inter-individual attraction and repulsion, that is, each individual can neither move away from the whole group nor get too close to other members. Moreover, two functions are introduced to reveal...
This paper introduces alternating direction method of multipliers (ADMM) to decrease the computational workload of DOA estimation which uses the framework of compressive sensing, i.e., Basis Pursuit De-Noising (BPDN). BPDN transforms the DOA estimation problem to an optimization problem. And interior-point method (IPM) is traditionally used to solve this optimization problem. Though IPM can obtain...
Recently, many works demonstrated that block-sparse signals recoveries applied model based algorithm could achieve better performance than conventional sense manner. Furthermore, a carefully designed measurement matrix can not only improve the recovery success rate, but also reduce the number of sampling. In this paper, we introduce a novel approach to construct measurement matrix for block-sparse...
Many academic researchers have been engaged in the visual servoing based regulation of quadrotors over the past decade, and proposed a lot of controllers for this challenging problem. The regulation controller presented in this paper adopts the Position Based Visual Servoing (PBVS) methodology. Most of the PBVS controllers, if not all, are assuming the position of the quadrotor w.r.t. the marker is...
This paper studies secure leader-following consensus of linear multi-agent systems under a directed communication network subject to Denial-of-Service (DoS) attacks. We consider time-sequence-based DoS attacks allowed to occur aperiodically in an unknown attack strategy. The frequency and duration of DoS attacks are analyzed and investigated for a secure leader-following consensus problem. A distributed...
This paper presents the gait design and comparison study of a quadruped robot. The main contributions of this paper are: (i) Explore the modularized system design of an 8 degree-of-freedom quadruped robot with a power management system. (ii) Propose a gait design method based on drive function. (iii) Propose another gait design method based on foot trajectory. (iv) The simulation of the walk and trot...
This paper proposes a novel control strategy for the smooth transition between grid-attached and islanded mode of microgrid. The proposed control strategy is based on a proportional resonant current controller to regulate inverter current, without requiring any islanding detection algorithm or switching between different controllers. Equal power sharing is achieved as well by droop control using reference...
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