In the narrow, submarine, unstructured environment, the present localization approaches, such as GPS measurement, dead?rcckoning, acoustic positioning, artificial landmarks-based method, are hard to be used for multip...In the narrow, submarine, unstructured environment, the present localization approaches, such as GPS measurement, dead?rcckoning, acoustic positioning, artificial landmarks-based method, are hard to be used for multiple small-scale underwater robots. Therefore, this paper proposes a novel RGB-D camera and Inertial Measurement Unit (IMU) fusion-based cooperative and relative close-range localization approach for special environments, such as underwater caves. Owing to the rotation movement with zero-radius, the cooperative localization of Multiple Turtle-inspired Amphibious Spherical Robot (MTASRs) is realized. Firstly, we present an efficient Histogram of Oriented Gradient (HOG) and Color Names (CNs) fusion feature extracted from color images ofTASRs. Then, by training Support Vector Machine (SVM) classifier with this fusion feature, an automatic recognition method of TASRs is developed. Secondly, RGB-D camerabased measurement model is obtained by the depth map In order to realize the cooperative and relative close-range localization of MTASRs, the MTASRs model is established with RGB-D camera and IMU. Finally, the depth measurement in water is corrected and the efficiency of RGB-D camera for underwater application is validated. Then experiments of our proposed localization method with three robots were conducted and the results verified the feasibility of the proposed method for MTASRs.展开更多
A method of cooperative localization for multi-robot in an unknown environment is described. They share information and perform localization by using relative observations and necessary communication. At initial time,...A method of cooperative localization for multi-robot in an unknown environment is described. They share information and perform localization by using relative observations and necessary communication. At initial time, robots do not know their positions. Once the robot that can obtain the absolute position information has its position, other robots use particle filter to fuse relative observations and maintain a set of samples respectively representing their positions. When the particles are close to s Gsussian distribution after a number of steps, we switch to an EKF to track the pose of the robots. Simulation results and real experiment show that PF-EKF method combines the robustness of PF and the efficiency of EKF. Robots can share the absolute position information and effectively localize themselves in an unknown environment.展开更多
针对SDGPSN(Scalable and D istributed GPS free Positioning for Sensor Networks)算法通信开销过大的问题,通过改进其局部坐标系和全局坐标系构建过程,提出了一种新的相对定位算法。仿真实验结果显示,改进后的算法较之原算法具有更...针对SDGPSN(Scalable and D istributed GPS free Positioning for Sensor Networks)算法通信开销过大的问题,通过改进其局部坐标系和全局坐标系构建过程,提出了一种新的相对定位算法。仿真实验结果显示,改进后的算法较之原算法具有更小的通信开销,使之更适于节点移动频率较低的无线传感器网络的节点定位应用。展开更多
Cooperative localization(CL)utilizing multiple unmanned aerial vehides(UAVs)has become the current development trend and research hotspot.The tnditional distance-based CL method.typically uses principle of the spheric...Cooperative localization(CL)utilizing multiple unmanned aerial vehides(UAVs)has become the current development trend and research hotspot.The tnditional distance-based CL method.typically uses principle of the spherical intersection to achieve UAV high-precision positioning.However,this distance based CL strategy requires several leader UAVs at the known positions.Thus,a cooperative localization method for leader-follower multiple UA Vs using continuous relative ranging information is proposed in this paper.Aiming at the UAV formation consists of a leader UAV node with the known position and at least a follower UAV that needs to be located.Using the Inertial short-time high-precision relative position constraint and the con-tinuous relative distance constraints with the leader UAV nodes,the closed-form solution of follower UAV's three-dimensional position can be obtained using spherical intersection prin-ciple.On this basis,we derive and construct follower UAV's position observation equation.The:developed strategy requires a single known position leader UAV node to realize high-precision CL,which can efctively solve the taditional distance-based collaborative location problem in case the number of leader UAVs is small.The simulation and experimental results demonstrate that the proposed method significantly improves follower UAV's positioning accuracy,and neglects the limitation of the traditional distance-based CL method on the number of leader UAV nodes at known positions.展开更多
Let X be a ringed space together with the data Μ of a set Μ of prime ideals of ΟΧx for each point x∈Χ . We introduce the localization of (X,M') , which is a locally ringed space Y and a map of ringed spaces ...Let X be a ringed space together with the data Μ of a set Μ of prime ideals of ΟΧx for each point x∈Χ . We introduce the localization of (X,M') , which is a locally ringed space Y and a map of ringed spaces Y→Χ enjoying a universal property similar to the localization of a ring at a prime ideal. We use this to prove that the category of locally ringed spaces has all inverse limits, to compare them to the inverse limit in ringed spaces, and to construct a very general Spec functor. We conclude with a discussion of relative schemes.展开更多
基金the National Natural Science Foundation of China (Nos. 61773064, 61503028)Graduate Technological Innovation Project of Beijing Institute of Technology (No. 2018CX10022)National High Tech. Research and Development Program of China (No. 2015AA043202).
文摘In the narrow, submarine, unstructured environment, the present localization approaches, such as GPS measurement, dead?rcckoning, acoustic positioning, artificial landmarks-based method, are hard to be used for multiple small-scale underwater robots. Therefore, this paper proposes a novel RGB-D camera and Inertial Measurement Unit (IMU) fusion-based cooperative and relative close-range localization approach for special environments, such as underwater caves. Owing to the rotation movement with zero-radius, the cooperative localization of Multiple Turtle-inspired Amphibious Spherical Robot (MTASRs) is realized. Firstly, we present an efficient Histogram of Oriented Gradient (HOG) and Color Names (CNs) fusion feature extracted from color images ofTASRs. Then, by training Support Vector Machine (SVM) classifier with this fusion feature, an automatic recognition method of TASRs is developed. Secondly, RGB-D camerabased measurement model is obtained by the depth map In order to realize the cooperative and relative close-range localization of MTASRs, the MTASRs model is established with RGB-D camera and IMU. Finally, the depth measurement in water is corrected and the efficiency of RGB-D camera for underwater application is validated. Then experiments of our proposed localization method with three robots were conducted and the results verified the feasibility of the proposed method for MTASRs.
基金the Ministry Research Fund Project(Grant No.51416070305KG0180)the National Natural Science Foundation of China(Grant Nos.60675056 and 60334010)
文摘A method of cooperative localization for multi-robot in an unknown environment is described. They share information and perform localization by using relative observations and necessary communication. At initial time, robots do not know their positions. Once the robot that can obtain the absolute position information has its position, other robots use particle filter to fuse relative observations and maintain a set of samples respectively representing their positions. When the particles are close to s Gsussian distribution after a number of steps, we switch to an EKF to track the pose of the robots. Simulation results and real experiment show that PF-EKF method combines the robustness of PF and the efficiency of EKF. Robots can share the absolute position information and effectively localize themselves in an unknown environment.
文摘针对SDGPSN(Scalable and D istributed GPS free Positioning for Sensor Networks)算法通信开销过大的问题,通过改进其局部坐标系和全局坐标系构建过程,提出了一种新的相对定位算法。仿真实验结果显示,改进后的算法较之原算法具有更小的通信开销,使之更适于节点移动频率较低的无线传感器网络的节点定位应用。
基金supported by the National Natural Science Foundation of China(61973160).
文摘Cooperative localization(CL)utilizing multiple unmanned aerial vehides(UAVs)has become the current development trend and research hotspot.The tnditional distance-based CL method.typically uses principle of the spherical intersection to achieve UAV high-precision positioning.However,this distance based CL strategy requires several leader UAVs at the known positions.Thus,a cooperative localization method for leader-follower multiple UA Vs using continuous relative ranging information is proposed in this paper.Aiming at the UAV formation consists of a leader UAV node with the known position and at least a follower UAV that needs to be located.Using the Inertial short-time high-precision relative position constraint and the con-tinuous relative distance constraints with the leader UAV nodes,the closed-form solution of follower UAV's three-dimensional position can be obtained using spherical intersection prin-ciple.On this basis,we derive and construct follower UAV's position observation equation.The:developed strategy requires a single known position leader UAV node to realize high-precision CL,which can efctively solve the taditional distance-based collaborative location problem in case the number of leader UAVs is small.The simulation and experimental results demonstrate that the proposed method significantly improves follower UAV's positioning accuracy,and neglects the limitation of the traditional distance-based CL method on the number of leader UAV nodes at known positions.
文摘Let X be a ringed space together with the data Μ of a set Μ of prime ideals of ΟΧx for each point x∈Χ . We introduce the localization of (X,M') , which is a locally ringed space Y and a map of ringed spaces Y→Χ enjoying a universal property similar to the localization of a ring at a prime ideal. We use this to prove that the category of locally ringed spaces has all inverse limits, to compare them to the inverse limit in ringed spaces, and to construct a very general Spec functor. We conclude with a discussion of relative schemes.
