检索结果-内蒙古大学图书馆

Multi-agent Gaussian Process Motion Planning via Probabilistic Inference

IFAC-PapersOnLine 2018年第22期51卷 160-165页

作者： Petrovi, Luka Markovi, Ivan Seder, Marija University of Zagreb Faculty of Electrical Engineering and Computing Laboratory for Autonomous Systems and Mobile Robotics Croatia

This paper deals with motion planning for multiple agents by representing the problem as a simultaneous optimization of every agent's trajectory. Each trajectory is considered as a sample from a one-dimensional continuous-time Gaussian process (GP) generated by a linear time-varying stochastic differential equation driven by white noise. By formulating the planning problem as probabilistic inference on a factor graph, the structure of the pertaining GP can be exploited to find the solution efficiently using numerical optimization. In contrast to planning each agent's trajectory individually, where only the current poses of other agents are taken into account, we propose simultaneous planning of multiple trajectories that works in a predictive manner. It takes into account the information about each agent's whereabouts at every future time instant, since full trajectories of each agent are found jointly during a single optimization procedure. We compare the proposed method to an individual trajectory planning approach, demonstrating significant improvement in both success rate and computational efficiency. © 2018

关键词： Motion planning Computational efficiency Continuous time systems Differential equations Gaussian distribution Gaussian noise (electronic) Multi agent systems One dimensional Optimization Stochastic systems Trajectories White noise Factor graphs Numerical optimizations Optimization procedures Probabilistic inference Simultaneous optimization Stochastic differential equations Trajectory optimization Trajectory Planning

来源：评论

学校读者我要写书评

暂无评论

Robust Self-Scheduled Fault-Tolerant Control of a Quadrotor UAV

引用

IFAC-PapersOnLine 2017年第1期50卷 5761-5767页

作者： Nguyen D.-T. Saussié D. Saydy L. Mobile Robotics and Autonomous Systems Laboratory Polytechnique Montreal Canada

This paper deals with active fault-tolerant control (FTC) of a quadrotor in the presence of actuator faults. In previous studies, authors generally assume that the fault has been detected, isolated or identified and then proceed with a reconfigurable controller. This paper presents a complete active fault-tolerant control system with both fault detection and diagnosis (FDD) and FTC. The proposed FTC design is based on gain-scheduling control in the framework of structured H∞ synthesis. The scheduled gains are parameterized as polynomial functions of the loss of control effectiveness of the quadrotor's actuators, estimated by a two-stage Kalman filter. Then, the MATLAB-based function systune tune the polynomial coefficients to meet the robustness and performance requirement. In comparison with other FTC systems which use switching mechanisms, this smooth self-scheduled controller allows one to avoid undesirable transient phenomenons during the controller reconfiguration process. Numerical simulations based on an underactuated 6DoF quadrotor nonlinear model show the good effectiveness of the proposed FTC in accommodating different levels of actuator faults. © 2017

关键词： Actuator faults Fault Detection Fault-Tolerant Control Gain scheduling Quadrotor Structured H-Infinity Control Two-Stage Kalman filter

来源：评论

学校读者我要写书评

暂无评论

Computationally efficient dense moving object detection based on reduced space disparity estimation

引用

IFAC-PapersOnLine 2018年第22期51卷 360-365页

作者： Popovi, Goran Hadviger, Antea Markovi, Ivan Petrovi, Ivan University of Zagreb Faculty of Electrical Engineering and Computing Laboratory for Autonomous Systems and Mobile Robotics Zagreb Croatia

Computationally efficient moving object detection and depth estimation from a stereo camera is an extremely useful tool for many computer vision applications, including robotics and autonomous driving. In this paper we show how moving objects can be densely detected by estimating disparity using an algorithm that improves complexity and accuracy of stereo matching by relying on information from previous frames. The main idea behind this approach is that by using the ego-motion estimation and the disparity map of the previous frame, we can set a prior base that enables us to reduce the complexity of the current frame disparity estimation, subsequently also detecting moving objects in the scene. For each pixel we run a Kalman filter that recursively fuses the disparity prediction and reduced space semi-global matching (SGM) measurements. The proposed algorithm has been implemented and optimized using streaming single instruction multiple data instruction set and multi-threading. Furthermore, in order to estimate the process and measurement noise as reliably as possible, we conduct extensive experiments on the KITTI suite using the ground truth obtained by the 3D laser range sensor. Concerning disparity estimation, compared to the OpenCV SGM implementation, the proposed method yields improvement on the KITTI dataset sequences in terms of both speed and accuracy. © 2018

关键词： Computer vision Computational complexity Computational efficiency Motion estimation Object detection Object recognition Stereo image processing Stereo vision 3D laser range sensors Computationally efficient Computer vision applications Dense disparity estimation Detecting moving objects Moving object detection Semi global matching Single instruction multiple data instructions

来源：评论

学校读者我要写书评

暂无评论

autonomous Landing of a Multirotor Micro Air Vehicle on a High Velocity Ground Vehicle

引用

IFAC-PapersOnLine 2017年第1期50卷 10488-10494页

作者： Borowczyk A. Nguyen D.-T. Phu-Van Nguyen A. Nguyen D.Q. Saussié D. Ny J.L. Mobile Robotics and Autonomous Systems Laboratory Polytechnique Montreal and GERAD Montreal Canada

While autonomous multirotor micro aerial vehicles (MAVs) are uniquely well suited for certain types of missions benefiting from stationary flight capabilities, their more widespread usage still faces many hurdles, due in particular to their limited range and the difficulty of fully automating the deployment and retrieval. In this paper we address these issues by solving the problem of the automated landing of a quadcopter on a ground vehicle moving at relatively high speed. We present our system architecture, including the structure of our Kalman filter for the estimation of the relative position and velocity between the quadcopter and the landing pad, as well as our controller design for the full rendezvous and landing maneuvers. The system is experimentally validated by successfully landing in multiple trials a commercial quadcopter on the roof of a car moving at speeds of up to 50 km/h. © 2017

关键词： Aerospace control autonomous vehicles Computer vision Guidance systems Kalman filters mobile robots

来源：评论

学校读者我要写书评

暂无评论

Fault-Tolerant Control of a Hexacopter UAV based on Self-Scheduled Control Allocation

Fault-Tolerant Control of a Hexacopter UAV based on Self-Sch...

引用

2018 International Conference on Unmanned Aircraft systems, ICUAS 2018

作者： Nguyen, Duc-Tien Saussie, David Saydy, Lahcen Polytechnique Montreal Mobile Robotics and Autonomous Systems Laboratory Canada

ISBN: (纸本)9781538613535

In this paper, a control allocation (CA) algorithm for the fault-tolerant control (FTC) system of a multirotor unmanned aerial vehicle (UAV) is presented. The proposed CA design is based on gain-scheduling control in the framework of structured H synthesis. Given the appropriate fault detection and diagnosis (FDD) system, allocation laws are parameterized as polynomial functions of actuators effectiveness levels. The polynomial coefficients are then tuned with Matlab-based function systune to meet the robustness and fault tolerance requirements. Unlike conventional CA schemes in the literature, the proposed method has the advantage of not solving any online optimization problem. Moreover, actuator constraints after a failure are also taken into account during the tuning process using a multi-model approach. In comparison with other FTC systems based on reconfigurable controller, this smooth self-scheduled CA has a very simple structure and allows one to avoid undesirable transient phenomena during the controller reconfiguration process. High fidelity simulations and experimental results performed on a hexacopter show the effectiveness and robustness of the proposed FTC in accommodating different levels of actuator degradation. © 2018 IEEE.

关键词： Actuators

来源：评论

学校读者我要写书评

暂无评论

Multi-agent Gaussian Process Motion Planning via Probabilistic Inference

Multi-agent Gaussian Process Motion Planning via Probabilist...

引用

作者： Petrović, Luka Marković, Ivan Seder, Marija University of Zagreb Faculty of Electrical Engineering and Computing Laboratory for Autonomous Systems and Mobile Robotics Croatia

关键词： Trajectories

来源：评论

学校读者我要写书评

暂无评论

Human Localization in Warehouse Environments based on a Wearable Camera Sensor Suite and Dynamic Ultra-Wide Band Nodes 20

Human Localization in Warehouse Environments based on a Wear...

引用

20th International Conference on Advanced robotics, ICAR 2021

作者： Popovic, Goran Cviic, Igor Markovic, Ivan Petrovic, Ivan Laboratory For Autonomous Systems and Mobile Robotics University of Zagreb Faculty of Electrical Engineering and Computing Zagreb Croatia

ISBN: (纸本)9781665436847

Modern warehouses, equipped with an autonomous robots fleet, suffer from an efficiency deficit during human interventions in the shop floor area, since, during such interventions, all the robots must stop for safety reasons. This particularly affects large warehouses which could extremely benefit from a solution that would allow human-robot collaboration during such interventions. This solution should only stop the robots that are in the vicinity of the human and reroute the others, and it requires the following prerequisites: (i) reliable relative ranging of robots with respect to human workers that would ensure safety, and (ii) reliable localization of human workers in the warehouse. In this paper we propose a system for reliable human localization that is based on fusing cues from measured relative ranges with respect to moving robots and a camera system that is worn by the human worker. Since global locations of the robots in the warehouse are known, we use the relative ranges to robots in an indoor GPS-like fashion to provide global human location updates, while the wearable cameras provide visual odometry, i.e., the relative motion of the human, and another global cue by detecting ground fiducial markers used by robots. The fusion is performed within a graph-based optimization framework that also includes a visual odometry error model. We carried out an experimental analysis on three different datasets to validate the performance of the proposed approach and compared it to a state-of-the-art visual SLAM solution, namely ORB-SLAM2. The results demonstrate that our approach yields reliable human location within warehouse like environments. © 2021 IEEE.

关键词： Warehouses

来源：评论

学校读者我要写书评

暂无评论

Computationally efficient dense moving object detection based on reduced space disparity estimation

Computationally efficient dense moving object detection base...

引用

作者： Popović, Goran Hadviger, Antea Marković, Ivan Petrović, Ivan University of Zagreb Faculty of Electrical Engineering and Computing Laboratory for Autonomous Systems and Mobile Robotics Zagreb Croatia

关键词： Stereo vision

来源：评论

学校读者我要写书评

暂无评论

Universal Adaptive Fault-Tolerant Control of a Multicopter UAV ⁎

引用

IFAC-PapersOnLine 2020年第2期53卷 9340-9347页

作者： Duc-Tien Nguyen David Saussié Lahcen Saydy Mobile Robotics and Autonomous Systems Laboratory Polytechnique Montreal Canada

This paper presents a universal adaptive fault-tolerant control (FTC) design for multicopter unmanned aerial vehicles (UAVs). The proposed architecture consists of a two-loop control structure: a fault-tolerant controller generates normalized virtual control inputs to track the desired trajectory subject to actuator faults, and an adaptive augmentation controller deals with system uncertainties and also balances the design requirements for specific platform. The FTC approach is based on gain-scheduling control in the framework of structured H ∞ synthesis. In order to implement the overall control system on most types of multicopter UAVs, an adaptive mapping algorithm is proposed. High fidelity simulations and experimental results, performed on various multicopters with different payload and configuration, show the effectiveness and robustness of the proposed approach in accommodating different levels of actuator degradation including total failures of the rotors as well as unknown mass and inertia, all using a single controller with fixed coefficients.

关键词： Multicopter Fault-Tolerant Control Robust Adaptive Control Gain-Scheduling Structured H-Infinity Control

来源：评论

学校读者我要写书评

暂无评论

Full body human motion estimation on lie groups using 3D marker position measurements 16

Full body human motion estimation on lie groups using 3D mar...

引用

16th IEEE-RAS International Conference on Humanoid Robots, Humanoids 2016

作者： Ćesić, Josip Joukov, Vladimir Petrović, Ivan Kulić, Dana University of Zagreb Faculty of Electrical Engineering and Computing Laboratory for Autonomous Systems and Mobile Robotics Croatia University of Waterloo Department of Electrical and Computer Engineering Adaptive Systems Laboratory Canada

ISBN: (纸本)9781509047185

This paper proposes a new algorithm for full body human motion estimation using 3D marker position measurements. The joints are represented with Lie group members, including special orthogonal groups SO(2) and SO(3), and a special euclidean group SE(3). We employ the Lie Group Extended Kalman Filter (LG-EKF) for stochastic inference on groups, thus explicitly accounting for the non-euclidean geometry of the state space, and provide the derivation of the LG-EKF recursion for articulated motion estimation. We evaluate the performance of the proposed algorithm in both simulation and on real-world motion capture data, comparing it with the Euler angles based EKF. The results show that the proposed filter significantly outperforms the Euler angles based EKF, since it estimates human motion more accurately and is not affected by gimbal lock. © 2016 IEEE.

关键词： Extended Kalman filters

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：