With development of LiDAR technology, solid-state LiDARs receive a lot attention for their high reliability, low cost and light weight. However, compared with traditional rotating LiDARs, these pose new challenges on simultaneous localization mapping (SLAM) due to small field view (FoV) in horizontal direction irregular scanning pattern, which arises the issue degeneracy indoor environments. To this end, we propose an accurate, robust real-time LiDAR-inertial SLAM method LiDARs. Firstly,...

In this paper, we present a distributed framework for the lidar-based relative state estimator which achieves highly accurate, real-time trajectory estimation of multiple Unmanned Aerial Vehicles (UAVs) in GPS-denied environments. The system builds atop factor graph, and only on-board sensors computing power are utilized. Benefiting from keyframe strategy, each UAV performs individually broadcasts very partial information without exchanging raw data. complete runs is evaluated with three...

Collaboration localization and mapping in GPS-denied environments is a challenging problem, due to the computing power communication bandwidth constraints of onboard equipment. In this article, voxel-based system developed, which achieves real-time trajectory estimation for multirobot utilizing only sensors, power, module. The key idea matching approach formulate registration problem as maximum <i>a posteriori</i> (MAP) simplify it nonlinear least-squares using Gauss approximation principal...

Autonomous exploration of unknown environments with multiple Unmanned Aerial Vehicles (UAVs) is a challenging problem. In this paper, we present DPPM, Decentralized exPloration Planning framework for Multi-UAV systems. To conserve communication bandwidth, lightweight information structure spatial and developed, which can be saved as sparse topological graph. Supported by the structure, hierarchical planner performed. The local filters frontiers to avoid overlap refines viewpoints sampling...

In this work, we propose a reaction-based local planner for autonomous collision avoidance of quadrotor in obstacle-cluttered environment without relying on an explicit map. Our approach searches feasible trajectory using set motion primitives state lattice and represents the optimal one as polynomial by solving control problem. A modified Q-network, termed LPNet, is presented to predict action-values from current depth image estimation directly. To train proposed primitive-based expert...

Most current automated phonocardiogram (PCG) classification methods are relied on PCG segmentation. It is universal to make use of the segmented signals and then extract efficiency features for computer-aided auscultation or heart sound classification. However, accurate segmentation fundamental sounds depends greatly quality signals. In addition these that heavily algorithm considerably increase computational burden. To solve above two issues, we have developed a novel approach classify...

Real-time localization and mapping for micro aerial vehicles (MAV) is a challenging problem, due to the limitation of onboard computational power. In this article, tightly coupled light detection ranging (LiDAR)-inertial odometry developed, which achieves high accuracy, real-time trajectories estimation MAV utilizing only sensors low-power computer. The key idea proposed method integrate IMU measurements, correct LiDAR matching outliers into one nonlinear noncontinuous objective function,...

Autonomous flight is a fundamental problem for various applications of micro aerial vehicles (MAVs). Thanks to the development Guidance, Navigation and Control (GNC) technologies, research on this also becoming mature. However, safe in unknown, cluttered environments remains an open question, especially with real-time requirement onboard computer. This paper proposes framework including parallelly mapping planning implements it Graphics Processing Unit (GPU). First, spherical coordinate...

Perceiving the environment semantically in real-time is challenging for unmanned aerial vehicles (UAVs) with limited computational resources. In this article, a instance-aware segmentation and semantic mapping method on small edge devices proposed. Taking red, green, blue, depth (RGB-D) image as input, presented instance pipeline able to run at speed of 38 frames/s AGX Xavier. To achieve this, we take lightweight object detection model backbone reformulate mask generation problem threshold...

In this work, we propose a learning-based one-stage planner for trajectory generation of quadrotor in obstacle-cluttered environment without relying on explicit map. We integrate perception and mapping, front-end path searching, back-end optimization into single network. frame the motion planning problem as regression spatially separated polynomial trajectories associated scores. Specifically, our approach adopts set primitives to cover searching space, predicts offsets scores local forward...

This article proposes a distributed bundle algorithm for task allocation problems multirobot systems. Specifically, in the developed formulation of vehicle routing problem with time windows (VRPTW), robots are assigned to dispatch necessities survivors. The utility each robot is evaluated by preference index, composed distance cost and reward. Considering requirements structure real-time computing, we propose weighted buffered Voronoi partition-based algorithm. proposed dynamically updates...

In recent years, infrastructure-based localization methods have achieved significant progress thanks to their reliable and drift-free capability. However, the pre-installed infrastructures suffer from inflexibilities high maintenance costs. This poses an interesting problem of how develop a system without using infrastructures. this paper, infrastructure-free is proposed ambient magnetic field (MF) information, namely IDF-MFL. IDF-MFL distinctiveness MF information produced by inherent...

This paper proposes Safe Tracker, an autonomous aerial tracking framework based on vision sensor that can deal with challenging missions and guarantee safety visibility. Firstly, a RGB-D segmentation method is employed to locate the target in real-time. Then motion predicted for short time horizon, which heuristic path searching applied generate occlusion-free path. Finally, particular formulations balance visibility are designed, effective non-linear trajectory optimization enables optimal...

In the power harmonic detection algorithm, disadvantages of Fast Fourier Transform (FFT) are difficult to accurately detect in non-synchronous sampling and non-integer periodic truncation need be solved. Therefore, this paper considers various advantages traditional window functions such as Hanning new function, for example: Blackman-Harris Nuttall window. Four three-order was adopted, which more suitable analysis. Meanwhile, double-line interpolation analysis algorithm correction function...

In this paper, a state estimation and control system in GPS-denied environments is presented for micro aerial vehicle (MAV). For full estimation, we formulate the lidar-inertial odometry as factor graph which can solved by nonlinear optimizer. hovering trajectory control, propose dual-mode cascaded controller, ensures accuracy tracking performance. extensive flight tests, evaluate performance of developed algorithms proposed paper on onboard computer.

To make full use of the residual audible frequency band hearing-loss patients and improve intelligibility speech, an adaptive nonlinear compression (NFC) algorithm is proposed, which amplifies signals be... | Find, read cite all research you need on Tech Science Press