Entropy Flow-Aided Navigation

2010 ◽  
Vol 64 (1) ◽  
pp. 109-125 ◽  
Author(s):  
He Deng ◽  
Chao Pan ◽  
Tongxin Wen ◽  
Jianguo Liu

Integrating the visual navigation mechanism of flying insects with a nonlinear Kalman filter, this paper proposes a novel navigation algorithm. New concepts of entropic map and entropy flow are presented, which can characterize topographic features and measure changes of the image respectively. Meanwhile, an auto-selecting algorithm of assessment threshold is proposed to improve computational accuracy and efficiency of global motion estimation. The simulation results suggest that the navigation algorithm can perform real-time rectification of the missile's trajectory well, and can reduce the cost of the missile's hardware.

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yoel Sebbag ◽  
Eliran Talker ◽  
Alex Naiman ◽  
Yefim Barash ◽  
Uriel Levy

AbstractRecently, there has been growing interest in the miniaturization and integration of atomic-based quantum technologies. In addition to the obvious advantages brought by such integration in facilitating mass production, reducing the footprint, and reducing the cost, the flexibility offered by on-chip integration enables the development of new concepts and capabilities. In particular, recent advanced techniques based on computer-assisted optimization algorithms enable the development of newly engineered photonic structures with unconventional functionalities. Taking this concept further, we hereby demonstrate the design, fabrication, and experimental characterization of an integrated nanophotonic-atomic chip magnetometer based on alkali vapor with a micrometer-scale spatial resolution and a magnetic sensitivity of 700 pT/√Hz. The presented platform paves the way for future applications using integrated photonic–atomic chips, including high-spatial-resolution magnetometry, near-field vectorial imaging, magnetically induced switching, and optical isolation.


2012 ◽  
Vol 239-240 ◽  
pp. 1421-1427
Author(s):  
Yu Rong Lin ◽  
Liang Chen ◽  
Zhen Xian Fu

Dual quaternion navigation algorithm gain higher accuracy than traditional strapdown inertial navigation algorithm at the cost of real-time performance. In order to reduce tremendous computation amount of the former, a simplified design scheme for navigation integration algorithms is presented in this paper. First, based on update principle and computation rules of dual quaternion we separate rotational and translational increment information from dual quaternion increment, and deduce exact solutions defined by the spiral vector for thrust velocity increment, gravitational velocity increment and displacement increment. Then, considering characteristics of a strapdown inertial navigation system, implementation schemes of simplified integration algorithms for dual quaternion differential equations in three frames, including thrust velocity coordinates, gravitational velocity coordinates and position coordinates, are designed separately. Under the premise of ensuring the accuracy advantage of the original dual quaternion inertial navigation algorithm, the proposed simplified algorithm significantly improve the computational efficiency. This will lay favorable foundation for engineering realization of the dual quaternion strapdown inertial navigation algorithm.


Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2976 ◽  
Author(s):  
Yunwang Li ◽  
Sumei Dai ◽  
Yong Shi ◽  
Lala Zhao ◽  
Minghua Ding

Computer simulation is an effective means for the research of robot navigation algorithms. In order to implement real-time, three-dimensional, and visual navigation algorithm simulation, a method of algorithm simulation based on secondary development of Unity3D is proposed. With this method, a virtual robot prototype can be created quickly with the imported 3D robot model, virtual joints, and virtual sensors, and then the navigation simulation can be carried out using the virtual prototype with the algorithm script in the virtual environment. Firstly, the scripts of the virtual revolute joint, virtual LiDAR sensors, and terrain environment are written. Secondly, the A* algorithm is improved for navigation in unknown 3D space. Thirdly, taking the Mecanum wheel mobile robot as an example, the 3D robot model is imported into Unity3D, and the virtual joint, sensor, and navigation algorithm scripts are added to the model. Then, the navigation is simulated in static and dynamic environments using a virtual prototype. Finally, the navigation tests of the physical robot are carried out in the physical environment, and the test trajectory is compared with the simulation trajectory. The simulation and test results validate the algorithm simulation method based on the redevelopment of Unity3d, showing that it is feasible, efficient, and flexible.


Author(s):  
Tarang Parashar ◽  
Katie Grantham Lough ◽  
Robert B. Stone

This paper presents a part count tool that automates the consideration of manufacturing cost during the conceptual design phase by predicting part count for a particular product concept. With an approximate number of parts per product in the conceptual design phase, the designer can estimate the cost associated with the product. On the basis of the cost, the designer can make changes according to budget requirements. The part count tool will also aid in ranking the design concepts by number of components for a product. This tool utilizes existing automated concept generation algorithms to generate the design concepts. It extracts the available data from the Missouri S&T Design Repository to compute an average number of parts per component type in the repository and then calculates an average part count for new concepts. This data can subsequently be used by designers to estimate product cost. The part count tool also uses an algorithm to determine how to connect two non compatible components through the addition of mutually compatible components. While emphasis is placed on the average parts per product in evaluating designs, the overall functional requirement of the product is also considered.


Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4544
Author(s):  
Congyang Zhao ◽  
Jianing Yang ◽  
Fuqiang Zhou ◽  
Junhua Sun ◽  
Xiaosong Li ◽  
...  

Environmental sensing is a key technology for the development of unmanned cars, drones and robots. Many vision sensors cannot work normally in an environment with insufficient light, and the cost of using multiline LiDAR is relatively high. In this paper, a novel and inexpensive visual navigation sensor based on structured-light vision is proposed for environment sensing. The main research contents of this project include: First, we propose a laser-stripe-detection neural network (LSDNN) that can eliminate the interference of reflective noise and haze noise and realize the highly robust extraction of laser stripes region. Then we use a gray-gravity approach to extract the center of laser stripe and used structured-light model to reconstruct the point clouds of laser center. Then, we design a single-line structured-light sensor, select the optimal parameters for it and build a car–platform for experimental evaluation. This approach was shown to be effective in our experiments and the experimental results show that this method is more accurate and robust in complex environment.


2021 ◽  
Vol 52 (1) ◽  
pp. 214510
Author(s):  
Wei SHAO ◽  
BoNing WANG ◽  
LingFei DOU ◽  
HanXue ZHAO ◽  
JinCheng XIE ◽  
...  

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