High-quality Panorama Stitching based on Asymmetric Bidirectional Optical Flow

In this paper, we propose a panorama stitching algorithm based on asymmetric bidirectional optical flow. This algorithm expects multiple photos captured by fisheye lens cameras as input, and then, through the proposed algorithm, these photos can be merged into a high-quality 360-degree spherical panoramic image. For photos taken from a distant perspective, the parallax among them is relatively small, and the obtained panoramic image can be nearly seamless and undistorted. For photos taken from a close perspective or with a relatively large parallax, a seamless though partially distorted panoramic image can also be obtained. Besides, with the help of Graphics Processing Unit (GPU), this algorithm can complete the whole stitching process at a very fast speed: typically, it only takes less than 30s to obtain a panoramic image of 9000-by-4000 pixels, which means our panorama stitching algorithm is of high value in many real-time applications. Our code is available at https://github.com/MungoMeng/Panorama-OpticalFlow.Comment: Published at the 5th International Conference on Computational Intelligence and Applications (ICCIA 2020

A new wireless sensor platform with camera

Abstractthere are several platforms of wireless sensor networks such as micaz, mica2, etc. Each of them has specific characteristics. But the complexity of novel applications requires new characteristics, which more and more new designs of wireless sensor networks are needed. In this paper, the design of a sensor named Lacuna is proposed, which is a new sensor network platform implementing reliable detecting by taking real-time pictures. The paper presents a simplified model of wireless sensor networks (WSN) which is composed of the Lacuna sensors using IEEE 802.15.4 wireless technology. This model has been tested for many times and the model experimental results show that this system can run stably, reliably and efficiently. Stability, reliability, and efficiency are important because they make the operation robust to temporary disconnections or high packet loss. Due to the stability, reliability, and efficiency, the WSN transmits large amounts of continuous stable picture data messages to notebook when one of the nodes finishes taking a picture

Robotic Planning under Hierarchical Temporal Logic Specifications

Past research into robotic planning with temporal logic specifications, notably Linear Temporal Logic (LTL), was largely based on singular formulas for individual or groups of robots. But with increasing task complexity, LTL formulas unavoidably grow lengthy, complicating interpretation and specification generation, and straining the computational capacities of the planners. In order to maximize the potential of LTL specifications, we capitalized on the intrinsic structure of tasks and introduced a hierarchical structure to LTL specifications. In contrast to the "flat" structure, our hierarchical model has multiple levels of compositional specifications and offers benefits such as greater syntactic brevity, improved interpretability, and more efficient planning. To address tasks under this hierarchical temporal logic structure, we formulated a decomposition-based method. Each specification is first broken down into a range of temporally interrelated sub-tasks. We further mine the temporal relations among the sub-tasks of different specifications within the hierarchy. Subsequently, a Mixed Integer Linear Program is utilized to generate a spatio-temporal plan for each robot. Our hierarchical LTL specifications were experimentally applied to domains of robotic navigation and manipulation. Results from extensive simulation studies illustrated both the enhanced expressive potential of the hierarchical form and the efficacy of the proposed method.Comment: 8 pages, 4 figure

Geometry of power flows and convex-relaxed power flows in distribution networks with high penetration of renewables

AbstractRenewable energies are increasingly integrated in electric distribution networks and will cause severe overvoltage issues. Smart grid technologies make it possible to use coordinated control to mitigate the overvoltage issues and the optimal power flow (OPF) method is proven to be efficient in the applications such as curtailment management and reactive power control. Nonconvex nature of the OPF makes it difficult to solve and convex relaxation is a promising method to solve the OPF very efficiently. This paper investigates the geometry of the power flows and the convex-relaxed power flows when high penetration level of renewables is present in the distribution networks. The geometry study helps understand the fundamental nature of the OPF and its convex-relaxed problem, such as the second-order cone programming (SOCP) problem. A case study based on a three-node system is used to illustrate the geometry profile of the feasible sub-injection (injection of nodes excluding the root/substation node) region