In this paper we present a distributed, autonomous network calibration algorithm, which enables visual sensor networks to gather knowledge about the network topology. A calibrated sensor network provides the basis for more robust applications, since nodes are aware of their spatial neighbors. In our approach, sensor nodes estimate relative positions and orientations of nodes with overlapping fields of view based on jointly detected objects and geometric relations. Distance and angle measurements are the only information required to be exchanged between nodes. The process works iteratively, first calibrating camera neighbors in a pairwise manner and then spreading the calibration information through the network. Further, each node operates within its local coordinate system avoiding the need for any global coordinates. While existing methods mostly exploit computer vision algorithms to relate nodes to each other based on their images, we solely rely on geometric constraints.
{"title":"Distributed Visual Sensor Network Calibration Based on Joint Object Detections","authors":"Jennifer Simonjan, B. Rinner","doi":"10.1109/DCOSS.2017.17","DOIUrl":"https://doi.org/10.1109/DCOSS.2017.17","url":null,"abstract":"In this paper we present a distributed, autonomous network calibration algorithm, which enables visual sensor networks to gather knowledge about the network topology. A calibrated sensor network provides the basis for more robust applications, since nodes are aware of their spatial neighbors. In our approach, sensor nodes estimate relative positions and orientations of nodes with overlapping fields of view based on jointly detected objects and geometric relations. Distance and angle measurements are the only information required to be exchanged between nodes. The process works iteratively, first calibrating camera neighbors in a pairwise manner and then spreading the calibration information through the network. Further, each node operates within its local coordinate system avoiding the need for any global coordinates. While existing methods mostly exploit computer vision algorithms to relate nodes to each other based on their images, we solely rely on geometric constraints.","PeriodicalId":399222,"journal":{"name":"2017 13th International Conference on Distributed Computing in Sensor Systems (DCOSS)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125988447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atis Elsts, Xenofon Fafoutis, James Pope, G. Oikonomou, R. Piechocki, I. Craddock
The upcoming Internet of Things (IoT) applications include real-time human activity monitoring with wearable sensors. Compared to the traditional environmental sensing with low-power wireless nodes, these new applications generate a constant stream of a much higher rate. Nevertheless, the wearable devices remain battery powered and therefore restricted to low-power wireless standards such as IEEE 802.15.4 or Bluetooth Low Energy (BLE). Our work tackles the problem of building a reliable autonomous schedule for forwarding this kind of dynamic data in IEEE 802.15.4 TSCH networks. Due to the a priori unpredictability of these data source locations, the quality of the wireless links, and the routing topology of the forwarding network, it is wasteful to reserve the number of slots required for the worst-case scenario, under conditions of high expected datarate, it is downright impossible. The solution we propose is a hybrid approach where dedicated TSCH cells and shared TSCH slots coexist in the same schedule. We show that under realistic assumptions of wireless link diversity, adding shared slots to a TSCH schedule increases the overall packet delivery rate and the fairness of the system.
{"title":"Scheduling High-Rate Unpredictable Traffic in IEEE 802.15.4 TSCH Networks","authors":"Atis Elsts, Xenofon Fafoutis, James Pope, G. Oikonomou, R. Piechocki, I. Craddock","doi":"10.1109/DCOSS.2017.20","DOIUrl":"https://doi.org/10.1109/DCOSS.2017.20","url":null,"abstract":"The upcoming Internet of Things (IoT) applications include real-time human activity monitoring with wearable sensors. Compared to the traditional environmental sensing with low-power wireless nodes, these new applications generate a constant stream of a much higher rate. Nevertheless, the wearable devices remain battery powered and therefore restricted to low-power wireless standards such as IEEE 802.15.4 or Bluetooth Low Energy (BLE). Our work tackles the problem of building a reliable autonomous schedule for forwarding this kind of dynamic data in IEEE 802.15.4 TSCH networks. Due to the a priori unpredictability of these data source locations, the quality of the wireless links, and the routing topology of the forwarding network, it is wasteful to reserve the number of slots required for the worst-case scenario, under conditions of high expected datarate, it is downright impossible. The solution we propose is a hybrid approach where dedicated TSCH cells and shared TSCH slots coexist in the same schedule. We show that under realistic assumptions of wireless link diversity, adding shared slots to a TSCH schedule increases the overall packet delivery rate and the fairness of the system.","PeriodicalId":399222,"journal":{"name":"2017 13th International Conference on Distributed Computing in Sensor Systems (DCOSS)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116706386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}