50results about How to "Reduce node energy consumption" patented technology

The invention relates to an energy-saving clustering routing method based on network regional division and distances. Aiming at the hotspot problem of a wireless sensor network, the invention provides an unbalanced clustering protocol (UCNDD) based on distances and network regional division; in the UCNDD algorithm design, an algorithm that the network regional division is combined with clustering is adopted; a ring node neighbour domain by taking a base station as the circle centre is defined at first; network division is carried out according to the distance between a node and the base station; the neighbour domain node is only used as a node contacting with the base station; nodes in other ranges perform an optimized clustering routing protocol; a cluster is established by adopting a timing mechanism; different competition radiuses of the nodes are set, such that the whole network has unequal clustering; and, in the selection of an information sending path, the next-hop node is selected by comprehensively considering the energy, the distance and the node degree information of cluster head nodes. By means of combination of the two mechanisms, the energy consumption of the whole network can be balanced better in an applied region; and thus, the life cycle of the network is prolonged.

The invention relates to a lifetime optimization method of a mobile Sink-based wireless sensor network. The method includes the following steps that: 1) after the network is started, a sink node broadcasts an information query packet and receives the position coordinate information of sensor nodes, and adds the position coordinate information of the sensor nodes into a sensor node information table of the Sink node; 2) the Sink node analyzes constraint conditions, and establishes a data transmission delay and hop count-constrained network lifetime optimization model; 3) the Sink node uses a modified genetic algorithm to solve a network lifetime optimization model, and optimal schemes about network lifetime, the movement path of the Sink node and stay time at each stay position of the Sink node are calculated. With the lifetime optimization method of the mobile Sink-based wireless sensor network of the invention adopted, network lifetime can be prolonged, and node energy consumption and node data loss can be decreased.

The invention discloses a clustering routing control method oriented to a heterogeneous wireless sensor network. The clustering routing control method comprises the following steps of: firstly, carrying out average network energy estimation and accurately estimating next turn of average residual network energy by considering average energy prediction in an ideal state and a historical energy consumption reference value; secondly, carrying out optimal cluster head election and calculating the probability that nodes become cluster heads according to more accurate residual network energy and further determining an optimal cluster head set; thirdly, in the forming process of clusters, introducing a universal-gravitation-like idea and determining that non-cluster-head nodes join in certain cluster according to the magnitude of gravitational force; and fourthly, in a stable data transmission process, carrying out fusion processing on data information collected by each sensor node and forwarding the processed data which are accumulated to a set degree to a base station through the cluster heads. According to the clustering routing control method disclosed by the invention, more accurate average network energy predication estimation is realized, so that the cluster heads generated by electing are distributed more uniformly; meanwhile, a cluster structure is more reasonable, so that energy consumption of each node is reduced and network load balance of the multi-stage heterogeneous wireless sensor network is realized.

The invention discloses an event-driven coal mine underground wireless sensor network system which comprises a base station device and an underground node device. An underground node wireless communication module comprises a sending state, a receiving state and a hibernation state. Three working states of the underground node wireless communication module can be converted to each other. An event-driven wireless sensor network in operation determines whether to trigger an event and transmit data to a base station by monitoring and judging whether data exceed a threshold value. The system has the characteristics of high communication efficiency and low operation energy consumption. According to the invention, the system is combined with coal mine underground safety production needs; through reasonable threshold setting and an improved routing protocol, the number of times of invalid communication among nodes is remarkably reduced; the communication efficiency is improved; the energy consumption of the nodes is reduced; the service life of a network is prolonged; collected useless data are reduced; in the case of an accident or alarm, useful alarm data can be quickly extracted; the event-driven network technology is applied to coal mine underground safety monitoring; and the system is an efficient coal mine safety monitoring system.

The invention discloses an efficient routing method of a high rate-wireless personal area network (HR-WPAN) mesh network and relates to routing technology based on topology servers in the WPAN mesh network. According to the routing method, broadcasting Link State Registration information, converging the Link State Registration information, shortening the length of relay node lists, releasing optimal path information through self-adaptive routing and a routing mechanism based on node dump energy are adopted, and the problems that the unicast control information of an existing routing method of the WPAN Mesh network based on the topology servers can not release network topology information sufficiently, the number, the content and the forwarding path of the control information are redundant, node energy is not considered in a routing process under the multi-path conditions and the like are solved. Control overload is reduced, path constructing time is shortened, node energy consumption is balanced, network bandwidth is saved, the efficiency of the routing method and the performance including time delay and the like are improved, and service life of the network is prolonged.

The invention discloses an unmanned aerial vehicle-assisted wireless sensor network data collection method, which comprises the following steps that: (1) sensor nodes collect information in a communication range, generate corresponding event packets and send the event packets back to a base station; (2) a base station classifies the nodes of which the information value attenuation indexes are notzero as key nodes, and classifies the nodes of which the information value attenuation indexes are zero as common nodes; (3) access paths of all key nodes are planned by adopting a greedy algorithm according to the geographic positions of the nodes; (4) access paths of all common nodes are planned by adopting an ant colony algorithm of neighborhood search according to geographic positions of the nodes; (5) the total length of the path is calculated and whether the total length of the path is greater than the maximum flight length of the unmanned aerial vehicle is judged; (6) if so, the deletion gain of each common node is calculated, nodes corresponding to the maximum deletion gain are removed in the path, and the step (5) is executed; if not, the step (7) is executed; and (7) an unmannedaerial vehicle sequentially collects data of the sensor nodes according to the planned path. The method is low in energy consumption and simple in structure.

The invention discloses an energy-saving transmission self-adaption recursive least squares (RLS) distributed-type detection method of a wireless sensor network. Through the updating process of an increment of a distributed-type RLS weight number, the situation that measurement data of all-network nodes are utilized to train the distributed-type RLS weight number of a medium bridge of a bridge node set is achieved, convergence performance of an RLS algorithm is ensured, and the convergence performance is equivalent with that of an existing all-network distributed-type RLS algorithm. Distributed-type RLS weight number estimation is conducted on bridge nodes, adjacent transmission of the weight number is conducted on a sub-network of the bridge nodes, transmission updating of the weight number is achieved, and distributed-type detection is achieved. The energy-saving transmission self-adaption RLS distributed-type detection method of the wireless sensor network has the advantages that all-network parameter calculation and transmission in the prior art are avoided, communication traffic and node operation quantity are reduced, energy consumption is saved, and stability is high. In addition, the RLS weight number is calculated on the bridge nodes, all-network node data information is utilized, and performance of the algorithm is ensured. Under conditions of less energy consumption and lower network communication traffic, all-network detection performance can be achieved, and performance of the wireless sensor network is improved.

The invention discloses a compression method for sensor network data based on Huffman encoding and a random optimization policy. The current data compression methods have inefficiency. The invention aims at the fact that an encoding threshold is a dynamically changing value in the practical application, and by executing the random optimization policy, a base station can judge the values received by nodes every time in real time to determine the optimum transmission threshold, and the energy consumption of the nodes for receiving the base station information and the energy consumption for transmitting raw data or codes can be effectively balanced, thereby adapting to different network sizes and the fluctuation range of different monitoring values. By using the method of the invention, the average energy consumption of the nodes can be effectively reduced, the accuracy of the base station restoring the perception data of the nodes is improved, and an overall indicator formed by data accuracy, the average energy consumption of transmitting unit data nodes and the number of network failure nodes is optimized, thereby prolonging the service life of the network and expanding the overall performance of the network.

The invention discloses a WSN MAC protocol based on bidirectional curve traffic command system. The protocol includes that: a superframe structure is divided into non-active period and an active period, and the active period includes a contend access period, a beacon period and a non-contend access period; in the non-active period, a sensor node sleeps, a gathering node executes data fusion, and atraffic control command is generated; in the contend access period, the sensor node detecting an event reports brief information of event to the gathering node according to access authority and contend timeslot regulated by the gathering node; in the beacon period, the gathering configures contend access period access authority according to the reported event information and allocates the timeslot in the non-contend access period to a specific sensor node; and in the non-contend access period, and the sensor node sends detail data of the event to the gathering node in time division multiplexing manner in regulated timeslot according to timeslot allocation of the gathering node.

The invention relates to a a wireless sensor network non-uniform clustering algorithm, in particular to an annular wireless sensor network non-uniform clustering algorithm based on fuzzy control ring.In this algorithm, the sensor nodes are randomly distributed in concentric rings with the same interval; based on the annular network, a fuzzy control module is utilized, five input variables are adopted, the five input variables are residual energy, distance from each node to a base station, node degree, starting energy and ring width, and then the optimal cluster number of each ring, the opportunity that the nodes become cluster heads and the competition radius of the cluster heads are output in real time through an if-gen rule device. Therefore, the problem of non-uniform network energy consumption can be effectively balanced, the network energy consumption is obviously reduced, and the network life cycle is prolonged.

The invention discloses a real-time multicast method in a wireless multi-hop network. The method comprises the following steps of: constructing a mesh network; assessing a network condition; adaptively selecting an optimum coding mechanism and coding parameters; performing coding operating by using a core node; processing by using an intermediate node; and processing by using a receiving node. The real-time multicast method in the wireless multi-hop network designed in the invention is applied to a real-time multicast service in a mobile ad hoc network, the optimum coding mechanism and the parameter can be adaptively selected according to the current network condition, the reliability and throughput of the network are improved, the overall energy consumption of the network is reduced and the requirement on the real-time property of services can be met.

The invention discloses an N policy-based Internet of things cooperation node power control method, which belongs to the technical field of Internet of things. The method comprises steps: a cooperation node service queuing model is built; a cooperation node energy consumption model is built; a queuing theory is adopted to analyze the system performance; and a convex optimization theory is used for solving the optimal cooperation node energy consumption problem in a delay tolerant threshold. Compared with the previous Internet of things node life cycle prolonging method, the N policy-based cooperation node dormancy method focuses on research on the cooperation node from reality, while the node energy consumption is reduced as much as possible, the average delay of the system is also considered, compromise between the node energy consumption and the average delay of a data packet can be made, and a realistic guiding significance is realized when the relation between the node dormancy and the service is integrally considered.

The invention discloses a JPEG image compression method based on polygon clipping DCT, which includes reading original uncompressed images, transforming the images into luminance and chromatic aberration images, and dividing the luminance and chromatic aberration images into 8-line and 8-column image blocks; utilizing the method combining Arai Agui Nakajima (AAN) fast DCT algorithm with polygon clipping DCT, and performing calculation based on clipping coefficients to obtain DCT coefficients of the 8-line and 8-column image blocks; and quantizing and encoding the DCT coefficients respectively based on an AAN quantization table and a JPEG standard encoding table to obtain JPEG compression image data. According to the JPEG image compression method based on polygon clipping DCT, complete DCT transformation of 8-line and 8-column image blocks is not needed, instead, the calculating number of the DCT coefficients is adjusted flexibly according to the clipping coefficients, and the polygon clipping DCT is effectively combined with the AAN fast DCT algorithm, so that DCT, the calculated amount of image compression quality during the quantitative phase is greatly reduced in the condition that application filed requirements are satisfied.

The invention provides a path scheduling and controller design method of a networked control system based on multipath routing. The path scheduling and controller design method of the networked control system based on the multipath routing comprises the following steps: establishing a state space model for the networked control system, and establishing a switching system model based on delay considering a time-varying delay model caused by path switching; designing and using a cone complement linearization algorithm to solve a control gain of a subsystem according to a switching subsystem model; giving the design of a path scheduling scheme and calculating a path cost value of the network; and using a branch and bound method to design specific parameters of the scheduling scheme combined with the path cost value and the control gain of the subsystem.

The invention discloses a wireless ad hoc network neighbor node discovery method for a power construction site. Static edge nodes, static non-edge nodes and dynamic nodes are defined according to deployment positions; the static edge node and the non-edge node initialize an adjacent node table according to the deployment position; each node calculates the scanning probability of each beam direction according to the scanning coefficient, and selects the beam direction according to the scanning probability to execute neighbor node discovery; and the dynamic node detects whether a static edge node is found in each beam direction at a certain frequency, if so, further detects whether an adjacent node table in an adjacent 90-degree range on two sides of the dynamic node is empty, and if so, reduces the scanning coefficient in the beam direction in the 90-degree range and increases the scanning coefficient in the 180-degree symmetrical beam direction. The method has the advantages that through identity definition and edge detection of the node, limited energy of the node is concentrated in a wave beam direction which is more likely to be non-edge to execute neighbor node discovery, so that the energy consumption of the node is reduced, and the discovery efficiency is improved.

The invention discloses an environmental process warehouse communication system. The environmental process warehouse communication system comprises an environmental process warehouse network system, the environmental technology network warehouse system comprises a sensor network and a CAN network. The sensor network comprises a plurality of sensor nodes which are wirelessly interconnected; the CANnetwork includes a CAN bus, the plurality of sensor networks are respectively connected to the aggregation node in a multi-hop manner. The aggregation node is connected to a CAN bus of a CAN networkthrough the CAN interface unit. A plurality of sensor networks and a CAN network form a combined network through aggregation nodes, and the CAN network of a CAN bus is connected with a core switch through a CAN-to-Ethernet converter, is connected to the Internet through the core switch, and is interconnected with a data platform through the Internet; through common networking of the separated sensor network and the on-site CAN network, the network architecture is optimized, the requirement for the coverage range of the wireless sensor nodes is reduced, the node energy consumption is reduced, and the method is worthy of vigorous popularization.