Wireless sensor network charging method for multi-charge nodes

Patent metadata

Field	Value
Publication number	US-10110026-B2
Application number	US-201515536138-A
Country	US
Kind code	B2
Filing date	Nov 24, 2015
Priority date	May 12, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A wireless sensor network sensor network charging method for multi-charge nodes, including the following steps: (1) establishing a WSNs model; (2) dividing field ranges of charging trolleys; and (3) charging the charging trolleys: (a) initializing: l=0 and j=0, wherein l is the total number of received alarm nodes, and j is the serial number of an alarmed node; (b) receiving an alarm signal, updating values of l and j, generating a shortest charging path s l , and computing an energy discriminate vector; (c) if a vector element satisfies Q lj ≤5% B and j=1, 2, . . . , l, then executing a charging task on l alarm nodes according to the shortest charging path s l corresponded thereby, otherwise, returning to continuously update the values of l and j; (d) executing the charging task; and (e) determining whether the charging trolleys are required to go back to a parking lot for recharging, enabling the charging trolleys to go back to the parking lot for recharging if yes, and otherwise, returning to continuously update the values of l and j and the vector element Q lj .

First claim

What is claimed is:

1. A wireless sensor network charging method for multi-charge nodes, comprising the following steps:
(1) establishing a wireless sensor network (WSNs) model: by randomly distributing hundreds or thousands of sensors in a large surveillance area, with q number of charging trolleys and q number of parking lots, wherein a surveillance cycle is T;
a set of sensors being V, that is: V={v 1 , v 2 , v 3 . . . } and v 1 , v 2 and v 3 are respectively a first sensor, a second sensor and a third sensor; a battery capacity of each sensor being B, a consumption rate of a j th sensor being ρ j , a low energy alarm threshold being M j , M j =α·B, and 0<α<1, wherein α is a percentage of the low energy alarm threshold M j accounted for the battery capacity B;
i being a serial number of the charging trolley which is parked in the parking lot at a position r i , wherein r i =(x i , y i ), 1≤i≤q, x i and y i respectively represent two dimensional map coordinates of the position r i , and q represents the quantity of the charging trolleys; a base station being used to collect sensor information and communicate with the charging trolleys; the parking lots being used to recharge the charging trolleys; the battery capacity of every charging trolleys being E, a moving speed being a stable value S, and a sensor charging time for every charging trolley being a fixed value C;
(2) dividing a field range for every charging trolley; and
(3) conducting a charging task by each charging trolley.

2. The wireless sensor network charging method for multi-charge nodes according to claim 1 , wherein in the step (2), detail steps of dividing the field range for every charging trolleys comprise:
(2.1) generating an expansion node: by using a closed circuit η to encircle q number of charging trolleys and q number of parking lots corresponded thereby in the sensor network, wherein the circuit η does not include other sensor node therein;
(2.2) by using the expansion node as a root node, the sensor node being a smallest spanning tree ψ generated by a tree branch node;
(2.3) decomposing the smallest creation tree ψ: by taking the q number of parking lots as root nodes, decomposing the smallest spanning tree into q number of un-intersected root trees, and the upper limit for the total number of nodes in every root tree being:

K
=

⌈

A
q

⌉

,

 wherein A is a total number of sensor nodes in the sensor network, q is the quantity of the charging trolleys, and ┌·┐ indicates to round up; and
(2.4) connecting outer surrounding nodes of every root tree to form q number of circuits ζ 1 , ζ 2 . . . ζ q , wherein the circuit ζ i (i=1, 2, . . . , q) represents the field range of an i th charging trolley.

3. The wireless sensor network charging method for multi-charge nodes according to claim 1 wherein in the step (3), detailed steps of conducting the charging task by each charging trolley comprise:
(3.1) receiving a total number of alarm sensor nodes and a serial number of an alarmed sensor node by the charging trolleys, and initializing: l=0, j=0, wherein l is a total number of alarm sensor nodes being received, and j is a serial number of an alarmed sensor node;
(3.2) receiving signals emitted from a low energy sensor, updating values of l, j after receiving the alarm signals, generating a shortest charging path s l for every l value, and calculating an energy discriminant vector Q by the charging trolleys;
(3.3) if an element Q lj of the energy vector satisfies Q lj ≤5% B and j=1, 2, . . . , l, then conducting the step (3.4) based on the shortest charging path s l , otherwise, returning back to the step (3.2);
(3.4) conducting the charging tasks: that is, the charging trolleys start to charge the sensors; and
(3.5) determining by the charging trolleys on whether returning back to the parking lots for recharging is required, and it is if required, then the charging trolleys return back to the parking lots for recharging; otherwise, returning back to the steps (3.2).

4. The wireless sensor network charging method for multi-charge nodes according to claim 3 , wherein in the step (3.2), a method of generating the shortest charging path s l comprises:
a set of alarmed sensors being V c =(v 1 c , v 2 c , v 3 c . . . v l c );
by using the charging trolleys as a start-point, selecting in a path e m with the smallest Euclidean distance in l number of paths that connect with the charging trolleys, wherein e m connects another alarmed sensor node v i c with the charging trolleys;
by further using the sensor node v i c as the start-point, selecting a path e n with the smallest Euclidean distance from the remaining l−1 paths which excludes the path e m , wherein e n connects the alarmed sensor node v i c and the alarmed sensor node v i c ; and
obtaining the shortest charging path s l in which the charging trolleys are being used as the start-point and l number of to-be-charged sensor nodes are being passed by.

5. The wireless sensor network charging method for multi-charge nodes according to claim 3 , wherein in the step (3.2), the energy discriminant vector Q is defined by: a vector consisting of the minimum residual energy under conditions of assuming that the charging task starts when l number of alarm signals are received, and a j th alarmed sensor node is arranged to be charged at the last.

6. The wireless sensor network charging method for multi-charge nodes according to claim 5 , wherein in the step (3.2), the form of the energy discriminant vector Q is: └Q l1 Q l2 . . . Q lj . . . Q ll ┘, j=1, 2, . . . l; and a method of calculating the element Q lj of the energy discriminant vector is:

Q
lj

=

M
j

-

ρ
j

·

[

D
S

+

l
·
C

+

(

t
-

t
j

)

]

,

wherein M j is a low energy alarm threshold, the threshold is set as M j =20% B, B represents the battery capacity of each sensor, ρ j is an energy consumption rate of the j th alarmed sensor node, l is the total number of alarm sensor nodes being received, D is a total length of the shortest charging path corresponded by l, S is the moving speed of the charging trolleys, C is a charging time required each sensor, C is a

Assignees

• Univ Hefei Technology

Inventors

• Yuan Lifen
• Chen Peng
• He Yigang
• Luo Shuai
• Yuan Zhijie
• Cheng Zhen
• Zhao Deqin
• Sun Yesheng
• Wu Lei

Classifications

• B60L53/50

  Charging stations characterised by energy-storage or power-generation means · CPC title

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/42

  with electronic devices having internal batteries, e.g. mobile phones · CPC title

• H02J7/50

  acting upon multiple batteries simultaneously or sequentially · CPC title

• H04W84/18

  Self-organising networks, e.g. ad-hoc networks or sensor networks · CPC title