无线传感器网络的节点自定位技术
SLR定位算法的MATLAB实现
(2009-06-1219:02:44)
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标签：分类：无线定位
杂谈
SLR定位算法的MATLAB实现,针对2006IEEE中的一篇文章写的,实现和文中一致。%2008.1.17开始SL_R定位了Num个未知节点--2008.1.20结束
%Author:jason_deng
%Instrutor::LiuHao
%初始部分花时13秒左右
%优化部分花时80秒左右
%硬件环境:Core24400双核2.0GHz,RAM:DDRII667HD:160GSATA
%软件环境:windowsxpSP2MATLAB7.0.4
clearall
tic
%产生100个随机节点node(x(i),y(i))
Num=210;
%产生的节点所在区域大小为10*10的正方形区域
area=500;
%锚节点数10个
AnchorNum=90;
%锚节点变量AnchorX,AnchorY
%随机生成Num个未知节点
figure(1)
fori=1:Num
temp=area*rand(1,2);
node(i,1)=temp(1);%x
node(i,2)=temp(2);%y
node1(i,1)=node(i,1);
node1(i,2)=node(i,2);
text(node(i,1),node(i,2),num2str(i),'FontSize',5);
end
%随机生成AnchorNum个锚节点
fori=1:AnchorNum
temp=area*rand(1,2);
anchor(i,1)=temp(1);%x
anchor(i,2)=temp(2);%y
end
%画图
holdon
plot(node(:,1),node(:,2),'rO');%红圈
plot(anchor(:,1),anchor(:,2),'k^','MarkerFaceColor','k');%上三角形填充色黑色
%SL-R算法开始实现......
%未知节点一跳内与锚节点的距离为Rn_A,先申明这个量
%EPXNO即距离的差值
EPXNO=5;
%选点用于计算估计节点个数N
N=50
%节点的通信半径
Radio=50.0;%即一跳
%寻找未知节点一跳内的某个锚节点
count=0;%记录一跳内未找到锚节点的未知节点的计数
count2=0;%记录一跳到二跳间的未找到锚节点的未知节点的计数
fori=1:Num
Flag=1;
forj=1:AnchorNum
Rn_A(i)=sqrt((node(i,1)-anchor(j,1))^2+(node(i,2)-anchor(j,2))^2);%R13
ifRn_A(i)
Anchor_1(i,1)=anchor(j,1);%未知节点一跳内的一个锚节点
Anchor_1(i,2)=anchor(j,2);
Flag=0;
break;
end
end
ifFlag==1
%一跳找不到的未知节点,留后处理,目前采用丢弃处理%后面处理除去这些节点(不为之定位)
count=count+1;
RecordNoOneHop(count)=i;
%做标记
node(i,1)=-1;
else
%寻找未知节点二跳内的某个锚节点
Flag2=1;
forj=1:AnchorNum
Rn_A2=sqrt((node(i,1)-anchor(j,1))^2+(node(i,2)-anchor(j,2))^2);%R13.引入40%的误差
ifRn_A2Radio
Anchor_2(i,1)=anchor(j,1);%未知节点二跳内的一个锚节点
Anchor_2(i,2)=anchor(j,2);
Flag2=0;
break;
end
end
ifFlag2==1
%两跳找不到的未知节点,留后处理
count2=count2+1;
RecordNoTwoHop(count2)=i;
%后面处理除去这些节点(不为之定位)
node(i,1)=-1;
end
end
end
%随机产生5000个点,根据条件找到估计节点坐标
randNum=2000;
countN=100;
fori=1:Num
%除去不符合要求的节点,不予定位
if(node(i,1)==-1)
continue;
end
nodes(i,1)=0;%为后面优化用时的初始化
countnum=0;
ex(i,1)=0;
ex(i,2)=0;
forj=1:randNum
tempR=rand(1);
tempA=6.28*rand(1);
randnode(j,1)=Radio*tempR*cos(tempA)+Anchor_1(i,1);
randnode(j,2)=Radio*tempR*sin(tempA)+Anchor_1(i,2);
if(randnode(j,1)>=500)|(randnode(j,2)>=500)|(randnode(j,1)
end
if(sqrt((randnode(j,1)-Anchor_1(i,1))^2+(randnode(j,2)-Anchor_1(i,2))^2)
&&(sqrt((randnode(j,1)-Anchor_2(i,1))^2
+(randnode(j,2)-Anchor_2(i,2))^2)
&&abs(Rn_A(i)-abs(sqrt((randnode(j,1)-Anchor_1(i,1))^2
+(randnode(j,2)-Anchor_1(i,2))^2)))
countnum=countnum+1;
ex(i,1)=ex(i,1)+randnode(j,1);
ex(i,2)=ex(i,2)+randnode(j,2);
end
ifcountnum==countN
break;
end
end
countnum;
if(countnum)
ex(i,1)=ex(i,1)/countnum;
ex(i,2)=ex(i,2)/countnum;
else%找不到时
%ex(i,1)=node(i,1);
%ex(i,2)=node(i,2);
node(i,1)=-1;
end
end
%显示运行状态
count
size(ex(:,1))
size(node(:,1))
size(Anchor_1)
size(Anchor_2)
%输出初始处理后的结果
rangebaseerr=0;
rberrcount=0;
fori=1:Num
if(node(i,1)==-1)
continue;
end
plot(ex(i,1),ex(i,2),'bO')%
line([node(i,1)ex(i,1)],[node(i,2)ex(i,2)]);
%求定位误差
tes(i)=abs(sqrt((ex(i,1)-node(i,1))^2+(ex(i,2)-node(i,2))^2))
rangebaseerr=rangebaseerr+abs(sqrt((ex(i,1)-node(i,1))^2+(ex(i,2)-node(i,2))^2))/Radio;rberrcount=rberrcount+1;
end
t1=toc
rangebaseerr=rangebaseerr/rberrcount
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%优化........
tic
Delta=1;
%可处理节点个数
excount=Num-count-count2
%找100个节点
%先找出邻居节点再算,先存放下每个节点的邻层节点
fori=1:Num
ci(i)=0;%记i节点的邻居个数
end
Neighbor(Num,1)=0;
fori=1:Num-1
if(node(i,1)==-1)
continue;
end
forj=i+1:Num
if(node(j,1)==-1)
continue;
end
distance=sqrt((node(i,1)-node(j,1))^2+(node(i,2)-node(j,2))^2)*0.55;%计算距离ifdistance
ci(i)=ci(i)+1;%
Neighbor(i,ci(i))=j;
%同时相对的j也认为i是他的邻居
ci(j)=ci(j)+1;
Neighbor(j,ci(j),1)=i;
end
end
end
%找节点的对应的一跳内的锚节点
fori=1:Num
if(node(i,1)==-1)
continue;
end
cAnchor(i)=0;%记录i节点的邻居锚节点数
forj=1:AnchorNum
distance=sqrt((node(i,1)-anchor(j,1))^2+(node(i,2)-anchor(j,2))^2);%R13
ifdistance
cAnchor(i)=cAnchor(i)+1;
NeighborAnchor(i,cAnchor(i))=j;
end
end
end
toc
tic
while(1)
fori=1:Num
if(node(i,1)==-1)
continue;
end
if(nodes(i,1)==-2)
continue;
end
countnum=0;
forj=1:randNum
tempR=rand(1);
tempA=6.28*rand(1);
randnode(j,1)=Radio*tempR*cos(tempA)+Anchor_1(i,1);
randnode(j,2)=Radio*tempR*sin(tempA)+Anchor_1(i,2);
if(randnode(j,1)>=500)|(randnode(j,2)>=500)|(randnode(j,1)
end
%根据公式二获得估计节点
%if(((randnode(j,1)-Anchor_1(i,1))^2+(randnode(j,2)-Anchor_1(i,2))^2)
%&(Rn_A(i)-EPXNO)^2
(randnode(j,2)-Anchor_1(i,2))^2)
if(sqrt((randnode(j,1)-Anchor_1(i,1))^2
+(randnode(j,2)-Anchor_1(i,2))^2)
&&(sqrt((randnode(j,1)-Anchor_2(i,1))^2
+(randnode(j,2)-Anchor_2(i,2))^2)
&&abs(Rn_A(i)-abs(sqrt((randnode(j,1)-Anchor_1(i,1))^2
+(randnode(j,2)-Anchor_1(i,2))^2)))
countnum=countnum+1;
RiA(i,countnum)=0;%第i个需定位的节点的第countnum个随机节点的权值
fork=1:cAnchor(i)
ik=NeighborAnchor(i,k);
distance=sqrt((randnode(j,1)-anchor(ik,1))^2+(randnode(j,2)-anchor(ik,2))^2);%计算距离
RiA(i,countnum)=RiA(i,countnum)+...
1.5*((sqrt((node(i,1)-anchor(ik,1))^2+(node(i,2)-anchor(ik,2))^2)-distance)^2);end%fork=1:cAnchor(i)
%找与一跳内的相邻节点
randnodeiN(i,countnum)=0;
fork=1:ci(i)
ik=Neighbor(i,k);
distance=sqrt((node(i,1)-node(ik,1))^2+(node(i,2)-node(ik,2))^2);%计算距离
%判断邻居节点是否在一跳内(除锚节点)
ifdistance
randnodeiN(i,countnum)=randnodeiN(i,countnum)+...
(distance-sqrt((randnode(j,1)-ex(ik,1))^2+(randnode(j,2)-ex(ik,2))^2))^2;
end
end%fork=1:ci(i)
w(i,countnum)=RiA(i,countnum)+randnodeiN(i,countnum);
tex(countnum,1)=randnode(j,1);
tex(countnum,2)=randnode(j,2);
end%if(
+(randnode(j,2)-Anchor_1(i,2))^2)
ifcountnum==countN
break;
end
end%forj=1:randNumsqrt((randnode(j,1)-Anchor_1(i,1))^2
%如果5000中一个满足条件的节点也没有找到话
if(countnum==0)
ext(i,1)=ex(i,1);
ext(i,2)=ex(i,2);
else
%找权值最小的那个随机节点
tmin=w(i,1);
posion=1;%获位置值
fork=2:countnum
iftmin>w(i,k)
tmin=w(i,k);
posion=k;
end
end
ext(i,1)=tex(posion,1);%第n次优化得到估计坐标值
ext(i,2)=tex(posion,2);
end%if(countnum==0)
if(sqrt((ex(i,1)-ext(i,1))^2+(ex(i,2)-ext(i,2))^2))
nodes(i,1)=-2;%之后这个节点就不再优化了
excount=excount-1;
end
ex(i,1)=ext(i,1);
ex(i,2)=ext(i,2);
end%fori=1:Num
ifexcount==0
break;
end
end%while(1)
tx=toc
%绘制优化后的结果
figure(2)
%输出初始处理后的结果
rangebaseerr=0;
rberrcount=0;
fori=1:Num
plot(node1(i,1),node1(i,2),'rO');%红圈
if(node(i,1)==-1)
continue;
end
holdon
plot(ex(i,1),ex(i,2),'b*')%
line([node(i,1)ex(i,1)],[node(i,2)ex(i,2)]);
%求定位误差
rangebaseerr=rangebaseerr+norm(ex(i,:)-node(i,:))/Radio;
rberrcount=rberrcount+1;
end
plot(anchor(:,1),anchor(:,2),'k^','MarkerFaceColor','k');%上三角形填充色黑色rangebaseerr=rangebaseerr/rberrcount