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【路径规划】基于A星算法和改进A星算法求解路径规划问题matlab代码

news 2026/8/13 21:12:31

1 简介

一种基于A星算法的最短寻路方法.其包括将搜索区域划分为多个网格并将起点放入开启列表中,搜索起点所在网格相邻的网格并计算相邻的网格点与目标点的距离,采用A星算法计算从初始状态到目标状态的代价估计,通过判断起点至目标点各路径对应代价估计值是否为最小值寻找新起点,再通过判断新的起点是否为目标点完成寻路.

2 部分代码

%************************************************************************

%**************************************************************************

close all;

%**************************************************************************

%**************** Choose System Architecture ***************************

%**************************************************************************

% Here you can choose the hardware architecture implementation

% 1 . Single Robot mode

% 2 . Dual Robot Single Computer

% 3 . Dual Roboto Dual Computer

% 4 . Multi Robot Single Computer

% 5 . Multi Robot Ethernet Based

disp(' Generating Grid ... ');

co=or;

crn=s;

noOfNodes = nooc*noor;

nodmat=ones(nooc,noor,3);

nodmat(1:noOfNodes)=1:noOfNodes;

nodmat(:,:,2)=(find(nodmat(:,2,2)==1))*ones(1,noor);

nodmat(:,:,3)=ones(nooc,1)*(find(nodmat(2,:,3)==1));

nodmat(:,:,1)=flipdim((nodmat(:,:,1)),2);

nodmat(:,:,2)=flipdim((nodmat(:,:,2)),2);

nodmat(:,:,3)=flipdim((nodmat(:,:,3)),2);

noddata=reshape(nodmat,noOfNodes,3);

%rand('state', 0);

if plot_flag==1

scrsz = get(0,'ScreenSize');

h=figure(gcf);

set(h,'Position',[scrsz(3)/8 scrsz(4)/8 scrsz(3)-2*scrsz(3)/8 ...

scrsz(4)-2*scrsz(4)/8]);

clf;

hold on;

end

Astar_coor=noddata(:,2:3)*GTS;

netXloc = Astar_coor(:,1)';

netYloc = Astar_coor(:,2)';

axis([min(netXloc)-20 max(netXloc)+30 min(netYloc)-20 max(netYloc)+30])

Astar_connect = zeros(noOfNodes, noOfNodes);

Astar_coord = zeros(noOfNodes, 2);

for i = 1:noOfNodes

Astar_coord(i,1) = netXloc(i);

Astar_coord(i,2) = netYloc(i);

for j = 1:noOfNodes

distance = sqrt((netXloc(i) - netXloc(j))^2 + (netYloc(i) - netYloc(j))^2);

ll=isempty(find(o==i, 1));

lm=isempty(find(o==j, 1));

if (distance <= R && ll==1 && lm==1)

matrix(i, j) = distance; % if set to '1', Dijkstra computes Spath in terms of hops; if set to 'distance', it is the real shortest path

if i~=j % must be satisfied

Astar_connect(i, j) = 1;

else

Astar_connect(i, j) = 0;

end

if plot_flag==1

line([netXloc(i) netXloc(j)], [netYloc(i) netYloc(j)], 'color',[.65 .65 .65],'LineStyle', ':');

end

else

matrix(i, j) = inf;

Astar_connect(i, j) = 0;

end;

end

for i = 1:noOfNodes

if plot_nodenum

text(netXloc(i)+20, netYloc(i), num2str(i));

end

if plot_flag==1

if i==s

plot(netXloc(i), netYloc(i),'square','MarkerSize',12,'MarkerFaceColor','g');

hold on;

end

if i==d

plot(netXloc(i), netYloc(i),'square','MarkerSize',12,'MarkerFaceColor','r');

end

if isempty(find(o==i))

plot(netXloc(i), netYloc(i),'.');

end

end;

% activeNodes = [];

% for i = 1:noOfNodes,

% % initialize the farthest node to be itself;

% farthestPreviousHop(i) = i; % used to compute the RTS/CTS range;

% farthestNextHop(i) = i;

% end;

Astar_coord=Astar_coord';

%Astar_connect;

disp('Generating Paths ... ')

%[path, totalCost, farthestPreviousHop, farthestNextHop] = dijkstra(noOfNodes, matrix, s, d, farthestPreviousHop, farthestNextHop);

% combo = [noOfNodes s-1 d-1 R/2];

%[Astar_path, Astar_search] = Astar(Astar_coord', Astar_connect, combo); % notice, we must put Astar_coord' rather than Astar_coord

%[Astar_paths,cost_astar,astar_time] = Astarm(Astar_coord, Astar_connect, s , d);

%[Astar_path,Astar_search]=Astar(Astar_coord, Astar_connect, combo);

[Astar_path,cost_astar,astar_time,Astar_dist] =komegaA(Astar_coord, Astar_connect, s, d, 1, inf, 0);

[komega_path,cost_komega,ko_time,komega_dist]=komegaA(Astar_coord, Astar_connect, s, d, k , b, n);

if disp_summary==1

Astar_path, komega_path,cost_astar,cost_komega,astar_time,ko_time, Astar_dist, komega_dist

end

if ~isempty(Astar_path)

for i = 1:(length(Astar_path)-1)

if plot_flag==1

astr=line([netXloc(Astar_path(i)) netXloc(Astar_path(i+1))], [netYloc(Astar_path(i)) netYloc(Astar_path(i+1))], 'Color','r','LineWidth', 2, 'LineStyle', '-.');

if plot_nodenum==1

text(netXloc(i), netYloc(i), num2str(i));

end

end;

if ~isempty(komega_path)

for i = 1:(length(komega_path)-1)

if plot_flag==1

kom=line([netXloc(komega_path(i)) netXloc(komega_path(i+1))], [netYloc(komega_path(i)) netYloc(komega_path(i+1))], 'Color','g','LineWidth', 2, 'LineStyle', '-');

if plot_nodenum==1

text(netXloc(i), netYloc(i), num2str(i));

end

end;

rest=title('Comparison Between A-Star and K-Omega');

set(rest,'Interpreter','latex');

dkstr=strcat('K-Omega(k=',num2str(k),' b=',num2str(b),' n=',num2str(n),')');

kleg=legend([astr kom],'A-Star',dkstr);hold on;

set(kleg,'Interpreter','latex');

if plot_flag == 1

hold off;

end