利用Matlab写出路径规划的A*二次规划代码
时间: 2023-08-06 22:02:58 浏览: 169
好的,以下是一个简单的A*二次规划代码的实现,使用Matlab语言:
```matlab
function [path, cost] = Astar_QP(start, goal, obs, res)
% start: 起点坐标
% goal: 终点坐标
% obs: 障碍物信息(包括障碍物位置和大小)
% res: 地图分辨率(用于计算代价)
% 初始化A*算法
open_list = [start; heuristic(start, goal)];
closed_list = [];
parent = zeros(size(obs, 1), 1);
g = zeros(size(obs, 1), 1);
% 初始化二次规划器
Q = diag([1, 1]);
f = zeros(2, 1);
A = [];
b = [];
lb = [-inf; -inf];
ub = [inf; inf];
% 执行A*算法
while ~isempty(open_list)
% 选择代价最小的节点
[~, idx] = min(open_list(:, 3));
current = open_list(idx, 1:2);
% 到达终点
if isequal(current, goal)
path = reconstruct_path(parent, current);
cost = g(idx);
return
end
% 从开启列表中移除当前节点
open_list(idx, :) = [];
% 将当前节点加入关闭列表
closed_list(end+1, :) = [current, heuristic(current, goal)];
% 扩展当前节点
neighbors = get_neighbors(current, obs, res);
for i = 1:size(neighbors, 1)
neighbor = neighbors(i, :);
% 如果邻居节点已经在关闭列表中,则跳过
if ismember(neighbor, closed_list(:, 1:2), 'rows')
continue
end
% 计算邻居节点代价
g_new = g(idx) + norm(neighbor - current);
% 如果邻居节点不在开启列表中,则加入
idx_new = find(ismember(open_list(:, 1:2), neighbor, 'rows'), 1);
if isempty(idx_new)
h_new = heuristic(neighbor, goal);
open_list(end+1, :) = [neighbor, g_new+h_new];
idx_new = size(open_list, 1);
elseif g_new >= g(idx_new)
continue
end
% 更新邻居节点信息
parent(idx_new) = idx;
g(idx_new) = g_new;
% 更新二次规划器信息
Aeq = [1, 0; -1, 0; 0, 1; 0, -1];
beq = [neighbor(1); -neighbor(1)+obs(:, 1)-obs(:, 3)/2; neighbor(2); -neighbor(2)+obs(:, 2)-obs(:, 4)/2];
[x, cost, exitflag] = quadprog(Q, f, Aeq, beq, [], [], lb, ub);
% 如果二次规划失败,则跳过
if exitflag ~= 1
continue
end
% 更新邻居节点代价
open_list(idx_new, 3) = g_new + cost;
end
end
% 如果无法找到路径,则返回空
path = [];
cost = Inf;
end
% 估价函数
function h = heuristic(current, goal)
h = norm(current - goal);
end
% 获取邻居节点
function neighbors = get_neighbors(current, obs, res)
d = res;
x = current(1);
y = current(2);
neighbors = [x-d, y; x+d, y; x, y-d; x, y+d];
idx = neighbors(:, 1) < 0 | neighbors(:, 2) < 0 | neighbors(:, 1) > 100 | neighbors(:, 2) > 100;
neighbors(idx, :) = [];
for i = 1:size(obs, 1)
idx = neighbors(:, 1) > obs(i, 1)-obs(i, 3)/2 & neighbors(:, 1) < obs(i, 1)+obs(i, 3)/2 & neighbors(:, 2) > obs(i, 2)-obs(i, 4)/2 & neighbors(:, 2) < obs(i, 2)+obs(i, 4)/2;
neighbors(idx, :) = [];
end
end
% 重构路径
function path = reconstruct_path(parent, current)
path = current;
while parent(current) ~= 0
current = parent(current);
path = [current; path];
end
end
```
上述代码实现了一个简单的A*二次规划算法,用于路径规划。其中,`get_neighbors`函数用于获取邻居节点,`heuristic`函数用于计算估价函数,`reconstruct_path`函数用于重构路径。在主函数`Astar_QP`中,我们使用开启列表和关闭列表来实现A*算法,同时使用二次规划器计算路径代价。
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