rrt算法matlab
时间: 2023-09-26 09:08:45 浏览: 108
RRT (Rapidly-exploring Random Tree) 是一种用于路径规划的算法。在 MATLAB 中实现 RRT 算法可以通过以下步骤进行:
1. 定义问题空间:首先,你需要定义问题的状态空间和可行域。状态空间是指机器人或物体可能存在的位置和方向的集合。可行域则是指机器人或物体可以在其中移动的区域。
2. 初始化树:创建一个包含起始状态(节点)的树。起始状态是指机器人或物体的初始位置。
3. 随机采样:随机在问题空间中采样一个点作为目标状态。
4. 最近邻搜索:从树中找到与目标状态最近的节点。
5. 扩展树:从最近邻节点向目标状态方向扩展一条新的边,并创建一个新的节点。
6. 碰撞检测:检测新产生的边是否与障碍物碰撞。如果没有碰撞,则将新节点添加到树中。
7. 迭代:重复步骤3-6,直到达到终止条件(例如,达到目标状态或超过最大迭代次数)。
8. 路径回溯:从目标状态回溯树,找到一条从起始状态到目标状态的路径。
9. 可视化路径:将路径可视化以进行验证和展示。
这是一个简单的 RRT 算法的实现步骤。你可以根据具体的问题进行修改和扩展。
相关问题
rrt matlab算法,rrt算法matlab代码
以下是基于 RRT(Rapidly-exploring Random Tree)算法的 Matlab 代码,用于构建机器人路径规划:
```matlab
clear all; close all; clc
% Environment and robot parameters
xMin = 0;
xMax = 10;
yMin = 0;
yMax = 10;
obs = [4 4 1; 6 6 1];
robotLength = 0.5;
robotWidth = 0.5;
% Start and goal positions
startPos = [1,1];
goalPos = [9,9];
% RRT parameters
maxNodes = 5000;
stepSize = 0.5;
nodes(1).x = startPos(1);
nodes(1).y = startPos(2);
nodes(1).parent = 0;
for i = 2:maxNodes
x = rand*(xMax-xMin) + xMin;
y = rand*(yMax-yMin) + yMin;
node = [x,y];
% Check if node is inside an obstacle
insideObs = 0;
for j = 1:size(obs,1)
if sqrt((node(1)-obs(j,1))^2 + (node(2)-obs(j,2))^2) < obs(j,3)
insideObs = 1;
break;
end
end
if insideObs == 1
continue;
end
% Find the nearest node
dist = inf;
nearestNode = 0;
for j = 1:length(nodes)
d = sqrt((node(1)-nodes(j).x)^2 + (node(2)-nodes(j).y)^2);
if d < dist
dist = d;
nearestNode = j;
end
end
% Check if there is a direct path between the nearest node and the new node
theta = atan2(node(2)-nodes(nearestNode).y, node(1)-nodes(nearestNode).x);
xTest = nodes(nearestNode).x + stepSize*cos(theta);
yTest = nodes(nearestNode).y + stepSize*sin(theta);
if sqrt((xTest-node(1))^2 + (yTest-node(2))^2) > stepSize
continue;
end
% Check if the direct path is inside an obstacle
insideObs = 0;
for j = 1:size(obs,1)
if sqrt((xTest-obs(j,1))^2 + (yTest-obs(j,2))^2) < obs(j,3)
insideObs = 1;
break;
end
end
if insideObs == 1
continue;
end
% Add the new node to the tree
nodes(end+1).x = xTest;
nodes(end).y = yTest;
nodes(end).parent = nearestNode;
% Check if the goal has been reached
if sqrt((nodes(end).x-goalPos(1))^2 + (nodes(end).y-goalPos(2))^2) < stepSize
break;
end
end
% Plot the obstacles
figure(1)
hold on
axis([xMin xMax yMin yMax])
for i = 1:size(obs,1)
rectangle('Position',[obs(i,1)-obs(i,3), obs(i,2)-obs(i,3), 2*obs(i,3), 2*obs(i,3)], 'Curvature', [1,1], 'FaceColor', 'r')
end
% Plot the tree
for i = 2:length(nodes)
x = [nodes(i).x, nodes(nodes(i).parent).x];
y = [nodes(i).y, nodes(nodes(i).parent).y];
plot(x,y,'k')
end
% Find the path from start to goal
path = [nodes(end).x, nodes(end).y];
while nodes(end).parent ~= 0
endNode = nodes(end);
path = [endNode.x, endNode.y; path];
endNode = nodes(endNode.parent);
end
path = [startPos; path];
% Plot the path
plot(path(:,1), path(:,2), 'b', 'LineWidth', 2)
```
这段代码会生成一个基于 RRT 算法的路径规划过程,其中包括环境参数、机器人参数、起始位置、目标位置和 RRT 参数。代码将生成一个随机树,以搜索从起始位置到目标位置的路径。最终,该代码会绘制出路径和环境。
rrt算法 matlab代码
以下是RRT算法的MATLAB实现:
```
% RRT algorithm
% Written by Yifan Hou, 2018
% Define the map boundaries
map = [0 100; 0 100];
% Define the start and goal positions
start_pos = [10 10];
goal_pos = [90 90];
% Define the step size
step_size = 5;
% Define the maximum number of iterations
max_iter = 1000;
% Define the maximum distance to connect to the tree
max_dist = 10;
% Define the radius of the goal region
goal_radius = 2;
% Initialize the tree with the start position
tree = [start_pos 0];
% Initialize the list of explored nodes
explored = [];
% Run the RRT algorithm
for i = 1:max_iter
% Generate a random point in the map
random_point = [randi(map(1,:), 1) randi(map(2,:), 1)];
% Find the nearest node in the tree
[nearest_node, nearest_dist] = nearestNode(random_point, tree);
% Calculate the new node in the direction of the random point
new_node = steer(nearest_node, random_point, step_size);
% Check if the new node is within the map boundaries
if checkBounds(new_node, map)
% Check if the new node is collision-free
if checkCollision(nearest_node, new_node, map)
% Add the new node to the tree
tree = [tree; new_node nearest_node];
% Check if the new node is within the goal region
if norm(new_node - goal_pos) <= goal_radius
% Add the goal node to the tree
tree = [tree; goal_pos size(tree, 1)];
% Trace the path from the goal node to the start node
path = tracePath(tree);
% Plot the final path
plotPath(path, explored, map);
break;
end
% Add the new node to the list of explored nodes
explored = [explored; new_node];
% Connect the new node to the tree if it is within the maximum
% distance
if nearest_dist <= max_dist
tree = [tree; new_node size(tree, 1)];
end
end
end
end
```
其中,nearestNode函数用于查找离给定点最近的树节点,steer函数用于从最近的节点朝着随机点方向延伸一定长度,checkBounds函数用于检查点是否在地图边界内,checkCollision函数用于检查两个点之间的路径是否与障碍物相交,tracePath函数用于从终点向根节点遍历树,plotPath函数用于绘制路径和探索节点。这些函数在代码中并未给出,需要根据实际情况自行实现。
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