带你玩转PX4无人机仿真(2) —— 定点飞行
前言： 本教程是在仿真中实现无人机定点飞行（如果想要在真机上实现，还要修改代码）
注：搭建仿真环境可以看下面教程 👇
(最新)ubuntu搭建PX4无人机仿真环境(1) —— 概念介绍及环境建议
(最新)ubuntu搭建PX4无人机仿真环境(2) —— MAVROS安装
(最新)ubuntu搭建PX4无人机仿真环境(3) —— ubuntu安装QGC地面站
(最新)ubuntu搭建PX4无人机仿真环境(4) —— 仿真环境搭建
ubuntu安装ROS melodic(最新、超详细图文教程)
前期回顾：
带你玩转PX4无人机仿真(1) —— 运行官方案例（C++）
一. 仿真代码
我们继续使用 带你玩转PX4无人机仿真(1) 中的功能包，在 off_node 功能包下的 src 目录下新建一个 rect_no_rc.cpp 文件
cd ~/catkin_ws/src/off_node/src/
touch rect_no_rc.cpp // 创建文件
gedit rect_no_rc.cpp // 打开文件
打开文件，将代码粘贴上去
目标点：(0,0,2) (5,0,2) (5,5,2) (0,5,2)
/**
* @file rect_no_rc.cpp
* @brief Offboard control example node, written with MAVROS version 0.19.x, PX4 Pro Flight
* Stack and tested in Gazebo Classic SITL
*/
#include <ros/ros.h>
#include <geometry_msgs/PoseStamped.h>
#include <mavros_msgs/CommandBool.h>
#include <mavros_msgs/SetMode.h>
#include <mavros_msgs/State.h>
#define GREEN "\033[0;1;32m"
using namespace std;
mavros_msgs::State current_state; // 无人机当前状态
geometry_msgs::PoseStamped curr_pos; // 无人机当前位置
geometry_msgs::PoseStamped aim_pos; // 无人机目标位置
void state_cb(const mavros_msgs::State::ConstPtr& msg){
current_state = *msg;
ROS_INFO("current mode: %s",current_state.mode.c_str());
ROS_INFO("system_status: %d",current_state.system_status);
}
void arrive_pos(const geometry_msgs::PoseStamped::ConstPtr& msg){
curr_pos = *msg;
cout <<GREEN <<fabs((*msg).pose.position.z - aim_pos.pose.position.z) <<endl;
}
int main(int argc, char **argv)
{
ros::init(argc, argv, "rect_no_rc");
ros::NodeHandle nh;
ros::Subscriber state_sub = nh.subscribe<mavros_msgs::State>
("mavros/state", 10, state_cb);
ros::Publisher local_pos_pub = nh.advertise<geometry_msgs::PoseStamped>
("mavros/setpoint_position/local", 10);
ros::ServiceClient arming_client = nh.serviceClient<mavros_msgs::CommandBool>
("mavros/cmd/arming");
ros::ServiceClient set_mode_client = nh.serviceClient<mavros_msgs::SetMode>
("mavros/set_mode");
ros::Subscriber local_pos_sub = nh.subscribe<geometry_msgs::PoseStamped>
("mavros/local_position/pose",10,arrive_pos);
//the setpoint publishing rate MUST be faster than 2Hz
ros::Rate rate(20.0); // 20Hz
// wait for FCU connection
while(ros::ok() && !current_state.connected){
ros::spinOnce();
rate.sleep();
}
//geometry_msgs::PoseStamped aim_pos;
aim_pos.pose.position.x = 0;
aim_pos.pose.position.y = 0;
aim_pos.pose.position.z = 2;
//send a few setpoints before starting
for(int i = 100; ros::ok() && i > 0; --i){
local_pos_pub.publish(aim_pos);
ros::spinOnce();
rate.sleep();
}
mavros_msgs::SetMode offb_set_mode;
offb_set_mode.request.custom_mode = "OFFBOARD";
mavros_msgs::CommandBool arm_cmd;
arm_cmd.request.value = true;
ros::Time last_request = ros::Time::now();
int count = 0; // 计时
while(ros::ok()){
if( current_state.mode != "OFFBOARD" &&
(ros::Time::now() - last_request > ros::Duration(5.0))){
if( set_mode_client.call(offb_set_mode) &&
offb_set_mode.response.mode_sent){
ROS_INFO("Offboard enabled");
} // 代码切换 Offboard 模式
last_request = ros::Time::now();
} else {
if( !current_state.armed &&
(ros::Time::now() - last_request > ros::Duration(5.0))){
if( arming_client.call(arm_cmd) &&
arm_cmd.response.success){
ROS_INFO("Vehicle armed");
} // 解锁
last_request = ros::Time::now();
}
}
if(fabs(curr_pos.pose.position.z - aim_pos.pose.position.z) <= 0.3){
count++;
// 时间只是参考，运行后会有误差
if(count == 300) // 15s
{
aim_pos.pose.position.x = 5;
}
if(count == 600) // 30s
{
aim_pos.pose.position.y = 5;
}
if(count == 900) // 45s
{
aim_pos.pose.position.x = 0;
}
if(count == 1200) // 60s
{
aim_pos.pose.position.x = 0;
aim_pos.pose.position.y = 0;
}
if(count >= 1500) // 75s
{
mavros_msgs::SetMode land_set_mode;
land_set_mode.request.custom_mode = "AUTO.LAND"; // 切换降落模式
if(set_mode_client.call(land_set_mode) && land_set_mode.response.mode_sent){
ROS_INFO("land enabled");
}
//任务结束,关闭该节点
ros::shutdown();
}
}
local_pos_pub.publish(aim_pos);
ros::spinOnce();
rate.sleep();
}
return 0;
}
将下面内容添加到 off_node 功能包下的 CMakeLists.txt 文件里
add_executable(rect_no_rc src/rect_no_rc.cpp)
target_link_libraries(rect_no_rc ${catkin_LIBRARIES})
二. 编译运行
运行下面命令，编译代码
cd ~/catkin_ws
catkin_make # 使用catkin build话，则为 catkin build
创建一个启动脚本 rect.sh
#!/bin/bash
source ~/.bashrc
gnome-terminal --window -e 'bash -c "roscore; exec bash"' \
--tab -e 'bash -c "sleep 5; roslaunch px4 mavros_posix_sitl.launch; exec bash"' \
--tab -e 'bash -c "sleep 10; rosrun off_node rect_no_rc; exec bash"' \
运行
chmod +x rect.sh
./rect.sh
运行效果如下：👇
PX4无人机仿真——定点飞行