安装PX4

下载源码

git clone https://github.com/PX4/PX4-Autopilot.git --recursive

进入PX4-Autopilot文件夹，继续下载未下载的组件

cd PX4-Autopilot/
git submodule update --init --recursive

执行Ubuntun.sh脚本

bash ./PX4-Autopilot/Tools/setup/ubuntu.sh

出现python部分包的版本问题

python3 -m pip install --upgrade pip
python3 -m pip install --upgrade Pillow

再执行

bash ./PX4-Autopilot/Tools/setup/ubuntu.sh --fix-missing

reboot系统
测试进入PX4-Autopilot文件夹内

make px4_sitl_default gazebo

添加到环境变量

source ~/PX4-Autopilot/Tools/simulation/gazebo-classic/setup_gazebo.bash ~/PX4-Autopilot ~/PX4-Autopilot/build/px4_sitl_default
export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:~/PX4-Autopilot
export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:~/PX4-Autopilot/Tools/simulation/gazebo-classic/sitl_gazebo-classic

安装MAVROS

sudo apt-get install ros-noetic-mavros ros-noetic-mavros-extras

mavlink

wget https://raw.githubusercontent.com/mavlink/mavros/master/mavros/scripts/install_geographiclib_datasets.sh

chmod +x install_geographiclib_datasets.sh

./install_geographiclib_datasets.sh

启动PX4和MAVROS之间的连接

roslaunch mavros px4.launch fcu_url:="udp://:14540@127.0.0.1:14557"#gazebo方针的端口号

出现下面，表示成功启动

ROS程序测试

创建工程

#创建工作空间
mkdir catkin_ws
cd catkin_ws
mkdir src
cd src
catkin_init_workspace

#编译工作空间
cd ..
catkin_make

#设置环境变量
source devel/setup.bash

#创建功能包
cd catkin_ws/src
catkin_create_pkg offboard roscpp mavros geometry_msgs
cd ../
catkin_make 
#编译成功则完成

位置输入悬停代码

#include <ros/ros.h>
#include <geometry_msgs/PoseStamped.h>
#include <mavros_msgs/CommandBool.h>
#include <mavros_msgs/SetMode.h>
#include <mavros_msgs/State.h>

mavros_msgs::State current_state;
void state_cb(const mavros_msgs::State::ConstPtr& msg)
{
  current_state = *msg;
}

int main(int argc, char**argv)
{
  ros::init(argc, argv, "offb_node");
  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::Rate rate(20.0);

  // wait for FCU connection
  while(ros::ok() && !current_state.connected){
    ros::spinOnce();
    rate.sleep();
  }

  geometry_msgs::PoseStamped pose;
  pose.pose.position.x = 0;
  pose.pose.position.y = 0;
  pose.pose.position.z = 2;

  //send a few setpoints before starting
  for (int i = 100; ros::ok() && i > 0;--i){
    local_pos_pub.publish(pose);
    ros::spinOnce();
    rate.sleep();
  }

  mavros_msgs::SetMode offboard_set_mode;
  offboard_set_mode.request.custom_mode = "OFFBOARD";

  mavros_msgs::CommandBool arm_cmd;
  arm_cmd.request.value = true;

  ros::Time last_request = ros::Time::now();
  while(ros::ok())
  {
    if(current_state.mode!="OFFBOARD"&&(ros::Time::now()-last_request>ros::Duration(5.0))){
      if(set_mode_client.call(offboard_set_mode)&&offboard_set_mode.response.mode_sent){
        ROS_INFO("Offboard enabled");
      }
      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");
        }
        last_request = ros::Time::now();
      }
    }
    local_pos_pub.publish(pose);
    ros::spinOnce();
    rate.sleep();
  }

  return 0;
}

启动流程

#启动gazebo方针
cd ~/PX4-Autopilot
make px4_sitl_default gazebo
#启动mavlink通信
roslaunch mavros px4.launch fcu_url:="udp://:14540@127.0.0.1:14557"
#运行节点
rosrun offboard offboard_node
#查看模式
rostopic echo /mavros/state

终端开启仿真

gedit ～/.bashrc
#放入以下的内容
source ~/catkin_ws/devel/setup.bash
source ~/PX4_Firmware/Tools/setup_gazebo.bash ~/PX4_Firmware/ ~/PX4_Firmware/build/px4_sitl_default
export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:~/PX4_Firmware
export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:~/PX4_Firmware/Tools/sitl_gazebo
#关闭
source ~/.bashrc

启动：

roslaunch px4 mavros_posix_sitl.launch

当出现gazebo进程报错，大概率是之前的gazebo进程未完全关闭，可以输入

killall gzserver