ROS IMU 服务、客户端和服务器节点模板

Question

我想创建 IMU ROS 服务。我有一个服务器（在我的例子中是一个微控制器 ESC32），它可以获得 IMU 读数，并且在请求进一步处理时应该将 IMU 数据传递给客户端（在我的例子中是 Raspberry PI 4B）。所以我只需要传递原始数据IMU 数据。我想从 IMU 服务器和客户端节点的一些 ros 服务模板开始。这是我的 .srv 文件

float64 x_orient_in
float64 y_orient_in
float64 z_orient_in
float64 w_orient_in
float64 x_veloc_in
float64 y_veloc_in
float64 z_veloc_in
float64 x_accel_in
float64 y_accel_in
float64 z_accel_in
---
float64 x_orient_out
float64 y_orient_out
float64 z_orient_out
float64 w_orient_out
float64 x_veloc_out
float64 y_veloc_out
float64 z_veloc_out
float64 x_accel_out
float64 y_accel_out
float64 z_accel_out
bool success

这是我的服务器 cpp

#include "ros/ros.h"
#include <sensor_msgs/Imu.h>
#include "ros_services/ImuValue.h"

bool get_val(ros_services::ImuValue::Request  &req, ros_services::ImuValue::Response &res)
{
    
    ROS_INFO("sending back response");
    res.x_orient_out= req.x_orient_in;
    res.y_orient_out= req.y_orient_in;
    res.z_orient_out= req.z_orient_in;
    res.w_orient_out= req.w_orient_in;
    res.x_veloc_out= req.x_veloc_in;
    res.y_veloc_out= req.y_veloc_in;
    res.z_veloc_out= req.z_veloc_in;
    res.x_accel_out= req.x_accel_in;
    res.x_accel_out= req.x_accel_in;
    res.x_accel_out= req.x_accel_in;
    
}

int main(int argc, char **argv)
{
  ros::init(argc, argv, "imu_status_server");
  ros::NodeHandle n;
  ros::ServiceServer service = n.advertiseService("imu_status_server", get_val);
  ROS_INFO("Starting server...");
  ros::spin();

  return 0;
}

我的 IMU ros 主题是这个

header: 
  seq: 45672
  stamp: 
    secs: 956
    nsecs: 962000000
  frame_id: "thrbot/imu_link"
orientation: 
  x: 0.0697171053094
  y: 0.00825242210747
  z: 0.920964387685
  w: -0.383270164991
orientation_covariance: [0.0001, 0.0, 0.0, 0.0, 0.0001, 0.0, 0.0, 0.0, 0.0001]
angular_velocity: 
  x: 0.00156996015527
  y: 0.0263644782572
  z: -0.0617661883137
angular_velocity_covariance: [1.1519236000000001e-07, 0.0, 0.0, 0.0, 1.1519236000000001e-07, 0.0, 0.0, 0.0, 1.1519236000000001e-07]
linear_acceleration: 
  x: 1.32039048367
  y: -0.376341478938
  z: 9.70643773249
linear_acceleration_covariance: [1.6e-05, 0.0, 0.0, 0.0, 1.6e-05, 0.0, 0.0, 0.0, 1.6e-05]

Answer 1

我强烈建议您查看ros wiki tutorials。他们有很多信息，也可以为您节省一些时间。话虽如此，您只需像任何其他服务调用一样进行设置。您可能还必须创建自己的消息，看起来像这样：

float64 x_accel
float64 y_accel
float64 z_accel
---
bool success

那么你只需要一个服务器节点来处理这样的传入请求：

#include "ros/ros.h"
#include "your_service/service_file.h"

bool get_val(your_service::service_file::Request  &req,
         your_service::service_file::Response &res)
{
  res.x_accel = get_accel_x(); //Defined somewhere else by you
  res.y_accel = get_accel_y(); //Defined somewhere else by you
  res.z_accel = get_accel_z(); //Defined somewhere else by you
  return true;
}

int main(int argc, char **argv)
{
  ros::init(argc, argv, "imu_status_server");
  ros::NodeHandle n;

  ros::ServiceServer service = n.advertiseService("imu_status_server", add);
  ROS_INFO("Starting server...");
  ros::spin();

  return 0;
}

最后，客户端可以像这样调用服务器了

ros::ServiceClient client = n.serviceClient<beginner_tutorials::AddTwoInts>("imu_status_server");
your_service::service_file srv;
client.call(srv);
std::cout << "Got accel x: " << srv.response.x_accel << std::endl;