ros学习笔记15~40

本学习内容来自机器人工匠阿杰，本人仅作学习笔记记录，方便后续查看学习。详细内容可自行搜索去看机器人工匠阿杰up主，讲的很好。

launch文件启动多个节点

单独调试某个节点

发发送cmd_vel话题让机器人原地沿z轴正向旋转

同时订阅发布进行避障模拟

#include<ros/ros.h> #include<sensor_msgs/LaserScan.h> #include<geometry_msgs/Twist.h> ros::Publisher vel_pub; int nCount = 0; void LidarCallback(const sensor_msgs::LaserScan msg){ float fMidDist = msg.ranges[180]; ROS_INFO("前方测距 range[180] = %.2f 米", fMidDist); geometry_msgs::Twist vel_cmd; if(nCount>0){ nCount--; return; } if (fMidDist<1.5) { vel_cmd.angular.z=0.3; nCount = 50; }else{ vel_cmd.linear.x=0.05; } vel_pub.publish(vel_cmd); } int main(int argc, char *argv[]) { ros::init(argc, argv, "lidar_node"); ros::NodeHandle n; ros::Subscriber lidar_sub = n.subscribe("/scan", 10, &LidarCallback); vel_pub = n.advertise<geometry_msgs::Twist>("cmd_vel",10); ros::spin(); return 0; }

imu航向锁定

#include<ros/ros.h> #include<sensor_msgs/Imu.h> #include<tf/tf.h> #include<geometry_msgs/Twist.h> ros::Publisher vel_pub; void IMUCallback(const sensor_msgs::Imu msg){ // 检测消息包中四元数数据是否存在 if(msg.orientation_covariance[0]<0) return; // 四元数转换 转换后的四元术对象quaternion tf::Quaternion quaternion( msg.orientation.x, msg.orientation.y, msg.orientation.z, msg.orientation.w ); // 欧拉角 double roll,pitch,yaw; tf::Matrix3x3(quaternion).getRPY(roll,pitch,yaw); // 弧度转角度 roll = roll*180/M_PI; pitch = pitch*180/M_PI; yaw = yaw*180/M_PI; ROS_INFO("滚转= %.0f 仰俯= %0.f 朝向= %0.f",roll,pitch,yaw); // 速度消息包 geometry_msgs::Twist vel_cmd; // 目标朝向角 double target_yaw = 90; // 当前机器人与目标朝向角差 double diff_angle = target_yaw-yaw; // 计算速度 vel_cmd.angular.z = diff_angle*0.01; vel_cmd.linear.x = 0.1; vel_pub.publish(vel_cmd); } int main(int argc, char *argv[]) { setlocale(LC_ALL,""); ros::init(argc,argv,"imu_node"); ros::NodeHandle n; ros::Subscriber imu_sub = n.subscribe("/imu/data",10,IMUCallback); vel_pub = n.advertise<geometry_msgs::Twist>("/cmd_vel",10); ros::spin(); }

catkin_create_pkg qq_msgs roscpp rospy std_msgs message_generation message_runtime

修改完毕直接catkin_ws 进行 catkin_make 编译

sxd@sxd:~/catkin_ws$ rosmsg show qq_msgs/Carry string grade int64 star string data sxd@sxd:~/catkin_ws$