Question

总结：我有一个节点在~300hz发布消息，但订阅另一个节点中的主题的回调只能在~25hz调用。订阅者节点中的spinOnce在~700hz时被调用，所以我不知道它为什么会丢失消息。

发布商节点：

#include <ros/ros.h>
#include <ros/console.h>
#include <nav_msgs/Odometry.h>

...

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

    ...

    // Publishers
    tf::TransformBroadcaster tfbr;
    ros::Publisher odomPub = nh.advertise<nav_msgs::Odometry>("pose",10);

   ...

    ros::Rate r(300); // loop rate
    while(ros::ok())
    {
        ...

        // Publish pose and velocity
            ...
        odomPub.publish(msg);

        ros::spinOnce();
        r.sleep();
    }

    ros::waitForShutdown();
    return 0;
}

订阅者节点：

#include <ros/ros.h>
#include <ros/console.h>
#include <nav_msgs/Odometry.h>

...

std::mutex mtx1, mtx2;

class DataHandler
{
private:
    ros::NodeHandle nh;
    ros::Publisher odomPub;
    double lastTime;
    int lastSeq;

public:
    Eigen::Vector3d x, xDot, w;
    Eigen::Vector3d xDes, xDesDot, xDesDotDot, b1Des, b1DesDot;
    Eigen::Matrix3d R;

    DataHandler()
    {
        // Initialize data
        xDes = Eigen::Vector3d(1,0,1);
        xDesDot = Eigen::Vector3d::Zero();
        xDesDotDot = Eigen::Vector3d::Zero();
        b1Des = Eigen::Vector3d(1,0,0);
        b1DesDot = Eigen::Vector3d::Zero();
        x = Eigen::Vector3d::Zero();
        xDot = Eigen::Vector3d::Zero();
        R = Eigen::Matrix3d::Identity();

        odomPub = nh.advertise<nav_msgs::Odometry>("controller_pose",10);
        trajPub = nh.advertise<asap_control::DesiredTrajectory>("controller_desTraj",10);
        lastTime = ros::Time::now().toSec();
        lastSeq = 0;
    }

    // Get current pose and velocity
    void odomCB(const nav_msgs::OdometryConstPtr& odomMsg)
    {

        mtx1.lock();
        // Get data
        double time1 = ros::Time::now().toSec();
        x << odomMsg->pose.pose.position.x, odomMsg->pose.pose.position.y, ...;
        xDot << odomMsg->twist.twist.linear.x, odomMsg->twist.twist.linear.y, ...;
        R = Eigen::Quaterniond(odomMsg->pose.pose.orientation.w, odomMsg->pose.pose.orientation.x,...;
        w << odomMsg->twist.twist.angular.x, odomMsg->twist.twist.angular.y, ...;
        double time2 = ros::Time::now().toSec();

        // Time to extract data, < 1ms
        double delTproc = time2 - time1;
        std::cout << "\n\n";
        std::cout << "proc elapsed time: " << delTproc << "\n";
        std::cout << "proc frequency: " << 1.0/delTproc << "\n";

        odomPub.publish(odomMsg); // rostopic hz says this is publishing at ~25Hz

        // Time between callback calls, ~25Hz
        double timeNow = ros::Time::now().toSec();
        double delT = timeNow - lastTime;
        lastTime = timeNow;
        std::cout << "elapsed time: " << delT << "\n";
        std::cout << "frequency: " << 1.0/delT << "\n";

        // Message sequence IDs, shows 12 msgs skipped every call
        int seqNow = odomMsg->header.seq;
        int delSeq = seqNow - lastSeq;
        lastSeq = seqNow;
        std::cout << "delta seq: " << delSeq << "\n";
        mtx1.unlock();
    }

};

...

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

    ...

    // Publishers
    ros::Publisher outputPub = nh.advertise<geometry_msgs::WrenchStamped>("wrench_command",10);
    ros::Publisher debugPub = nh.advertise<asap_control::ControllerSignals>("controller_debug",10);
    tf::TransformBroadcaster tfbr;

    // Subscribers
    DataHandler callbacks;
    ros::Subscriber poseSub = nh.subscribe("pose",10,&DataHandler::odomCB,&callbacks);

    // Asynchronous threads for callback handling
    //ros::AsyncSpinner spinner(2);
    //spinner.start();

    double lastTime = ros::Time::now().toSec();


    // Main loop
    ros::Rate r(700); // loop rate
    while(ros::ok())
    {
        // Data (extracted for cleanliness further down, and thread safety)
        mtx1.lock();
        Eigen::Vector3d x = callbacks.x;
        Eigen::Vector3d xDot = callbacks.xDot;
        Eigen::Matrix3d R = callbacks.R;
        Eigen::Vector3d w = callbacks.w;
        mtx1.unlock();

            ...

        // Publish
            ...
        outputPub.publish(msg);

        // Publish debug signals
        asap_control::ControllerSignals debugMsg;
        debugMsg.x[0] = x(0);
        ...
        debugPub.publish(debugMsg);

        //double timeNow = ros::Time::now().toSec();
        //double delT = timeNow - lastTime;
        //lastTime = timeNow;
        //std::cout << "\n\n";
        //std::cout << "elapsed time: " << delT << "\n";
        //std::cout << "frequency: " << 1.0/delT << "\n";

        ros::spinOnce();
        r.sleep();
    }

    ros::waitForShutdown();
    return 0;
}

其他信息：

发布商以~300Hz发布（由rostopic hz“姿势”主题确认）
订户节点中的主循环以~700Hz运行（由rostopic hz确认正在循环中发布的“wrench_command”主题，以及通过ros::Time::now()）循环定时，以及因此，spinOnce被调用的速度相同。
在25 Hz时调用pose主题的回调（由rostopic hz确认在回调中发布的“controller_pose”主题，以及通过ros::Time::now()）<循环定时< / LI>
即使我使用AsyncSpinner代替spinOnce，我也会遇到相同的行为，但只能使用rostopic hz进行确认。正如预期的那样，时间产生不稳定的输出
将订户queue_length增加到例如10会将回调率提高到~250Hz，但是，我想保持queue_length为1以仅获取最新数据。
Ubuntu中的系统监视器显示CPU利用率低于50％，所以我认为这不是cpu瓶颈问题。

Answer 1

我解决了一段时间发送测距数据的类似问题，其中测距数据以100Hz传输但仅以25Hz接收。事实证明，底层TCP套接字正在缓冲数据，将4条消息集中到一个TCP数据包中，以节省运输成本。我相信你需要在TransportHints（）中将tcpNoDelay设置为true：

node.subscribe（...，ROS :: TransportHints（）tcpNoDelay（真）。）;

请注意，这发生在订阅方面。

http://wiki.ros.org/roscpp/Overview/Publishers%20and%20Subscribers#Transport_Hints

ROS订阅者回调丢失消息

1 个答案: