How to use TimeSynchronizer filter inside nodelet?

Question

Hello,

I started using ROS (indigo on Ubuntu 14.04) and I want convert my node (which running well and using TimeSynchronizer for two topics synchronized by timestamp that call manta_callback function) to nodelet. But after initialising my nodelet, TimeSynchronizer doesn't synchronize input topics & doesn't call manta_callback(). How can I debug TimeSynchronizer under nodelet or should I check another solution e.g. NodeletMUX for synchronize two topics under nodelet? Sources:

header file:

namespace detect_control_nodelet {

class MarkerDetectControl : public nodelet::Nodelet
{
    public:
        virtual void onInit();
    void manta_callback(const sensor_msgs::ImageConstPtr & image_msg,  ar_track_alvar_msgs_ext::AlvarMarkerExtConstPtr  arMarkerCorners);       

};

}

src file:

namespace detect_control_nodelet { void MarkerDetectControl::onInit() { NODELET_DEBUG("Initializing nodelet..."); ros::NodeHandle n("~"); ros::NodeHandle nh = getNodeHandle(); ros::NodeHandle& private_nh = getPrivateNodeHandle(); ROS_INFO("In onInit()"); message_filters::Subscriber image_sub(private_nh, "camera/image_raw", 1); message_filters::Subscriber info_sub(private_nh, "ar_corners_marker",1); TimeSynchronizer sync(image_sub, info_sub, 50); sync.registerCallback(boost::bind(&MarkerDetectControl::manta_callback,this,_1, _2));} } void MarkerDetectControl::manta_callback(const sensor_msgs::ImageConstPtr & image_msg, ar_track_alvar_msgs_ext::AlvarMarkerExtConstPtr arMarkerCorners) {
ROS_INFO("In function manta_callback"); } --- [Originally posted](https://answers.ros.org/question/195238/how-to-use-timesynchronizer-filter-inside-nodelet?/) by [ArturK](https://answers.ros.org/users/20496/arturk/) on ROS Answers with karma: 23 on 2014-10-17 Post score: 2

Answer 1

The variables image_sub, info_sub, and sync need to be class variables instead of local. When the subscribers go out of scope at the end of onInit(), their destructors unsubscribe from the topics.

---

Originally posted by kmhallen with karma: 1416 on 2014-10-17

This answer was ACCEPTED on the original site

Post score: 2