Template Class TimeSynchronizer

Defined in File time_synchronizer.hpp

Inheritance Relationships

Base Type

public message_filters::Synchronizer< sync_policies::ExactTime< Ms... > > (Template Class Synchronizer)

Class Documentation

template<class ...Ms> class TimeSynchronizer : public message_filters::Synchronizer<sync_policies::ExactTime<Ms...>>

Synchronizes up to N messages by their timestamps.

TimeSynchronizer synchronizes up to N incoming channels by the timestamps contained in their messages’ headers. TimeSynchronizer takes anywhere from 2 to N message types as template parameters, and passes them through to a callback which takes a shared pointer of each.

The required queue size parameter when constructing the TimeSynchronizer tells it how many sets of messages it should store (by timestamp) while waiting for messages to arrive and complete their “set”

CONNECTIONS

The input connections for the TimeSynchronizer object is the same signature as for rclcpp subscription callbacks, ie.

void callback(const std::shared_ptr<M const>&);

The output connection for the TimeSynchronizer object is dependent on the number of messages being synchronized. For a 3-message synchronizer for example, it would be:

void callback(const std::shared_ptr<M0 const>&, const std::shared_ptr<M1 const>&, const std::shared_ptr<M2 const>&);

USAGE

Example usage would be:

TimeSynchronizer<sensor_msgs::msg::CameraInfo, sensor_msgs::msg::Image, sensor_msgs::msg::Image> sync_policies(caminfo_sub, limage_sub, rimage_sub, 3);
sync_policies.registerCallback(callback);

The callback is then of the form:

void callback(const sensor_msgs::msg::CameraInfo::SharedPtr, const sensor_msgs::msg::Image::SharedPtr, const sensor_msgs::msg::Image::SharedPtr);

Public Types

typedef sync_policies::ExactTime<Ms...> Policy

typedef Synchronizer<Policy> Base

Public Functions

template<class ...Fs> inline TimeSynchronizer(uint32_t queue_size, Fs&... fs)

template<int i> inline void add(const std::shared_ptr<typename std::tuple_element<i, Messages>::type const> &msg)

template<class ...Fs> inline void connectInput(Fs&... fs)

template<class C> inline Connection registerCallback(C &callback)

template<class C> inline Connection registerCallback(const C &callback)

template<class C, typename T> inline Connection registerCallback(const C &callback, T *t)

template<class C, typename T> inline Connection registerCallback(C &callback, T *t)

inline void setName(const std::string &name)

inline const std::string &getName()

template<class C> inline Connection registerDropCallback(const C &callback)

template<class C> inline Connection registerDropCallback(C &callback)

template<class C, typename T> inline Connection registerDropCallback(const C &callback, T *t)

template<class C, typename T> inline Connection registerDropCallback(C &callback, T *t)