laser_assembler::BaseAssemblerSrv< T > Class Template Reference

Maintains a history of point clouds and generates an aggregate point cloud upon request. More...

#include <base_assembler_srv.h>

Public Member Functions
	BaseAssemblerSrv ()
virtual void	ConvertToCloud (const std::string &fixed_frame_id, const T &scan_in, sensor_msgs::PointCloud &cloud_out)=0
	Converts the current scan into a cloud in the specified fixed frame.
virtual unsigned int	GetPointsInScan (const T &scan)=0
	Returns the number of points in the current scan.
void	start ()
	Tells the assembler to start listening to input data It is possible that a derived class needs to initialize and configure various things before actually beginning to process scans. Calling start create subcribes to the input stream, thus allowing the scanCallback and ConvertToCloud to be called. Start should be called only once.
	~BaseAssemblerSrv ()
Protected Attributes
ros::NodeHandle	n_
ros::NodeHandle	private_ns_
tf::TransformListener *	tf_
Private Member Functions
bool	buildCloud (AssembleScans::Request &req, AssembleScans::Response &resp)
	Service Callback function called whenever we need to build a cloud.
void	scansCallback (const boost::shared_ptr< const T > &scan_ptr)
	Callback function for every time we receive a new scan.
Private Attributes
ros::ServiceServer	cloud_srv_server_
unsigned int	downsample_factor_
	Specify how much to downsample the data. A value of 1 preserves all the data. 3 would keep 1/3 of the data.
std::string	fixed_frame_
	The frame to transform data into upon receipt.
unsigned int	max_scans_
	The max number of scans to store in the scan history.
std::deque < sensor_msgs::PointCloud >	scan_hist_
	Stores history of scans.
boost::mutex	scan_hist_mutex_
message_filters::Subscriber< T >	scan_sub_
tf::MessageFilter< T > *	tf_filter_
message_filters::Connection	tf_filter_connection_
double	tf_tolerance_secs_
	How long we should wait before processing the input data. Very useful for laser scans.
unsigned int	total_pts_
	The number points currently in the scan history.

Detailed Description

template<class T>
class laser_assembler::BaseAssemblerSrv< T >

Maintains a history of point clouds and generates an aggregate point cloud upon request.

Todo:: Clean up the doxygen part of this header

ROS Parameters

Reads the following parameters from the parameter server

"~tf_cache_time_secs" (double) - The cache time (in seconds) to holds past transforms
"~tf_tolerance_secs (double) - The time (in seconds) to wait after the transform for scan_in is available. - \b "~max_scans" (unsigned int) - The number of scans to store in the assembler's history, until they're thrown away - \b "~fixed_frame" (string) - The frame to which received data should immeadiately be transformed to - \b "~downsampling_factor" (int) - Specifies how often to sample from a scan. 1 preserves all the data. 3 keeps only 1/3 of the points.

ROS Service Calls

"~build_cloud" (AssembleScans.srv) - Accumulates scans between begin time and end time and returns the aggregated data as a point cloud

Definition at line 72 of file base_assembler_srv.h.

Constructor & Destructor Documentation

template<class T >

laser_assembler::BaseAssemblerSrv< T >::BaseAssemblerSrv ( ) [inline]

Definition at line 147 of file base_assembler_srv.h.

template<class T >

laser_assembler::BaseAssemblerSrv< T >::~BaseAssemblerSrv ( ) [inline]

Definition at line 219 of file base_assembler_srv.h.

Member Function Documentation

template<class T >

bool laser_assembler::BaseAssemblerSrv< T >::buildCloud	(	AssembleScans::Request &	req,
		AssembleScans::Response &	resp
	)			`[inline, private]`

Service Callback function called whenever we need to build a cloud.

Definition at line 261 of file base_assembler_srv.h.

template<class T>

virtual void laser_assembler::BaseAssemblerSrv< T >::ConvertToCloud	(	const std::string &	fixed_frame_id,
		const T &	scan_in,
		sensor_msgs::PointCloud &	cloud_out
	)			`[pure virtual]`

Converts the current scan into a cloud in the specified fixed frame.

Note: Once implemented, ConvertToCloud should NOT catch TF exceptions. These exceptions are caught by BaseAssemblerSrv, and will be counted for diagnostic information

Parameters:

	fixed_frame_id	The name of the frame in which we want cloud_out to be in
	scan_in	The scan that we want to convert
	cloud_out	The result of transforming scan_in into a cloud in frame fixed_frame_id

template<class T>

virtual unsigned int laser_assembler::BaseAssemblerSrv< T >::GetPointsInScan ( const T & scan ) [pure virtual]

Returns the number of points in the current scan.

Parameters:

scan

The scan for for which we want to know the number of points

Returns:: the number of points in scan

Implemented in laser_assembler::LaserScanAssemblerSrv, and laser_assembler::PointCloudAssemblerSrv.

template<class T>

void laser_assembler::BaseAssemblerSrv< T >::scansCallback ( const boost::shared_ptr< const T > & scan_ptr ) [inline, private]

Callback function for every time we receive a new scan.

Definition at line 228 of file base_assembler_srv.h.

template<class T >

void laser_assembler::BaseAssemblerSrv< T >::start ( ) [inline]

Tells the assembler to start listening to input data It is possible that a derived class needs to initialize and configure various things before actually beginning to process scans. Calling start create subcribes to the input stream, thus allowing the scanCallback and ConvertToCloud to be called. Start should be called only once.

Definition at line 204 of file base_assembler_srv.h.