prmTransformationManager Class Reference

#include <prmTransformationManager.h>

Inheritance diagram for prmTransformationManager:

[legend]Collaboration diagram for prmTransformationManager:

Detailed Description

This class is intended to support computation of relationships between different coordinate systems in a CIS system. The tree consists of nodes (various coordinate systems ) and the edges (static or dynamic transformations between the connected coordinate systems). Transformations between coordinate systems are retrieved using a user provided command.

See also:: mtsCommandRead.

Examples:

setup joints transformation vctFrm3 setupPos; setupPos.Translation() = vct3(10.0, 4.0, 3.0); prmTransformationFixed setupFrame("Setup frame", setupPos);

robot transformation prmTransformationDynamic robotFrame("Robot frame", setupFrame, robot.GetCommandRead("GetTipPosition"));

add a camera defined in world frame vctFrm3 cameraPos; cameraPos.Translation() = vct3(-10.0, 3.4, 5.34); vctRandom(cameraPos.Rotation()); // artificial move! prmTransformationFixed cameraFrame("Camera frame", cameraPos);

Get the position of the camera wrt to the robot std::cout << prmWRTReference(cameraFrame, robotFrame) << std::endl;

Compute the robot motion wrt its base so that the tip moves in the x direction of the camera. vctFrm3 moveWRTCamera; PositionCartesianArg goalArgs;

move.Translation() = vct3(1.0, 0.0, 0.0); vctFrm3 moveWRTRobot = prmWRTReference(cameraFrame, setupFrame) * move; goalArgs.SetGoal(moveWRTRobot); myRobot.MovePositionCart(goalArgs);

Note:: There can only be one transformation manager per application, hence this class is implemented as a singleton.

Definition at line 80 of file prmTransformationManager.h.

Public Types

typedef std::list< prmTransformationBasePtr > NodeListType

Static Public Member Functions

static void Clear ()
static bool NodeCreatesCycle (const prmTransformationBasePtr &attachPoint, const prmTransformationBasePtr &newFrame)
static bool NodeCreatesCycle (const std::string &pName, const prmTransformationBasePtr &newFrame)
static vctFrm3 WRTReference (const prmTransformationBasePtr &tipFrame, const prmTransformationBasePtr &refFrame)
static unsigned int ReplaceReference (const prmTransformationBasePtr &nodePtr, const prmTransformationBasePtr &newReference)
static unsigned int ReplaceReference (const prmTransformationBasePtr &nodePtr, const std::string &parentName)
static void ToStreamDot (std::ostream &outputStream)
static void ToStreamDotHelper (std::ostream &outputStream, prmTransformationBasePtr parent)
static bool FindPath (const prmTransformationBasePtr &target, const prmTransformationBasePtr &reference)
static bool FindPathConnectedTree (const prmTransformationBasePtr &target, const prmTransformationBasePtr &reference)
static prmTransformationBasePtr GetTransformationNodePtr (const std::string pName)
static void PathToStreamDot (std::ostream &outputStream)

Static Public Attributes

static prmTransformationFixed TheWorld

Static Protected Member Functions

static bool Attach (const prmTransformationBasePtr &attachPoint, const prmTransformationBasePtr &newFrame)
static bool Attach (const std::string &parentName, const prmTransformationBasePtr &newFrame)
static bool Detach (const prmTransformationBasePtr &frame)

Static Protected Attributes

Friends

class prmTransformationBase

Member Function Documentation

static bool prmTransformationManager::Attach	(	const prmTransformationBasePtr &	attachPoint,
		const prmTransformationBasePtr &	newFrame
	)			`[static, protected]`

Add the frame to the tree in the transformation manager. This method is private and can only be accessed by the "friend" class prmTransformationBase.

Parameters:

	attachPoint	prmTransformationBasePtr pointer to the new frame
	newFrame	prmTransformationBasePtr pointer to parent in the tree

Returns:: bool success/failure boolean status.

static bool prmTransformationManager::Detach ( const prmTransformationBasePtr & frame ) [static, protected]

Remove the frame from the tree Internally calls ReplaceReference(frame, theWorld).

Parameters:

frame

prmTransformationBase* pointer to the frame to be discarded.

Returns:: bool success/failure code (When do we define status codes?)

static void prmTransformationManager::Clear ( ) [static]

A method to clean up a transformation tree. Deletes all nodes and restores clean state. This should never need to be used as every node should attach or detach itself. It is primarily meant for testing and debugging purposes.

static bool prmTransformationManager::NodeCreatesCycle	(	const prmTransformationBasePtr &	attachPoint,
		const prmTransformationBasePtr &	newFrame
	)			`[static]`

Test if attaching a reference frame at a particular node will introduce a circular dependency. The implementation is a simple depth first search, that returns true if a node is revisited more than once.

Parameters:

	attachPoint	prmTransformationBasePr new parent
	newFrame	prmTransformationBasePtr candidate frame

Returns:: bool true if a newFrame node is already present in the tree AND is an ancestor of the attachPoint.

static vctFrm3 prmTransformationManager::WRTReference	(	const prmTransformationBasePtr &	tipFrame,
		const prmTransformationBasePtr &	refFrame
	)			`[static]`

Compute the transformation between two frames (WRT = With Respect To). The computation will use registered get mtsCommandRead methods for the nodes on the path from node refFrame to node tipFrame. The implementation is a breadth first search from refFrame to tipFrame.

Parameters:

	tipFrame	prmTransformationBasePtr the frame transform to be computed
	refFrame	prmTransformationBasePtr the reference frame chosen

Returns:: vctFrame3 homogenous transform representing current relationship between tipFrame and refFrame.

Referenced by prmWRTReference(), and prmWRTWorld().

static unsigned int prmTransformationManager::ReplaceReference	(	const prmTransformationBasePtr &	nodePtr,
		const prmTransformationBasePtr &	newReference
	)			`[static]`

Update all frames using a given frame as reference.

May be useful before a call to prmTransformationManager::Detach or its equivalent prmTransformationBase::~prmTransformationBase

Parameters:

	currentReference	prmTransformationBase* old Reference frame
	newReference	prmTransformationBase* new Reference frame

Returns:: number of frames modified.

static void prmTransformationManager::ToStreamDot ( std::ostream & outputStream ) [static]

Print the tree to a graphviz dot file

If you have graphviz then "dot -Tjpg -o tree.jpg tree.dot" where tree.dot is the output of this function will print a tree representation of the transformation tree.

Parameters:

outputStream

std::ostream stream to dump dot file

Returns:: void

static void prmTransformationManager::ToStreamDotHelper	(	std::ostream &	outputStream,
		prmTransformationBasePtr	parent
	)			`[static]`

Helper function for printing the tree to a graphviz dot file

Returns:: void

static bool prmTransformationManager::FindPath	(	const prmTransformationBasePtr &	target,
		const prmTransformationBasePtr &	reference
	)			`[static]`

Helper function for computing transformations. Traverses the tree and stores the path between target and reference in path

Returns:: bool true if path exists

static bool prmTransformationManager::FindPathConnectedTree	(	const prmTransformationBasePtr &	target,
		const prmTransformationBasePtr &	reference
	)			`[static]`

Helper function for computing transformations. In contrast to above, this assumes a path exists and only merges two traversals from target/reference to tree root