StablePlacementComputation

Classes
class	gpTriangle
class	gpPlacement
Functions
int	gpCompute_stable_placements (p3d_rob *object, std::list< gpPlacement > &placementList)
int	gpFind_placements_on_object (p3d_rob *object, p3d_rob *support, std::list< p3d_rob * > robotList, std::list< gpPlacement > placementListIn, double translationStep, unsigned int nbOrientations, double verticalOffset, std::list< gpPlacement > &placementListOut)
int	gpCompute_placement_clearances (p3d_rob *object, std::list< p3d_rob * > robotList, std::list< gpPlacement > &placementList)
int	gpFind_placement_from_base_configuration (p3d_rob *robot, p3d_rob *object, std::list< gpPlacement > &placementList, gpArm_type arm_type, configPt qbase, gpGrasp &grasp, gpHand_properties &hand, double distance, configPt qpreplacement, configPt qplacement, gpPlacement &placement)

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Detailed Description

This module implements some classes to compute a set of stable placements for a body.

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Function Documentation

int gpCompute_placement_clearances	(	p3d_rob *	object,
		std::list< p3d_rob * >	robotList,
		std::list< gpPlacement > &	placementList
	)

Parameters:

object	the object to place
robotList	a list of robots that will not be taken into account in the clearance computation
placementList	a list of placements

Returns:

GP_OK in case of success, GP_ERROR otherwise

int gpCompute_stable_placements	(	p3d_rob *	object,
		std::list< gpPlacement > &	placementList
	)

Computes a list of stable placements (on a plane) of the given object. The function first computes the convex hull of the object. Each face of the object's convex hull defines a support polygon. If the orthogonal projection of the object's center of mass on the plane of a face is inside the face, then this face corresponds to a stable placement.

Parameters:

object	pointer to the object (a freeflyer robot whose only the first polyhedron of the first body will be considered)
placementList	the computed placement list (sorted from best to weaker stability)

Returns:

GP_OK in case of success, GP_ERROR otherwise

int gpFind_placement_from_base_configuration	(	p3d_rob *	robot,
		p3d_rob *	object,
		std::list< gpPlacement > &	placementList,
		gpArm_type	arm_type,
		configPt	qbase,
		gpGrasp &	grasp,
		gpHand_properties &	hand,
		double	distance,
		configPt	qpreplacement,
		configPt	qplacement,
		gpPlacement &	placement
	)

Finds, for a given mobile base configuration of the robot, a placement from the given placement list, that is reachable by the arm and hand, and computes for the placement a configuration for the whole robot. It also computes an intermediate configuration (a configuration slightly before placing the object)

Parameters:

robot	the robot
object	the object to place
robotList	a list of robots that will not be taken into account in the collision tests
placementList	a list of placements
arm_type	the robot arm type
qbase	a configuration of the robot (only the part corresponding to the mobile base will be used)
grasp	the grasp used to hold the object
hand	parameters of the hand
distance	distance between the grasp and pregrasp configurations (meters)
qpreplacement	the preplacement configuration (must have been allocated before)
qplacement	the placement configuration (must have been allocated before)
placement	the found object placement

Returns:

GP_OK in case of success, GP_ERROR otherwise

int gpFind_placements_on_object	(	p3d_rob *	object,
		p3d_rob *	support,
		std::list< p3d_rob * >	robotList,
		std::list< gpPlacement >	placementListIn,
		double	translationStep,
		unsigned int	nbOrientations,
		double	verticalOffset,
		std::list< gpPlacement > &	placementListOut
	)

Computes a list of stable placements of an object onto another object. The function receives an initial list of stable placements of the object on infinite planes. The almost horizontal faces of the support are sampled according to specified steps and each placement of the input list is then tested for each sample. The following collisions are checked: the object versus the environment, the object versus the other robots (including the support). It is possible to skip the collision tests between the object and some robots specified in a list given as an input.

Parameters:

object	pointer to the object
support	pointer to the object (the support) we want to place the first object on
robotList	a list of robots that will not be taken into account in the collision tests
placementListIn	the input placement list (NB: its size is reduced inside the function)
translationStep	the translation step of the discretization of the horizontal faces of the support
nbOrientations	the number of orientations (around vertical axis) that will be tested to place the object
verticalOffset	vertical offset on the object placements (to avoid collision between object and support)
placementListOut	the output placement list

Returns:

GP_OK in case of success, GP_ERROR otherwise