pycram.designators.location_designator

Module Contents

Classes

Location	Default location designator which only wraps a pose.
ObjectRelativeLocation	Location relative to an object
CostmapLocation	Uses Costmaps to create locations for complex constrains
AccessingLocation	Location designator which describes poses used for opening drawers
SemanticCostmapLocation	Locations over semantic entities, like a table surface

class pycram.designators.location_designator.Location(pose: pycram.datastructures.pose.Pose, resolver=None)

Bases: pycram.designator.LocationDesignatorDescription

Default location designator which only wraps a pose.

Basic location designator that represents a single pose.

Parameters:

• pose – The pose that should be represented by this location designator

• resolver – An alternative resolver that returns a resolved location

class Location

Bases: pycram.designator.LocationDesignatorDescription.Location

Resolved location that represents a specific point in the world which satisfies the constraints of the location designator description.

ground() → Location

Default resolver which returns a resolved designator which contains the pose given in init.

Returns:

A resolved designator

class pycram.designators.location_designator.ObjectRelativeLocation(relative_pose: pycram.datastructures.pose.Pose = None, reference_object: pycram.designators.object_designator.ObjectDesignatorDescription = None, resolver=None)

Bases: pycram.designator.LocationDesignatorDescription

Location relative to an object

Location designator representing a location relative to a given object.

Parameters:

• relative_pose – Pose that should be relative, in world coordinate frame

• reference_object – Object to which the pose should be relative

• resolver – An alternative resolver that returns a resolved location for the input parameter

class Location

Bases: pycram.designator.LocationDesignatorDescription.Location

Resolved location that represents a specific point in the world which satisfies the constraints of the location designator description.

relative_pose: pycram.datastructures.pose.Pose

Pose relative to the object

reference_object: pycram.designators.object_designator.ObjectDesignatorDescription.Object

Object to which the pose is relative

ground() → Location

Default resolver which returns a resolved location for description input. Resolved location is the first result of the iteration of this instance.

Returns:

A resolved location

__iter__() → typing_extensions.Iterable[Location]

Iterates over all possible solutions for a resolved location that is relative to the given object.

Yield:

An instance of ObjectRelativeLocation.Location with the relative pose

class pycram.designators.location_designator.CostmapLocation(target: typing_extensions.Union[pycram.datastructures.pose.Pose, pycram.designators.object_designator.ObjectDesignatorDescription.Object], reachable_for: typing_extensions.Optional[pycram.designators.object_designator.ObjectDesignatorDescription.Object] = None, visible_for: typing_extensions.Optional[pycram.designators.object_designator.ObjectDesignatorDescription.Object] = None, reachable_arm: typing_extensions.Optional[str] = None, resolver: typing_extensions.Optional[typing_extensions.Callable] = None)

Bases: pycram.designator.LocationDesignatorDescription

Uses Costmaps to create locations for complex constrains

Location designator that uses costmaps as base to calculate locations for complex constrains like reachable or visible. In case of reachable the resolved location contains a list of arms with which the location is reachable.

Parameters:

• target – Location for which visibility or reachability should be calculated

• reachable_for – Object for which the reachability should be calculated, usually a robot

• visible_for – Object for which the visibility should be calculated, usually a robot

• reachable_arm – An optional arm with which the target should be reached

• resolver – An alternative resolver that returns a resolved location for the given input of this description

class Location

Bases: pycram.designator.LocationDesignatorDescription.Location

Resolved location that represents a specific point in the world which satisfies the constraints of the location designator description.

reachable_arms: typing_extensions.List[str]

List of arms with which the pose can be reached, is only used when the ‘rechable_for’ parameter is used

ground() → Location

Default resolver which returns the first result from the iterator of this instance.

Returns:

A resolved location

__iter__()

Generates positions for a given set of constrains from a costmap and returns them. The generation is based of a costmap which itself is the product of merging costmaps, each for a different purpose. In any case an occupancy costmap is used as the base, then according to the given constrains a visibility or gaussian costmap is also merged with this. Once the costmaps are merged, a generator generates pose candidates from the costmap. Each pose candidate is then validated against the constraints given by the designator if all validators pass the pose is considered valid and yielded.

Yield:

An instance of CostmapLocation.Location with a valid position that satisfies the given constraints

class pycram.designators.location_designator.AccessingLocation(handle_desig: pycram.designators.object_designator.ObjectPart.Object, robot_desig: pycram.designators.object_designator.ObjectDesignatorDescription.Object, resolver=None)

Bases: pycram.designator.LocationDesignatorDescription

Location designator which describes poses used for opening drawers

Describes a position from where a drawer can be opened. For now this position should be calculated before the drawer will be opened. Calculating the pose while the drawer is open could lead to problems.

Parameters:

• handle_desig – ObjectPart designator for handle of the drawer

• robot – Object designator for the robot which should open the drawer

• resolver – An alternative resolver to create the location

class Location

Bases: pycram.designator.LocationDesignatorDescription.Location

Resolved location that represents a specific point in the world which satisfies the constraints of the location designator description.

arms: typing_extensions.List[str]

List of arms that can be used to for accessing from this pose

ground() → Location

Default resolver for this location designator, just returns the first element from the iteration

Returns:

A location designator for a pose from which the drawer can be opened

__iter__() → Location

Creates poses from which the robot can open the drawer specified by the ObjectPart designator describing the handle. Poses are validated by checking if the robot can grasp the handle while the drawer is closed and if the handle can be grasped if the drawer is open.

Yield:

A location designator containing the pose and the arms that can be used.

class pycram.designators.location_designator.SemanticCostmapLocation(urdf_link_name, part_of, for_object=None, resolver=None)

Bases: pycram.designator.LocationDesignatorDescription

Locations over semantic entities, like a table surface

Creates a distribution over a urdf link to sample poses which are on this link. Can be used, for example, to find poses that are on a table. Optionally an object can be given for which poses should be calculated, in that case the poses are calculated such that the bottom of the object is on the link.

Parameters:

• urdf_link_name – Name of the urdf link for which a distribution should be calculated

• part_of – Object of which the urdf link is a part

• for_object – Optional object that should be placed at the found location

• resolver – An alternative resolver that creates a resolved location for the input parameter of this description

class Location

Bases: pycram.designator.LocationDesignatorDescription.Location

Resolved location that represents a specific point in the world which satisfies the constraints of the location designator description.

ground() → Location

Default resolver which returns the first element of the iterator of this instance.

Returns:

A resolved location

__iter__()

Creates a costmap on top of a link of an Object and creates positions from it. If there is a specific Object for which the position should be found, a height offset will be calculated which ensures that the bottom of the Object is at the position in the Costmap and not the origin of the Object which is usually in the centre of the Object.

Yield:

An instance of SemanticCostmapLocation.Location with the found valid position of the Costmap.