robot.py

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# Author: Ioan Sucan

from moveit_commander import MoveGroupCommander, MoveItCommanderException
from moveit_ros_planning_interface import _moveit_robot_interface
from moveit_msgs.msg import RobotState
import conversions

class RobotCommander(object):

    class Joint(object):
        def __init__(self, robot, name):
            self._robot = robot
            self._name = name
        def name(self):
            return self._name
        def variable_count(self):
            return len(self.__get_joint_limits())
        def bounds(self):
            l = self.__get_joint_limits()
            if len(l) == 1:
                return l[0]
            else:
                return l
        def min_bound(self):
            limits = self.__get_joint_limits()
            if len(limits) == 1:
                return limits[0][0]
            else:
                return [l[0] for l in limits]
        def max_bound(self):
            limits = self.__get_joint_limits()
            if len(limits) == 1:
                return limits[0][1]
            else:
                return [l[1] for l in limits]
        def value(self):
            vals = self._robot._r.get_current_joint_values(self._name)
            if len(vals) == 1:
                return vals[0]
            else:
                return vals
        def move(self, position, wait = True):
            group = self._robot.get_default_owner_group()
            if group is None:
                raise MoveItCommanderException("There is no known group containing joint %s. Cannot move." % self._name)
            gc = self._robot.get_group(group)
            if gc is not None:
                gc.set_joint_value_target(gc.get_current_joint_values())
                gc.set_joint_value_target(self._name, position)
                return gc.go(wait)
            return False
        def __get_joint_limits(self):
            return self._robot._r.get_joint_limits(self._name)

    class Link(object):
        def __init__(self, robot, name):
            self._robot = robot
            self._name = name
        def name(self):
            return self._name
        def pose(self):
            return conversions.list_to_pose_stamped(self._robot._r.get_link_pose(self._name), self._robot.get_planning_frame())

    def __init__(self):
        self._r = _moveit_robot_interface.RobotInterface("robot_description")
        self._groups = {}
        self._joint_owner_group = {}

    def get_planning_frame(self):
        """Get the frame of reference in which planning is done (and environment is maintained)"""
        return self._r.get_planning_frame()

    def get_root_link(self):
        """Get the name of the root link of the robot model """
        return self._r.get_robot_root_link()

    def get_joint_names(self, group = None):
        """Get the names of all the movable joints that make up a group (mimic joints and fixed joints are excluded). If no group name is specified, all joints in the robot model are returned, including fixed and mimic joints """
        if group is not None:
            if self.has_group(group):
                return self._r.get_group_joint_names(group)
            else:
                raise MoveItCommanderException("There is no group named %s" % group)
        else:
            return self._r.get_joint_names()

    def get_link_names(self, group = None):
        """Get the links that make up a group. If no group name is specified, all the links in the robot model are returned. """
        if group is not None:
            if self.has_group(group):
                return self._r.get_group_link_names(group)
            else:
                raise MoveItCommanderException("There is no group named %s" % group)
        else:
            return self._r.get_link_names()

    def get_group_names(self):
        """Get the names of the groups defined for the robot"""
        return self._r.get_group_names()

    def get_current_state(self):
        """ Get a RobotState message describing the current state of the robot"""
        s = RobotState()
        s.deserialize(self._r.get_current_state())
        return s

    def get_current_variable_values(self):
        """Get a dictionary mapping variable names to values. Note that a joint may consist of one or more variables """
        return self._r.get_current_variable_values()

    def get_joint(self, name):
        if name in self.get_joint_names():
            return self.Joint(self, name)
        else:
            raise MoveItCommanderException("There is no joint named %s" % name)

    def get_link(self, name):
        if name in self.get_link_names():
            return self.Link(self, name)
        else:
            raise MoveItCommanderException("There is no link named %s" % name)

    def get_group(self, name):
        if not self._groups.has_key(name): 
            if not self.has_group(name):
                raise MoveItCommanderException("There is no group named %s" % name)
            self._groups[name] = MoveGroupCommander(name)
        return self._groups[name]

    def has_group(self, name):
        return self._r.has_group(name)

    def get_default_owner_group(self, joint_name):
        """Get the name of the smallest group (fewest joints) that includes the joint name specified as argument"""
        if not self._joint_owner_groups.has_key(joint_name):
            group = None
            for g in self.get_group_names():
                if joint_name in self.get_joint_names(g):
                    if group is None:
                        group = g
                    else:
                        if len(self.get_link_names(g)) < len(self.get_link_names(group)):
                            group = g
            self._joint_owner_groups[joint_name] = group
        return self._joint_owner_groups[joint_name]

    def __getattr__(self, name):
        """ We catch the names of groups, joints and links to allow easy access to their properties """
        if name in self.get_group_names():
            return self.get_group(name)
        elif name in self.get_joint_names():
            return self.Joint(self,name)
        elif name in self.get_link_names():
            return self.Link(self,name)
        else:
            return object.__getattribute__(self, name)