class Abbe_Gripper(object):
def __init__(self):
self._gripper = Gripper('left')
self._gripper.calibrate()
#don't want it to drop rfid reader so disabling right gripperq
self._gripper_right = Gripper('right')
self._gripper_right.calibrate()
def close(self,left=True):
if left:
self._gripper.close(block=True)
else:
self._gripper_right.close(block=True)
def open(self,left=True):
if left:
self._gripper.open(block=True)
else:
self._gripper_right.open(block=True)
def gripping(self,left=True):
if left:
return self._gripper.gripping()
else:
return self._gripper_right.gripping()
class Abbe_Gripper(object):
def __init__(self):
self._gripper = Gripper('left')
self._gripper.calibrate()
#right gripper isn't calibrated so it won't drop the RFID reader
#self._gripper_right = Gripper('right')
#self._gripper_right.calibrate()
def close(self,left=True):
if left:
self._gripper.close(block=True)
else:
self._gripper_right.close(block=True)
def open(self,left=True):
if left:
self._gripper.open(block=True)
else:
self._gripper_right.open(block=True)
def gripping(self,left=True):
if left:
return self._gripper.gripping()
else:
return self._gripper_right.gripping()
class Robot_Gripper(object):
def __init__(self):
self._gripper = Gripper('left')
self._gripper.calibrate()
#right gripper isn't calibrated so it won't drop the RFID reader
#self._gripper_right = Gripper('right')
#self._gripper_right.calibrate()
def close(self, left=True):
if left:
self._gripper.close(block=True)
else:
self._gripper_right.close(block=True)
def open(self, left=True):
if left:
self._gripper.open(block=True)
else:
self._gripper_right.open(block=True)
def gripping(self, left=True):
if left:
return self._gripper.gripping()
else:
return self._gripper_right.gripping()
class ArmCommander(Limb):
"""
This class overloads Limb from the Baxter Python SDK adding the support of trajectories via RobotState and RobotTrajectory messages
Allows to control the entire arm either in joint space, or in task space, or (later) with path planning, all with simulation
"""
def __init__(self, name, rate=100, fk='robot', ik='trac', default_kv_max=1., default_ka_max=0.5):
"""
:param name: 'left' or 'right'
:param rate: Rate of the control loop for execution of motions
:param fk: Name of the Forward Kinematics solver, "robot", "kdl", "trac" or "ros"
:param ik: Name of the Inverse Kinematics solver, "robot", "kdl", "trac" or "ros"
:param default_kv_max: Default K maximum for velocity
:param default_ka_max: Default K maximum for acceleration
"""
Limb.__init__(self, name)
self._world = 'base'
self.kv_max = default_kv_max
self.ka_max = default_ka_max
self._gripper = Gripper(name)
self._rate = rospy.Rate(rate)
self._tf_listener = TransformListener()
self.recorder = Recorder(name)
# Kinematics services: names and services (if relevant)
self._kinematics_names = {'fk': {'ros': 'compute_fk'},
'ik': {'ros': 'compute_ik',
'robot': 'ExternalTools/{}/PositionKinematicsNode/IKService'.format(name),
'trac': 'trac_ik_{}'.format(name)}}
self._kinematics_services = {'fk': {'ros': {'service': rospy.ServiceProxy(self._kinematics_names['fk']['ros'], GetPositionFK),
'func': self._get_fk_ros},
'kdl': {'func': self._get_fk_pykdl},
'robot': {'func': self._get_fk_robot}},
'ik': {'ros': {'service': rospy.ServiceProxy(self._kinematics_names['ik']['ros'], GetPositionIK),
'func': self._get_ik_ros},
'robot': {'service': rospy.ServiceProxy(self._kinematics_names['ik']['robot'], SolvePositionIK),
'func': self._get_ik_robot},
'trac': {'service': rospy.ServiceProxy(self._kinematics_names['ik']['trac'], GetConstrainedPositionIK),
'func': self._get_ik_trac},
'kdl': {'func': self._get_ik_pykdl}}}
self._selected_ik = ik
self._selected_fk = fk
# Kinematics services: PyKDL
self._kinematics_pykdl = baxter_kinematics(name)
if self._selected_ik in self._kinematics_names['ik']:
rospy.wait_for_service(self._kinematics_names['ik'][self._selected_ik])
if self._selected_fk in self._kinematics_names['fk']:
rospy.wait_for_service(self._kinematics_names['fk'][self._selected_fk])
# Execution attributes
rospy.Subscriber('/robot/limb/{}/collision_detection_state'.format(name), CollisionDetectionState, self._cb_collision, queue_size=1)
rospy.Subscriber('/robot/digital_io/{}_lower_cuff/state'.format(name), DigitalIOState, self._cb_dig_io, queue_size=1)
self._stop_reason = '' # 'cuff' or 'collision' could cause a trajectory to be stopped
self._stop_lock = Lock()
action_server_name = "/robot/limb/{}/follow_joint_trajectory".format(self.name)
self.client = SimpleActionClient(action_server_name, FollowJointTrajectoryAction)
self._display_traj = rospy.Publisher("/move_group/display_planned_path", DisplayTrajectory, queue_size=1)
self._gripper.calibrate()
self.client.wait_for_server()
######################################### CALLBACKS #########################################
def _cb_collision(self, msg):
if msg.collision_state:
with self._stop_lock:
self._stop_reason = 'collision'
def _cb_dig_io(self, msg):
if msg.state > 0:
with self._stop_lock:
self._stop_reason = 'cuff'
#############################################################################################
def endpoint_pose(self):
"""
Returns the pose of the end effector
:return: [[x, y, z], [x, y, z, w]]
"""
pose = Limb.endpoint_pose(self)
return [[pose['position'].x, pose['position'].y, pose['position'].z],
[pose['orientation'].x, pose['orientation'].y, pose['orientation'].z, pose['orientation'].w]]
def endpoint_name(self):
return self.name+'_gripper'
def group_name(self):
return self.name+'_arm'
def joint_limits(self):
xml_urdf = rospy.get_param('robot_description')
dict_urdf = xmltodict.parse(xml_urdf)
joints_urdf = []
joints_urdf.append([j['@name'] for j in dict_urdf['robot']['joint'] if j['@name'] in self.joint_names()])
joints_urdf.append([[float(j['limit']['@lower']), float(j['limit']['@upper'])] for j in dict_urdf['robot']['joint'] if j['@name'] in self.joint_names()])
# reorder the joints limits
return dict(zip(self.joint_names(),
[joints_urdf[1][joints_urdf[0].index(name)] for name in self.joint_names()]))
def get_current_state(self, list_joint_names=[]):
"""
Returns the current RobotState describing all joint states
:param list_joint_names: If not empty, returns only the state of the requested joints
:return: a RobotState corresponding to the current state read on /robot/joint_states
"""
if len(list_joint_names) == 0:
list_joint_names = self.joint_names()
state = RobotState()
state.joint_state.name = list_joint_names
state.joint_state.position = map(self.joint_angle, list_joint_names)
state.joint_state.velocity = map(self.joint_velocity, list_joint_names)
state.joint_state.effort = map(self.joint_effort, list_joint_names)
return state
def get_ik(self, eef_poses, seeds=(), source=None, params=None):
"""
Return IK solutions of this arm's end effector according to the method declared in the constructor
:param eef_poses: a PoseStamped or a list [[x, y, z], [x, y, z, w]] in world frame or a list of PoseStamped
:param seeds: a single seed or a list of seeds of type RobotState for each input pose
:param source: 'robot', 'trac', 'kdl'... the IK source for this call (warning: the source might not be instanciated)
:param params: dictionary containing optional non-generic IK parameters
:return: a list of RobotState for each input pose in input or a single RobotState
TODO: accept also a Point (baxter_pykdl's IK accepts orientation=None)
Child methods wait for a *list* of pose(s) and a *list* of seed(s) for each pose
"""
if not isinstance(eef_poses, list) or isinstance(eef_poses[0], list) and not isinstance(eef_poses[0][0], list):
eef_poses = [eef_poses]
if not seeds:
seeds=[]
elif not isinstance(seeds, list):
seeds = [seeds]*len(eef_poses)
input = []
for eef_pose in eef_poses:
if isinstance(eef_pose, list):
input.append(list_to_pose(eef_pose, self._world))
elif isinstance(eef_pose, PoseStamped):
input.append(eef_pose)
else:
raise TypeError("ArmCommander.get_ik() accepts only a list of Postamped or [[x, y, z], [x, y, z, w]], got {}".format(str(type(eef_pose))))
output = self._kinematics_services['ik'][self._selected_ik if source is None else source]['func'](input, seeds, params)
return output if len(eef_poses)>1 else output[0]
def get_fk(self, frame_id=None, robot_state=None):
"""
Return The FK solution oth this robot state according to the method declared in the constructor
robot_state = None will give the current endpoint pose in frame_id
:param robot_state: a RobotState message
:param frame_id: the frame you want the endpoint pose into
:return: [[x, y, z], [x, y, z, w]]
"""
if frame_id is None:
frame_id = self._world
if isinstance(robot_state, RobotState) or robot_state is None:
return self._kinematics_services['fk'][self._selected_fk]['func'](frame_id, robot_state)
else:
raise TypeError("ArmCommander.get_fk() accepts only a RobotState, got {}".format(str(type(robot_state))))
def _get_fk_pykdl(self, frame_id, state=None):
if state is None:
state = self.get_current_state()
fk = self._kinematics_pykdl.forward_position_kinematics(dict(zip(state.joint_state.name, state.joint_state.position)))
return [fk[:3], fk[-4:]]
def _get_fk_robot(self, frame_id = None, state=None):
# Keep this half-working FK, still used by generate_cartesian_path (trajectories.py)
if state is not None:
raise NotImplementedError("_get_fk_robot has no FK service provided by the robot except for its current endpoint pose")
ps = list_to_pose(self.endpoint_pose(), self._world)
return self._tf_listener.transformPose(frame_id, ps)
def _get_fk_ros(self, frame_id = None, state=None):
rqst = GetPositionFKRequest()
rqst.header.frame_id = self._world if frame_id is None else frame_id
rqst.fk_link_names = [self.endpoint_name()]
if isinstance(state, RobotState):
rqst.robot_state = state
elif isinstance(state, JointState):
rqst.robot_state.joint_state = state
elif state is None:
rqst.robot_state = self.get_current_state()
else:
raise AttributeError("Provided state is an invalid type")
fk_answer = self._kinematics_services['fk']['ros']['service'].call(rqst)
if fk_answer.error_code.val==1:
return fk_answer.pose_stamped[0]
else:
return None
def _get_ik_pykdl(self, eef_poses, seeds=(), params=None):
solutions = []
for pose_num, eef_pose in enumerate(eef_poses):
if eef_pose.header.frame_id.strip('/') != self._world.strip('/'):
raise NotImplementedError("_get_ik_pykdl: Baxter PyKDL implementation does not accept frame_ids other than {}".format(self._world))
pose = pose_to_list(eef_pose)
resp = self._kinematics_pykdl.inverse_kinematics(pose[0], pose[1],
[seeds[pose_num].joint_state.position[seeds[pose_num].joint_state.name.index(joint)]
for joint in self.joint_names()] if len(seeds)>0 else None)
if resp is None:
rs = None
else:
rs = RobotState()
rs.is_diff = False
rs.joint_state.name = self.joint_names()
rs.joint_state.position = resp
solutions.append(rs)
return solutions
def _get_ik_robot(self, eef_poses, seeds=(), params=None):
ik_req = SolvePositionIKRequest()
for eef_pose in eef_poses:
ik_req.pose_stamp.append(eef_pose)
ik_req.seed_mode = ik_req.SEED_USER if len(seeds) > 0 else ik_req.SEED_CURRENT
for seed in seeds:
ik_req.seed_angles.append(seed.joint_state)
resp = self._kinematics_services['ik']['robot']['service'].call(ik_req)
solutions = []
for j, v in zip(resp.joints, resp.isValid):
solutions.append(RobotState(is_diff=False, joint_state=j) if v else None)
return solutions
def _get_ik_trac(self, eef_poses, seeds=(), params=None):
ik_req = GetConstrainedPositionIKRequest()
if params is None:
ik_req.num_steps = 1
else:
ik_req.end_tolerance = params['end_tolerance']
ik_req.num_steps = params['num_attempts']
for eef_pose in eef_poses:
ik_req.pose_stamp.append(eef_pose)
if len(seeds) == 0:
seeds = [self.get_current_state()]*len(eef_poses)
for seed in seeds:
ik_req.seed_angles.append(seed.joint_state)
resp = self._kinematics_services['ik']['trac']['service'].call(ik_req)
solutions = []
for j, v in zip(resp.joints, resp.isValid):
solutions.append(RobotState(is_diff=False, joint_state=j) if v else None)
return solutions
def _get_ik_ros(self, eef_poses, seeds=()):
rqst = GetPositionIKRequest()
rqst.ik_request.avoid_collisions = True
rqst.ik_request.group_name = self.group_name()
solutions = []
for pose_num, eef_pose in enumerate(eef_poses):
rqst.ik_request.pose_stamped = eef_pose # Do we really to do a separate call for each pose? _vector not used
ik_answer = self._kinematics_services['ik']['ros']['service'].call(rqst)
if len(seeds) > 0:
rqst.ik_request.robot_state = seeds[pose_num]
if ik_answer.error_code.val==1:
# Apply a filter to return only joints of this group
try:
ik_answer.solution.joint_state.velocity = [value for id_joint, value in enumerate(ik_answer.solution.joint_state.velocity) if ik_answer.solution.joint_state.name[id_joint] in self.joint_names()]
ik_answer.solution.joint_state.effort = [value for id_joint, value in enumerate(ik_answer.solution.joint_state.effort) if ik_answer.solution.joint_state.name[id_joint] in self.joint_names()]
except IndexError:
pass
ik_answer.solution.joint_state.position = [value for id_joint, value in enumerate(ik_answer.solution.joint_state.position) if ik_answer.solution.joint_state.name[id_joint] in self.joint_names()]
ik_answer.solution.joint_state.name = [joint for joint in ik_answer.solution.joint_state.name if joint in self.joint_names()]
solutions.append(ik_answer.solution)
else:
solutions.append(None)
return solutions
def translate_to_cartesian(self, path, frame_id, time, n_points=50, max_speed=np.pi/4, min_success_rate=0.5, display_only=False,
timeout=0, stop_test=lambda:False, pause_test=lambda:False):
"""
Translate the end effector in straight line, following path=[translate_x, translate_y, translate_z] wrt frame_id
:param path: Path [x, y, z] to follow wrt frame_id
:param frame_id: frame_id of the given input path
:param time: Time of the generated trajectory
:param n_points: Number of 3D points of the cartesian trajectory
:param max_speed: Maximum speed for every single joint in rad.s-1, allowing to avoid jumps in joints configuration
:param min_success_rate: Raise RuntimeError in case the success rate is lower than min_success_rate
:param display_only:
:param timeout: In case of cuff interaction, indicates the max time to retry before giving up (default is 0 = do not retry)
:param stop_test: pointer to a function that returns True if execution must stop now. /!\ Should be fast, it will be called at 100Hz!
:param pause_test: pointer to a function that returns True if execution must pause now. If yes it blocks until pause=False again and relaunches the same goal
/!\ Test functions must be fast, they will be called at 100Hz!
:return:
:raises: RuntimeError if success rate is too low
"""
def trajectory_callable(start):
traj, success_rate = trajectories.generate_cartesian_path(path, frame_id, time, self, None, n_points, max_speed)
if success_rate < min_success_rate:
raise RuntimeError("Unable to generate cartesian path (success rate : {})".format(success_rate))
return traj
return self._relaunched_move_to(trajectory_callable, display_only, timeout, stop_test, pause_test)
def move_to_controlled(self, goal, rpy=[0, 0, 0], display_only=False, timeout=15, stop_test=lambda:False, pause_test=lambda:False):
"""
Move to a goal using interpolation in joint space with limitation of velocity and acceleration
:param goal: Pose, PoseStamped or RobotState
:param rpy: Vector [Roll, Pitch, Yaw] filled with 0 if this axis must be preserved, 1 otherwise
:param display_only:
:param timeout: In case of cuff interaction, indicates the max time to retry before giving up
:param stop_test: pointer to a function that returns True if execution must stop now. /!\ Should be fast, it will be called at 100Hz!
:param pause_test: pointer to a function that returns True if execution must pause now. If yes it blocks until pause=False again and relaunches the same goal
/!\ Test functions must be fast, they will be called at 100Hz!
:return: None
:raises: ValueError if IK has no solution
"""
assert callable(stop_test)
assert callable(pause_test)
if not isinstance(goal, RobotState):
goal = self.get_ik(goal)
if goal is None:
raise ValueError('This goal is not reachable')
# collect the robot state
start = self.get_current_state()
# correct the orientation if rpy is set
if np.array(rpy).any():
# convert the starting point to rpy pose
pos, rot = states.state_to_pose(start,
self,
True)
for i in range(3):
if rpy[i]:
rpy[i] = rot[i]
goal = states.correct_state_orientation(goal, rpy, self)
# parameters for trapezoidal method
kv_max = self.kv_max
ka_max = self.ka_max
return self._relaunched_move_to(lambda start: trajectories.trapezoidal_speed_trajectory(goal, start=start ,kv_max=kv_max, ka_max=ka_max),
display_only, timeout, stop_test, pause_test)
def rotate_joint(self, joint_name, goal_angle, display_only=False, stop_test=lambda:False, pause_test=lambda:False):
goal = self.get_current_state()
joint = goal.joint_state.name.index(joint_name)
# JTAS accepts all angles even out of limits
#limits = self.joint_limits()[joint_name]
goal.joint_state.position[joint] = goal_angle
return self.move_to_controlled(goal, display_only=display_only, stop_test=stop_test, pause_test=pause_test)
def _relaunched_move_to(self, trajectory_callable, display_only=False, timeout=15, stop_test=lambda:False, pause_test=lambda:False):
"""
Relaunch several times (until cuff interaction or failure) a move_to() whose trajectory is generated by the callable passed in parameter
:param trajectory_callable: Callable to call to recompute the trajectory
:param display_only:
:param timeout: In case of cuff interaction, indicates the max time to retry before giving up
:param stop_test: pointer to a function that returns True if execution must stop now. /!\ Should be fast, it will be called at 100Hz!
:param pause_test: pointer to a function that returns True if execution must pause now. If yes it blocks until pause=False again and relaunches the same goal
:return:
"""
assert callable(trajectory_callable)
retry = True
t0 = rospy.get_time()
while retry and rospy.get_time()-t0 < timeout or timeout == 0:
start = self.get_current_state()
trajectory = trajectory_callable(start)
if display_only:
self.display(trajectory)
break
else:
retry = not self.execute(trajectory, test=lambda: stop_test() or pause_test())
if pause_test():
if not stop_test():
retry = True
while pause_test():
rospy.sleep(0.1)
if timeout == 0:
return not display_only and not retry
if retry:
rospy.sleep(1)
return not display_only and not retry
def get_random_pose(self):
# get joint names
joint_names = self.joint_names()
# create a random joint state
bounds = []
for key, value in self.joint_limits().iteritems():
bounds.append(value)
bounds = np.array(bounds)
joint_state = np.random.uniform(bounds[:, 0], bounds[:, 1], len(joint_names))
# append it in a robot state
goal = RobotState()
goal.joint_state.name = joint_names
goal.joint_state.position = joint_state
goal.joint_state.header.stamp = rospy.Time.now()
goal.joint_state.header.frame_id = 'base'
return goal
######################## OPERATIONS ON TRAJECTORIES
# TO BE MOVED IN trajectories.py
def interpolate_joint_space(self, goal, total_time, nb_points, start=None):
"""
Interpolate a trajectory from a start state (or current state) to a goal in joint space
:param goal: A RobotState to be used as the goal of the trajectory
param total_time: The time to execute the trajectory
:param nb_points: Number of joint-space points in the final trajectory
:param start: A RobotState to be used as the start state, joint order must be the same as the goal
:return: The corresponding RobotTrajectory
"""
dt = total_time*(1.0/nb_points)
# create the joint trajectory message
traj_msg = JointTrajectory()
rt = RobotTrajectory()
if start == None:
start = self.get_current_state()
joints = []
start_state = start.joint_state.position
goal_state = goal.joint_state.position
for j in range(len(goal_state)):
pose_lin = np.linspace(start_state[j],goal_state[j],nb_points+1)
joints.append(pose_lin[1:].tolist())
for i in range(nb_points):
point = JointTrajectoryPoint()
for j in range(len(goal_state)):
point.positions.append(joints[j][i])
# append the time from start of the position
point.time_from_start = rospy.Duration.from_sec((i+1)*dt)
# append the position to the message
traj_msg.points.append(point)
# put name of joints to be moved
traj_msg.joint_names = self.joint_names()
# send the message
rt.joint_trajectory = traj_msg
return rt
def display(self, trajectory):
"""
Display a joint-space trajectory or a robot state in RVIz loaded with the Moveit plugin
:param trajectory: a RobotTrajectory, JointTrajectory, RobotState or JointState message
"""
# Publish the DisplayTrajectory (only for trajectory preview in RViz)
# includes a convert of float durations in rospy.Duration()
def js_to_rt(js):
rt = RobotTrajectory()
rt.joint_trajectory.joint_names = js.name
rt.joint_trajectory.points.append(JointTrajectoryPoint(positions=js.position))
return rt
dt = DisplayTrajectory()
if isinstance(trajectory, RobotTrajectory):
dt.trajectory.append(trajectory)
elif isinstance(trajectory, JointTrajectory):
rt = RobotTrajectory()
rt.joint_trajectory = trajectory
dt.trajectory.append(rt)
elif isinstance(trajectory, RobotState):
dt.trajectory.append(js_to_rt(trajectory.joint_state))
elif isinstance(trajectory, JointState):
dt.trajectory.append(js_to_rt(trajectory))
else:
raise NotImplementedError("ArmCommander.display() expected type RobotTrajectory, JointTrajectory, RobotState or JointState, got {}".format(str(type(trajectory))))
self._display_traj.publish(dt)
def execute(self, trajectory, test=None, epsilon=0.1):
"""
Safely executes a trajectory in joint space on the robot or simulate through RViz and its Moveit plugin (File moveit.rviz must be loaded into RViz)
This method is BLOCKING until the command succeeds or failure occurs i.e. the user interacted with the cuff or collision has been detected
Non-blocking needs should deal with the JointTrajectory action server
:param trajectory: either a RobotTrajectory or a JointTrajectory
:param test: pointer to a function that returns True if execution must stop now. /!\ Should be fast, it will be called at 100Hz!
:param epsilon: distance threshold on the first point. If distance with first point of the trajectory is greater than espilon execute a controlled trajectory to the first point. Put float(inf) value to bypass this functionality
:return: True if execution ended successfully, False otherwise
"""
def distance_to_first_point(point):
joint_pos = np.array(point.positions)
return np.linalg.norm(current_array - joint_pos)
self.display(trajectory)
with self._stop_lock:
self._stop_reason = ''
if isinstance(trajectory, RobotTrajectory):
trajectory = trajectory.joint_trajectory
elif not isinstance(trajectory, JointTrajectory):
raise TypeError("Execute only accept RobotTrajectory or JointTrajectory")
ftg = FollowJointTrajectoryGoal()
ftg.trajectory = trajectory
# check if it is necessary to move to the first point
current = self.get_current_state()
current_array = np.array([current.joint_state.position[current.joint_state.name.index(joint)] for joint in trajectory.joint_names])
if distance_to_first_point(trajectory.points[0]) > epsilon:
# convert first point to robot state
rs = RobotState()
rs.joint_state.name = trajectory.joint_names
rs.joint_state.position = trajectory.points[0].positions
# move to the first point
self.move_to_controlled(rs)
# execute the input trajectory
self.client.send_goal(ftg)
# Blocking part, wait for the callback or a collision or a user manipulation to stop the trajectory
while self.client.simple_state != SimpleGoalState.DONE:
if callable(test) and test():
self.client.cancel_goal()
return True
if self._stop_reason!='':
self.client.cancel_goal()
return False
self._rate.sleep()
return True
def close(self):
"""
Open the gripper
:return: True if an object has been grasped
"""
return self._gripper.close(True)
def open(self):
"""
Close the gripper
return: True if an object has been released
"""
return self._gripper.open(True)
def gripping(self):
return self._gripper.gripping()
def wait_for_human_grasp(self, threshold=1, rate=10, ignore_gripping=True):
"""
Blocks until external motion is given to the arm
:param threshold:
:param rate: rate of control loop in Hertz
:param ignore_gripping: True if we must wait even if no object is gripped
"""
def detect_variation():
new_effort = np.array(self.get_current_state([self.name+'_w0',
self.name+'_w1',
self.name+'_w2']).joint_state.effort)
delta = np.absolute(effort - new_effort)
return np.amax(delta) > threshold
# record the effort at calling time
effort = np.array(self.get_current_state([self.name+'_w0',
self.name+'_w1',
self.name+'_w2']).joint_state.effort)
# loop till the detection of changing effort
rate = rospy.Rate(rate)
while not detect_variation() and not rospy.is_shutdown() and (ignore_gripping or self.gripping()):
rate.sleep()
class ArmCommander(Limb):
"""
This class overloads Limb from the Baxter Python SDK adding the support of trajectories via RobotState and RobotTrajectory messages
Allows to control the entire arm either in joint space, or in task space, or (later) with path planning, all with simulation
"""
def __init__(self,
name,
rate=100,
fk='robot',
ik='trac',
default_kv_max=1.,
default_ka_max=0.5):
"""
:param name: 'left' or 'right'
:param rate: Rate of the control loop for execution of motions
:param fk: Name of the Forward Kinematics solver, "robot", "kdl", "trac" or "ros"
:param ik: Name of the Inverse Kinematics solver, "robot", "kdl", "trac" or "ros"
:param default_kv_max: Default K maximum for velocity
:param default_ka_max: Default K maximum for acceleration
"""
Limb.__init__(self, name)
self._world = 'base'
self.kv_max = default_kv_max
self.ka_max = default_ka_max
self._gripper = Gripper(name)
self._rate = rospy.Rate(rate)
self._tf_listener = TransformListener()
self.recorder = Recorder(name)
# Kinematics services: names and services (if relevant)
self._kinematics_names = {
'fk': {
'ros': 'compute_fk'
},
'ik': {
'ros':
'compute_ik',
'robot':
'ExternalTools/{}/PositionKinematicsNode/IKService'.format(
name),
'trac':
'trac_ik_{}'.format(name)
}
}
self._kinematics_services = {
'fk': {
'ros': {
'service':
rospy.ServiceProxy(self._kinematics_names['fk']['ros'],
GetPositionFK),
'func':
self._get_fk_ros
},
'kdl': {
'func': self._get_fk_pykdl
},
'robot': {
'func': self._get_fk_robot
}
},
'ik': {
'ros': {
'service':
rospy.ServiceProxy(self._kinematics_names['ik']['ros'],
GetPositionIK),
'func':
self._get_ik_ros
},
'robot': {
'service':
rospy.ServiceProxy(self._kinematics_names['ik']['robot'],
SolvePositionIK),
'func':
self._get_ik_robot
},
'trac': {
'service':
rospy.ServiceProxy(self._kinematics_names['ik']['trac'],
GetConstrainedPositionIK),
'func':
self._get_ik_trac
},
'kdl': {
'func': self._get_ik_pykdl
}
}
}
self._selected_ik = ik
self._selected_fk = fk
# Kinematics services: PyKDL
self._kinematics_pykdl = baxter_kinematics(name)
if self._selected_ik in self._kinematics_names['ik']:
rospy.wait_for_service(
self._kinematics_names['ik'][self._selected_ik])
if self._selected_fk in self._kinematics_names['fk']:
rospy.wait_for_service(
self._kinematics_names['fk'][self._selected_fk])
# Execution attributes
rospy.Subscriber(
'/robot/limb/{}/collision_detection_state'.format(name),
CollisionDetectionState,
self._cb_collision,
queue_size=1)
rospy.Subscriber('/robot/digital_io/{}_lower_cuff/state'.format(name),
DigitalIOState,
self._cb_dig_io,
queue_size=1)
self._stop_reason = '' # 'cuff' or 'collision' could cause a trajectory to be stopped
self._stop_lock = Lock()
action_server_name = "/robot/limb/{}/follow_joint_trajectory".format(
self.name)
self.client = SimpleActionClient(action_server_name,
FollowJointTrajectoryAction)
self._display_traj = rospy.Publisher(
"/move_group/display_planned_path",
DisplayTrajectory,
queue_size=1)
self._gripper.calibrate()
self.client.wait_for_server()
######################################### CALLBACKS #########################################
def _cb_collision(self, msg):
if msg.collision_state:
with self._stop_lock:
self._stop_reason = 'collision'
def _cb_dig_io(self, msg):
if msg.state > 0:
with self._stop_lock:
self._stop_reason = 'cuff'
#############################################################################################
def endpoint_pose(self):
"""
Returns the pose of the end effector
:return: [[x, y, z], [x, y, z, w]]
"""
pose = Limb.endpoint_pose(self)
return [[pose['position'].x, pose['position'].y, pose['position'].z],
[
pose['orientation'].x, pose['orientation'].y,
pose['orientation'].z, pose['orientation'].w
]]
def endpoint_name(self):
return self.name + '_gripper'
def group_name(self):
return self.name + '_arm'
def joint_limits(self):
xml_urdf = rospy.get_param('robot_description')
dict_urdf = xmltodict.parse(xml_urdf)
joints_urdf = []
joints_urdf.append([
j['@name'] for j in dict_urdf['robot']['joint']
if j['@name'] in self.joint_names()
])
joints_urdf.append(
[[float(j['limit']['@lower']),
float(j['limit']['@upper'])] for j in dict_urdf['robot']['joint']
if j['@name'] in self.joint_names()])
# reorder the joints limits
return dict(
zip(self.joint_names(), [
joints_urdf[1][joints_urdf[0].index(name)]
for name in self.joint_names()
]))
def get_current_state(self, list_joint_names=[]):
"""
Returns the current RobotState describing all joint states
:param list_joint_names: If not empty, returns only the state of the requested joints
:return: a RobotState corresponding to the current state read on /robot/joint_states
"""
if len(list_joint_names) == 0:
list_joint_names = self.joint_names()
state = RobotState()
state.joint_state.name = list_joint_names
state.joint_state.position = map(self.joint_angle, list_joint_names)
state.joint_state.velocity = map(self.joint_velocity, list_joint_names)
state.joint_state.effort = map(self.joint_effort, list_joint_names)
return state
def get_ik(self, eef_poses, seeds=(), source=None, params=None):
"""
Return IK solutions of this arm's end effector according to the method declared in the constructor
:param eef_poses: a PoseStamped or a list [[x, y, z], [x, y, z, w]] in world frame or a list of PoseStamped
:param seeds: a single seed or a list of seeds of type RobotState for each input pose
:param source: 'robot', 'trac', 'kdl'... the IK source for this call (warning: the source might not be instanciated)
:param params: dictionary containing optional non-generic IK parameters
:return: a list of RobotState for each input pose in input or a single RobotState
TODO: accept also a Point (baxter_pykdl's IK accepts orientation=None)
Child methods wait for a *list* of pose(s) and a *list* of seed(s) for each pose
"""
if not isinstance(eef_poses, list) or isinstance(
eef_poses[0], list) and not isinstance(eef_poses[0][0], list):
eef_poses = [eef_poses]
if not seeds:
seeds = []
elif not isinstance(seeds, list):
seeds = [seeds] * len(eef_poses)
input = []
for eef_pose in eef_poses:
if isinstance(eef_pose, list):
input.append(list_to_pose(eef_pose, self._world))
elif isinstance(eef_pose, PoseStamped):
input.append(eef_pose)
else:
raise TypeError(
"ArmCommander.get_ik() accepts only a list of Postamped or [[x, y, z], [x, y, z, w]], got {}"
.format(str(type(eef_pose))))
output = self._kinematics_services['ik'][
self._selected_ik if source is None else source]['func'](input,
seeds,
params)
return output if len(eef_poses) > 1 else output[0]
def get_fk(self, frame_id=None, robot_state=None):
"""
Return The FK solution oth this robot state according to the method declared in the constructor
robot_state = None will give the current endpoint pose in frame_id
:param robot_state: a RobotState message
:param frame_id: the frame you want the endpoint pose into
:return: [[x, y, z], [x, y, z, w]]
"""
if frame_id is None:
frame_id = self._world
if isinstance(robot_state, RobotState) or robot_state is None:
return self._kinematics_services['fk'][self._selected_fk]['func'](
frame_id, robot_state)
else:
raise TypeError(
"ArmCommander.get_fk() accepts only a RobotState, got {}".
format(str(type(robot_state))))
def _get_fk_pykdl(self, frame_id, state=None):
if state is None:
state = self.get_current_state()
fk = self._kinematics_pykdl.forward_position_kinematics(
dict(zip(state.joint_state.name, state.joint_state.position)))
ps = list_to_pose([fk[:3], fk[-4:]], self._world)
return self._tf_listener.transformPose(frame_id, ps)
def _get_fk_robot(self, frame_id=None, state=None):
# Keep this half-working FK, still used by generate_cartesian_path (trajectories.py)
if state is not None:
raise NotImplementedError(
"_get_fk_robot has no FK service provided by the robot except for its current endpoint pose"
)
ps = list_to_pose(self.endpoint_pose(), self._world)
return self._tf_listener.transformPose(frame_id, ps)
def _get_fk_ros(self, frame_id=None, state=None):
rqst = GetPositionFKRequest()
rqst.header.frame_id = self._world if frame_id is None else frame_id
rqst.fk_link_names = [self.endpoint_name()]
if isinstance(state, RobotState):
rqst.robot_state = state
elif isinstance(state, JointState):
rqst.robot_state.joint_state = state
elif state is None:
rqst.robot_state = self.get_current_state()
else:
raise AttributeError("Provided state is an invalid type")
fk_answer = self._kinematics_services['fk']['ros']['service'].call(
rqst)
if fk_answer.error_code.val == 1:
return fk_answer.pose_stamped[0]
else:
return None
def _get_ik_pykdl(self, eef_poses, seeds=(), params=None):
solutions = []
for pose_num, eef_pose in enumerate(eef_poses):
if eef_pose.header.frame_id.strip('/') != self._world.strip('/'):
raise NotImplementedError(
"_get_ik_pykdl: Baxter PyKDL implementation does not accept frame_ids other than {}"
.format(self._world))
pose = pose_to_list(eef_pose)
resp = self._kinematics_pykdl.inverse_kinematics(
pose[0], pose[1], [
seeds[pose_num].joint_state.position[
seeds[pose_num].joint_state.name.index(joint)]
for joint in self.joint_names()
] if len(seeds) > 0 else None)
if resp is None:
rs = None
else:
rs = RobotState()
rs.is_diff = False
rs.joint_state.name = self.joint_names()
rs.joint_state.position = resp
solutions.append(rs)
return solutions
def _get_ik_robot(self, eef_poses, seeds=(), params=None):
ik_req = SolvePositionIKRequest()
for eef_pose in eef_poses:
ik_req.pose_stamp.append(eef_pose)
ik_req.seed_mode = ik_req.SEED_USER if len(
seeds) > 0 else ik_req.SEED_CURRENT
for seed in seeds:
ik_req.seed_angles.append(seed.joint_state)
resp = self._kinematics_services['ik']['robot']['service'].call(ik_req)
solutions = []
for j, v in zip(resp.joints, resp.isValid):
solutions.append(
RobotState(is_diff=False, joint_state=j) if v else None)
return solutions
def _get_ik_trac(self, eef_poses, seeds=(), params=None):
ik_req = GetConstrainedPositionIKRequest()
if params is None:
ik_req.num_steps = 1
else:
ik_req.end_tolerance = params['end_tolerance']
ik_req.num_steps = params['num_attempts']
for eef_pose in eef_poses:
ik_req.pose_stamp.append(eef_pose)
if len(seeds) == 0:
seeds = [self.get_current_state()] * len(eef_poses)
for seed in seeds:
ik_req.seed_angles.append(seed.joint_state)
resp = self._kinematics_services['ik']['trac']['service'].call(ik_req)
solutions = []
for j, v in zip(resp.joints, resp.isValid):
solutions.append(
RobotState(is_diff=False, joint_state=j) if v else None)
return solutions
def _get_ik_ros(self, eef_poses, seeds=()):
rqst = GetPositionIKRequest()
rqst.ik_request.avoid_collisions = True
rqst.ik_request.group_name = self.group_name()
solutions = []
for pose_num, eef_pose in enumerate(eef_poses):
rqst.ik_request.pose_stamped = eef_pose # Do we really to do a separate call for each pose? _vector not used
ik_answer = self._kinematics_services['ik']['ros']['service'].call(
rqst)
if len(seeds) > 0:
rqst.ik_request.robot_state = seeds[pose_num]
if ik_answer.error_code.val == 1:
# Apply a filter to return only joints of this group
try:
ik_answer.solution.joint_state.velocity = [
value for id_joint, value in enumerate(
ik_answer.solution.joint_state.velocity)
if ik_answer.solution.joint_state.name[id_joint] in
self.joint_names()
]
ik_answer.solution.joint_state.effort = [
value for id_joint, value in enumerate(
ik_answer.solution.joint_state.effort)
if ik_answer.solution.joint_state.name[id_joint] in
self.joint_names()
]
except IndexError:
pass
ik_answer.solution.joint_state.position = [
value for id_joint, value in enumerate(
ik_answer.solution.joint_state.position)
if ik_answer.solution.joint_state.name[id_joint] in
self.joint_names()
]
ik_answer.solution.joint_state.name = [
joint for joint in ik_answer.solution.joint_state.name
if joint in self.joint_names()
]
solutions.append(ik_answer.solution)
else:
solutions.append(None)
return solutions
def translate_to_cartesian(self,
path,
frame_id,
time,
n_points=50,
max_speed=np.pi / 4,
min_success_rate=0.5,
display_only=False,
timeout=0,
stop_test=lambda: False,
pause_test=lambda: False):
"""
Translate the end effector in straight line, following path=[translate_x, translate_y, translate_z] wrt frame_id
:param path: Path [x, y, z] to follow wrt frame_id
:param frame_id: frame_id of the given input path
:param time: Time of the generated trajectory
:param n_points: Number of 3D points of the cartesian trajectory
:param max_speed: Maximum speed for every single joint in rad.s-1, allowing to avoid jumps in joints configuration
:param min_success_rate: Raise RuntimeError in case the success rate is lower than min_success_rate
:param display_only:
:param timeout: In case of cuff interaction, indicates the max time to retry before giving up (default is 0 = do not retry)
:param stop_test: pointer to a function that returns True if execution must stop now. /!\ Should be fast, it will be called at 100Hz!
:param pause_test: pointer to a function that returns True if execution must pause now. If yes it blocks until pause=False again and relaunches the same goal
/!\ Test functions must be fast, they will be called at 100Hz!
:return:
:raises: RuntimeError if success rate is too low
"""
def trajectory_callable(start):
traj, success_rate = trajectories.generate_cartesian_path(
path, frame_id, time, self, None, n_points, max_speed)
if success_rate < min_success_rate:
raise RuntimeError(
"Unable to generate cartesian path (success rate : {})".
format(success_rate))
return traj
return self._relaunched_move_to(trajectory_callable, display_only,
timeout, stop_test, pause_test)
def move_to_controlled(self,
goal,
rpy=[0, 0, 0],
display_only=False,
timeout=15,
stop_test=lambda: False,
pause_test=lambda: False):
"""
Move to a goal using interpolation in joint space with limitation of velocity and acceleration
:param goal: Pose, PoseStamped or RobotState
:param rpy: Vector [Roll, Pitch, Yaw] filled with 0 if this axis must be preserved, 1 otherwise
:param display_only:
:param timeout: In case of cuff interaction, indicates the max time to retry before giving up
:param stop_test: pointer to a function that returns True if execution must stop now. /!\ Should be fast, it will be called at 100Hz!
:param pause_test: pointer to a function that returns True if execution must pause now. If yes it blocks until pause=False again and relaunches the same goal
/!\ Test functions must be fast, they will be called at 100Hz!
:return: None
:raises: ValueError if IK has no solution
"""
assert callable(stop_test)
assert callable(pause_test)
if not isinstance(goal, RobotState):
goal = self.get_ik(goal)
if goal is None:
raise ValueError('This goal is not reachable')
# collect the robot state
start = self.get_current_state()
# correct the orientation if rpy is set
if np.array(rpy).any():
# convert the starting point to rpy pose
pos, rot = states.state_to_pose(start, self, True)
for i in range(3):
if rpy[i]:
rpy[i] = rot[i]
goal = states.correct_state_orientation(goal, rpy, self)
# parameters for trapezoidal method
kv_max = self.kv_max
ka_max = self.ka_max
return self._relaunched_move_to(
lambda start: trajectories.trapezoidal_speed_trajectory(
goal, start=start, kv_max=kv_max, ka_max=ka_max), display_only,
timeout, stop_test, pause_test)
def rotate_joint(self,
joint_name,
goal_angle,
display_only=False,
stop_test=lambda: False,
pause_test=lambda: False):
goal = self.get_current_state()
joint = goal.joint_state.name.index(joint_name)
# JTAS accepts all angles even out of limits
#limits = self.joint_limits()[joint_name]
goal.joint_state.position[joint] = goal_angle
return self.move_to_controlled(goal,
display_only=display_only,
stop_test=stop_test,
pause_test=pause_test)
def _relaunched_move_to(self,
trajectory_callable,
display_only=False,
timeout=15,
stop_test=lambda: False,
pause_test=lambda: False):
"""
Relaunch several times (until cuff interaction or failure) a move_to() whose trajectory is generated by the callable passed in parameter
:param trajectory_callable: Callable to call to recompute the trajectory
:param display_only:
:param timeout: In case of cuff interaction, indicates the max time to retry before giving up
:param stop_test: pointer to a function that returns True if execution must stop now. /!\ Should be fast, it will be called at 100Hz!
:param pause_test: pointer to a function that returns True if execution must pause now. If yes it blocks until pause=False again and relaunches the same goal
:return:
"""
assert callable(trajectory_callable)
retry = True
t0 = rospy.get_time()
while retry and rospy.get_time() - t0 < timeout or timeout == 0:
start = self.get_current_state()
trajectory = trajectory_callable(start)
if display_only:
self.display(trajectory)
break
else:
retry = not self.execute(
trajectory, test=lambda: stop_test() or pause_test())
if pause_test():
if not stop_test():
retry = True
while pause_test():
rospy.sleep(0.1)
if timeout == 0:
return not display_only and not retry
if retry:
rospy.sleep(1)
return not display_only and not retry
def get_random_pose(self):
# get joint names
joint_names = self.joint_names()
# create a random joint state
bounds = []
for key, value in self.joint_limits().iteritems():
bounds.append(value)
bounds = np.array(bounds)
joint_state = np.random.uniform(bounds[:, 0], bounds[:, 1],
len(joint_names))
# append it in a robot state
goal = RobotState()
goal.joint_state.name = joint_names
goal.joint_state.position = joint_state
goal.joint_state.header.stamp = rospy.Time.now()
goal.joint_state.header.frame_id = 'base'
return goal
######################## OPERATIONS ON TRAJECTORIES
# TO BE MOVED IN trajectories.py
def interpolate_joint_space(self, goal, total_time, nb_points, start=None):
"""
Interpolate a trajectory from a start state (or current state) to a goal in joint space
:param goal: A RobotState to be used as the goal of the trajectory
param total_time: The time to execute the trajectory
:param nb_points: Number of joint-space points in the final trajectory
:param start: A RobotState to be used as the start state, joint order must be the same as the goal
:return: The corresponding RobotTrajectory
"""
dt = total_time * (1.0 / nb_points)
# create the joint trajectory message
traj_msg = JointTrajectory()
rt = RobotTrajectory()
if start == None:
start = self.get_current_state()
joints = []
start_state = start.joint_state.position
goal_state = goal.joint_state.position
for j in range(len(goal_state)):
pose_lin = np.linspace(start_state[j], goal_state[j],
nb_points + 1)
joints.append(pose_lin[1:].tolist())
for i in range(nb_points):
point = JointTrajectoryPoint()
for j in range(len(goal_state)):
point.positions.append(joints[j][i])
# append the time from start of the position
point.time_from_start = rospy.Duration.from_sec((i + 1) * dt)
# append the position to the message
traj_msg.points.append(point)
# put name of joints to be moved
traj_msg.joint_names = self.joint_names()
# send the message
rt.joint_trajectory = traj_msg
return rt
def display(self, trajectory):
"""
Display a joint-space trajectory or a robot state in RVIz loaded with the Moveit plugin
:param trajectory: a RobotTrajectory, JointTrajectory, RobotState or JointState message
"""
# Publish the DisplayTrajectory (only for trajectory preview in RViz)
# includes a convert of float durations in rospy.Duration()
def js_to_rt(js):
rt = RobotTrajectory()
rt.joint_trajectory.joint_names = js.name
rt.joint_trajectory.points.append(
JointTrajectoryPoint(positions=js.position))
return rt
dt = DisplayTrajectory()
if isinstance(trajectory, RobotTrajectory):
dt.trajectory.append(trajectory)
elif isinstance(trajectory, JointTrajectory):
rt = RobotTrajectory()
rt.joint_trajectory = trajectory
dt.trajectory.append(rt)
elif isinstance(trajectory, RobotState):
dt.trajectory.append(js_to_rt(trajectory.joint_state))
elif isinstance(trajectory, JointState):
dt.trajectory.append(js_to_rt(trajectory))
else:
raise NotImplementedError(
"ArmCommander.display() expected type RobotTrajectory, JointTrajectory, RobotState or JointState, got {}"
.format(str(type(trajectory))))
self._display_traj.publish(dt)
def execute(self, trajectory, test=None, epsilon=0.1):
"""
Safely executes a trajectory in joint space on the robot or simulate through RViz and its Moveit plugin (File moveit.rviz must be loaded into RViz)
This method is BLOCKING until the command succeeds or failure occurs i.e. the user interacted with the cuff or collision has been detected
Non-blocking needs should deal with the JointTrajectory action server
:param trajectory: either a RobotTrajectory or a JointTrajectory
:param test: pointer to a function that returns True if execution must stop now. /!\ Should be fast, it will be called at 100Hz!
:param epsilon: distance threshold on the first point. If distance with first point of the trajectory is greater than espilon execute a controlled trajectory to the first point. Put float(inf) value to bypass this functionality
:return: True if execution ended successfully, False otherwise
"""
def distance_to_first_point(point):
joint_pos = np.array(point.positions)
return np.linalg.norm(current_array - joint_pos)
self.display(trajectory)
with self._stop_lock:
self._stop_reason = ''
if isinstance(trajectory, RobotTrajectory):
trajectory = trajectory.joint_trajectory
elif not isinstance(trajectory, JointTrajectory):
raise TypeError(
"Execute only accept RobotTrajectory or JointTrajectory")
ftg = FollowJointTrajectoryGoal()
ftg.trajectory = trajectory
# check if it is necessary to move to the first point
current = self.get_current_state()
current_array = np.array([
current.joint_state.position[current.joint_state.name.index(joint)]
for joint in trajectory.joint_names
])
if distance_to_first_point(trajectory.points[0]) > epsilon:
# convert first point to robot state
rs = RobotState()
rs.joint_state.name = trajectory.joint_names
rs.joint_state.position = trajectory.points[0].positions
# move to the first point
self.move_to_controlled(rs)
# execute the input trajectory
self.client.send_goal(ftg)
# Blocking part, wait for the callback or a collision or a user manipulation to stop the trajectory
while self.client.simple_state != SimpleGoalState.DONE:
if callable(test) and test():
self.client.cancel_goal()
return True
if self._stop_reason != '':
self.client.cancel_goal()
return False
self._rate.sleep()
return True
def close(self):
"""
Open the gripper
:return: True if an object has been grasped
"""
return self._gripper.close(True)
def open(self):
"""
Close the gripper
return: True if an object has been released
"""
return self._gripper.open(True)
def gripping(self):
return self._gripper.gripping()
def wait_for_human_grasp(self, threshold=1, rate=10, ignore_gripping=True):
"""
Blocks until external motion is given to the arm
:param threshold:
:param rate: rate of control loop in Hertz
:param ignore_gripping: True if we must wait even if no object is gripped
"""
def detect_variation():
new_effort = np.array(
self.get_current_state(
[self.name + '_w0', self.name + '_w1',
self.name + '_w2']).joint_state.effort)
delta = np.absolute(effort - new_effort)
return np.amax(delta) > threshold
# record the effort at calling time
effort = np.array(
self.get_current_state(
[self.name + '_w0', self.name + '_w1',
self.name + '_w2']).joint_state.effort)
# loop till the detection of changing effort
rate = rospy.Rate(rate)
while not detect_variation() and not rospy.is_shutdown() and (
ignore_gripping or self.gripping()):
rate.sleep()
