runtime/rbs_skill_servers/scripts/move_to_pose.py

197 lines
7.3 KiB
Python
Executable file

#!/usr/bin/python
import rclpy
from rclpy.action import ActionServer
from rclpy.node import Node
import numpy as np
from rclpy.callback_groups import ReentrantCallbackGroup
from rclpy.executors import MultiThreadedExecutor
import math
from geometry_msgs.msg import Pose, PoseStamped
from rbs_skill_interfaces.action import MoveitSendPose
from scipy.spatial.transform import Rotation as R
from scipy.spatial.transform import Slerp
class CartesianMoveToPose(Node):
def __init__(self):
super().__init__('cartesian_move_to_pose') # pyright: ignore[]
self.declare_parameter("base_link", "base_link")
self.declare_parameter("robot_name", "")
self._callback_group = ReentrantCallbackGroup()
self._action_server = ActionServer(
self,
MoveitSendPose,
'cartesian_move_to_pose',
self.execute_callback, callback_group=self._callback_group)
# for multirobot setup where each robot name is a namespace
self.robot_name: str = self.get_parameter("robot_name").get_parameter_value().string_value
self.robot_name = self.robot_name.lstrip('/').rstrip('/')
self.robot_name = f"/{self.robot_name}" if self.robot_name else ""
self._pub = self.create_publisher(PoseStamped,
f"{self.robot_name}/cartesian_motion_controller/target_frame", 1,
callback_group=self._callback_group)
self.current_pose = None
self.goal_tolerance = 0.05
self.max_speed = 0.1
self.max_acceleration = 0.05
self.base_link = self.get_parameter("base_link").get_parameter_value().string_value
def on_pose_callback(self, msg: PoseStamped):
if isinstance(msg, PoseStamped):
self.current_pose = msg
def execute_callback(self, goal_handle):
self.get_logger().debug(f"Executing goal {goal_handle.request.target_pose}")
target_pose = goal_handle.request.target_pose
start_pose = self.current_pose.pose if self.current_pose else None
result = MoveitSendPose.Result()
if start_pose is None:
self.get_logger().error("Current pose is not available")
goal_handle.abort()
result.success = False
return result
trajectory = self.generate_trajectory(start_pose, target_pose)
for point in trajectory:
tp = PoseStamped()
tp.pose = point
tp.header.stamp = self.get_clock().now().to_msg()
tp.header.frame_id = self.base_link
self._pub.publish(tp)
rclpy.spin_once(self, timeout_sec=0.1)
goal_handle.succeed()
result.success = True
return result
def generate_trajectory(self, start_pose, target_pose):
start_position = np.array([
start_pose.position.x,
start_pose.position.y,
start_pose.position.z
])
target_position = np.array([
target_pose.position.x,
target_pose.position.y,
target_pose.position.z
])
start_orientation = R.from_quat([
start_pose.orientation.x,
start_pose.orientation.y,
start_pose.orientation.z,
start_pose.orientation.w
])
target_orientation = R.from_quat([
target_pose.orientation.x,
target_pose.orientation.y,
target_pose.orientation.z,
target_pose.orientation.w
])
distance = np.linalg.norm(target_position - start_position)
max_speed = self.max_speed
max_acceleration = self.max_acceleration
t_acc = max_speed / max_acceleration
d_acc = 0.5 * max_acceleration * t_acc**2
if distance < 2 * d_acc:
t_acc = math.sqrt(distance / max_acceleration)
t_flat = 0
else:
t_flat = (distance - 2 * d_acc) / max_speed
total_time = 2 * t_acc + t_flat
num_points = int(total_time * 10)
trajectory = []
times = np.linspace(0, total_time, num_points + 1)
key_rots = R.from_quat([start_orientation.as_quat(), target_orientation.as_quat()])
slerp = Slerp([0, total_time], key_rots)
for t in times:
if t < t_acc:
fraction = 0.5 * max_acceleration * t**2 / distance
elif t < t_acc + t_flat:
fraction = (d_acc + max_speed * (t - t_acc)) / distance
else:
t_decel = t - t_acc - t_flat
fraction = (d_acc + max_speed * t_flat + 0.5 * max_acceleration * t_decel**2) / distance
intermediate_position = start_position + fraction * (target_position - start_position)
intermediate_orientation = slerp([t])[0]
intermediate_pose = Pose()
intermediate_pose.position.x = intermediate_position[0]
intermediate_pose.position.y = intermediate_position[1]
intermediate_pose.position.z = intermediate_position[2]
intermediate_orientation_quat = intermediate_orientation.as_quat()
intermediate_pose.orientation.x = intermediate_orientation_quat[0]
intermediate_pose.orientation.y = intermediate_orientation_quat[1]
intermediate_pose.orientation.z = intermediate_orientation_quat[2]
intermediate_pose.orientation.w = intermediate_orientation_quat[3]
trajectory.append(intermediate_pose)
return trajectory
def get_distance_to_target(self, target_pose: Pose):
if self.current_pose is None or self.current_pose.pose is None:
self.get_logger().warn("Current pose is not available")
return None
current_pose = self.current_pose.pose
current_position = np.array([
current_pose.position.x,
current_pose.position.y,
current_pose.position.z
])
target_position = np.array([
target_pose.position.x,
target_pose.position.y,
target_pose.position.z
])
if np.any(np.isnan(current_position)) or np.any(np.isnan(target_position)):
self.get_logger().error("Invalid coordinates")
return None
distance = np.linalg.norm(current_position - target_position)
return distance
class PoseSubscriber(Node):
def __init__(self, parent: CartesianMoveToPose, robot_name: str):
super().__init__('pose_subscriber') # pyright: ignore[]
self.parent = parent
self._sub = self.create_subscription(PoseStamped,
f"{robot_name}/cartesian_motion_controller/current_pose",
self.parent.on_pose_callback, 1,
callback_group=self.parent._callback_group)
self.get_logger().info('PoseSubscriber node initialized')
def main(args=None):
rclpy.init(args=args)
cartesian_move_to_pose = CartesianMoveToPose()
pose_subscriber = PoseSubscriber(parent=cartesian_move_to_pose,
robot_name=cartesian_move_to_pose.robot_name)
executor = MultiThreadedExecutor()
executor.add_node(cartesian_move_to_pose)
executor.add_node(pose_subscriber)
executor.spin()
rclpy.shutdown()
if __name__ == '__main__':
main()