Modified guidance algorithim

guidance/guidance_pkg/guidance_pkg/guidance.py

@@ -0,0 +1,150 @@
+import rclpy
+from rclpy.node import Node
+from std_msgs.msg import Float32MultiArray
+from nav_msgs.msg import Odometry
+import numpy as np
+import math
+from transforms3d.euler import quat2euler
+
+class GuidanceNode(Node):
+    def __init__(self):
+        super().__init__('guidance_pkg')
+
+        # Publisher to output the surge velocity, pitch angle, and heading angle
+        self.output_pub = self.create_publisher(Float32MultiArray, '/guidance/waypoints', 10)
+
+        # Subscriber to receive odometry data from '/nucleus/odom'
+        self.create_subscription(Odometry, '/nucleus/odom', self.odom_callback, 10)
+
+        # Initialize variables
+        self.current_position = None
+        self.current_velocity = None
+        self.current_orientation = None
+
+        # Parameters for the guidance algorithm
+        self.U = 1.0    # Desired speed
+        self.delta = 1.2  # Lookahead distance
+
+        # Define waypoints as a list of dictionaries with x, y, z coordinates
+        self.waypoints = [
+            {'x': 5.0, 'y': -5.0, 'z': -8.0},
+            {'x': 10.0, 'y': 5.0, 'z': -5.0},
+            {'x': 15.0, 'y': 0.0, 'z': 0.0},
+            # Add more waypoints as needed
+        ]
+        self.current_waypoint_index = 0
+
+        # Timer to periodically run the guidance algorithm
+        self.create_timer(0.1, self.timer_callback)
+
+    def odom_callback(self, msg):
+        """
+        Callback function to process odometry data.
+        """
+        self.current_position = msg.pose.pose.position
+        self.current_velocity = msg.twist.twist.linear
+        orientation_q = msg.pose.pose.orientation
+
+        # Convert quaternion to Euler angles
+        # ROS quaternion format: (x, y, z, w)
+        quaternion = [orientation_q.w, orientation_q.x, orientation_q.y, orientation_q.z]
+        roll, pitch, yaw = quat2euler(quaternion)
+        self.current_orientation = {'roll': roll, 'pitch': pitch, 'yaw': yaw}
+
+    def timer_callback(self):
+        """
+        Timer callback to compute and publish guidance commands.
+        """
+        if self.current_position is None or self.current_orientation is None:
+            # Wait until odometry data is received
+            return
+
+        if self.current_waypoint_index >= len(self.waypoints):
+            # All waypoints have been reached
+            self.get_logger().info('All waypoints reached.')
+            return
+
+        # Get the current waypoint
+        waypoint = self.waypoints[self.current_waypoint_index]
+
+        # Extract current position
+        current_x = self.current_position.x
+        current_y = self.current_position.y
+        current_z = self.current_position.z
+
+        # Extract current orientation
+        psi = self.current_orientation['yaw']    # Heading angle
+        theta = self.current_orientation['pitch']  # Pitch angle
+
+        # Extract target waypoint position
+        target_x = waypoint['x']
+        target_y = waypoint['y']
+        target_z = waypoint['z']
+
+        # Compute distance to the waypoint
+        distance = math.sqrt(
+            (target_x - current_x) ** 2 +
+            (target_y - current_y) ** 2 +
+            (target_z - current_z) ** 2
+        )
+
+        # Check if the waypoint is reached
+        if distance < 0.5:
+            self.get_logger().info(f'Reached waypoint {self.current_waypoint_index}')
+            self.current_waypoint_index += 1
+            if self.current_waypoint_index >= len(self.waypoints):
+                self.get_logger().info('All waypoints reached.')
+                return
+            else:
+                waypoint = self.waypoints[self.current_waypoint_index]
+
+        # Guidance calculations using a Line-of-Sight (LOS) algorithm
+        ref_x = current_x
+        ref_y = current_y
+        ref_z = current_z
+
+        dx = target_x - ref_x
+        dy = target_y - ref_y
+        dz = target_z - ref_z
+
+        # Compute desired heading angle (psi_d)
+        pi_p = math.atan2(dy, dx)
+        pi_p = normalize_angle(pi_p)
+
+        # Compute desired pitch angle (theta_d)
+        gamma = math.atan2(-dz, math.hypot(dx, dy))
+
+        # Compute cross-track error
+        e_ct = -(dx * (current_y - ref_y) - dy * (current_x - ref_x)) / math.hypot(dx, dy)
+
+        # Compute desired course angle
+        course_d = pi_p - math.atan(e_ct / self.delta)
+        course_d = normalize_angle(course_d)
+
+        # Set desired surge velocity
+        surge_velocity = self.U
+
+        # Set desired heading and pitch angles
+        heading_angle = course_d
+        pitch_angle = gamma
+
+        # Prepare and publish the output message
+        output_msg = Float32MultiArray()
+        output_msg.data = [surge_velocity, pitch_angle, heading_angle]
+        self.output_pub.publish(output_msg)
+
+def normalize_angle(angle):
+    """
+    Normalize an angle to the range [-π, π].
+    """
+    return (angle + np.pi) % (2 * np.pi) - np.pi
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = GuidanceNode()
+    rclpy.spin(node)
+    node.destroy_node()
+    rclpy.shutdown()
+
+if __name__ == '__main__':
+    main()

guidance/guidance_pkg/package.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0"?>
+<package format="3">
+  <name>guidance_pkg</name>
+  <version>0.0.0</version>
+  <description>Package for guidance node implementing PID control.</description>
+  <maintainer email="badawi@todo.todo">badawi</maintainer>
+  <license>TODO: License declaration</license>
+
+  <!-- Build tool dependency -->
+  <buildtool_depend>ament_python</buildtool_depend>
+
+  <!-- Build dependencies -->
+  <build_depend>rclpy</build_depend>
+  <build_depend>std_msgs</build_depend>
+  <build_depend>nav_msgs</build_depend>
+
+  <!-- Execution dependencies -->
+  <exec_depend>rclpy</exec_depend>
+  <exec_depend>std_msgs</exec_depend>
+  <exec_depend>nav_msgs</exec_depend>
+  <exec_depend>tf_transformations</exec_depend>
+
+  <!-- Test dependencies -->
+  <test_depend>ament_copyright</test_depend>
+  <test_depend>ament_flake8</test_depend>
+  <test_depend>ament_pep257</test_depend>
+  <test_depend>python3-pytest</test_depend>
+
+  <export>
+    <build_type>ament_python</build_type>
+  </export>
+</package>

guidance/guidance_pkg/setup.cfg

@@ -0,0 +1,4 @@
+[develop]
+script_dir=$base/lib/guidance_pkg
+[install]
+install_scripts=$base/lib/guidance_pkg

guidance/guidance_pkg/setup.py

@@ -0,0 +1,26 @@
+from setuptools import find_packages, setup
+
+package_name = 'guidance_pkg'
+
+setup(
+    name=package_name,
+    version='0.0.0',
+    packages=find_packages(exclude=['test']),
+    data_files=[
+        ('share/ament_index/resource_index/packages',
+            ['resource/' + package_name]),
+        ('share/' + package_name, ['package.xml']),
+    ],
+    install_requires=['setuptools'],
+    zip_safe=True,
+    maintainer='badawi',
+    maintainer_email='badawi@todo.todo',
+    description='TODO: Package description',
+    license='TODO: License declaration',
+    tests_require=['pytest'],
+    entry_points={
+        'console_scripts': [
+            'guidance = guidance_pkg.guidance:main',
+        ],
+    },
+)

guidance/guidance_pkg/test/test_copyright.py

@@ -0,0 +1,25 @@
+# Copyright 2015 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from ament_copyright.main import main
+import pytest
+
+
+# Remove the `skip` decorator once the source file(s) have a copyright header
+@pytest.mark.skip(reason='No copyright header has been placed in the generated source file.')
+@pytest.mark.copyright
+@pytest.mark.linter
+def test_copyright():
+    rc = main(argv=['.', 'test'])
+    assert rc == 0, 'Found errors'

guidance/guidance_pkg/test/test_flake8.py

@@ -0,0 +1,25 @@
+# Copyright 2017 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from ament_flake8.main import main_with_errors
+import pytest
+
+
+@pytest.mark.flake8
+@pytest.mark.linter
+def test_flake8():
+    rc, errors = main_with_errors(argv=[])
+    assert rc == 0, \
+        'Found %d code style errors / warnings:\n' % len(errors) + \
+        '\n'.join(errors)

guidance/guidance_pkg/test/test_pep257.py

@@ -0,0 +1,23 @@
+# Copyright 2015 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from ament_pep257.main import main
+import pytest
+
+
+@pytest.mark.linter
+@pytest.mark.pep257
+def test_pep257():
+    rc = main(argv=['.', 'test'])
+    assert rc == 0, 'Found code style errors / warnings'