Motion Planning

Master path planning algorithms, kinematics, and obstacle avoidance to enable robots to navigate and manipulate objects in complex environments.

What is Motion Planning?

Motion planning is the problem of finding a sequence of valid configurations (positions and orientations) that move a robot from a start state to a goal state while avoiding obstacles. It is one of the most fundamental challenges in robotics, spanning both mobile robot navigation and robotic arm manipulation.

Planning Approaches

Mobile Robot Navigation with Nav2

# Launch Nav2 navigation stack
ros2 launch nav2_bringup navigation_launch.py \
    use_sim_time:=True \
    params_file:=/path/to/nav2_params.yaml

# Send a navigation goal programmatically
from geometry_msgs.msg import PoseStamped
from nav2_simple_commander.robot_navigator import BasicNavigator

navigator = BasicNavigator()
goal = PoseStamped()
goal.header.frame_id = 'map'
goal.pose.position.x = 3.0
goal.pose.position.y = 2.0
goal.pose.orientation.w = 1.0

navigator.goToPose(goal)
while not navigator.isTaskComplete():
    feedback = navigator.getFeedback()
    print(f'Distance remaining: {feedback.distance_remaining:.2f}m')

Robotic Arm Planning with MoveIt 2

MoveIt 2 is the standard motion planning framework for robotic manipulators in ROS 2. It provides:

• Inverse kinematics (IK): Computing joint angles to reach a desired end-effector pose
• Collision checking: Ensuring the robot doesn't collide with itself or the environment
• Multiple planners: OMPL (RRT, PRM), STOMP, Pilz industrial planner
• Grasp planning: Generating feasible grasp poses for pick-and-place tasks

Algorithm Comparison