Manipulator Motion Planning

Manipulator Motion Planning

Plan collision-free paths for manipulators and convert them to time-optimal trajectories that respect velocity and acceleration limits.

When to Use

• Moving a robot arm between joint configurations or Cartesian poses — regardless of whether the user says "trajectory," "motion," "path," or "plan"
• Generating any trajectory between waypoints (time-optimal, constant-velocity, trapezoidal, minimum-jerk)
• Planning a collision-free path between configurations
• Modeling obstacles as collision environments for planning
• Choosing between motion planners (RRT, CHOMP, dlCHOMP)
• Verifying a trajectory is collision-free
• Any task where the robot moves through space and geometry exists in the workspace — collision safety is implicit even if the user doesn't mention it

When NOT to Use

• Building, loading, or importing the robot model — use /matlab-model-robot-kinematics
• Solving IK/FK or validating solutions — use /matlab-model-robot-kinematics
• Attaching grippers or configuring end-effectors — use /matlab-model-robot-kinematics
• Mobile robot navigation (wheeled platforms, ground vehicles)
• Dynamics simulation (inverseDynamics, forwardDynamics)
• Code generation / MEX deployment of planners

Pre-conditions

Before planning, verify these are satisfied:

0. MANDATORY: Invoke /matlab-model-robot-kinematics first — Do NOT proceed with any step below until the robot model exists in the MATLAB workspace AND was set up by that skill. Never call loadrobot, importrobot, or build a rigidBodyTree inline in a motion-planning workflow — even if it seems trivial. No exceptions. The modeling skill handles collision mesh validation, gripper selection, EE frame alignment, and known pitfalls (e.g., articulated grippers causing self-collisions with planners). Skipping it leads to wasted iterations.

1. Robot has collision meshes — A robot without collision geometry causes planners to report "collision-free" for paths that actually collide. Confirm with:

bodies = robot.Bodies;
hasCollision = any(cellfun(@(b) ~isempty(b.Collisions), bodies));
assert(hasCollision, "Robot has no collision meshes — planning results will be invalid.");

2. DataFormat="row" — All planning functions expect row-vector configurations. Verify: