PathPlanner Autonomous Routes
Autonomous routing combines preplanned paths, event markers, robot constraints, and live pathfinding.
Site connection
The robotics season used PathPlanner for swerve autonomous paths, hard-coded routes, on-the-fly generation, and pathfinding.
Visual model
Preplanned paths and live pathfinding share a core idea
The grid visualizer shows the search side; real FRC paths add robot dynamics, field coordinates, and event timing.
Interactive
A* expands likely paths first instead of flooding the whole grid
A good autonomous route is not just a line. It is a timed plan that respects drivetrain limits, field obstacles, mechanism actions, game-piece locations, and fallback behavior when the robot starts slightly off pose.
Preplanned vs On-the-Fly
Preplanned paths are predictable and easy to rehearse. They work well for known starting positions and known scoring sequences.
On-the-fly generation and pathfinding help when the robot needs to move from a live pose to a target while avoiding obstacles. They are more flexible but require more runtime trust.
Events and Mechanisms
Autonomous success depends on coordinating drivetrain motion with intake, shooter, arm, and sensor states. Event markers let the route trigger commands at specific parts of the path.
The hard part is timing under uncertainty: battery voltage, defense, wheel slip, and pose error can shift when the robot reaches each point.
| Route component | Failure mode |
|---|---|
| Initial pose | Path starts from the wrong place |
| Constraints | Robot cannot physically follow the path |
| Event marker | Mechanism fires too early or too late |
| Vision update | Pose correction arrives with latency |
| Obstacle map | Pathfinder drives through a blocked area if map is wrong |
Common Pitfalls
- Assuming simulation timing matches match timing.
- Creating paths that exceed drivetrain acceleration.
- Ignoring initial pose error.
- Triggering mechanisms without checking readiness.
- Confusing path generation with obstacle-aware pathfinding.
Quick check
Quiz
What do event markers usually coordinate?
- Mechanism commands during a path
- CSS styles
- API rate limits
- Database migrations
Event markers trigger robot commands at points along autonomous paths.