Path Validation

Path Validation

Path Validation is a crucial feature that checks your FTC autonomous routines for potential issues before you run them on a real robot. It analyzes your paths for collisions with obstacles or field boundaries, and ensures the planned movements are kinematically possible based on your robot’s configured constraints.

Using the Validation Tools

You can run validation manually or enable it to run continuously in the background.

Manual Validation

To perform a single check of your entire sequence:

• Shortcut: Shift + V
• Command Palette: Open the Command Palette (Ctrl + P / Cmd + P) and select Validate Path.

When you run manual validation, the visualizer will scan the path and display an alert or overlay indicating any detected issues.

Continuous Validation

For real-time feedback while you edit, you can enable Continuous Validation.

• Shortcut: Alt + V
• Command Palette: Open the Command Palette and toggle Continuous Validation.

When enabled, the visualizer will constantly check the path as you drag points or adjust headings. This is highly recommended when fine-tuning complex routines around obstacles.

What Validation Checks

The validation system evaluates your path against four primary check types. Each has custom logic to ensure your robot moves safely and realistically:

1. boundary (Field Boundaries)

Ensures the robot does not attempt to drive outside the 144x144 inch field perimeter.

• Validation accurately uses the Length and Width specified in your Robot Settings to simulate the robot’s exact footprint along the entire path. If any part of the robot’s bumper crosses the field wall, it triggers a boundary error.

2. obstacle (Obstacles)

Checks against any custom polygons you have defined in the Obstacles panel.

• If the robot’s projected path and physical dimensions intersect with an obstacle polygon, it triggers an obstacle error.

3. keep-in (Keep-In Zones)

Special zones where the robot is required to stay inside.

• If the robot’s path or footprint exits the boundaries of a designated keep-in zone, it triggers a keep-in error.

4. zero-length (Zero-Length Segments)

A sanity check that prevents paths from having a distance of zero.

• If a path segment’s start point and end point are in the exact same location with no actual movement required, it triggers a zero-length error, as this can cause mathematical anomalies in the robot’s path follower.

Configuring Validation Settings

Validation behavior can be customized in the Settings > Robot menu to match your workflow:

• Safety Margin (in): This setting allows you to configure a buffer zone (e.g., 2 inches). Validation will treat obstacles and boundaries as being slightly larger/closer than drawn, giving you a safety buffer against real-world mechanical slop or odometry drift.
• Validate Field Boundaries: A toggle that allows you to completely disable the boundary checks. Useful if you are testing isolated movements without worrying about the field walls.
• Restrict Dragging: When enabled, this prevents you from manually moving control points or waypoints outside the field boundaries on the canvas.

Resolving Validation Errors

When an error is detected, the visualizer will typically highlight the problematic segment of the path in red or display warning icons.

Tips for fixing errors:

• Boundary/Obstacle Collisions: Try dragging control points to widen the curve around the obstacle, or use the Path Optimizer (Ctrl + Shift + O) to let the visualizer find a safe route automatically.
• Zero-Length Errors: Delete the redundant path segment or space the points out.

Best Practices

• Set Accurate Robot Dimensions: Validation is only as good as the data it has. Ensure your robot Length and Width in the Settings menu accurately reflect your real-world robot footprint.
• Use Safety Margins: Always set a realistic Safety Margin. A value of 1.5 to 2.5 inches is recommended for most drivetrains.