Reject Limelight vision frames relying on far AprilTags

[YehudaRothstein]

Summary

Vision pose updates now ignore any frame that includes an AprilTag farther than 5 m from the turret Limelight, so far/noisy tags no longer pull the robot pose.

Why

Swerve.periodic() uses getBotPoseEstimate_wpiBlue (MegaTag1), which fuses every visible tag into a single pose. A single distant tag is noisy and degrades the whole estimate. Rather than averaging it in, we drop the entire frame when any contributing tag is out of range.

Changes

• Constants.SwerveConstants.MAX_VISION_TAG_DISTANCE_METERS = 5.0 — new, tunable threshold.
• Swerve.periodic() — added an allTagsWithinRange(...) gate to the existing visionReliable condition. The frame is accepted only if all rawFiducials have distToCamera <= 5 m (in addition to the existing tag-count, motion, and ambiguity checks).

Notes

• Filtering is per-frame on distToCamera; to change the cutoff, edit the one constant.
• A softer alternative (keep far tags but scale addVisionMeasurement std devs with distance) was considered; this PR uses the hard cutoff as requested. Easy to switch later if smoother boundary behavior is wanted.

Testing

• ./gradlew compileJava passes.

🤖 Generated with Claude Code

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Generated by Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Improved vision-based driving accuracy by ignoring unreliable tag detections that are too far from the camera.
  • Reduced the chance of pose updates being applied from weak or low-confidence vision readings.
  • Added a configurable distance limit for accepting vision measurements.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 9d8896f3-05a5-4e5a-a538-26b7d0b0adae

📥 Commits

Reviewing files that changed from the base of the PR and between 883a0ea and 297787f.

📒 Files selected for processing (2)

• src/main/java/frc/excalib/swerve/Swerve.java
• src/main/java/frc/robot/Constants.java

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📝 Walkthrough

Walkthrough

Adds a MAX_VISION_TAG_DISTANCE_METERS constant (5.0 m) to SwerveConstants and a private allTagsWithinRange helper in Swerve. The helper rejects pose estimates with zero fiducials or any fiducial beyond the threshold. The periodic() vision reliability check is extended to call this helper before inserting odometry measurements.

Changes

Vision Tag Distance Filter

Layer / File(s)	Summary
Constant, filter helper, and periodic wiring src/main/java/frc/robot/Constants.java, src/main/java/frc/excalib/swerve/Swerve.java	MAX_VISION_TAG_DISTANCE_METERS = 5.0 added to SwerveConstants; allTagsWithinRange helper implemented to return false when no fiducials exist or any exceeds the limit; periodic() visionReliable condition extended to call the helper.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: rejecting Limelight vision frames with distant AprilTags.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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• Create PR with unit tests
• Commit unit tests in branch district-one-day-one

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[Copilot]

Pull request overview

This PR tightens Limelight (MegaTag1) vision integration in Swerve.periodic() by rejecting pose-estimate frames that include any AprilTag beyond a configurable distance threshold, preventing distant/noisy tags from degrading fused pose updates.

Changes:

• Added MAX_VISION_TAG_DISTANCE_METERS (default 5.0) as a tunable vision cutoff in Constants.SwerveConstants.
• Added allTagsWithinRange(...) gating in Swerve.periodic() so a frame is only accepted when every rawFiducial.distToCamera is within the threshold.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/main/java/frc/robot/Constants.java	Introduces a single tunable constant to define the maximum acceptable AprilTag distance for vision pose frames.
src/main/java/frc/excalib/swerve/Swerve.java	Filters Limelight pose updates by rejecting frames containing any AprilTag farther than the configured threshold before fusing into odometry.

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