frc4123 / 2024 Goto Github PK

For easiest troubleshooting, use the following lines to smart dashboard:

SmartDashboard.putNumber("Robot Heading", getHeading());
SmartDashboard.putString("Robot Location", getPose().getTranslation().toString());
SmartDashboard.putString("Swerve[" + cancoder.getDeviceID() + "] state", state.toString());
SmartDashboard.putNumber("Swerve[" + cancoder.getDeviceID() + "] abs enc", getAbsoluteEncoderRad());
SmartDashboard.putString("swerve inputs", String.format("xSpeed: %.2f\tySpeed: %.2f\tturningSpeed: %.2f", xSpeed, ySpeed, turningSpeed));
SmartDashboard.putString("Front Left State", frontLeft.getState().toString());
SmartDashboard.putString("Front Right State", frontRight.getState().toString());
SmartDashboard.putString("Back Left State", backLeft.getState().toString());
SmartDashboard.putString("Back Right State", backRight.getState().toString());

Problems + Solutions:

1. When driving command activated from controller, wheels spin chaotically with no pattern

• Check (Class Constants)
  public static final double kDriveMotorGearRatio = 1 / 6.75; and
  public static final double TurningMotorGearRatio = 1.0 / (150 / 7);
  ensure proper gear ratio of drive and turn
• Check (Class SwerveModule)
  angleRotations = Math.IEEEremainder(angleRotations, 1);
  ensure a redundant unit to unit calculation

2. Wheels turning without chaos, but not facing the right direction

   A. If all driving is reversed, (forward = backward | left = right)

   • Check (Phoenix X OR Constants)
     Proper inversion of CANcoders. Make sure that x and y in SmartDashboard are giving positive outputs when moving forward

   B. If Wheels are in "X" formation

   • Check (Class Constants)
     new Translation2d(kWheelBase / 2, kTrackWidth / 2), // front left
new Translation2d(kWheelBase / 2, -kTrackWidth / 2), // front right
new Translation2d(-kWheelBase / 2, kTrackWidth / 2), // back left
new Translation2d(-kWheelBase / 2, -kTrackWidth / 2)); // back right
     ensure correct positive and negative values relative to wheel position on robot

   C. If Wheels will face correct direction when aligned in same direction (before robot booting) but will not work if wheels are turned to all different directions (before robot booting)

   • Check (Class SwerveModule)
     driveEncoder.setPosition(0);
turnEncoder.setPosition(getAbsoluteEncoderRad());
     ensure turning encoder is set by radians from absolute encoder

3. Wheels seem to be turning and overcorrecting themselves (too jerky turns)

• Check (Class Constants)
  public static final double kPTurning = 0.4;
  ensure that "P" value is properly tuned, "I" and "D" are irrelevant

4. Bot can drive straight, but cannot maintain straight path while rotating

• Check (Class SwerveSubsystem)
  return Math.IEEEremainder(-gyro.getAngle(), 360);
  ensure that gyro is either positive or negative depending on roborio orientation on robot