Advanced Swerve Improvements

[ErikCald]

There are some advanced swerve improvements that I have been researching for awhile now. The first list will be very important because they are related to prevent carpet damage:

• Reduce speed of the a drive motor based on error is steering motor. Basically copy paste the line of code from here: https://github.com/wpilibsuite/allwpilib/blob/437cc91af5184308038baebf4e047c240ce29c64/wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/swervecontrollercommand/subsystems/SwerveModule.java#L116. (The idea here is to multiply the speed by the this equation: cos(desiredAngle - measuredAngle))

desiredState.speedMetersPerSecond *= desiredState.angle.minus(getAngle()).getCos();

• The TeleopSwerve command needs to have acceleration limiters (SlewRateLimiter) that have sensible units . It is very important that the unit of the limiter is done in m/s/s which just means you need to do the limit after multiplying the joystick value by the desired max speed.

Some less critical ideas and improvements:

• Account for the coupling ratio. This accounts for an inaccuracy due to the design of the co-axle swerve module design. Anytime the steering rotates, the drive motor moves a little bit which is untracked by the encoder. The coupling ratio accounts for this movement. Most important when passing to odometry but can also be used to adjust the speed of a module when setting a velocity.

[ErikCald]

• Adjust heading on inverse kinematics based on angular velocity to make sure the robot goes in a straight line when rotating also https://www.chiefdelphi.com/t/team-2910-code-release-2023/443663/2
• Sync encoders when possible: https://github.com/BroncBotz3481/YAGSL/blob/04466ef81d5d6c98d5761f0dd3836adf4073fd00/swervelib/SwerveDrive.java#L917
• Retry multiple times when configuring sparkmax: https://github.com/BroncBotz3481/YAGSL/blob/04466ef81d5d6c98d5761f0dd3836adf4073fd00/swervelib/motors/SparkMaxSwerve.java#L82
• Thread.sleep(200) in burnFlash: https://github.com/BroncBotz3481/YAGSL/blob/04466ef81d5d6c98d5761f0dd3836adf4073fd00/swervelib/motors/SparkMaxSwerve.java#L297

[ErikCald]

Fix singleton class issue. Only use SwerveSubsystem.getInstance() to get the subsytem

[ErikCald]

• Better way to account for skew than the 2910 way: https://github.com/BroncBotz3481/YAGSL/blob/3fd8493ccbbd0cc274aaac029d39d9626f78d82b/swervelib/SwerveDrive.java#L396

This equation was added into the ChassisSpeed object to account for skew:

Example for using the ChassisSpeed to account for skew: https://github.com/wpilibsuite/allwpilib/blob/6a2d3c30a6df21b841d3bce11c4e3d48f0282189/wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/swervebot/Drivetrain.java#L62

[ErikCald]

• If commanding no rotational movement, use a pid to hold the heading constant: https://github.com/BroncBotz3481/YAGSL/blob/3fd8493ccbbd0cc274aaac029d39d9626f78d82b/swervelib/SwerveDrive.java#L409

[ErikCald]

• Synchronize encoders every 100ms if the robot is not moving https://github.com/BroncBotz3481/YAGSL/blob/3fd8493ccbbd0cc274aaac029d39d9626f78d82b/swervelib/SwerveDrive.java#L918

[ErikCald]

Run setCANTimeout(500) after factory defaults but before doing any settings. Then run setCANTimeout(0) after all settings are completed but before burn flash. Example here: https://github.com/Mechanical-Advantage/RobotCode2023/blob/9884d13b2220b76d430e82248fd837adbc4a10bc/src/main/java/org/littletonrobotics/frc2023/subsystems/gripper/GripperIOSparkMax.java#L45

[ErikCald]

Super stretch goal for way later, prob after comp. Setup the swerve code ecosystem to transfer EASILY to students in future years who aren't as proficient in code. My ideas right now are to just add all the different gear ratios of SDS modules into the config, add code to handle inverted SDS modules, and put comments explaining certain necessary changes per year, stuff like the Translation2d for each module, etc.