Package com.flarerobotics.lib.control.shooter.data

Class LibShooterDescriptor.Builder

java.lang.Object
com.flarerobotics.lib.control.shooter.data.LibShooterDescriptor.Builder
Enclosing class:
LibShooterDescriptor
public static class LibShooterDescriptor.Builder extends Object
A builder class for ShooterDescriptor paramters.

  • Constructor Details

    • Builder

      public Builder(double pivotHeight, double rollerRadius, edu.wpi.first.math.system.plant.DCMotor gearbox, double rollerReduction, int numMotors)
      Constructs a new Builder.
      Parameters:
      pivotHeight - The height of the pivot point relative to the ground in meters.
      rollerRadius - The radius of the rollers in meters.
      gearbox - The DC motor gearbox for the driving motors.
      rollerReduction - The reduction ratio of the rollers, where >1 is a reduction.
      numMotors - The number of motors driving the shooter rollers.

  • Method Details

    • rollerMOI

      public LibShooterDescriptor.Builder rollerMOI(double value)
      Sets the moment of inertia for the rollers.
      Parameters:
      value - The moment of inertia in kg*m^2.
      Returns:
      The builder instance for chaining.

    • angleRange

      public LibShooterDescriptor.Builder angleRange(double minDeg, double maxDeg)
      Sets the vertical angle range for the shooter, in degrees.
      Parameters:
      minDeg - The minimum angle in degrees.
      maxDeg - The maximum angle in degrees.
      Returns:
      The builder instance for chaining.

    • flywheel

      public LibShooterDescriptor.Builder flywheel(double moi, double reduction)
      Sets the moment of inertia for the flywheel. Do not use if a flywheel is not attached.
      Parameters:
      moi - The moment of inertia in kg*m^2.
      reduction - The reduction ratio from the flywheel to the shooter.
      Returns:
      The builder instance for chaining.

    • hopperDelay

      public LibShooterDescriptor.Builder hopperDelay(double seconds)
      Sets the hopper delay, defined as the time it takes the game piece from the hopper to being launched, not including the spin-up time.
      Parameters:
      seconds - The delay.
      Returns:
      The builder instance for chaining.

    • dataSet

      public LibShooterDescriptor.Builder dataSet(BilinearInterpolator2D angleInterpolator, BilinearInterpolator2D rpmInterpolator, edu.wpi.first.math.interpolation.InterpolatingDoubleTreeMap windupTimes)
      Adds a fully-empirical dataset to the shooter descriptor.

      Example arrays: 

       
 // Sorted Arrays
 double[] horizontalDistances = { 2.0, 3.0, 4.0, 5.0 }; // meters
 double[] heightDiffs = { -0.5, 0.0, +0.5, +1.0 }; // meters, relative to ground
 double[][] angleGrid = {
         // -----------------> HeightDiff (-0.5 -> +1.0)
         { 45, 40, 35, 30 }, // at d=2.0
         { 42, 38, 33, 28 }, // at d=3.0
         { 39, 35, 31, 27 }, // at d=4.0
         { 37, 33, 29, 25 }, // at d=5.0
 };
 double[][] rpmGrid = {
         // -----------------> HeightDiff (-0.5 -> +1.0)
         { 4500, 4000, 3500, 3000 }, // at d=2.0
         { 4200, 3800, 3300, 2800 }, // at d=3.0
         { 3900, 3500, 3100, 2700 }, // at d=4.0
         { 3700, 3300, 2900, 2500 }, // at d=5.0
 }

 // Build windup-time map from 0->4500 RPM
 InterpolatingDoubleTreeMap windupTimes = new InterpolatingDoubleTreeMap();
 // Always include the (0,0) point:
 windupTimes.put(0.0, 0.0);

 windupTimes.put(2500.0, 0.02703);
 windupTimes.put(2700.0, 0.02919);
 windupTimes.put(2800.0, 0.03027);
 windupTimes.put(2900.0, 0.03135);
 windupTimes.put(3000.0, 0.03244);
 windupTimes.put(3100.0, 0.03352);
 windupTimes.put(3300.0, 0.03568);
 windupTimes.put(3500.0, 0.03784);
 windupTimes.put(3700.0, 0.04000);
 windupTimes.put(3800.0, 0.04108);
 windupTimes.put(3900.0, 0.04217);
 windupTimes.put(4000.0, 0.04325);
 windupTimes.put(4200.0, 0.04541);
 windupTimes.put(4500.0, 0.04865);

      Notes:

      - The emprical data must be measured from the shooter's pivot point, not the barrel.

      - The grids must be sorted in ascending order.

      - The wind-up times must have the data point (0, 0).

      - The data should be large enough to avoid extrapolation due to out-of-bounds data, which may lead to significant inacuracies.

      - The RPM speeds use the roller RPMs.

      Parameters:
      angleInterpolator - The bilinear interpolator for the angles, as described above.
      rpmInterpolator - The bilinear interpolator for the RPMs, as described above.
      windupTimes - The time it takes the motors to spin up to the given RPM from 0 RPM.
      Returns:
      The builder instance for chaining.

    • dataSet

      public LibShooterDescriptor.Builder dataSet(BilinearInterpolator2D angleInterpolator, BilinearInterpolator2D rpmInterpolator)
      Adds a fully-empirical dataset to the shooter descriptor. Assumes the wind-up times are negligible.

      Example arrays: 

       
 // Sorted Arrays
 double[] horizontalDistances = { 2.0, 3.0, 4.0, 5.0 }; // meters
 double[] heightDiffs = { -0.5, 0.0, +0.5, +1.0 }; // meters, relative to ground
 double[][] angleGrid = {
         // -----------------> HeightDiff (-0.5 -> +1.0)
         { 45, 40, 35, 30 }, // at d=2.0
         { 42, 38, 33, 28 }, // at d=3.0
         { 39, 35, 31, 27 }, // at d=4.0
         { 37, 33, 29, 25 }, // at d=5.0
 };
 double[][] rpmGrid = {
         // -----------------> HeightDiff (-0.5 -> +1.0)
         { 4500, 4000, 3500, 3000 }, // at d=2.0
         { 4200, 3800, 3300, 2800 }, // at d=3.0
         { 3900, 3500, 3100, 2700 }, // at d=4.0
         { 3700, 3300, 2900, 2500 }, // at d=5.0
 }

      Notes:

      - The emprical data must be measured from the shooter's pivot point, not the barrel.

      - The grids must be sorted in ascending order.

      - The wind-up times must have the data point (0, 0).

      - The data should be large enough to avoid extrapolation due to out-of-bounds data, which may lead to significant inacuracies.

      - The RPM speeds use the roller RPMs.

      Parameters:
      angleInterpolator - The bilinear interpolator for the angles, as described above.
      rpmInterpolator - The bilinear interpolator for the RPMs, as described above.
      Returns:
      The builder instance for chaining.

    • nominalVoltage

      public LibShooterDescriptor.Builder nominalVoltage(double value)
      Sets the nominal battery voltage.
      Parameters:
      value - The nominal voltage in Volts, typically 12V - 12.5V.
      Returns:
      The builder instance for chaining.

    • setRPMLimits

      public LibShooterDescriptor.Builder setRPMLimits(double maxRPM)
      Sets the RPM limits for the shooter. Defaults to the value computed via maxRPM/reduction, the hardware maximum.
      Parameters:
      maxRPM - The maximum RPM.
      Returns:
      The builder instance for chaining.

    • build

      public LibShooterDescriptor build()
      Builds the ShooterDescriptor instance with the provided parameters.
      Returns:
      A new ShooterDescriptor instance.