Create the y2021_bot3 folder

It builds! yay

Change-Id: I732955c018ce2988de64486e2457e673efd2cbb8
diff --git a/y2021_bot3/control_loops/python/drivetrain.py b/y2021_bot3/control_loops/python/drivetrain.py
new file mode 100644
index 0000000..e5b001a
--- /dev/null
+++ b/y2021_bot3/control_loops/python/drivetrain.py
@@ -0,0 +1,46 @@
+#!/usr/bin/python3
+
+from __future__ import print_function
+from frc971.control_loops.python import drivetrain
+from frc971.control_loops.python import control_loop
+import sys
+
+import gflags
+import glog
+
+FLAGS = gflags.FLAGS
+
+gflags.DEFINE_bool('plot', False, 'If true, plot the loop response.')
+
+kDrivetrain = drivetrain.DrivetrainParams(
+    J=6.0,
+    mass=58.0,
+    # TODO(austin): Measure radius a bit better.
+    robot_radius=0.7 / 2.0,
+    wheel_radius=6.0 * 0.0254 / 2.0,
+    motor_type=control_loop.Falcon(),
+    G=(8.0 / 70.0) * (17.0 / 24.0),
+    q_pos=0.24,
+    q_vel=2.5,
+    efficiency=0.80,
+    has_imu=True,
+    force=True,
+    kf_q_voltage=1.0,
+    controller_poles=[0.82, 0.82])
+
+
+def main(argv):
+    argv = FLAGS(argv)
+    glog.init()
+
+    if FLAGS.plot:
+        drivetrain.PlotDrivetrainMotions(kDrivetrain)
+    elif len(argv) != 5:
+        print("Expected .h file name and .cc file name")
+    else:
+        # Write the generated constants out to a file.
+        drivetrain.WriteDrivetrain(argv[1:3], argv[3:5], 'y2021_bot3', kDrivetrain)
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv))