Initial tuning of the control loops.

These were tuned by looking at the plots and looking at how aggressive
the controller is.

Change-Id: I68d7b396ccdcc79640bbffaea8102414720fe164
diff --git a/y2020/control_loops/python/drivetrain.py b/y2020/control_loops/python/drivetrain.py
index 696c8a2..95b9fcf 100644
--- a/y2020/control_loops/python/drivetrain.py
+++ b/y2020/control_loops/python/drivetrain.py
@@ -13,7 +13,7 @@
 
 kDrivetrain = drivetrain.DrivetrainParams(
     J=6.0,
-    mass=58.0,
+    mass=68.0,
     # TODO(austin): Measure radius a bit better.
     robot_radius=0.7 / 2.0,
     wheel_radius=6.0 * 0.0254 / 2.0,
@@ -25,8 +25,7 @@
     has_imu=True,
     force=True,
     kf_q_voltage=13.0,
-    controller_poles=[0.82, 0.82],
-    robot_cg_offset=0.0)
+    controller_poles=[0.82, 0.82])
 
 
 def main(argv):
@@ -41,5 +40,6 @@
         # Write the generated constants out to a file.
         drivetrain.WriteDrivetrain(argv[1:3], argv[3:5], 'y2020', kDrivetrain)
 
+
 if __name__ == '__main__':
     sys.exit(main(sys.argv))