renamed lift to stilts

Change-Id: I38e058ba7eadb4f45c8ef4639e8abb387c1f0afb
diff --git a/y2019/control_loops/python/stilts.py b/y2019/control_loops/python/stilts.py
new file mode 100755
index 0000000..8faa5d4
--- /dev/null
+++ b/y2019/control_loops/python/stilts.py
@@ -0,0 +1,54 @@
+#!/usr/bin/python
+
+from frc971.control_loops.python import control_loop
+from frc971.control_loops.python import linear_system
+import numpy
+import sys
+import gflags
+import glog
+
+FLAGS = gflags.FLAGS
+
+try:
+    gflags.DEFINE_bool('plot', False, 'If true, plot the loop response.')
+except gflags.DuplicateFlagError:
+    pass
+
+kStilts = linear_system.LinearSystemParams(
+    name='Stilts',
+    motor=control_loop.Vex775Pro(),
+    G=(12.0 / 100.0) * (14.0 / 52.0),
+    # 5mm pitch, 18 tooth
+    radius=0.005 * 18.0 / (2.0 * numpy.pi),
+    # Or, 2.34 lb * 2 (2.1 kg) when lifting back up
+    mass=40.0,
+    q_pos=0.070,
+    q_vel=1.2,
+    kalman_q_pos=0.12,
+    kalman_q_vel=2.00,
+    kalman_q_voltage=35.0,
+    kalman_r_position=0.05,
+    dt=0.00505)
+
+
+def main(argv):
+    if FLAGS.plot:
+        R = numpy.matrix([[1.5], [0.0]])
+        linear_system.PlotKick(kStilts, R)
+        linear_system.PlotMotion(kStilts, R, max_velocity=5.0)
+
+    # Write the generated constants out to a file.
+    if len(argv) != 5:
+        glog.fatal(
+            'Expected .h file name and .cc file name for the elevator and integral elevator.'
+        )
+    else:
+        namespaces = ['y2019', 'control_loops', 'superstructure', 'stilts']
+        linear_system.WriteLinearSystem(kStilts, argv[1:3], argv[3:5],
+                                        namespaces)
+
+
+if __name__ == '__main__':
+    argv = FLAGS(sys.argv)
+    glog.init()
+    sys.exit(main(argv))