Import shooter from 2013

Taken from commit a085044

I liberally delete some things in the Python code to get
things compiling. I also added TODOs where I am unsure whether
my changes are appropriate.

Change-Id: I4f3ae9b69ca9c2b1917e73136c766275a44d3665
diff --git a/y2016/control_loops/python/shooter.py b/y2016/control_loops/python/shooter.py
new file mode 100644
index 0000000..f34a1f1
--- /dev/null
+++ b/y2016/control_loops/python/shooter.py
@@ -0,0 +1,72 @@
+#!/usr/bin/python
+
+from frc971.control_loops.python import control_loop
+import numpy
+import sys
+from matplotlib import pylab
+
+class Shooter(control_loop.ControlLoop):
+  def __init__(self):
+    super(Shooter, self).__init__("Shooter")
+    # Stall Torque in N m
+    self.stall_torque = 0.49819248
+    # Stall Current in Amps
+    self.stall_current = 85
+    # Free Speed in RPM
+    self.free_speed = 19300.0 - 1500.0
+    # Free Current in Amps
+    self.free_current = 1.4
+    # Moment of inertia of the shooter wheel in kg m^2
+    self.J = 0.0032
+    # Resistance of the motor, divided by 2 to account for the 2 motors
+    self.R = 12.0 / self.stall_current / 2
+    # Motor velocity constant
+    self.Kv = ((self.free_speed / 60.0 * 2.0 * numpy.pi) /
+              (12.0 - self.R * self.free_current))
+    # Torque constant
+    self.Kt = self.stall_torque / self.stall_current
+    # Gear ratio
+    self.G = 11.0 / 34.0
+    # Control loop time step
+    self.dt = 0.005
+
+    # State feedback matrices
+    self.A_continuous = numpy.matrix(
+        [[0, 1],
+         [0, -self.Kt / self.Kv / (self.J * self.G * self.G * self.R)]])
+    self.B_continuous = numpy.matrix(
+        [[0],
+         [self.Kt / (self.J * self.G * self.R)]])
+    self.C = numpy.matrix([[1, 0]])
+    self.D = numpy.matrix([[0]])
+
+    self.A, self.B = self.ContinuousToDiscrete(
+        self.A_continuous, self.B_continuous, self.dt)
+
+    self.PlaceControllerPoles([.6, .981])
+
+    self.rpl = .45
+    self.ipl = 0.07
+    self.PlaceObserverPoles([self.rpl + 1j * self.ipl,
+                             self.rpl - 1j * self.ipl])
+
+    self.U_max = numpy.matrix([[12.0]])
+    self.U_min = numpy.matrix([[-12.0]])
+
+
+def main(argv):
+  if len(argv) != 3:
+    print "Expected .h file name and .cc file name"
+  else:
+    namespaces = ['y2016', 'control_loops', 'shooter']
+    shooter = Shooter()
+    loop_writer = control_loop.ControlLoopWriter("Shooter", [shooter],
+                                                 namespaces=namespaces)
+    if argv[1][-3:] == '.cc':
+      loop_writer.Write(argv[2], argv[1])
+    else:
+      loop_writer.Write(argv[1], argv[2])
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))