y2016/control_loops/python/shooter.py

#!/usr/bin/python3

from frc971.control_loops.python import control_loop
from frc971.control_loops.python import controls
import numpy
import sys
from matplotlib import pylab

import gflags
import glog

FLAGS = gflags.FLAGS

gflags.DEFINE_bool('plot', False, 'If true, plot the loop response.')


class VelocityShooter(control_loop.ControlLoop):

    def __init__(self, name='VelocityShooter'):
        super(VelocityShooter, self).__init__(name)
        # Stall Torque in N m
        self.stall_torque = 0.71
        # Stall Current in Amps
        self.stall_current = 134
        # Free Speed in RPM
        self.free_speed = 18730.0
        # Free Current in Amps
        self.free_current = 0.7
        # Moment of inertia of the shooter wheel in kg m^2
        self.J = 0.00032
        # Resistance of the motor, divided by 2 to account for the 2 motors
        self.R = 12.0 / self.stall_current
        # 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 = 12.0 / 18.0
        # Control loop time step
        self.dt = 0.005

        # State feedback matrices
        # [angular velocity]
        self.A_continuous = numpy.matrix(
            [[-self.Kt / self.Kv / (self.J * self.G * self.G * self.R)]])
        self.B_continuous = numpy.matrix(
            [[self.Kt / (self.J * self.G * self.R)]])
        self.C = numpy.matrix([[1]])
        self.D = numpy.matrix([[0]])

        self.A, self.B = self.ContinuousToDiscrete(self.A_continuous,
                                                   self.B_continuous, self.dt)

        self.PlaceControllerPoles([.87])

        self.PlaceObserverPoles([0.3])

        self.U_max = numpy.matrix([[12.0]])
        self.U_min = numpy.matrix([[-12.0]])

        qff_vel = 8.0
        self.Qff = numpy.matrix([[1.0 / (qff_vel**2.0)]])

        self.Kff = controls.TwoStateFeedForwards(self.B, self.Qff)


class Shooter(VelocityShooter):

    def __init__(self, name='Shooter'):
        super(Shooter, self).__init__(name)

        self.A_continuous_unaugmented = self.A_continuous
        self.B_continuous_unaugmented = self.B_continuous

        self.A_continuous = numpy.matrix(numpy.zeros((2, 2)))
        self.A_continuous[1:2, 1:2] = self.A_continuous_unaugmented
        self.A_continuous[0, 1] = 1

        self.B_continuous = numpy.matrix(numpy.zeros((2, 1)))
        self.B_continuous[1:2, 0] = self.B_continuous_unaugmented

        # State feedback matrices
        # [position, angular velocity]
        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.rpl = .45
        self.ipl = 0.07
        self.PlaceObserverPoles(
            [self.rpl + 1j * self.ipl, self.rpl - 1j * self.ipl])

        self.K_unaugmented = self.K
        self.K = numpy.matrix(numpy.zeros((1, 2)))
        self.K[0, 1:2] = self.K_unaugmented
        self.Kff_unaugmented = self.Kff
        self.Kff = numpy.matrix(numpy.zeros((1, 2)))
        self.Kff[0, 1:2] = self.Kff_unaugmented

        self.InitializeState()


class IntegralShooter(Shooter):

    def __init__(self, name="IntegralShooter"):
        super(IntegralShooter, self).__init__(name=name)

        self.A_continuous_unaugmented = self.A_continuous
        self.B_continuous_unaugmented = self.B_continuous

        self.A_continuous = numpy.matrix(numpy.zeros((3, 3)))
        self.A_continuous[0:2, 0:2] = self.A_continuous_unaugmented
        self.A_continuous[0:2, 2] = self.B_continuous_unaugmented

        self.B_continuous = numpy.matrix(numpy.zeros((3, 1)))
        self.B_continuous[0:2, 0] = self.B_continuous_unaugmented

        self.C_unaugmented = self.C
        self.C = numpy.matrix(numpy.zeros((1, 3)))
        self.C[0:1, 0:2] = self.C_unaugmented

        self.A, self.B = self.ContinuousToDiscrete(self.A_continuous,
                                                   self.B_continuous, self.dt)

        q_pos = 0.08
        q_vel = 4.00
        q_voltage = 0.3
        self.Q = numpy.matrix([[(q_pos**2.0), 0.0, 0.0],
                               [0.0, (q_vel**2.0), 0.0],
                               [0.0, 0.0, (q_voltage**2.0)]])

        r_pos = 0.05
        self.R = numpy.matrix([[(r_pos**2.0)]])

        self.KalmanGain, self.Q_steady = controls.kalman(
            A=self.A, B=self.B, C=self.C, Q=self.Q, R=self.R)
        self.L = self.A * self.KalmanGain

        self.K_unaugmented = self.K
        self.K = numpy.matrix(numpy.zeros((1, 3)))
        self.K[0, 0:2] = self.K_unaugmented
        self.K[0, 2] = 1
        self.Kff_unaugmented = self.Kff
        self.Kff = numpy.matrix(numpy.zeros((1, 3)))
        self.Kff[0, 0:2] = self.Kff_unaugmented

        self.InitializeState()


class ScenarioPlotter(object):

    def __init__(self):
        # Various lists for graphing things.
        self.t = []
        self.x = []
        self.v = []
        self.a = []
        self.x_hat = []
        self.u = []
        self.offset = []

    def run_test(self,
                 shooter,
                 goal,
                 iterations=200,
                 controller_shooter=None,
                 observer_shooter=None):
        """Runs the shooter plant with an initial condition and goal.

        Args:
            shooter: Shooter object to use.
            goal: goal state.
            iterations: Number of timesteps to run the model for.
            controller_shooter: Shooter object to get K from, or None if we should
                use shooter.
            observer_shooter: Shooter object to use for the observer, or None if we
                should use the actual state.
        """

        if controller_shooter is None:
            controller_shooter = shooter

        vbat = 12.0

        if self.t:
            initial_t = self.t[-1] + shooter.dt
        else:
            initial_t = 0

        for i in range(iterations):
            X_hat = shooter.X

            if observer_shooter is not None:
                X_hat = observer_shooter.X_hat
                self.x_hat.append(observer_shooter.X_hat[1, 0])

            ff_U = controller_shooter.Kff * (goal - observer_shooter.A * goal)

            U = controller_shooter.K * (goal - X_hat) + ff_U
            U[0, 0] = numpy.clip(U[0, 0], -vbat, vbat)
            self.x.append(shooter.X[0, 0])

            if self.v:
                last_v = self.v[-1]
            else:
                last_v = 0

            self.v.append(shooter.X[1, 0])
            self.a.append((self.v[-1] - last_v) / shooter.dt)

            if observer_shooter is not None:
                observer_shooter.Y = shooter.Y
                observer_shooter.CorrectObserver(U)
                self.offset.append(observer_shooter.X_hat[2, 0])

            applied_U = U.copy()
            if i > 30:
                applied_U += 2
            shooter.Update(applied_U)

            if observer_shooter is not None:
                observer_shooter.PredictObserver(U)

            self.t.append(initial_t + i * shooter.dt)
            self.u.append(U[0, 0])

            glog.debug('Time: %f', self.t[-1])

    def Plot(self):
        pylab.subplot(3, 1, 1)
        pylab.plot(self.t, self.v, label='x')
        pylab.plot(self.t, self.x_hat, label='x_hat')
        pylab.legend()

        pylab.subplot(3, 1, 2)
        pylab.plot(self.t, self.u, label='u')
        pylab.plot(self.t, self.offset, label='voltage_offset')
        pylab.legend()

        pylab.subplot(3, 1, 3)
        pylab.plot(self.t, self.a, label='a')
        pylab.legend()

        pylab.show()


def main(argv):
    scenario_plotter = ScenarioPlotter()

    shooter = Shooter()
    shooter_controller = IntegralShooter()
    observer_shooter = IntegralShooter()

    initial_X = numpy.matrix([[0.0], [0.0]])
    R = numpy.matrix([[0.0], [100.0], [0.0]])
    scenario_plotter.run_test(
        shooter,
        goal=R,
        controller_shooter=shooter_controller,
        observer_shooter=observer_shooter,
        iterations=200)

    if FLAGS.plot:
        scenario_plotter.Plot()

    if len(argv) != 5:
        glog.fatal('Expected .h file name and .cc file name')
    else:
        namespaces = ['y2016', 'control_loops', 'shooter']
        shooter = Shooter('Shooter')
        loop_writer = control_loop.ControlLoopWriter(
            'Shooter', [shooter], namespaces=namespaces)
        loop_writer.Write(argv[1], argv[2])

        integral_shooter = IntegralShooter('IntegralShooter')
        integral_loop_writer = control_loop.ControlLoopWriter(
            'IntegralShooter', [integral_shooter], namespaces=namespaces)
        integral_loop_writer.Write(argv[3], argv[4])


if __name__ == '__main__':
    argv = FLAGS(sys.argv)
    sys.exit(main(argv))