Source code for smarts.core.controllers.actuator_dynamic_controller

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import numpy as np

METER_PER_SECOND_TO_KM_PER_HR = 3.6


class ActuatorDynamicControllerState:
    """Controller state information"""

    def __init__(self):
        self.last_steering_angle = 0


class ActuatorDynamicController:
    """A controller that maintains the last steering angle."""

    @classmethod
    def perform_action(cls, vehicle, action, state, dt_sec):
        """Perform throttle, break, and steering, keeping the previous steering angle as the start
        for the next steering angle.
        """
        throttle, brake, steering_change = action

        # The following is the normalized steering change
        # under the assumption that the steering angles at
        # wheels can reach to their maximum values in one
        # second.
        clipped_steering_change = np.clip(
            steering_change,
            -1,
            1,
        )

        p = 0.001  # XXX: Theorized to improve stability, this has yet to be seen.
        steering = np.clip(
            (1 - p) * state.last_steering_angle + clipped_steering_change * dt_sec,
            -1,
            1,
        )

        vehicle.control(
            throttle=np.clip(throttle, 0.0, 1.0),
            brake=np.clip(brake, 0.0, 1.0),
            steering=steering,
        )

        state.last_steering_angle = steering