ultrasonic_servo_env - Robot with ultrasonic sensor environment

class gym_ultrasonic.envs.ultrasonic_servo_env.UltrasonicEnv(n_obstacles=4, time_step=0.5, sonar_direction_angles=(0, ))[source]

Bases: gym.core.Env

A differential robot with one Ultrasonic sonar sensor, trying to avoid obstacles. Never stops (no target).

metadata = {'render.modes': ['human', 'rgb_array']}
action_space = Box(2,)
step(self, action)[source]
Make a single step:

  1. move forward by action[0] mm;

  2. rotate by action[1] radians;

  3. rotate servo by action[2] radians (UltrasonicServoEnv-v1 only).

Parameters
action: List[float]

Env action to perform.

Returns
observation: List[float]

A list that contains one value - min dist to an obstacle on its way.

reward: float

A reward, obtained by taking this action.

done: bool

Whether the episode has ended.

info: dict

An empty dict. Unused.

update_state(self)[source]
Returns
state: List[float]

Min dist to obstacles.

reward(self, trajectory, move_step, angle_rotate, servo_turn)[source]

Computes the reward.

Parameters
trajectory: LineString

Trajectory of this step.

move_step: float

Move robot with move_step mm along its main axis.

angle_rotate: float

Turn robot by angle_turn radians.

servo_turn: float

Turn servo by servo_turn radians, if not None.

Returns
reward: float

A reward, obtained by applying this step.

done: bool

Whether the robot collided with any of obstacles.

property init_state
Returns
List[float]

Initial env state (observation) which is the min dist to obstacles. It’s not clear what the default “min dist to obstacles” is - 0, sensor_max_dist or a value in-between. But since we update_state() after each reset(), it should not matter.

reset(self)[source]

Resets the state and spawns a new robot position.

init_view(self)[source]

Initializes the Viewer (for displaying purpose only).

render(self, mode='human')[source]

Renders the screen, robot, and obstacles.

Parameters
mode: str

The mode to render with. Either ‘human’ or ‘rgb_array’.

class gym_ultrasonic.envs.ultrasonic_servo_env.UltrasonicServoEnv(n_obstacles=4, time_step=0.5, sonar_direction_angles=(0, ), servo_angular_vel=0.5, observe_servo_angle=True)[source]

Bases: gym_ultrasonic.envs.ultrasonic_servo_env.UltrasonicEnv

A robot with one Ultrasonic sonar sensor and a servo that rotates the sonar. The task is the same: avoid obstacles. Never stops (no target).

update_state(self)[source]
Returns
state: List[float]

Min dist to obstacles and servo rotation angle.