diff --git a/flatland/envs/agent_utils.py b/flatland/envs/agent_utils.py
index d14167669796b031ff7141ab89ddebc16fa01325..40bca7e35e97374e0e3ab11f3161f184cbf56298 100644
--- a/flatland/envs/agent_utils.py
+++ b/flatland/envs/agent_utils.py
@@ -28,10 +28,13 @@ class EnvAgentStatic(object):
position = attrib()
direction = attrib()
target = attrib()
- moving = attrib()
- speed_data = attrib(default=dict({'position_fraction':0.0, 'speed':1.0, 'transition_action_on_cellexit':0}))
+ moving = attrib(default=False)
+ # speed_data: speed is added to position_fraction on each moving step, until position_fraction>=1.0,
+ # after which 'transition_action_on_cellexit' is executed (equivalent to executing that action in the previous
+ # cell if speed=1, as default)
+ speed_data = attrib(default=dict({'position_fraction': 0.0, 'speed': 1.0, 'transition_action_on_cellexit': 0}))
- def __init__(self, position, direction, target, moving=False, speed_data={'position_fraction':0.0, 'speed':1.0, 'transition_action_on_cellexit':0}):
+ def __init__(self, position, direction, target, moving=False, speed_data={'position_fraction': 0.0, 'speed': 1.0, 'transition_action_on_cellexit': 0}):
self.position = position
self.direction = direction
self.target = target
@@ -44,7 +47,7 @@ class EnvAgentStatic(object):
"""
speed_datas = []
for i in range(len(positions)):
- speed_datas.append( {'position_fraction':0.0, 'speed':1.0, 'transition_action_on_cellexit':0} )
+ speed_datas.append( {'position_fraction': 0.0, 'speed': 1.0, 'transition_action_on_cellexit': 0} )
return list(starmap(EnvAgentStatic, zip(positions, directions, targets, [False] * len(positions), speed_datas)))
def to_list(self):
diff --git a/flatland/envs/rail_env.py b/flatland/envs/rail_env.py
index c22e1c5120b54a170f9c59bb54c7666ca910f086..090e0cce499ea30b51d9e69f7004d22c10d94f12 100644
--- a/flatland/envs/rail_env.py
+++ b/flatland/envs/rail_env.py
@@ -101,7 +101,6 @@ class RailEnv(Environment):
self.action_space = [1]
self.observation_space = self.obs_builder.observation_space # updated on resets?
- self.actions = [0] * number_of_agents
self.rewards = [0] * number_of_agents
self.done = False
@@ -193,22 +192,24 @@ class RailEnv(Environment):
for iAgent in range(self.get_num_agents()):
agent = self.agents[iAgent]
- if iAgent not in action_dict: # no action has been supplied for this agent
- if agent.moving:
- # Keep moving
- # Change MOVE_FORWARD to DO_NOTHING
- action_dict[iAgent] = RailEnvActions.DO_NOTHING
- else:
- action_dict[iAgent] = RailEnvActions.DO_NOTHING
-
if self.dones[iAgent]: # this agent has already completed...
continue
- action = action_dict[iAgent]
- if action < 0 or action > len(RailEnvActions):
- print('ERROR: illegal action=', action,
- 'for agent with index=', iAgent)
- return
+ if np.equal(agent.position, agent.target).all():
+ self.dones[iAgent] = True
+ else:
+ self.rewards_dict[iAgent] += step_penalty
+
+ if iAgent not in action_dict: # no action has been supplied for this agent
+ action_dict[iAgent] = RailEnvActions.DO_NOTHING
+
+ if action_dict[iAgent] < 0 or action_dict[iAgent] > len(RailEnvActions):
+ print('ERROR: illegal action=', action_dict[iAgent],
+ 'for agent with index=', iAgent,
+ '"DO NOTHING" will be executed instead')
+ action_dict[iAgent] = RailEnvActions.DO_NOTHING
+
+ action = action_dict[iAgent]
if action == RailEnvActions.DO_NOTHING and agent.moving:
# Keep moving
@@ -224,46 +225,60 @@ class RailEnv(Environment):
self.rewards_dict[iAgent] += start_penalty
if action != RailEnvActions.DO_NOTHING and action != RailEnvActions.STOP_MOVING:
- cell_isFree, new_cell_isValid, new_direction, new_position, transition_isValid = \
- self._check_action_on_agent(action, agent)
- if all([new_cell_isValid, transition_isValid, cell_isFree]):
- agent.old_direction = agent.direction
- agent.old_position = agent.position
- agent.position = new_position
- agent.direction = new_direction
- else:
- # Logic: if the chosen action is invalid,
- # and it was LEFT or RIGHT, and the agent was moving, then keep moving FORWARD.
- if (action == RailEnvActions.MOVE_LEFT or action == RailEnvActions.MOVE_RIGHT) and agent.moving:
- cell_isFree, new_cell_isValid, new_direction, new_position, transition_isValid = \
- self._check_action_on_agent(RailEnvActions.MOVE_FORWARD, agent)
-
- if all([new_cell_isValid, transition_isValid, cell_isFree]):
- agent.old_direction = agent.direction
- agent.old_position = agent.position
- agent.position = new_position
- agent.direction = new_direction
+ # Now perform a movement.
+ # If the agent is in an initial position within a new cell (agent.speed_data['position_fraction']<eps)
+ # store the desired action in `transition_action_on_cellexit' (only if the desired transition is allowed! otherwise DO_NOTHING!)
+ # Then in any case (if agent.moving) and the `transition_action_on_cellexit' is valid, increment the position_fraction by the speed of the agent (regardless of action taken, as long as no STOP_MOVING, but that makes agent.moving=False)
+ # If the new position fraction is >= 1, reset to 0, and perform the stored transition_action_on_cellexit
+
+ if agent.speed_data['position_fraction'] < 0.01:
+ # Is the desired transition valid?
+
+ cell_isFree, new_cell_isValid, new_direction, new_position, transition_isValid = \
+ self._check_action_on_agent(action, agent)
+
+ if all([new_cell_isValid, transition_isValid, cell_isFree]):
+ agent.speed_data['transition_action_on_cellexit'] = action
+
+ else:
+ # But, if the chosen invalid action was LEFT/RIGHT, and the agent is moving,
+ # try to keep moving forward!
+ if (action == RailEnvActions.MOVE_LEFT or action == RailEnvActions.MOVE_RIGHT) and agent.moving:
+ cell_isFree, new_cell_isValid, new_direction, new_position, transition_isValid = \
+ self._check_action_on_agent(RailEnvActions.MOVE_FORWARD, agent)
+
+ if all([new_cell_isValid, transition_isValid, cell_isFree]):
+ agent.speed_data['transition_action_on_cellexit'] = RailEnvActions.MOVE_FORWARD
+
+ else:
+ # TODO: an invalid action was chosen after entering the cell. The agent cannot move.
+ self.rewards_dict[iAgent] += invalid_action_penalty
+ continue
else:
- # the action was not valid, add penalty
+ # TODO: an invalid action was chosen after entering the cell. The agent cannot move.
self.rewards_dict[iAgent] += invalid_action_penalty
+ continue
- else:
- # the action was not valid, add penalty
- self.rewards_dict[iAgent] += invalid_action_penalty
+ agent.speed_data['position_fraction'] += agent.speed_data['speed']
- if np.equal(agent.position, agent.target).all():
- self.dones[iAgent] = True
- else:
- self.rewards_dict[iAgent] += step_penalty
+ if agent.speed_data['position_fraction'] >= 1.0:
+ agent.speed_data['position_fraction'] = 0.0
+
+ # Perform stored action to transition to the next cell
+
+ # Now 'transition_action_on_cellexit' will be guaranteed to be valid; it was checked on entering the cell
+ cell_isFree, new_cell_isValid, new_direction, new_position, transition_isValid = \
+ self._check_action_on_agent(agent.speed_data['transition_action_on_cellexit'], agent)
+ agent.old_direction = agent.direction
+ agent.old_position = agent.position
+ agent.position = new_position
+ agent.direction = new_direction
# Check for end of episode + add global reward to all rewards!
if np.all([np.array_equal(agent2.position, agent2.target) for agent2 in self.agents]):
self.dones["__all__"] = True
self.rewards_dict = [0 * r + global_reward for r in self.rewards_dict]
- # Reset the step actions (in case some agent doesn't 'register_action'
- # on the next step)
- self.actions = [0] * self.get_num_agents()
return self._get_observations(), self.rewards_dict, self.dones, {}
def _check_action_on_agent(self, action, agent):
@@ -271,6 +286,7 @@ class RailEnv(Environment):
# cell used to check for invalid actions
new_direction, transition_isValid = self.check_action(agent, action)
new_position = get_new_position(agent.position, new_direction)
+
# Is it a legal move?
# 1) transition allows the new_direction in the cell,
# 2) the new cell is not empty (case 0),
@@ -281,11 +297,13 @@ class RailEnv(Environment):
np.clip(new_position, [0, 0], [self.height - 1, self.width - 1]))
and # check the new position has some transitions (ie is not an empty cell)
self.rail.get_transitions(new_position) > 0)
+
# If transition validity hasn't been checked yet.
if transition_isValid is None:
transition_isValid = self.rail.get_transition(
(*agent.position, agent.direction),
new_direction)
+
# Check the new position is not the same as any of the existing agent positions
# (including itself, for simplicity, since it is moving)
cell_isFree = not np.any(