Skip to content

max_collision

MaxCollision

Bases: FailureCondition

MaxCollision (failure condition) used for navigation tasks Episode terminates if the robot has collided more than max_collisions_allowed times Note that we ignore collisions with any floor objects.

Parameters:

Name Type Description Default
robot_idn int

robot identifier to evaluate collision checking with. Default is 0, corresponding to the first robot added to the scene

 0
ignore_self_collisions bool

Whether to ignore robot self-collisions or not

 True
max_collisions int

Maximum number of collisions allowed for any robots in the scene before a termination is triggered

 500
Source code in OmniGibson/omnigibson/termination_conditions/max_collision.py 
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
class MaxCollision(FailureCondition):
    """
    MaxCollision (failure condition) used for navigation tasks
    Episode terminates if the robot has collided more than max_collisions_allowed times
    Note that we ignore collisions with any floor objects.

    Args:
        robot_idn (int): robot identifier to evaluate collision checking with. Default is 0, corresponding to the first
            robot added to the scene
        ignore_self_collisions (bool): Whether to ignore robot self-collisions or not
        max_collisions (int): Maximum number of collisions allowed for any robots in the scene before a termination
            is triggered
    """

    def __init__(self, robot_idn=0, ignore_self_collisions=True, max_collisions=500):
        self._robot_idn = robot_idn
        self._ignore_self_collisions = ignore_self_collisions
        self._max_collisions = max_collisions
        self._n_collisions = None

        # Run super init
        super().__init__()

    def reset(self, task, env, env_indices):
        # Call super first
        super().reset(task, env, env_indices)

        # Also reset collision counter
        if self._n_collisions is None:
            self._n_collisions = th.zeros(env.num_envs, dtype=th.int64)
        self._n_collisions[env_indices] = 0

    def _step(self, task, env, action):
        # Terminate if the robot has collided more than self._max_collisions times
        for env_idx in range(env.num_envs):
            robot = env.scenes[env_idx].robots[self._robot_idn]
            floors = list(env.scenes[env_idx].object_registry("category", "floors", []))
            ignore_objs = floors + [robot] if self._ignore_self_collisions else floors
            in_contact = RigidContactAPI.is_in_contact(
                scene_idx=robot.scene.idx, query_set=[robot], with_set=None, ignore_set=ignore_objs, current_only=False
            )
            self._n_collisions[env_idx] += int(in_contact)
        return self._n_collisions > self._max_collisions