Skip to content

null_joint_controller

NullJointController

Bases: JointController

Dummy Controller class for a null-type of joint control (i.e.: no control or constant pass-through control). This class has a zero-size command space, and returns either an empty array for control if dof_idx is None else constant values as specified by @default_command (if not specified, uses zeros)

Source code in omnigibson/controllers/null_joint_controller.py 
 6
 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
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
class NullJointController(JointController):
    """
    Dummy Controller class for a null-type of joint control (i.e.: no control or constant pass-through control).
    This class has a zero-size command space, and returns either an empty array for control if dof_idx is None
    else constant values as specified by @default_command (if not specified, uses zeros)
    """

    def __init__(
        self,
        control_freq,
        motor_type,
        control_limits,
        dof_idx,
        command_input_limits="default",
        command_output_limits="default",
        default_command=None,
        kp=None,
        damping_ratio=None,
        use_impedances=False,
    ):
        """
        Args:
            control_freq (int): controller loop frequency
            control_limits (Dict[str, Tuple[Array[float], Array[float]]]): The min/max limits to the outputted
                control signal. Should specify per-dof type limits, i.e.:

                "position": [[min], [max]]
                "velocity": [[min], [max]]
                "effort": [[min], [max]]
                "has_limit": [...bool...]

                Values outside of this range will be clipped, if the corresponding joint index in has_limit is True.
            dof_idx (Array[int]): specific dof indices controlled by this robot. Used for inferring
                controller-relevant values during control computations
            command_input_limits (None or "default" or Tuple[float, float] or Tuple[Array[float], Array[float]]):
                if set, is the min/max acceptable inputted command. Values outside this range will be clipped.
                If None, no clipping will be used. If "default", range will be set to (-1, 1)
            command_output_limits (None or "default" or Tuple[float, float] or Tuple[Array[float], Array[float]]):
                if set, is the min/max scaled command. If both this value and @command_input_limits is not None,
                then all inputted command values will be scaled from the input range to the output range.
                If either is None, no scaling will be used. If "default", then this range will automatically be set
                to the @control_limits entry corresponding to self.control_type
            default_command (None or n-array): if specified, should be the same length as @dof_idx, specifying
                the default control for this controller to output
            kp (None or float): If @motor_type is "position" or "velocity" and @use_impedances=True, this is the
                proportional gain applied to the joint controller. If None, a default value will be used.
            damping_ratio (None or float): If @motor_type is "position" and @use_impedances=True, this is the
                damping ratio applied to the joint controller. If None, a default value will be used.
            use_impedances (bool): If True, will use impedances via the mass matrix to modify the desired efforts
                applied
        """
        # Store values
        self._default_command = th.zeros(len(dof_idx)) if default_command is None else default_command

        # Run super init
        super().__init__(
            control_freq=control_freq,
            motor_type=motor_type,
            control_limits=control_limits,
            dof_idx=dof_idx,
            command_input_limits=command_input_limits,
            command_output_limits=command_output_limits,
            kp=kp,
            damping_ratio=damping_ratio,
            use_impedances=use_impedances,
            use_delta_commands=False,
        )

    def compute_no_op_goal(self, control_dict):
        # Set the goal to be internal stored default value
        return dict(target=self._default_command)

    def _preprocess_command(self, command):
        # Override super and force the processed command to be internal stored default value
        return th.tensor(self._default_command)

    def update_default_goal(self, target):
        """
        Updates the internal default command value.

        Args:
            target (n-array): New default command values to set for this controller.
                Should be of dimension @command_dim
        """
        assert (
            len(target) == self.control_dim
        ), f"Default control must be length: {self.control_dim}, got length: {len(target)}"

        self._default_command = th.tensor(target)

__init__(control_freq, motor_type, control_limits, dof_idx, command_input_limits='default', command_output_limits='default', default_command=None, kp=None, damping_ratio=None, use_impedances=False)

Parameters:

Name Type Description Default
control_freq int

controller loop frequency

 required
control_limits Dict[str, Tuple[Array[float], Array[float]]]

The min/max limits to the outputted control signal. Should specify per-dof type limits, i.e.:

"position": [[min], [max]] "velocity": [[min], [max]] "effort": [[min], [max]] "has_limit": [...bool...]

Values outside of this range will be clipped, if the corresponding joint index in has_limit is True.

 required
dof_idx Array[int]

specific dof indices controlled by this robot. Used for inferring controller-relevant values during control computations

 required
command_input_limits None or default or Tuple[float, float] or Tuple[Array[float], Array[float]]

if set, is the min/max acceptable inputted command. Values outside this range will be clipped. If None, no clipping will be used. If "default", range will be set to (-1, 1)

 'default'
command_output_limits None or default or Tuple[float, float] or Tuple[Array[float], Array[float]]

if set, is the min/max scaled command. If both this value and @command_input_limits is not None, then all inputted command values will be scaled from the input range to the output range. If either is None, no scaling will be used. If "default", then this range will automatically be set to the @control_limits entry corresponding to self.control_type

 'default'
default_command None or n - array

if specified, should be the same length as @dof_idx, specifying the default control for this controller to output

 None
kp None or float

If @motor_type is "position" or "velocity" and @use_impedances=True, this is the proportional gain applied to the joint controller. If None, a default value will be used.

 None
damping_ratio None or float

If @motor_type is "position" and @use_impedances=True, this is the damping ratio applied to the joint controller. If None, a default value will be used.

 None
use_impedances bool

If True, will use impedances via the mass matrix to modify the desired efforts applied

 False
Source code in omnigibson/controllers/null_joint_controller.py 
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
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
def __init__(
    self,
    control_freq,
    motor_type,
    control_limits,
    dof_idx,
    command_input_limits="default",
    command_output_limits="default",
    default_command=None,
    kp=None,
    damping_ratio=None,
    use_impedances=False,
):
    """
    Args:
        control_freq (int): controller loop frequency
        control_limits (Dict[str, Tuple[Array[float], Array[float]]]): The min/max limits to the outputted
            control signal. Should specify per-dof type limits, i.e.:

            "position": [[min], [max]]
            "velocity": [[min], [max]]
            "effort": [[min], [max]]
            "has_limit": [...bool...]

            Values outside of this range will be clipped, if the corresponding joint index in has_limit is True.
        dof_idx (Array[int]): specific dof indices controlled by this robot. Used for inferring
            controller-relevant values during control computations
        command_input_limits (None or "default" or Tuple[float, float] or Tuple[Array[float], Array[float]]):
            if set, is the min/max acceptable inputted command. Values outside this range will be clipped.
            If None, no clipping will be used. If "default", range will be set to (-1, 1)
        command_output_limits (None or "default" or Tuple[float, float] or Tuple[Array[float], Array[float]]):
            if set, is the min/max scaled command. If both this value and @command_input_limits is not None,
            then all inputted command values will be scaled from the input range to the output range.
            If either is None, no scaling will be used. If "default", then this range will automatically be set
            to the @control_limits entry corresponding to self.control_type
        default_command (None or n-array): if specified, should be the same length as @dof_idx, specifying
            the default control for this controller to output
        kp (None or float): If @motor_type is "position" or "velocity" and @use_impedances=True, this is the
            proportional gain applied to the joint controller. If None, a default value will be used.
        damping_ratio (None or float): If @motor_type is "position" and @use_impedances=True, this is the
            damping ratio applied to the joint controller. If None, a default value will be used.
        use_impedances (bool): If True, will use impedances via the mass matrix to modify the desired efforts
            applied
    """
    # Store values
    self._default_command = th.zeros(len(dof_idx)) if default_command is None else default_command

    # Run super init
    super().__init__(
        control_freq=control_freq,
        motor_type=motor_type,
        control_limits=control_limits,
        dof_idx=dof_idx,
        command_input_limits=command_input_limits,
        command_output_limits=command_output_limits,
        kp=kp,
        damping_ratio=damping_ratio,
        use_impedances=use_impedances,
        use_delta_commands=False,
    )

update_default_goal(target)

Updates the internal default command value.

Parameters:

Name Type Description Default
target n - array

New default command values to set for this controller. Should be of dimension @command_dim

 required
Source code in omnigibson/controllers/null_joint_controller.py 
82
83
84
85
86
87
88
89
90
91
92
93
94
def update_default_goal(self, target):
    """
    Updates the internal default command value.

    Args:
        target (n-array): New default command values to set for this controller.
            Should be of dimension @command_dim
    """
    assert (
        len(target) == self.control_dim
    ), f"Default control must be length: {self.control_dim}, got length: {len(target)}"

    self._default_command = th.tensor(target)