SingleJointedArmSim

class wpilib.simulation.SingleJointedArmSim(*args, **kwargs)

Bases: LinearSystemSim_2_1_2

Represents a simulated arm mechanism.

Overloaded function.

  1. __init__(self: wpilib.simulation._simulation.SingleJointedArmSim, system: wpimath._wpimath.LinearSystem_2_1_2, gearbox: wpimath._wpimath.DCMotor, gearing: typing.SupportsFloat | typing.SupportsIndex, arm_length: wpimath.units.meters, min_angle: wpimath.units.radians, max_angle: wpimath.units.radians, simulate_gravity: bool, starting_angle: wpimath.units.radians, measurement_std_devs: typing.Annotated[collections.abc.Sequence[typing.SupportsFloat | typing.SupportsIndex], “FixedSize(2)”] = [0.0, 0.0]) -> None

Creates a simulated arm mechanism.

Parameters:

  • system – The system representing this arm. This system can be created with wpi::math::Models::SingleJointedArmFromPhysicalConstants().

  • gearbox – The type and number of motors on the arm gearbox.

  • gearing – The gear ratio of the arm (numbers greater than 1 represent reductions).

  • arm_length – The length of the arm.

  • min_angle – The minimum angle that the arm is capable of, with 0 being horizontal.

  • max_angle – The maximum angle that the arm is capable of, with 0 being horizontal.

  • simulate_gravity – Whether gravity should be simulated or not.

  • starting_angle – The initial position of the arm.

  • measurement_std_devs – The standard deviations of the measurements.

  1. __init__(self: wpilib.simulation._simulation.SingleJointedArmSim, gearbox: wpimath._wpimath.DCMotor, gearing: typing.SupportsFloat | typing.SupportsIndex, moi: wpimath.units.kilogram_square_meters, arm_length: wpimath.units.meters, min_angle: wpimath.units.radians, max_angle: wpimath.units.radians, simulate_gravity: bool, starting_angle: wpimath.units.radians, measurement_std_devs: typing.Annotated[collections.abc.Sequence[typing.SupportsFloat | typing.SupportsIndex], “FixedSize(2)”] = [0.0, 0.0]) -> None

Creates a simulated arm mechanism.

Parameters:

  • gearbox – The type and number of motors on the arm gearbox.

  • gearing – The gear ratio of the arm (numbers greater than 1 represent reductions).

  • moi – The moment of inertia of the arm. This can be calculated from CAD software.

  • arm_length – The length of the arm.

  • min_angle – The minimum angle that the arm is capable of, with 0 being horizontal.

  • max_angle – The maximum angle that the arm is capable of, with 0 being horizontal.

  • simulate_gravity – Whether gravity should be simulated or not.

  • starting_angle – The initial position of the arm.

  • measurement_std_devs – The standard deviation of the measurement noise.

static estimate_moi(length: wpimath.units.meters, mass: wpimath.units.kilograms) → wpimath.units.kilogram_square_meters

Calculates a rough estimate of the moment of inertia of an arm given its length and mass.

Parameters:

  • length – The length of the arm.

  • mass – The mass of the arm.

Returns:

The calculated moment of inertia.

get_angle() → wpimath.units.radians

Returns the current arm angle.

Returns:

The current arm angle.

get_angle_degrees() → wpimath.units.degrees
get_current_draw() → wpimath.units.amperes

Returns the arm current draw.

Returns:

The arm current draw.

get_velocity() → wpimath.units.radians_per_second

Returns the current arm velocity.

Returns:

The current arm velocity.

get_velocity_dps() → wpimath.units.degrees_per_second
has_hit_lower_limit() → bool

Returns whether the arm has hit the lower limit.

Returns:

Whether the arm has hit the lower limit.

has_hit_upper_limit() → bool

Returns whether the arm has hit the upper limit.

Returns:

Whether the arm has hit the upper limit.

set_input_voltage(voltage: wpimath.units.volts) → None

Sets the input voltage for the arm.

Parameters:

voltage – The input voltage.

set_state(angle: wpimath.units.radians, velocity: wpimath.units.radians_per_second) → None

Sets the arm’s state. The new angle will be limited between the minimum and maximum allowed limits.

Parameters:

  • angle – The new angle.

  • velocity – The new angular velocity.

would_hit_lower_limit(arm_angle: wpimath.units.radians) → bool

Returns whether the arm would hit the lower limit.

Parameters:

arm_angle – The arm height.

Returns:

Whether the arm would hit the lower limit.

would_hit_upper_limit(arm_angle: wpimath.units.radians) → bool

Returns whether the arm would hit the upper limit.

Parameters:

arm_angle – The arm height.

Returns:

Whether the arm would hit the upper limit.