multirotor.physics

Module Contents

Functions

thrustEqn(vi, *prop_params)
thrust(→ float)
torque(→ numpy.ndarray)	Calculates the torque acting on the three body axes (roll, pitch, yaw), due
_apply_forces_torques(→ numpy.ndarray)	Given forces and torqes, return the rate of change of state.

Attributes

apply_forces_torques

multirotor.physics.thrustEqn(vi, *prop_params)

multirotor.physics.thrust(prop_speed, airstream_velocity, R, A, rho, a, b, c, eta, theta0, theta1) → float

multirotor.physics.torque(position_vector: numpy.ndarray, force: numpy.ndarray, moment_of_inertia: float, prop_angular_acceleration: float, drag_coefficient: float, prop_angular_velocity: float, clockwise: int) → numpy.ndarray

Calculates the torque acting on the three body axes (roll, pitch, yaw), due to a single propeller.

Parameters

position_vectornp.ndarray

Position vector of force, relative to center of mass. If multiple vectors, should be in shape 3 x n_vectors.

forcenp.ndarray

Force vector acting at that position (nominally thrust). If multiple vectors, should be in shape 3 x n_vectors.

moment_of_inertiafloat

Moment of inertia of the body.

prop_angular_accelerationfloat

Angular acceleration experienced by propeller.

drag_coefficientfloat

The drag coefficient of propeller.

prop_angular_velocityfloat

Propeller speed (rad/s)

clockwiseint

Whether propeller is spinning clockwise or counter clockwise.

Returns

np.ndarray

The torque due to the propeller acting on the center of mass.

multirotor.physics._apply_forces_torques(forces: numpy.ndarray, torques: numpy.ndarray, x: numpy.ndarray, g: float, mass: float, inertia_matrix: numpy.matrix, inertia_matrix_inverse: numpy.matrix) → numpy.ndarray

Given forces and torqes, return the rate of change of state.

Parameters

forcesnp.ndarray

Forces acting in the body frame.

torquesnp.ndarray

Torques acting in the body frame.

xnp.ndarray

State of the vehicle.

gfloat

Gravitational acceleration.

massfloat

Mass of the vehicle.

inertia_matrixnp.matrix

Inertial matrix.

inertia_matrix_inversenp.matrix

Inverse of inertial matrix.

Returns

np.ndarray

The rate of change of state d(state)/dt

multirotor.physics.apply_forces_torques