rigid_body Class Reference

Rigid body dynamical model applying both force and torque to the spacecraft. More...

#include <rigid_body.h>

Inherits dsim_model.

Public Member Functions
void	initialize_data ()
	Initialize outlets and output variables.
void	initialization_complete ()
	Finish initialization.
void	initialize_timestep ()
	Computation done prior to numerical integration.
void	complete_timestep ()
	Computation done after numerical integration.
void	rhs (double t, double jd)
	Computation done during numerical integration. More...
dsim_value	handle_message (const std::string &sender_path, const std::string &message_name, const dsim_value &argument)
	Handle force and torque messages. More...

Protected Attributes
dsim_variable	spacecraft_name_dsim
	Spacecraft name.
dsim_variable	spacecraft_type_dsim
	Spacecraft type.
dsim_variable	position_dsim
	object position
dsim_variable	velocity_dsim
	object velocity
dsim_variable	quaternion_dsim
	attitude quaternion ([scalar;x;y;z])
dsim_variable	bodyRate_dsim
	body rotational rates (rad/s)
dsim_variable	mass_dsim
	total mass, including mass of children
dsim_variable	inertia_dsim
	total inertia, including children
dsim_variable	ang_momentum_dsim
	Angular momentum.
dsim_variable	acceleration_dsim
	object linear acceleration in body frame
dsim_variable	angular_acceleration_dsim
	Angular acceleration.
dsim_variable	frame_dsim
	frame for initial conditions
dsim_variable	centerOfMass_dsim
	Center of mass.
dsim_variable	quaternionCommand_dsim
	Commanded quaternion.
ml_matrix	inertia
	Stored inertia for computational efficiency.
ml_matrix	invInertia
	Stored inverse inertia for computational efficiency.
ml_matrix	force
	The external force on the spacecraft.
ml_matrix	torque
	The external torque on the spacecraft.
double	mass
	Mass.
double	m_to_km
	Convert meters to kilometers.

Detailed Description

Rigid body dynamical model applying both force and torque to the spacecraft.

Integrates the position, velocity, quaternion, and body rates. Allows the mass of the spacecraft to change. Children can use the apply_torque, apply_force, or mass_changed messages. Ignores any effect of or changes in center of mass. Does not add up or compute changes in inertia. Assumes all torques are about the center of mass.

Member Function Documentation

rhs()

void rigid_body::rhs	(	double	t,
		double	jd
	)

Computation done during numerical integration.

Dynamics and kinematics.

References acceleration_dsim, angular_acceleration_dsim, bodyRate_dsim, force, inertia, invInertia, m_to_km, mass, mass_dsim, position_dsim, quaternion_dsim, torque, and velocity_dsim.

handle_message()

dsim_value rigid_body::handle_message	(	const std::string &	sender_path,
		const std::string &	message_name,
		const dsim_value &	argument
	)

Handle force and torque messages.

Handle the messages.

The units should be N and Nm. Force should be in the ECI frame and torque should be in the body frame.

References force, and torque.

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The documentation for this class was generated from the following files:

• rigid_body.h
• rigid_body.cc