6DOF Angular Acceleration

R2026b

Compute angular acceleration of body in six-degrees-of-freedom motion

Since R2025a

• 

6DOF Angular Acceleration block

To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.

Libraries:
Aerospace Blockset / Equations of Motion / 6DOF

Description

The 6DOF Angular Acceleration computes the angular acceleration of a body in six-degrees-of-freedom motion. Use this block for only these 6DOF equations of motion blocks:

• 6DOF (Euler Angles)

• 6DOF (Quaternion)

• Custom Variable Mass 6DOF (Euler Angles)

• Custom Variable Mass 6DOF (Quaternion)

• Simple Variable Mass 6DOF (Euler Angles)

• Simple Variable Mass 6DOF (Quaternion)

To compute the angular acceleration for these blocks:

• Select Output mass properties for acceleration computation.

• Feed signals from the matching output ports of the associated 6DOF equation of motion block into the associated input ports of 6DOF Angular Acceleration.

Tip

Match all the parameter values for 6DOF Angular Acceleration and the 6DOF equations of motion blocks.

Ports

Input

ω_b (rad/s) — Angular rates in body-fixed axes

three-element vector

Angular rates in body-fixed axes, specified as a three-element vector, in radians per second.

Data Types: double

I — Inertia tensor matrix

3-by-3 matrix

Inertia tensor matrix, specified as a 3-by-3 matrix, in the units selected in Units.

Data Types: double

dI/dt coeff — Rate of change of inertia tensor matrix coefficient

3-by-3 matrix

Rate of change of inertia tensor matrix coefficient, specified as a 3-by-3 matrix.

Dependencies

To enable this port, set Mass type to Simple Variable, in m².

Data Types: double

M_xyz — Applied moments

three-element vector

Moment applied to the body with respect to center of mass in the body frame, specified as a three-element vector, in the units specified in Units.

Data Types: double

dI/dt — Rate of change of inertia tensor matrix

3-by-3 matrix

Rate of change of inertia tensor matrix, specified as a 3-by-3 matrix, in the units selected in Units.

Dependencies

To enable this port, set Mass type to Custom Variable.

Data Types: double

dm/dt — Rates of change of mass

scalar

One or more rates of change of mass (positive if accreted, negative if ablated), specified as a scalar, in the units selected in Units.

Dependencies

To enable this port, set Mass type to Simple Variable.

Data Types: double

Output

dω_b/dt — Angular accelerations

three-element vector

Angular accelerations in body-fixed axes, returned as a three-element vector, in radians per second squared.

Data Types: double

Parameters

To edit block parameters interactively, use the Property Inspector. From the Simulink^® Toolstrip, on the Simulation tab, in the Prepare gallery, select Property Inspector.

Units — Input and output units

Metric (MKS) (default) | English (Velocity in ft/s) | English (Velocity in kts)

Input and output units, specified as Metric (MKS), English (Velocity in ft/s), or English (Velocity in kts).

Units	Forces	Moment	Acceleration	Velocity	Position	Mass	Inertia
Metric (MKS)	Newton	Newton-meter	Meters per second squared	Meters per second	Meters	Kilogram	Kilogram meter squared
English (Velocity in ft/s)	Pound	Foot-pound	Feet per second squared	Feet per second	Feet	Slug	Slug foot squared
English (Velocity in kts)	Pound	Foot-pound	Feet per second squared	Knots	Feet	Slug	Slug foot squared

Programmatic Use

Block Parameter: units

Type: character vector

Values: Metric (MKS) | English (Velocity in ft/s) | English (Velocity in kts)

Default: Metric (MKS)

Mass type — Mass type

Fixed (default) | Simple Variable | Custom Variable

Mass type, specified according to the following table.

Mass Type	Description	Default for
Fixed	Mass is constant throughout the simulation.	6DOF (Euler Angles) 6DOF (Quaternion)
Simple Variable	Mass and inertia vary linearly as a function of mass rate.	Simple Variable Mass 6DOF (Euler Angles) Simple Variable Mass 6DOF (Quaternion)
Custom Variable	Mass and inertia variations are customizable.	Custom Variable Mass 6DOF (Euler Angles) Custom Variable Mass 6DOF (Quaternion)

The Simple Variable selection conforms to the previously described equations of motion.

Programmatic Use

Block Parameter: mtype

Type: character vector

Values: Fixed | Simple Variable | Custom Variable

Default: 'Fixed'

Programmatic Use: Add Block

To add the block programmatically, use the add_block function with one of these library block paths as the source.

"aerolib6dof2/6DOF Angular Acceleration"

Example: add_block("aerolib6dof2/6DOF Angular Acceleration","myModel/myBlock",MakeNameUnique="on")

Version History

Introduced in R2025a