Centrifugal Effect Model

Implement mathematical representation of centrifugal effect for planetary gravity

• Library:

• Aerospace Blockset / Environment / Gravity

• 

Description

The Centrifugal Effect Model block implements the mathematical representation of centrifugal effect for planetary gravity. The gravity centrifugal effect is the acceleration portion of centrifugal force effects due to the rotation of a planet. This block implements this representation using planetary rotation rates. You use centrifugal force values in rotating or non-inertial coordinate systems.

Ports

Input

Xecef — Planet-centered planet-fixed coordinates

m-by-3 matrix

Planet-centered planet-fixed coordinates from the center of the planet, specified as a scalar. If Planet model has a value of Earth, this matrix contains Earth-centered Earth-fixed (ECEF) coordinates. The block does not use explicit units.

Data Types: double

ω — Planetary rotation rate

scalar

Planetary rotation rate, specified as a scalar, in rad/sec.

Dependencies

To enable this parameter, set Planetary rotational rate (rad/sec) to Custom.

Data Types: double

Output

Output 1 — Gravity values

m-by-3 array

Gravity values, returned as an m-by-3 array, in the x-axis, y-axis, and z-axis of the planet-centered planet-fixed coordinates, in input distance units per second squared.

Data Types: double

Parameters

Planet model — Planetary model

Earth (default) | Venus | Mercury | Moon | Mars | Jupiter | Saturn | Uranus | Neptune | Custom

Planetary model, specified as Mercury, Venus, Earth, Moon, Mars, Jupiter, Saturn, Uranus, Neptune, or Custom. The block uses the rotation of the selected planet to implement the mathematical representation of the centrifugal effect.

Dependencies

Selecting Custom enables the Planetary rotational rate (rad/sec) and Input planetary rotation rate parameters.

Programmatic Use

Block Parameter: ptype

Type: character vector

Values: 'Mercury' | 'Venus' | 'Earth' | 'Moon' | 'Mars' | 'Jupiter' | 'Saturn' | 'Uranus' | 'Neptune' | 'Custom'

Default: 'Earth'

Planetary rotational rate (rad/sec) — Planetary rotational rate

7.2921150e-05 (default) | scalar

Planetary rotational rate in radians per second.

If you want to specify the planetary rotational rate as an input to the block, see the Input planetary rotation rate parameter.

Dependencies

Selecting the Input planetary rotation rate check box disables the Planetary rotational rate (rad/sec) parameter.

Programmatic Use

Block Parameter: omega

Type: character vector

Values: '7.2921150e-05' | scalar

Default: '7.2921150e-05'

Input planetary rotation rate — Planetary rotation rate port

off (default) | on

Select this check box to enable the ω input port. You can then input a planetary rotation rate as a block input.

Dependencies

Selecting this check box enables the ω and disables the Planetary rotational rate (rad/sec) parameter.

Programmatic Use

Block Parameter: rate_loc

Type: character vector

Values: 'off' | 'on'

Default: 'off'

References

[1] Vallado, David. Fundamentals of Astrodynamics and Applications. New York, NY: McGraw-Hill, 1997.

[2] "Department of Defense World Geodetic System 1984, Its Definition and Relationship with Local Geodetic Systems." NIMA TR8350.2.

Extended Capabilities

C/C++ Code Generation
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