Key Features

  • Simulates aerospace vehicle components, including propulsion systems, control systems, mass properties, and actuators
  • Models flight dynamics, including three- and six-degrees-of-freedom equations of motion with fixed or variable mass
  • Provides options for visualizing vehicle dynamics in a three-dimensional environment, including an interface to FlightGear flight simulator
  • Includes standards-based environmental models for atmosphere, gravity, wind, geoid height, celestial bodies, and magnetic field
  • Implements predefined utilities for converting units, transforming coordinate systems and spatial representations, and performing common aerospace math operations

Standards-based reference blocks, including environmental models for gravity, atmosphere, and wind, enable you to verify and validate your vehicle system design. Built-in variant capabilities let you alternate between mathematical representations, enabling you to modify modeling conditions within the same the model. You can automatically generate code for production deployment and for real-time execution in rapid prototyping and hardware-in-the-loop systems by using Aerospace Blockset software, the Simulink Coder™ and Simulink Real-Time™ products (both available separately).

Using Simulink and Aerospace Blockset to model and simulate vehicle dynamics of a NASA HL-20 lifting body (bottom left). The system is visualized with FlightGear flight simulator (bottom right).

Simulating Aerospace Vehicle Components

The aerospace vehicle component block libraries in Aerospace Blockset let you design and test a complete vehicle simulation in a single model. For example, you can perform analyses and trade-off studies to understand system behavior under a variety of environmental conditions and parameter constraints and use prebuilt guidance, navigation, and control (GNC) components to verify the response of a radar system before full system specification.

The GNC library includes guidance blocks for calculating the range between two crafts given their respective positions. Navigation blocks for modeling a three-axis accelerometer, a gyroscope, and an inertial measurement unit are also included. Multiple controller forms let you investigate the effects of implementation architecture on your design. Forms include predefined state-space controller blocks for one-, two-, and three-dimensional gain scheduling; linear interpolation; observer- and self-conditioned forms; and one-, two-, and three-dimensional matrix interpolation.

The Propulsion library includes a turbofan engine system block that implements a first-order representation of the engine and the controller. It computes the thrust and fuel flow at a specific throttle position, Mach number, and altitude.

The Actuators library includes component blocks for simulating second-order linear and nonlinear actuators.

The Mass Properties library includes blocks for estimating inertia tensor and symmetric inertia tensor and for calculating moments about center of gravity due to forces.

Aerospace Blockset specialized blocks for modeling, integrating, and simulating aerospace systems using mathematical representations from references and first principles.

Modeling and Visualizing Flight Dynamics

With Aerospace Blockset you can quickly construct the dynamics of your system, perform simulations, and understand system behavior under a variety of conditions.

The Equations of Motion library includes blocks for simulating three- and six-degrees-of-freedom equations of motion with fixed and variable mass. Coordinate representations of the equations of motion include body, wind, and Earth-centered Earth-fixed (ECEF). Fourth- and sixth-order point mass equations of motion provide simplified representations of vehicle dynamics for multiple body modeling.

The Flight Parameters library provides blocks for calculating common flight dynamics parameters: incidence, sideslip, airspeed, Mach number, dynamic pressure, relative ratios, equivalent airspeed, calibrated airspeed, wind angular rate vector, and, for a given geocentric latitude, planet radius.

The Aerodynamics library includes blocks for calculating aerodynamic forces and moments for a flight dynamics model. You can supply aerodynamic coefficients in body, stability, or wind axes, or you can import aerodynamic coefficients from the U.S. Air Force Digital Data Compendium (Datcom). You can also specify whether forces and moments will be calculated in body or wind axes.

The Flight Instrument library includes flight instrument gauge blocks so you can visualize signal data that represents navigation variables, such as altitude and heading. The library includes eight standard cockpit instruments: an airspeed indicator, altimeter, artificial horizon, climb-rate indicator, exhaust gas temperature (EGT) indicator, heading indicator, revolutions per minute (RPM) indicator, and turn coordinator.

The Animation library includes an interface to FlightGear flight simulator for visualizing vehicle flight dynamics in a sophisticated three-dimensional simulation framework. The FlightGear Preconfigured 6DoF Animation block lets you control position and attitude of a vehicle in FlightGear flight simulator using double-precision values of longitude, latitude, altitude, roll, pitch, and yaw from Simulink. For more detailed FlightGear animation you can combine the blocks Pack net_fdm Packet for FlightGear and Send net_fdm Packet to FlightGear to visualize effects, such as control surface motion, instrument interface readings, and landing gear operation.

As an alternative to visualizing in FlightGear flight simulator, you can use one of the MATLAB® Handle Graphics®blocks. The 3DoF Animation and 6DoF Animation blocks animate three-dimensional motion with three and six degrees of freedom, respectively. The MATLAB Animation block lets you specify the bounding box, camera offset, and field of view to visualize the three-dimensional position and attitude of one or more user-defined vehicle geometries. You can define geometries with MATLAB variables, .mat files, AC3D files, or custom formats. All animation library blocks support Simulink external mode execution for visualizing your rapid prototyping and hardware-in-the-loop applications.

Explore gallery (2 images)

Incorporating Environmental Conditions

Aerospace Blockset software provides standards-based reference models that you can use in your simulation.

The Environment library includes standards-based references for modeling atmosphere, gravity, geoid height, magnetic field, and wind.

The Atmosphere library provides blocks that implement mathematical representations from the 1976 Committee on Extension to the Standard Atmosphere (COESA), International Standard Atmosphere (ISA), and nonstandard day models from U.S. military specifications (MIL-HDBK-310 and MILSTD-210C).

Additional Atmosphere library blocks implement mathematical representations from these models: 2001 United States Naval Research Laboratory Mass Spectrometer and Incoherent Scatter Radar Exosphere (NRLMSISE) and 1986 Committee on Space Research (COSPAR) International Reference Atmosphere (CIRA). The NRLMSISE model provides atmospheric temperatures and densities at altitudes from 0 to 1,000 kilometers for a specified location and time. The CIRA model provides mean climatic data for atmospheric temperature, zonal wind, and either geopotential height or pressure for altitudes from 0 to 120 kilometers.

The Gravity library includes these models: 1984 World Geodetic System, 1996 Earth Geopotential Model (EGM96), the2015 version of the World Magnetic Model (WMM), and 12th Generation International Geomagnetic Reference Field (IGRF12). The EGM96 Geoid block provides the geoid height at a specified location using the EGM96 geopotential model. The WMM blocks use the mathematical representation of the National Imagery and Mapping Agency (NIMA) standard and calculate the horizontal intensity, declination, inclination, total intensity, and vector of the Earth's magnetic field at a specified location and time. The International Geomagnetic Reference Field 12 block makes use of IGRF12 to calculate the Earth’s magnetic field and secular variation for a given time and location.

The Wind library provides mathematical representations from MIL-F-8785C, MIL-HDBK-1797, and MIL-HDBK-1797B to calculate wind shear and generate discrete wind gusts and Dryden and Von Kármán turbulence. It also includes horizontal wind blocks to simulate background and high-altitude winds. These blocks offer various combinations of angular rate signs (q, r), as defined in versions of the military specifications .

The Celestial Phenomena library contains blocks that use Chebyshev coefficients to calculate the position and velocity of celestial bodies. The blocks also let you implement Earth nutation and moon librations for a given Julian date. The Planetary Ephemeris block obtains the position and velocity of celestial bodies relative to a specified center object. The Earth Nutation block implements the International Astronomical Union (IAU) 1980 nutation series to calculate longitude, obliquity, and angular rate. The Moon Libration block calculates the moon attitude described as Euler angles and rates. You can download Chebyshev coefficients from the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL) database using Aerospace Toolbox.

Dialog for the World Magnetic Model 2015 , one of the reference models included in the Environment library.

Fine-Tuning the Model

Aerospace Blockset software includes block libraries that transform axes representations and coordinate systems, and perform common aerospace math operations.

The Unit Conversions library provides blocks for converting typical physical property units, such as acceleration, density, and temperature, between metric and English units. It lets you add units to signal lines and enforces the Simulink units checking those blocks, helping you create intermediate models with units that can be migrated to Simulink.

The Axes Transformations library includes blocks for converting spatial representations between Euler angles, quaternion vectors, and Euler-Rodrigues vectors for creating direction cosine matrices. The Euler angles can be in any of the twelve standard rotation sequences. The direction cosine (rotation) matrix transfers between coordinate systems such as body and inertial; body and wind; ECEF and north-east-down (NED); and ECEF and latitude, longitude, and altitude (LLA). Blocks for axes transformations between coordinate systems include ECI to AER, ECI and LLA, ECEF and LLA, and Flat Earth and LLA. Other representations include geocentric and geodetic latitude.

The Math Operations library provides blocks for calculating the cross product, creating and inverting 3 × 3 matrices, and calculating the determinant and adjoint of a 3 × 3 matrix. Quaternion math operations, such as the conjugate, division, inverse, and modulus, are also included.

ECEF-to-LLA block, which lets you switch between planet models within the block dialog.