SIMNET Technical Overview

SIMNET is powered by the Typhon Physics Engine, a proprietary drone analysis and simulation software crafted by aerospace and computer engineers over the course of 8 years of development and validation.


The Typhon Physics Engine allows users to create a fully parametric model of virtually any type of fixed-wing, multicopter and VTOL drone, by arbitrarily combining over 15 different types of parametric components.

Typhon Physics Engine Component Types

  • Airframe:

    • Wing​

    • Airfoil

    • Fuselage

    • Structural Component

    • Wheel

    • Recovery Parachute

  • Propulsion:

    • Propeller​

    • Brushless Motor

    • Speed Controller

    • Lithium Polymer Battery

    • Internal Combustion Engine

    • Fuel Tank

  • Controls:

    • Flight Controller​

    • Mixer

    • Servo

    • Hinge

  • Payload:

    • Payload Mass

The Typhon Engine incorporates multidisciplinary physics-based simulation and analysis algorithms to predict the overall performance of the aircraft, as well as simulate its flight dynamics in real-time as the model is created and modified.

Aerodynamics Engine

Mass Engine

Dynamics Engine

Typhon Physics Engine

Performance Engine

Controls Engine

The following table provides an overview of the various algorithms used by the engine.  The algorithms are selected from published resources following the criteria of selecting the highest fidelity algorithms that can run on real-time.

Typhon Physics Engine Algorithm Overview

Category
Subcategory
Algorithm Description
Aerodynamics
Wings and Stabilizers
State of the art nonlinear real-time lifting line aerodynamic model
Aerodynamics
Airfoils
Database of over 1,000 commonly used airfoils with pre-computed aerodynamic coefficients over wide Reynolds range
Aerodynamics
Propellers
(1) Database of bench test data for common drone propellers. (2) Regression-based prediction of propeller performance (3) Blade Element Momentum Theory (BEMT) aerodynamic model
Aerodynamics
Fuselages and Structural Components
Empirical lift and drag prediction model based on geometric specifications
Mass and Balance
Aircraft Components
Combination of empirical and physics-based mass models for each component type
Mass and Balance
Aircraft
Physics-based real-time calculation of aircraft mass, center of gravity, and inertia
Propulsion System Dynamics
Brushless Motor
Physics-based model of brushless motor dynamics and performance
Propulsion System Dynamics
Lithium Polymer Battery
Physics-based dynamics and performance model accounting for variable battery energy densities and internal resistances
Propulsion System Dynamics
Electronic Speed Controller (ESC)
Physics and regression-based dynamics and performance model accounting for ESC efficiency and timing limitations
Propulsion System Dynamics
Internal Combustion Engine
Parametric dynamics and performance model based on user-supplied specifications
Aircraft Performance
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Custom real-time steady-flight aircraft performance solver applicable to any arbitrary drone configuration
Environmental Simulation
Atmospheric Model
Calculation of atmospheric temperature and density vs altitude based on Standard Atmospheric Model
Environmental Simulation
Wind Simulation
Simulation of steady and/or stochastic wind conditions and turbulent gusts
Environmental Simulation
Terrain Simulation
Worldwide 3D terrain model based on satellite imagery and terrain elevation data
Flight Simulation
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Six degree of freedom flight simulation model accounting for gyroscopic forces running at 400 Hz
Flight Control Simulation
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Software In The Loop (SITL) simulation of 3rd-party flight control systems including Ardupilot, PX4, and VTOL OS