Modelling And Simulating
Modelling and Simulating
Modelling and Simulating your system allows you to conceptualise and represent how your system will work without incuring any production costs, such as materials and components.
Models
Models are simplified representations of your system or sub-systems. They can be:
- Physical, such as cardboard prototypes, lego, or breadboard circuits.
- Mathematical, such as calculations showing gear ratios, Ohm's law, power, or torque.
- Graphic, such as block diagrams, flowcharts, and IPO diagrams.
- Digital, such as CAD models, circuit simulations, or code simulations.
Simulations
A simulation is when a model is used to test how a system behaves over time or under different conditions.
Simulation answers questions such as: - What happens if the load increases? - What happens if a component fails? - What happens if I used a different component? - How does the system respond to user input? - Does the system behave safely?
Simulation allows engineers to test “what if?” scenarios.
Modelling vs Simulation
| Modelling | Simulation |
|---|---|
| Creating a representation | Testing how it behaves |
| Static | Often dynamic |
| Describes the system | Predicts system response |
| Example: drawing a circuit | Example: running the circuit |
Software
There is a range of software available to allow engineers to create digital models and simulate them.
CircuitJS
https://www.falstad.com/circuit/circuitjs.html
Circuit JS allows you to build out simple electronic circuits using a range of basic components and common integrated circuits.
Wokwi
Wokwi allows you to not only create breadboard style models using a range of components and microcontrollers, such as Arduino Uno and Nano, Raspberry Pi Pico, and ESP32, but allows you to simulate code running on those systems as well.
Fusion
https://www.autodesk.com/products/fusion-360/
Fusion is industry-level software that is made available to schools for free. It allows you to create 3D models, as well as simulate joints, forces, and other factors.
TinkerCAD
TinkerCAD is a free piece of software that allows for simple modelling, circuit simulations, and coding. It is like the junior version of Fusion.
Fritzing
Fritzing is used to create clear circuit diagrams and breadboard layouts. It is especially useful for documenting how a prototype was wired so that it can be replicated or explained in a folio.
LTspice
https://www.analog.com/en/resources/design-tools-and-calculators/ltspice-simulator.html
LTspice is a professional-grade circuit simulation tool used to analyse voltage, current, and transient behaviour in electronic circuits. It is commonly used to test component values and circuit stability before physical construction.
Onshape
Onshape is a browser-based CAD tool that allows users to create 3D models and assemblies without installing software. It supports collaboration and version control, making it useful for team-based design projects.
FreeCAD
FreeCAD is an open-source CAD tool used to create parametric 3D models. It is suitable for modelling mechanical components and assemblies when commercial software is not available.
GeoGebra
GeoGebra can be used to create mathematical and graphical models, including relationships between variables. It is useful for visualising equations, motion, and proportional relationships in systems.