What is HMI?
Human-Machine Interface (HMI) provides intuitive visual and interactive systems that enable operators to efficiently monitor and control complex equipment or processes across manufacturing, automotive, and other industrial applications.
How does an HMI work?
An HMI works by translating information from machines, equipment, or automated systems into a visual interface that people can understand and interact with. It collects data from connected systems and presents relevant information through elements such as displays, controls, charts, alerts, and status indicators. Users can then monitor processes, adjust settings, and respond to changing conditions through the interface.
Effective HMI design organizes information according to its importance and uses elements such as layout, color, hierarchy, and interaction patterns to make critical information easy to identify. By reducing unnecessary complexity and presenting information in a clear, accessible way, an HMI helps operators maintain situational awareness, make decisions, and control systems more efficiently and safely.
How is an HMI used?
An HMI is used to help people monitor, control, and interact with machines and automated systems. In industrial environments, operators can use HMIs to view real-time data, adjust system settings, monitor equipment status, and respond to alerts or faults. As systems become more automated, HMIs increasingly support supervisory tasks such as exception handling, decision-making, and visibility into automated processes. Well-designed HMIs can improve operational safety, efficiency, and ease of use across manufacturing and other industrial applications.
Why use real-time 3D for HMI?
The processes for creating HMIs are often disconnected and inefficient. Real-time 3D technology brings together disconnected processes to build a single HMI toolchain for design, prototyping, development, deployment, and beyond.
Advantages include:
- Accelerated user interface (UI) prototyping.
- Real-time 3D visualization.
- Performant and scalable graphics.
- Intuitive user interfaces.
- The ability to design, develop, and debug in real-time.
- Enables instant view of design changes for 2D and 3D content.
Which industries have established HMI programs?
Human-machine interfaces let people interact with the operations of a physical system and its data. HMI applications span many industries.
Here are a few of the most advanced:
- Automotive: Connects drivers and passengers to physical sensors, maps, and other infotainment experiences.
- Smart home and consumer electronics: Connects consumers to product data, workout routines, special offers, maintenance, and more.
- Industrial: Connects engineers and technicians to data on smart machines and process control programmable logic controller (PLC) systems.
Why does automotive lead in HMI?
HMI is used most heavily in the automotive industry, where the complexity and high price point of passenger vehicles created an early need for advanced interfaces. As embedded chipsets capable of advanced graphics have gotten cheaper, and consumer electronics outside automotive have gotten more complex, other industries are starting to catch up, building rich, interactive experiences similar to automotive HMIs.
Automotive HMI began with a simple goal: letting drivers input commands, whether by voice or by pressing buttons, and get feedback in return.
That purpose has since widened to cover:
- Consumer usability improvement: Provide access to the car's complex systems in a more natural and less intrusive manner.
- Advanced in-car infotainment experiences: Ensure drivers and passengers are included.
- Driver efficiency increase: Provide drivers with more information and control over their vehicles.
- Guided maintenance: Deliver important vehicle diagnostics information, enabling easier troubleshooting and maintenance.
- Advanced Driver Assistance Systems (ADAS): Build driver confidence with visualizations of the perceived surroundings and traffic situation, while communicating any limitations of those features as a cue for driver intervention.
What are the best practices for automotive HMI?
1. Set clear parameters
An effective HMI program starts with clear parameters:
- End user focus: Understand your end user's needs and goals first. This helps engineers and designers identify what functionality the HMI actually requires.
- System and physical specifications: Consider in-vehicle specifications that will impact HMI design, like screen size and cockpit layouts, as well as any limitations imposed by existing hardware or software. See how TomTom overcame hardware constraints to deliver real-time map rendering in vehicles.
- Brand experience: Align the HMI experience with the OEM brand to extend and reinforce how customers perceive it. Learn how Mercedes-Benz AG built an HMI that reflects their luxury brand values.
2. Connect processes with real-time 3D
Many existing HMI design workflows have real inefficiencies:
- Slow review cycles: Looping between designers, engineers, and manufacturers can take days or weeks across several design iterations.
- Limited interoperability: Teams often collaborate across multiple disconnected tools.
- Low concept-to-production rate: Only a small portion of design concepts make it to mass production, leaving finished HMIs feeling dated next to smartphone experiences.
A connected HMI toolchain built with real-time 3D fixes this end-to-end: teams collaborate more effectively, iterate faster, and see changes on target devices in real time, creating one consistent visual source of truth across every design and development stage.
3. Build a future-ready system
A key consideration when building an HMI toolchain is making sure it can scale for what comes next. Building in flexibility now makes future innovation easier and cheaper to implement:
- Mixed reality (MR) experiences: Keep the HMI system flexible enough to support a range of hardware and software combinations.
- Monetizing consumer applications: Offering consumers the option to customize in-vehicle applications is a potential future revenue source.
- Updating deployed applications: The ability to update deployed HMI software "over the air" gives manufacturers control without needing to outsource.
Discover how Volkswagen Group of America is using Unity to create immersive content for future vehicle human-machine interfaces, going beyond the center console screen and into instrument clusters and head-up displays (HUDs).
What are the benefits of gaming technology for HMI?
Rapid iteration
Much like video games, HMIs are interactive experiences: they display a system's current state through unique visualizations and need to respond quickly to user input, and like games, they're often custom-built for a specific product.
Iterating on the whole HMI product from the beginning matters, because industries like automotive typically specify components early, then rely on a network of suppliers and in-house teams to build the final product. In a conventional waterfall process, any change means revising specifications, rebuilding prototypes, and redoing the implementation.
Using gaming technology like real-time 3D instead lets every team, from design to prototyping to implementation, work with the same tools. Even with the extensive QA and validation industrial products require, this integrated approach still meets those requirements more efficiently. See it in action.
Graphics optimization
Graphics pipelines for HMI differ from those built for games:
- Games move through a world where the camera looks at different things. Features like culling render only what's currently visible to the player.
- HMIs don't need culling, since the system's current state already determines what information the display requires.
Instead, HMI graphics rely on customized texture atlases and shaders that minimize shader switches, texture switches, and draw calls, delivering the optimized performance that smaller HMI chipsets need.
Reliable display of safety-critical data
Most embedded automotive systems must show safety-critical content on the HMI display. Rendering technology built for HMI recognizes that content and exports it separately from non-safety-critical data, so the experience can be both visually dynamic and reliably clear about safety information, using methods like colored icons.
Frequently asked questions (FAQ)
What is the difference between HMI and GUI?
A GUI (graphical user interface) is the visual layer, made of screens, buttons, and menus. An HMI is the broader system that connects a person to a machine, and often uses a GUI as part of how it displays information, but HMI can also include physical controls like buttons and switches that aren’t part of any GUI.
What is the difference between HMI and SCADA?
An HMI is the local operator interface for a single machine or process. SCADA is the larger system that collects data and coordinates control across many machines or an entire facility. An HMI is often one visible piece of a larger SCADA system.