Voice Assistant

Voice Assistant is one of the core human-machine interface (HMI) features in modern smart cockpits. It enables drivers and passengers to control vehicle functions via natural voice commands without operating screens or physical buttons, thereby enhancing driving safety and everyday convenience.

Working Principle

An in-vehicle voice assistant generally operates through a closed-loop "perception-cognition-expression" process:

1. Voice Wake-up and Signal Processing: Microphone arrays capture voice inputs, while beamforming technology isolates commands from either the driver or passenger seats. Advanced noise-cancelling algorithms simultaneously filter out ambient road and wind noise.

2. Automatic Speech Recognition (ASR): Converts captured analogue audio signals into digital text. Modern systems can accurately recognise regional accents, dialects, and continuous natural language phrasing (e.g., "I feel a bit cold").

3. Natural Language Understanding (NLU): The system deciphers the user's intent from the text (e.g., "navigate home") and extracts essential details (such as the home address).

4. Command Execution and Feedback: Generates operational instructions and routes them to the relevant Electronic Control Units (ECUs) (such as the air-conditioning or infotainment navigation), while providing real-time feedback via Text-to-Speech (TTS) technology.

Key Features

Voice assistants manage the majority of in-cabin controls beyond core driving operations:

• Vehicle Controls: Regulating air-con temperature, toggling air recirculation, operating power windows and the sunroof, as well as adjusting seat massage functions and ambient lighting colours.

• Navigation and Information: Setting destinations, locating nearby EV charging stations or petrol stations along the route, and retrieving live traffic updates or weather forecasts.

• Infotainment and Media: Playing specific tracks, switching radio stations, and adjusting volume or equaliser settings.

• Body Controls: Opening the boot, operating windscreen wipers, or power-folding the side mirrors (subject to hardware availability).

Mainstream Technologies and Emerging Trends

In-car voice assistants are shifting from "reactive systems" to "proactive AI companions", with key advancements including:

• Full-Scenario "See and Say": Any on-screen text or button displayed on the infotainment unit can be actuated directly by voice, removing the need to navigate through multi-tier menus.

• Large Language Model (LLM) Integration: Voice assistants powered by large models (such as DeepSeek) offer superior contextual understanding and reasoning, effortlessly handling complex multi-step prompts like "navigate to the office first, then find a coffee shop along the route".

• External Voice Control: Select models support exterior voice wake-up, allowing owners standing outside to open the boot or remotely park the car into tight bays via voice commands.

Notable Implementations

• Xiaomi SU7: Its intelligent voice system delivers ultra-responsive offline recognition, seamless activation without wake-up phrases, and multi-zone sound localisation, while integrating fully with the Xiao AI ecosystem for smart home control.

• XPENG: Renowned for its Full-Scenario Voice 2.0 system, offering lightning-fast response times, continuous multi-turn dialogue, and dedicated four-zone voice isolation across all seats.

• Mercedes-Benz MBUX: A pioneer in integrating ChatGPT into the cockpit, delivering more natural, human-like voice conversations capable of handling open-ended and nuanced queries.

Conclusion

Voice assistants have evolved into a standard interactive gateway in contemporary intelligent vehicles, transforming from basic voice-command tools into proactive virtual assistants. As AI large language models continue to integrate deeply with vehicle electronics, the intelligence and utility of in-car voice assistants will reach new heights.