In-cabin Monitoring System (IMS)

In-cabin Monitoring System (IMS)

The In-cabin Monitoring System (IMS) is an umbrella term for the comprehensive visual perception suite within an intelligent vehicle cabin, primarily comprising two core modules: the Driver Monitoring System (DMS) and the Occupant Monitoring System (OMS). Through an in-cabin network of cameras and sensors, the IMS captures real-time biometric and behavioural data from vehicle occupants. Processed via AI algorithms, it delivers safety alerts, driver authentication, and personalised interaction—serving as vital perception-layer infrastructure as intelligent cockpits evolve from "passive response" to "proactive care".

System Architecture and Working Principle

The IMS architecture comprises three core stages: perception, decision-making, and execution. At the perception end, cameras serve as primary sensors, typically utilising Near-Infrared (NIR) technology to guarantee image clarity at night and in low-light environments. Higher-spec setups also incorporate 60GHz millimetre-wave (mmWave) radar to complement visual cameras, eliminating blind spots caused by physical obstructions or privacy partitions. Captured footage is decoded by automotive-grade processing chips, with deep learning algorithms extracting facial features, gaze direction, and physical movements to deliver driver feedback via audio-visual alerts or seatbelt vibrations through the in-vehicle infotainment (IVI) system.

Driver Monitoring System (DMS)

The DMS is the most critical safety-centric module in the IMS ecosystem, focusing on three key areas: fatigue detection, distraction monitoring, and hazardous driving behaviour recognition. Fatigue monitoring assesses drowsiness levels by tracking eye-closure duration and yawning frequency alongside total driving time; distraction monitoring detects whether the driver's focus has wandered from the road by analysing gaze direction and head angle; hazardous behaviour detection identifies high-risk actions such as smoking, using a mobile phone, or eating while driving. With studies indicating that over 60% of road accidents stem from driver distraction or drowsiness, DMS has become a pivotal assessment criterion in Euro NCAP safety ratings, prompting the European Union to mandate DMS on all new vehicles starting July 2022.

Occupant Monitoring System (OMS)

The OMS extends monitoring coverage across all passengers, serving the twin roles of cabin safety and personalised convenience. On the safety front, the OMS detects unfastened rear seatbelts, recognises unattended children or pets left inside the cabin, and triggers emergency alerts when needed. In terms of user interaction, the system analyses passenger demographics and moods to automatically tailor seat positions, climate control, ambient lighting, and multimedia playback for a bespoke in-cabin experience. Selected systems also integrate gesture controls, enabling occupants to operate power windows, audio systems, and other cabin features with simple hand movements.

Extended Features and Industry Trends

The scope of IMS has expanded beyond standard DMS and OMS into advanced capabilities such as facial recognition (Face ID), gaze tracking, lip reading, liveness detection, and vital signs monitoring. Facial recognition enables driver authentication and cloud profile synchronisation, allowing the vehicle to automatically configure seat positions, wing mirrors, and drive modes to suit the specific driver. With cockpit domain controllers boasting higher computing performance, IMS is shifting from standalone ECU hardware towards integrated software-defined architectures within central domain controllers, whilst camera-plus-mmWave radar fusion is emerging as the preferred setup to mitigate camera-related privacy concerns.

When operating IMS features, captured facial imagery and behavioural patterns constitute sensitive biometric data. Industry-standard solutions adopt edge-based on-vehicle processing, whereby all raw footage and data are wiped immediately after local computation within the cockpit domain controller, transmitting only final execution commands so that sensitive data never leaves the vehicle. Without explicit user consent, uploading IMS visual data to cloud servers or using it for commercial analysis is strictly prohibited, safeguarding user privacy directly by design.