Abstract
Faced with urban labor shortages and 24/7 operational demands, self-service terminals are evolving from simple mechanical vending machines into intelligent, interactive systems. A key challenge is achieving precise perception of transactions, user behavior, and product status in unattended environments. This study explores the integration of a camera module with a 230° ultra-wide-angle lens and short focal length into next-generation smart vending systems. This design allows full coverage of the terminal's interaction area using a single visual sensor, enhancing operational efficiency and data-driven capabilities across payment verification, user interaction, inventory monitoring, and analytics.
1. Perception Challenges and Technical Requirements of Smart Self-Service Terminals
Modern vending machines are no longer just product dispensers-they also perform functions such as user identification, payment verification, consumption behavior analysis, and real-time inventory management. These functions rely on accurate perception of the surrounding environment and user actions.
Traditional cameras with limited fields of view often fail to capture all key areas simultaneously, such as facial recognition at the screen, motion at the retrieval port, and anomalies in the surrounding space. To overcome this, operators typically deploy multiple cameras, which increases costs, complexity, and challenges for data fusion and maintenance.
Therefore, there is an urgent need for a single-point visual module capable of wide-area coverage while maintaining close-range imaging clarity, enabling higher intelligence and operational reliability in self-service terminals.
2. Technical Features of the Imaging Module and Suitability for Retail Scenarios
The imaging module selected in this study addresses these challenges through innovative optical design:
Ultra-Wide Field of View: A 1.44mm short focal length fixed-focus lens provides up to 230° horizontal coverage. When mounted on top of a vending machine, it captures the full user interaction process-from approach to screen operation to item retrieval-without additional cameras.
High Imaging Clarity: Equipped with a high-performance sensor, the module offers sufficient effective pixels and dynamic range for retail environments.
Flexible Focus Range: The 30cm minimum focus allows clear capture of QR codes and retrieval ports, while infinity focus ensures effective tracking of approaching users.
Controlled Distortion: At 19.2%, distortion is manageable and correctable via software for applications requiring geometric accuracy, such as facial recognition.
Compact Design: Features an M12x0.5P threaded interface, steel base, and flexible PCB for quick installation and adaptation to limited wiring spaces.
Embedded Platform Compatibility: Standardized interfaces and low power consumption allow integration with industrial motherboards, IoT payment modules, and MIPI CSI-2 camera module systems, making it suitable for android camera borescope devices, endoscope USB cameras, and camera module boards.
3. Operational Enhancement Through Module Integration
Integration of the ultra-wide-angle module provides measurable benefits across multiple dimensions:
Transaction Security and User Identification: Facial recognition and QR code capture occur in real time, while the wide-angle view monitors peripheral areas for suspicious activity.
User Experience Optimization: Video analysis of dwell time, interaction sequences, and gaze focus informs interface design and product placement improvements.
Operational Maintenance and Analytics: Continuous monitoring enables real-time detection of stock shortages, jams, and usage patterns. Data collected over time informs predictive inventory management, marketing strategies, and dynamic pricing decisions.
The module's industrial-grade design ensures reliable 24/7 operation even in outdoor environments, while prototyping is facilitated through compatibility with the best Raspberry Pi camera module form factor.
4. Conclusion
Integrating a short focal length, ultra-wide-angle camera into smart vending terminals significantly enhances multi-dimensional perception capabilities using a single sensor. This solution balances transaction security, user experience optimization, and data-driven operational management, meeting the requirements of modern urban self-service systems.
Such advancements in visual perception technology are transforming retail terminals from passive transaction points into intelligent data portals connecting users, products, and operators, driving more proactive and refined self-service models.
