Urban utility tunnels, buried deep beneath the surface, serve as the hidden infrastructure that sustains the city’s supply of water, electricity, gas, and telecommunications. The tunnel interiors are narrow, elongated, and enclosed, with a combination of moisture, dust, and electromagnetic interference; pipeline hazards are often concealed and difficult to detect. Manual inspections conducted by personnel descending into the tunnels are not only inefficient but also expose workers to constant safety risks. Rail‑mounted inspection robots represent the key enabler for intelligent operation and maintenance of these tunnels. Whether such robots can accurately identify potential hazards and reliably perform inspection tasks depends on the performance of their visual acquisition and signal control modules. The Kaimorui KC9236M integrated core paired with HK-100 a comprehensive solution for the network control board establishes a perception and control link for the rail mounted inspection robot in utility tunnels, enabling it to handle the complex conditions of underground corridors and perform autonomous, round the clock inspections and monitoring.

I.36 Optical zoom mechanism, compatible with corridor type patrol scenarios featuring variable lighting conditions.

Underground utility tunnels lack a constant light source, with some areas plunged into complete darkness, while others suffer from intense glare and reflections, posing severe challenges to the imaging performance of camera modules. The KC9236M is a 2-megapixel all-in-one camera module equipped with a 1/2.8-inch CMOS sensor, supporting 36× optical zoom and covering a focal length range of 5.9–217.4 mm.-212.4mm, field-of-view angle range 59.8°-2.3°. When the robot travels at a constant speed along the track, its wide-angle lens captures the macroscopic environment of the entire corridor, while the telephoto lens can zoom in to focus on minute fault points such as pipeline welds, instrument scale markings, and damage to the anti-corrosion coating.

For the low light conditions typical of utility tunnels, the camera delivers color sensitivity of 0.05 lux and black and white sensitivity of 0.01 lux, paired with an ICR infrared filter that switches automatically, 120 dB wide dynamic range, and 3D digital noise reduction to balance contrast and suppress image noise. A built-in gyroscopic image stabilizer counteracts vibrations from rail mounted movement, ensuring clear, stable footage during mobile inspections. H.265 high efficiency encoding significantly compresses the video stream, adapting to the limited network bandwidth of utility tunnels and enabling continuous, reliable transmission of high definition video to the operations and maintenance platform.

II.Built-in AI-powered intelligent detection shifts from passive recording to proactive early warning for utility tunnels.

Traditional inspections rely solely on post event video review, leading to delayed detection of potential hazards and a high risk of missing critical response windows. The KC9236M is equipped with deep learning AI algorithms and integrates multiple intelligent analytics functions, including area intrusion detection, line crossing detection, abandoned object detection, and loitering detection. When unauthorized personnel enter the tunnel’s controlled zone, debris is left behind in the corridor, or individuals remain in the area for an extended period—triggering any of these abnormal events—the device performs on site recognition and immediately activates an alarm.

It simultaneously supports facial capture and video obstruction detection, enabling the registration of certified maintenance personnel within the tunnel to standardize on-site operations, while also monitoring for lens dust accumulation and foreign object obstructions to prevent inspection blind spots. This intelligent recognition capability transforms the rail mounted inspection robot from a mere mobile camera into an autonomous risk assessment sensing terminal, proactively advancing safety management in utility tunnels.

III.HK-100 Network control board, serving as a communication bridge between the movement and the robot’s main controller.

High-performance movement requires a reliable and stable signal transmission medium to unleash its full potential, HK-100 The network control board serves as the communication hub for the entire system. It utilizes military-grade PCB materials, offering resistance to humidity and electromagnetic interference, and is designed to withstand the harsh conditions of utility tunnels. With dimensions of 48×48 mm, the board features a compact form factor that fits the tight internal mounting space of rail mounted robots.

The board features a dedicated 36-pin camera interface, enabling direct connection to the KC9236M and supporting both VISCA and PELCO protocols-P/D Universal PTZ protocol, supports RS485 and RS232-TTL pass-through and multi-channel network output. The robot’s main controller sends commands such as zoom, focus adjustment, and day/night mode switching, which are transmitted via HK100 Fast forwarding execution enables synchronized, coordinated actions for robot locomotion, position adjustment, and image acquisition. Powered by 12V DC, it features a comprehensive interface layout and supports OEM and ODM custom development, allowing integrators to swiftly complete secondary system integration.

IV.A complete hardware solution has been implemented, meeting the integration requirements of the underground utility tunnel unmanned operation and maintenance project.

KC9236M movement and HK-100 The control board’s modular design is fully tailored to the implementation requirements of rail mounted inspection robot projects. The KC9236M features controllable power consumption, with a static power draw of 5 W and a dynamic draw of 7 W, and operates over a wide temperature range of –10°C to 60°C, making it well suited to accommodate diurnal temperature fluctuations in utility tunnels. It comes equipped with audio, alarm, and storage interfaces, supports local video recording via MicroSD card, and is compatible with ONVIF and SDK integrations, enabling seamless connectivity to existing tunnel management and maintenance platforms.

HK-100 Standard 38×38 mounting holes are provided, enabling clean wiring and simplifying the overall structural design. In addition to compatibility with the KC9236M, it also supports multiple domestically produced integrated control units, expanding options for project selection. With seamless software–hardware integration, the rail mounted robot can perform the entire workflow—image acquisition, intelligent analysis, command response, and alarm reporting—in a single pass during its reciprocating travel along the track, reducing the frequency of maintenance personnel access to the corridor and mitigating risks associated with high hazard operations.