Vision-based container locking prevention system (CLPS)

System introduction
STS/RTG cranes and container trucks are the major handling machines in container terminal yard operations, and are also equipment prone to production safety accidents.During container unloading from trucks, one major safety hazard is that the container may be lifted together with the truck (or partially lifted) due to the truck’s twist locks not being fully unlocked, commonly known as a truck-lifting accident.Based on machine vision and artificial intelligence, this system adopts image object detection, visual target tracking and automatic control technologies to realize real-time detection and tracking of containers, trucks and other key objects. According to safety control strategies, it performs protective emergency stop control on the hoisting mechanism to prevent truck lifting, avoid production accidents and improve the safety of container handling.

Technical Specifications
• Operating temperature: -30°C ~ +60°C
• Humidity: 95% (non-condensing)
• Ingress protection: IP67 for outdoor use
• Prevention lifting height: 40 cm

System functions
• During container unloading at the container terminal, when the spreader is locked and lifts the container from the truck, the system detects the movement status of characteristic parts on the container and the truck in real time. If the truck is detected being lifted, the system immediately sends an anti-lifting protection command, and the PLC actively triggers an emergency stop of the spreader hoisting.
• After the system stops the spreader, the crane operator can only lower the spreader and is not allowed to hoist upward. Hoisting control is restored only after the spreader is lowered until the rope is slack and the container is seated. The truck driver may then unlock the twist locks and resume operation.
• The system is equipped with a function enable/disable selector switch on the crane operator console. When the switch is in the “OFF” position, the anti-lifting function is bypassed, and the spreader hoisting has no anti-truck-lifting protection.
• A single bypass button is provided on the crane operator console. When pressed, single bypass is activated and the system disables anti-lifting protection for the current unloading cycle. Protection is automatically restored after the current operation is completed and the truck leaves.
• A status indicator light is provided on the crane operator console.Indicator off: anti-lifting function bypassed.Indicator steady on: anti-lifting function active.Indicator flashing + buzzer alarm: truck lifting detected or system fault.