I. Implementation Key Points and Optimization Strategies
(a) Installation and Calibration
1. Installation accuracy: The sensor mounting bracket must have a horizontal/vertical accuracy of ≤0.5° to avoid measurement errors caused by installation tilt; the perpendicularity of the sensor to the empty box conveyor line should be calibrated using a laser level.
2. Reference Calibration: In the empty box measurement area, place a standard-sized empty box (such as a 1AAA type empty box for calibration), collect the reference distance value of the sensor, and establish a "standard size - measurement distance" mapping relationship for subsequent measurement data compensation and correction.
(II) Anti-interference optimization
1. Ambient light filtering: A narrow-band filter (allowing only 905nm laser light to pass through) is installed on the sensor lens to reduce interference from reflected light from the terminal building's glass curtain wall and strong light from nighttime lighting.
2. Dust protection: The sensors in the loading and unloading area and baggage sorting area are equipped with compressed air blowing devices (which automatically blow the lenses every 5 minutes), and together with the IP67 protection-rated sensors, they can resist dust and water vapor corrosion.
(III) Data Fusion and System Integration
1. Multi-sensor fusion: Integrate ToF sensor data with the airport baggage handling system (BHS) and AGV scheduling system to achieve real-time sharing of empty container measurement data. For example, abnormal empty container size information can directly trigger the empty container sorting process of BHS.
2. Point cloud data application: For stacking monitoring and complex posture recognition scenarios, the point cloud data collected by the ToF sensor array is processed by the PCL (point cloud library) algorithm to generate an empty box 3D model to assist in the decision-making of automated equipment.
II. Typical Application Scenarios – Automated Loading and Unloading of Empty Cargo Containers at Airports
At the airport cargo terminal, empty containers are transported to the loading and unloading area via AGVs:
1. Entry verification: The ToF sensor array measures the size of the empty box to determine whether it is qualified; if the empty box is unqualified, the AGV branch line is triggered to transport it to the maintenance area.
2. Loading and unloading alignment: Sensors identify the position and tilt angle of the empty box on the AGV, guiding the robotic arm to accurately grasp it with a grasping error of ≤±5mm.
3. Stacking storage: Sensors in the storage area monitor the stacking height and outline, plan the optimal storage path for AGVs, and increase storage density by more than 20%.
Time-of-flight (ToF) laser rangefinders provide an efficient and accurate non-contact solution for empty container measurement at airports, meeting the stringent requirements of airports for container cleanliness, dynamic monitoring, and interference resistance. By strategically deploying sensors and integrating multi-dimensional data, they can cover the entire process, including empty container size verification, stacking monitoring, and automated loading and unloading alignment, thus facilitating the intelligent upgrade of airport logistics. With the iteration of ToF technology (such as the application of solid-state LiDAR), the accuracy and integration of ToF sensors in airport empty container measurement will be further improved in the future, propelling airport cargo efficiency to new heights.
