Determining the distance from aircraft when docking to passenger boarding bridges

Short description

To determine the position of an aircraft and the associated positioning of passenger boarding bridges, a laser measurement sensor is used as a basic component in an aircraft docking system.


FMT Aircraft Gate Support Systems AB, headquartered in Trelleborg, Sweden, develops and manufactures passenger boarding bridges for airports and harbors, visual docking guidance and information systems and apron management systems for airports around the world. FMT offers tailor-made solutions to improve safe, flexible and fast aircraft docking. Sales and product services are provided by the local subsidiaries and distribution partners worldwide.

FMT has developed a visual aircraft docking system that uses a display to guide an arriving aircraft to its parking position at the terminal. This display gives the pilot both information about the distance to the final stopping point as well as the message that he has to stop but also lateral direction instructions. The stand/flight number can also be displayed for the pilot. The distance between the aircraft and the stop position is measured and displayed to the pilot as visual information. One of the challenges in using laser light is to ensure that the laser has unlimited eye safety and is therefore harmless to the human eye. Another requirement is that the laser beam work reliably worldwide in all weather conditions like rain, sunshine, fog, and snow.


This application was implemented with a customized version of the time-of-flight laser measurement sensor LD-OEM. Vertical scans along the ideal approach line are used to measure the distance to the approaching aircraft. The LD-OEM communicates via a customized protocol with the computer of the FMT docking system and provides measured data based on distance and angle information. In the FMT computer, the specific aircraft data of the incoming aircraft type are stored in a database. The measured data are compared with those stored in the database, and the current distance to the stop position is shown on the display. The information presented on the docking system makes it possible for the pilot to dock safely and accurately, which saves fuel and time. In this way, the docking system can bring the aircraft precisely to the designated parking position to ensure the exact positioning of the passenger boarding bridges to the aircraft doors. The docking system sends the parking position of the aircraft to the passenger boarding bridge. The FMT docking system therefore significantly contributes to minimizing the turn-around time the aircraft spends at the stand, which has a positive impact on the profitability of both the airport and the airline.

Customer benefits

  • Non-contact, active measurement method
  • Adapted, customized data interface
  • Time-of-flight technology
  • Precise and reliable measurement even in low-visibility conditions

The standard laser measurement sensor LD-OEM adapted for this special application is an elementary component of FMT's aircraft docking system. Very intensive cooperation between FMT and SICK made it possible to successfully implement the customer-specific requirements in the development phase.

  • Following product families can be used
    Long-range laser technology for use in harsh industrial environments
    • Long sensing range even when detecting dark surfaces
    • Eye-safe laser technology
    • High angular resolution of up to 0.125 degrees
    • High level of immunity to solar radiation and other infrared light sources
    • Synchronous monitoring of up to four freely definable fields
    • Real-time output of measurement data via Ethernet interface
    • Gap-free scanning with uniform laser spot over the full 360-degree angle