How do tripod gates identify and prevent multiple people from consecutively passing through without tickets?
Publish Time: 2025-09-10
At crowded entrances and exits like scenic spots, subway stations, universities, and stadiums, the security and efficiency of ticket inspection systems are directly linked to venue management, order, and user experience. As one of the most widely used access control devices, tripod gates, with their simple structure, affordable cost, and strong durability, are widely used in various closed and semi-closed entrances and exits. However, traditional tripod gates have long faced a concern: how to effectively prevent "tailgating"—where one person swipes their card and multiple people continue to pass through, resulting in unauthorized entry without a ticket. With the advancement of intelligent security technology, tripod gates have achieved precise identification and effective interception of tailgating through the collaboration of multiple modules and upgraded intelligent algorithms.
Modern intelligent tripod gates typically integrate multiple high-density infrared sensors between the three-roller arm and the gate column. They typically employ a "transmitter-receiver" beam-based arrangement, forming one or more invisible beam barriers. When a passenger swipes their card or scans their QR code to pass through, the system activates pass mode, allowing the three-roller arm to rotate 90° or 120° to clear the person. During this process, the infrared system monitors the contours and movement trajectories of people in the passage in real time. If, after the first person passes, the system detects that subsequent body parts are blocking the infrared beam, it delays the lowering of the barrier. However, once the beam is restored, the pass is deemed complete, and the three-roller arm automatically locks or slowly resets, preventing a second person from passing without verification.
Simple physical sensing is insufficient to handle complex situations. For example, two people passing closely together, quickly colliding, or using objects to trigger sensors can still circumvent basic security measures. To this end, the new generation of tripod gates features a built-in intelligent control board and anti-tailgating algorithms. The system analyzes parameters such as the time difference between the card swipe signal and the infrared trigger, passage speed, and the changing curve of the obstructed area to establish a normal passage model. When detecting unusual patterns such as "multiple users per card," "rapid connection," or "unusually spaced passages," the system immediately identifies it as tailgating, triggering an audible and visual alarm and locking the three-roller arm until administrator intervention or a delayed reset.
3. Multimodal Authentication: Raising the Barrier to Entry
To eliminate card-swiping and card-hire transactions at the source, Hyundai Tripod Gate supports a combination of multiple identity verification methods. In addition to traditional IC/ID cards and QR codes, it can also optionally accept biometric identification or document verification devices such as facial recognition modules and ID card readers. When the system requires dual authentication (face + card swipe), even if someone is tailgating, the gate will not open due to a failure to pass facial recognition, thus completely blocking unauthorized passage. This combined authentication method significantly enhances tailgating prevention capabilities, especially in high-security scenarios such as university exams and corporate attendance management.
4. Mechanical Self-Lock and Damping: Physically Enhanced Interception Effectiveness
The mechanical structure of the Tripod Gate itself is also key to tailgating prevention. High-quality tripod gates utilize long-life bearings and a precision gear transmission system, coupled with electromagnetic braking or mechanical self-locking devices. Once a pass is completed, the three-roller arm quickly returns to the locked position under the action of springs or gravity, and provides a certain degree of damping to prevent forced movement. If anyone attempts to force their way through by ramming or pushing, the system detects abnormal torque or angle changes, immediately triggering an alarm and locking the mechanism. A log of the event is also uploaded to the backend management system.
5. Network Monitoring and Data Traceability
All access records (including normal access, tailgating attempts, and alarm events) are uploaded to a central management platform in real time via TCP/IP and RS485 interfaces. Administrators can monitor status on-site via a 7-inch high-definition LCD display and remotely access video footage and access logs for post-event tracking and analysis. The system supports integration with access control, time and attendance, and ticketing platforms for unified identity management and blacklist linkage, further enhancing overall security.
The tripod gate is no longer a simple mechanical barrier; it is an intelligent access control system that integrates infrared sensors, intelligent algorithms, multimodal recognition, and network management. Through infrared reset detection, anti-tailing algorithm, multiple verifications and mechanical self-locking, it can effectively identify and prevent multiple people from continuously passing through without tickets, thus ensuring the management order and safety of the entrances and exits.
