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China has become the world’s leading country in elevator production and sales, a testament to its rapid urbanization and high-rise building development. According to public data released by the State Administration for Market Regulation, the number of elevators in China reached a staggering 9.6446 million by the end of 2022. Elevators have become a major vertical transportation facility, significantly enhancing convenience in people’s daily lives. However, despite their widespread use, elevator cabs have raised safety concerns due to their enclosed nature, isolated from the outside world. Two primary issues have come to the forefront. Firstly, they present a risk of accidents, particularly for vulnerable individuals such as the elderly, the weak, the sick, or children, who may be at higher risk of falling when traveling alone in the elevator cab. Secondly, the confined space within elevators may offer opportunities for criminal activities, including robbery, kidnapping, violence, and other illicit acts.
In order to ensure a safe environment within elevator cabs, it is common practice to install cameras in the top corners to monitor passenger behavior. Currently, in most public places such as hotels, office buildings, hospitals, schools, and train stations, elevator monitoring still relies on manual surveillance. This traditional method has several issues and drawbacks. Firstly, if surveillance operators are tasked with monitoring multiple screens simultaneously, it can lead to fatigue and reduced attention spans. This makes it challenging to achieve 24/7 real-time monitoring, resulting in a potential loss of valuable information. Secondly, traditional monitoring systems merely record and save surveillance videos passively. In the event of an incident, operators must manually search through a massive amount of recorded footage to obtain evidence, which is a time-consuming process. Finally, abnormal behaviors in elevator cabs are relatively rare compared to the normal behaviors exhibited by passengers. If the surveillance system fails to respond to abnormal behaviors promptly and issue an alarm, it can lead to irreparable losses and pose a serious threat to social harmony and stability. Despite advancements in technology, video surveillance systems still rely on human operators due to the presence of false positives, which makes the task complex and challenging. As a result, there is a growing demand for intelligent and robust video surveillance systems capable of automatically detecting abnormal behaviors and raising alarms. In recent years, researchers have conducted extensive studies on various abnormal passenger behaviors in elevator cabs, including falling, jumping, fighting, and door jamming (Lan & Li, 2021; Liu et al., 2021; Roka et al., 2023; Shi et al., 2021; Shu et al., 2014a; Zhu & Wang., 2016). In this work, we aim to push the boundaries beyond conventional anomaly detection methods that merely distinguish abnormal behaviors from normal events.