Observation of weak synchronization in empirical elevator dynamics

Abstract

Oscillatory dynamics are ubiquitous in driven systems, but in real-world environments their regularity is often perturbed by time-dependent and stochastic inputs. Elevator systems provide a representative example of a nonautonomous oscillatory system under such external modulation. In this study, we analyze long-term measurements of two elevators operating in a multipurpose building. We developed a measurement system that records the elevator position and direction of motion over time and examined their relative dynamics using spatial-distane, correlation-based, and phase-based measures. The observed behavior varies across weekdays, weekends, and different parts of the observation period, reflecting nonstationary external driving associated with changing demand conditions. Although the motion shows mild variations in period and amplitude, the relative dynamics exhibit weak and intermittent coordination rather than a single persistent synchronized mode. These results suggest that real-world elevator systems can display nontrivial synchronization-like behavior under time-varying and noisy forcing, even far from the idealized conditions assumed in simple oscillator models.