Design and Timing Characterization of a Custom Controlled Falling-Object Hazard System

This study presents the design and timing characterization of a custom object-dropping apparatus developed to simulate falling-object hazards in realistic environments. The system enables controlled release of objects at three spatial locations using Arduino-controlled servos, with timing governed by E-Prime and Chronos. Time-synchronization and variability was evaluated by quantifying trigger onset and drop latency using analog input and force plate measurements. Trigger onset delay and variability remained below 1 ms across locations, indicating reliable synchronization with external systems. Drop latency delay and variability differed across locations. The front position exhibited the longest drop latency (111.0 ± 17.8 ms), followed by the left (66.8 ± 4.8 ms) and right (62.2 ± 7.2 ms) positions. These findings highlight the time lag and variability of a custom object dropping apparatus for future falling-object hazard experiments.