# MOIRA-UNIMORE Bearing Data Set for Independent Cart Systems
## 5 Experimental Data Acquisition  
The acquisition system for this study employs five accelerometers, comprising monoaxial and triaxial types, categorized into three groups according to the number of channels and the levels of sensitivity. A monoaxial accelerometer (Sensitivity S1), with a sensitivity of 100 mV/g, is mounted midway along the upper straight section of the system. This sensor is not directly attached to the guide rail; instead, it is mounted on an aluminum rod securely fastened to the guide rail. Two monoaxial accelerometers (Sensitivity S2), each with a sensitivity of 10 mV/g, are positioned midway along the upper and lower sections of the track. In addition, two triaxial accelerometers are mounted on the left and right curved modules, each channel offering a sensitivity of approximately 10 mV/g. These sensors are carefully mounted at important points along the track to capture vibration signals effectively. In addition to vibration data, system variables such as cart position, speed, following error, and set current are recorded for each cart, enriching the data set for advanced condition monitoring and fault diagnostics. Detailed specifications for these accelerometers can be found on the manufacturer's website using the part numbers provided in the system description section.  
The data acquisition strategy was carefully designed to collect complete data sets from an independent cart transport system operating under a variety of fault conditions, speed profiles, and cart configurations. The experiments were organized into two main categories: single-cart and three-cart fleet experiments. Each category was further divided into four distinct experimental types, covering variations in fault locations, fault orientations, fault severities, motion patterns, and operating speeds. These experimental classifications aimed to comprehensively capture the dynamic behavior of the system in various operational scenarios as illustrated in Figure 7. This structured approach ensures that the data accurately represent the interplay of system variables and fault characteristics in different configurations. The data were acquired at two cart speeds: 1000 mm/s and 2000 mm/s. The speed of 1000 mm/s was defined as the minimum speed at which vibration signals become clearly observable and measurable. Below this threshold, the vibration signals were found to be too weak or inconsistent for reliable analysis. The speed of 2000 mm/s was chosen, as it represents half of the system's maximum operational speed. This allows for a comparative analysis of how vibration signals change as the speed doubles, providing insights into the relationship between speed and vibration behavior. Both speeds are within the operational limits of the experimental setup, ensuring that the system can reliably achieve and maintain these speeds without compromising data quality or experimental integrity.  
Experiments were conducted both with and without bearing faults to ensure a comprehensive analysis. For small bearings, faults were always introduced on the top right bearing, and only one bearing was faulty at a time. Additionally, across all experiment types, either one of the top bearings or the bottom bearing carried an inner race (IR) or outer race (OR) fault, ensuring controlled and consistent fault conditions. The same cart was used for all tests, both in faulted and non-faulted conditions. To maintain experimental consistency, the same speed profile and program settings were applied for each type of experiment. The development of the test setup was an iterative process over several months, incorporating refinements such as improved fault injection techniques and data acquisition enhancements. These aspects are detailed in the experimental campaign section, which outlines the phases of data collection, improvements made, and the rationale behind the experimental design.