## 1 Introduction
### Background and Problem  
In the recycling industry, conveyor belt safety ensures optimal performance and workplace security. Conveyor belts are not just simple transport systems; in many industrial applications, such as BECS, they are integral to separating non-ferrous metals from other materials. The proper functioning of a conveyor belt in such systems directly impacts the accuracy of material separation, production efficiency, and operational costs. One of the most critical risks in barrier eddy current separator (BECS) systems is the accidental presence of ferromagnetic materials--such as iron--on the conveyor belt. These systems are designed to process non-ferromagnetic materials, and even a single iron-bearing object can disrupt the separation process, generate excessive friction, and create sparks when exposed to the magnetic drum. Figure 2 illustrates an actual instance of this hazard: a sizeable iron object mistakenly entered the system, becoming a hotspot of metallic concentration and posing a direct fire threat. This situation is hazardous as typical BECS systems lack automated mechanisms to detect and address such anomalies. Furthermore, since these machines often operate continuously, the magnetic drum accumulates significant heat over time, increasing the likelihood of fire. Combined with common issues, such as belt misalignment and surface wear, this creates a hazardous environment that threatens operational efficiency and technician safety [15; 16; 17; 18]. Implementing a robust temperature monitoring and anomaly detection system is beneficial and essential for maintaining system stability and preventing dangerous incidents. Ensuring conveyor belt safety extends beyond simple material transportation. In advanced recycling systems like barrier eddy current separators, the conveyor belt is a critical component of a complex sorting process, where any malfunction can impact the overall system's efficiency and precision. For instance, belt misalignment can lead to inaccurate material separation and increased waste generation [18; 19; 20; 21; 22]. Misalignment in a BECS systems does not merely threaten mechanical damage, such as belt wear or rupture. It also disrupts the material separation process itself. This is because the conveyor belt in this context is not a passive transport mechanism--it is one of the three core components of the BECS machine that actively contributes to the separation performance. Misalignment changes the material trajectory and alters the interaction timing between the materials and the rotating magnetic drum, reducing separation quality. There is no automated detection system for belt misalignment in BECS machines. Correction is done manually: if the deviation is visually noticed by technicians on site, they use two external metal levers connected to one of the conveyor rollers. As shown in Figure 3, these levers require considerable manual force and can only be adjusted while the system is actively running. This increases physical strain on technicians and often requires more than one person to realign the belt properly. This limitation highlights the urgent need for an intelligent misalignment detection and correction system to improve safety, reduce human intensity, and preserve separation efficiency. One of the significant challenges in recycling systems is the damage caused by sharp-edged materials [18; 20; 21; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34]. It is important to note that the performance of the magnetic drum is significantly more efficient when processing smooth and rounded materials. This is because the magnetic field calculations and interactions with such materials are more predictable and accurate. In contrast, sharp or angular fragments damage the conveyor belt and upstream equipment. It reduces the magnetic drum's separation accuracy, and the particles' trajectory, rotation, and magnetic response are more complex and less predictable.