## 1 Introduction  
In the course of coal mine production, the working environment is highly variable, and the operating conditions of hydraulic supports are complex. The hydraulic supports are subjected to massive impact loads from coal and rock. Additionally, the presence of coal dust and coal mist pollution exacerbates the challenges of monitoring hydraulic supports. All these factors contribute to the frequent occurrence of failures at the hydraulic support lifting ports. Such failures can lead to the paralysis of the entire coal production system and pose a threat to the life safety of coal miners. The working condition of hydraulic supports directly impacts the safe production of the working face in the following aspects. On the one hand, it influences the mining progress, the initial bracing force and working resistance of the support, the management efficiency, and the normal movement of the working face [1; 2; 3]. On the other hand, the working resistance of hydraulic supports and the inclination of roof supports can indirectly reflect the stress field conditions of the working face, which has long been a focal point among mining professionals. Coal mining activities re-distribute the original stresses within the coal seam, and the alterations in the stress field directly trigger the generation of mine pressure in the working face [4; 5]. Therefore, comprehensively understanding the changes in the stress field of the working face is of great significance for ensuring the safety of mining personnel. The national energy technology development outline explicitly stipulates the realization of intelligent coal mining, the complete phasing out of backward production capacity, the integration of large and medium-sized coal mines, and the energetic implementation of comprehensive mechanization at the working face and intelligent mining technologies. Among these, the hydraulic support, as a crucial safety device at the working face, exerts a significant influence on the safety and intelligence of the fully mechanized mining face. Currently, the existing electro-hydraulic control systems for hydraulic supports are mainly limited to monitoring the column pressure and the displacement of hydraulic supports. As a result, they are unable to effectively, comprehensively, and accurately monitor the attitude of hydraulic supports. Consequently, there is a shortage of real-time and precise attitude-monitoring data for the intelligization of hydraulic supports. Moreover, for the intelligization of mining, a large number of sensors need to be deployed to monitor relevant information. Fiber Bragg Grating (FBG), serving as a passive sensitive element, represents an emerging technology in the realm of sensing and monitoring. It exhibits remarkable environmental adaptability, safety, reliability, and cost effectiveness. The working temperature range of FBG can span from\(-40\)\({}^{\circ}\)C to \(80\)\({}^{\circ}\)C, endowing it with enhanced adaptability to the harsh conditions underground in coal mines. FBG exploits the grating within to sense external temperature and strain variations. Subsequently, without relying on intermediate variables, it can directly correlate the measured external variables with the optical conductivity of the fiber core. Given that optical fibers possess advantages such as high security and high sensitivity, passive sensors fabricated from optical fibers hold distinct advantages when compared to electromagnetic sensors [6; 7]. Since the first implantation of optical fibers into special composites by NASA in 1980, this field has been continuously expanding, and the number of Special Issues on smart sensing materials and structures has gradually increased [8; 9; 10]. To date, distributed monitoring networks founded on fiber-optic grating sensors have emerged as a novel research domain [11; 12; 13]. Nevertheless, the currently available Fiber Bragg Grating (FBG) inclinometer products for hydraulic supports typically suffer from substantial size, intricate processing requirements, and high costs.