## 1 Introduction  
With the accelerated process of modernization and construction, there is an increasing demand for various large-scale engineering construction tools [1]. In the construction process, which is affected by the complexity and variability of working conditions, frequent load changes, and other factors, construction machinery is often in a high-load operation state [2, 3]. Therefore, it is necessary to ensure that the construction machinery is well lubricated and is reliable to ensure its regular operation [4]. In recent years, with the development of artificial intelligence, the internet, and other technologies, the manufacturing industry has been gradually changing in the direction of intelligence [5, 6]. Construction machinery is essential to modern manufacturing, and its intelligent development is also attracting attention [7]. In the use of construction machinery, the lubrication system is one of its core components. Before the advent of intelligent lubrication, the lubrication field used three traditional lubricants, namely, single-wire progressive lubrication, double-wire and multi-wire lubrication, and double-wire and multi-wire hybrid lubrication. The traditional lubrication systems for construction machinery, with their increasingly obvious shortcomings, have not been able to meet the lubrication needs of modern construction machinery [8, 9]. Therefore, intelligent lubrication systems came into being, which combine hydraulic technology, sensor technology, numerical control technology, other technologies, a high degree of intelligence in the control system, monitoring, and detection, and strong human-computer interaction, and they can realize multi-point simultaneous lubrication and can control the amount of oil supplied [10; 11; 12; 13]. Intelligent lubrication systems are further developments in lubrication system intelligence and information technology, and the features of smart lubrication system mainly include the following: all lubrication points are maintained in a completely isolated state without any interference from external factors, and even if one lubrication point is blocked, the other lubrication points are not affected. Each lubrication point independently detects the grease displacement and can immediately reflect the lubrication point failure to the control cabinet. The independent detection of the grease displacement at each lubrication point can relay the lubrication point failure immediately to the control cabinet and directly to the central controller. The real-time monitoring of the lubricant supply, better control of the lubricant spraying volume, and the prevention of lubricant waste can be achieved. With the visualization of the monitoring interface, the user can adjust the cycle time and lubricant supply volume at each lubrication point according to the demand, and the same lubrication system can be adjusted on a large scale. However, in the use of construction machinery, friction-versus-material characteristics, environmental temperature changes, load conditions, and other factors will have an impact on the performance of the intelligent lubrication system [14; 15], so it is crucial to evaluate the performance of the intelligent lubrication system, not only to repair the system in advance of potential failures but also to greatly improve the lubrication effect. Both domestic and foreign research have been carried out on intelligent lubrication systems. For example, as early as 1997, [PERSON] et al. developed an automatic lubrication system for mining machinery that could detect the system function signal and automatically perform the lubrication system function, improving the efficiency of the mechanical equipment [16]. The centralized lubrication system developed by Germany's Fukuo Bird Vogel Company significantly improves upon the inadequacy of traditional manual lubrication, saving on lubricant by up to 80% and providing a more convenient service for users [17].