Unstable first order time delay systems are frequently encountered in industrial applications, such as chemical plants, hydraulic processes, in satellite communications or economic systems, to name just a few. The control of such processes is a challenging issue. In this paper a filtered Smith Predictor control structure is used to compensate for the process time delays and to ensure the stability of the overall closed loop system. A simplified type of a fractional order PI controller is then designed to meet zero steady state error and an overshoot requirement. The tuning is based on the root locus analysis of the closed loop fractional order system. Simulation examples are provided to validate the proposed method and to demonstrate the efficiency of the proposed control method. Comparisons with two existing methods are included to highlight the possibility of using the proposed method as an alternative solution for controlling these types of processes.

不稳定的一阶时滞系统在工业应用中经常遇到，例如化工厂、液压过程、卫星通信或经济系统等。对此类过程的控制是一个具有挑战性的问题。本文采用滤波史密斯预测器控制结构来补偿过程时间延迟并确保整个闭环系统的稳定性。然后设计一种简化类型的分数阶 PI 控制器以满足零稳态误差和超调要求。整定基于闭环分数阶系统的根轨迹分析。提供仿真例子来验证所提出的方法并证明所提出的控制方法的效率。与两种现有方法的比较是为了强调使用所提出的方法作为控制这些类型过程的替代解决方案的可能性。