The procedure of parameters identification of DC motor model using a method of recursive least squares is described in this paper. To identify the system an experimental measuring of signals was carrying out at input - supply of voltage and output of the system for identification - motor angle speed. For the needs of the experiment, a system has been configured with a motor and an optical encoder whose output is connected with the counter input of acquisition card LCK-6013 which over a block connector CB-68LP makes a connection with a computer. The speed of the motor measured by optical encoder is compared with the speed of identified system in order to confirm the quality of the motor model?s parameters estimation.

Liquid-level control in tanks is widely used in various industrial sectors. Due to problems arising from the case that the liquid level is above or below the recommended, the process of its control is of great significance. The proportional integral differential (PID) controller is one of the most widely used controllers in applications that require accuracy and optimal automatic control. In this paper, single and coupled ship fuel tank systems are discussed. In addition, mathematical models and their linearization using two different approaches are presented. The two control approaches are used to maintain the specified liquid level in tanks. The first is based on the design of standard PID controllers, with the application of the Ziegler–Nichols, Takahashi tuning, and Auto-tuning methods. The second approach, proposed by the authors, is based on the application of the Dahlin algorithm. The simple modification of the Dahlin controller, which can avoid the “ringing” of the control signal, is suggested in the paper. Moreover, the lower limit of the decrease in the desired time constant, which ensures the desired behavior of the system, is determined. The comparisons provided for different performance indexes show the advantages of the modified Dahlin algorithm approach compared to the standard PID controllers. Furthermore, the comparison with the literature-known approaches is realized.

A major concern in many electrical drives is the reliability of sensors and actuators. In the paper, the usage of the Drools expert system (ES) for Fault detection and isolation (FDI) of the additive actuator and sensor DC Motor faults using the Structured residuals design technique (SRDT) is presented. The SRDT is used to obtain essential knowledge about the system. Afterward, an expert system that can isolate faults based on the developed structure matrix and generated residuals is designed. Accordingly, following the structure matrix each residual becomes able to answer to a desired subset of faults and stands insensitive to the others. The proposed method is successfully applied in an analyzed laboratory system and can be used for online FDI.