Modern diagnostics methods ensuring the safety of production and operation, as well as the improvement of functional characteristics of electromechanical systems’ are discussed, method of diagnostics according to the spectrum and hodograph of the engine’s equivalent current is presented. Functional concept is presented for the system of control, diagnostic and monitoring of technical condition of thermal control systems’ electromechanical part in the spacecraft. The decision-making and forecasting algorithm for the operational resource is based on ground-based studies and diagnostic results. This approach to device diagnostics and monitoring is also used in other servo drives, mechatronic and robotic systems of space vehicles and other objects that are inaccessible and left unattended. Hardware-algorithmic implementation of the system is described, recommendations on the components base selection are given.

The paper describes the design of a novel control law for step motor under participially unknown parameters and bounded external disturbances. The unknown parameters and disturbances are related to the motor torque, the rotor moment of inertia, the viscous friction, the resistance and the load torque. The design of a novel control law is based on feedback linearization and linear robust control. The gain of a linear control law is calculated by solving the linear matrix inequality and some optimization problems. The simulations illustrate the efficiency of the proposed scheme in comparison with classical PID-controller and adaptive control law.

The article gives a brief description of the electric pump unit of the satellite thermal control system as an electromechanical subsystem. General issues of development of diagnostics systems for electromechanical systems are considered. Defects of system parts and the reasons leading to failures of electromechanical units are determined. Using modern sources, an overview of methods and approaches to solving problems of diagnosing defects in the mechanical, electrical, and electromagnetic parts of the systems under study is presented. The advantages and disadvantages of modern approaches are noted. A diagnostic chart of prospective current diagnostics is shown. The paper gives an effectiveness assessment of various methods and practical recommendations for the use of the presented methods for the diagnostics system design for electric pump units of satellite systems. Promising areas of research in the field of diagnostics of electromechanical systems, such as the use of current methods or methods based on neural networks, have been identified.