IMPROVING THE ROBUSTNESS OF THE ELECTRIC DRIVE STATE OBSERVER

Abstract

The paper substantiates the feasibility of improving the adaptive state observer of surface-to-air missile systems guidance electric drives in order to ensure their effective operation in mode of exceeding the executive motor nominal rotation speed, as well as to increase the overall speed of the guidance system. The structure of the well-known adaptive state observer, implemented on the basis of Luenberger observers, which is used in electric drives of combat vehicles, is analyzed. A hypothesis is put forward regarding its potential unsuitability when the electric drive operates in the zone of increased speeds. The structure of the electric drive state observer is synthesized and modernized using the modal method, taking into account the nonlinear characteristic of the executive motor magnetization. This characteristic was previously linearized and presented in the form of a linear dependence of the EMF coefficient and torque on the excitation current. The influence of the parametric uncertainty of the direct current motor type D-135 on the operation of the basic observer structure as a part of the 9K35 surface-to-air missile guidance system was studied by simulation in the Matlab/Simulink environment. The results showed that such a structure demonstrates high robustness to deviations in the active resistance of the armature winding and the moment of inertia, while the error in estimating the rotational speed does not exceed 4%. At the same time, when the magnetic flux corresponding to the operation of the electric drive in the speed range higher than the nominal one decreases, a complete loss of the basic observer structure operability was detected. Numerical simulation of the operation of the improved state observer as part of the 9K35 surface-to-air missile guidance system was carried out. The simulation results confirmed its effectiveness and stable operation of the electric drive in both speed modes.