Optimization of Combined Electric Motor Drive Control when Load Changes as a Function of the Position of the Working Element
The choice of the electric drive control system is provided by various destabilizing factors due to the nonlinear characteristics of the controlled converters and electric machines, limited manufacturing accuracy and final stiffness of the elements of the kinematic circuits, the complex nature of technological processes as well as incomplete a priori information about the parameters and properties of the control object. In this regard, in most cases it is impossible to achieve the desired results using classical synthesis methods to build control systems for complex technical objects. In each case, a special approach is required to avoid a detailed analysis of the whole spectrum of destabilizing factors acting on the system, all the variety of which can be divided into parametric (internal) and coordinate (external) disturbances. The most complex electromechanical systems are multi-motor technologically interconnected electric drives. Such systems are used at the enterprises of a number of industries (metallurgical, mining, construction, printing, etc.) in the form of transport units in which the electric motors are mechanically connected through the processed product or transmission due to the friction forces of the driving moments to the general elastic traction body. In the first case, the control system is required to ensure the adjustable tension of the belt, in the second one, the drives must maintain optimal relations between the oncoming and escaping branches of the traction body. The article presents the results of studies of optimal control systems of positional electric drive. As a basic device in the combined control system, a multi-channel master model can be used, which forms the master actions that change in time in proportion to the desired change in the controlled coordinates and compensates for the tracking error. If, in addition to the master model, the monitoring unit is used to monitor the compliance of the actual mode with the specified one, the control system will have two degrees of freedom and, therefore, the accuracy of the specified mode will increase.