Comparative Study and Improvement of Methods of Compensating the Influence of Backlash in Kinematic Transmissions of Electromechanical Tracking Systems

We have indicated the major shortcomings of existing methods of compensating the influence of mechanical backlash on the work of kinematically rigid single-channel electric drive systems fulfilling position and tracking control of production machines. A detailed analysis has been conducted regarding solutions to the problem of the influence of backlash based on using a variable structure position controller, and an alternative approach, implementing the replacement of operating unit position feedback with feedback for angular displacement of the electric motor shaft at the moments of gap opening. In both cases, the control systems were supplemented with stabilizing feedback for the difference in angular displacement of the electric motor shaft and operating unit. It has been established that the advantage of the second approach lies in lower sensitivity of the system to tuning the backlash monitor to the actual gap size in the kinematic transmission. Increased accuracy of operating unit motion in the final tracking stage and in positioning mode for both system versions may be achieved by introducing additional switching elements ensuring forced switching of the integrator in the structure of the position controller in the first control system version, or feedback for the position of the operating unit in the second version. The high efficiency of the systems of controlling tracking electric drive under review is confirmed by the results of mathematical simulation using Matlab software and field tests on a multifunctional experimental stand.