Nonlinear Control of Dual-Axis Platform

Improving control accuracy in robotic platforms remains a highly relevant challenge, particularly in the presence of mechanical nonlinearities. One of the most common issues is backlash, which causes deviations from a straight trajectory during motion, and adversely affects the overall stability and precision of the control system. ( Research purpose ) The objective of this study is to develop a control system for a dual-axis platform with two degrees of mobility that effectively recognizes and compensates for the mechanical backlash effects. To achieve this, a system was designed to ensure stable platform motion while minimizing the impact of backlash on trajectory accuracy. ( Materials and methods ) A mathematical model of the control system was developed, representing backlash as a hysteresis effect. Several backlash compensation methods were investigated. The implemented control algorithms included linear controllers such as the Proportional–Integral–Derivative (PID) controller and a phase-shift controller, as well as nonlinear algorithms based on fuzzy logic (Fuzzy Logic Controller). The system model and control algorithms were simulated using MATLAB and the Simulink library. ( Results and discussion ) Simulation results demonstrate that the proposed control methods effectively compensate for mechanical backlash, ensuring more stable and accurate platform motion. The effectiveness of these methods was confirmed under both idealized and real-world operating conditions. ( Conclusions ) The developed control system significantly improves platform accuracy and stability, broadening its applicability across a wide range of robotic applications.