Adaptive Joint Friction Estimation Model For Laboratory 2 DOF Double Dual Twin Rotor Aerodynamical Helicopter System

Abstract

Dual Twin Rotor Aero-dynamical Helicopter System (DTAHS) include nonlinearities due to frictions in the horizontal and vertical joints. In this study, an adaptive friction coefficients estimation model was developed to estimate the joint frictions of the Two DOF Double Dual Twin Rotor Aero-dynamical Helicopter System (TDDTRAHS) and compared with existing Linear and Non-Linear friction models. Joint accelerations of TDDTRAHS were classified into three different groups, for example low, medium and high. The adaptive friction coefficients were optimized based on this classification of acceleration. Based on the position RMSEs obtained from each joint friction model, the adaptive friction estimation method was much better than the existing friction estimation models in the literature. the joint frictions of the TDDTRAHS are estimated better using the Adaptive Non-Linear Friction Model (ANLFM). A robust mathematical model with ANLFM was developed for simulation and controller, which will be used in the inverse dynamic model for the PID controller. PID controllers designed based on the mathematical model with ANLFM. Accurate inverse model and the joint friction compensation improved PID controller performance for the TDDTRAHS.