An Experimental Method for Estimating Combined Friction Torque in Vane Type Pneumatic Semi Rotary Actuators

Abstract

In this paper, an experimental method is proposed for estimation of friction torque in vane type pneumatic semi rotary actuators. The friction is modelled in the form of fully combined Stribeck model since this combined friction model provides good solutions for precise control applications. The study aims estimating static friction torque, Coulomb friction torque, Stribeck speed and viscous friction&damping coefficient which is included in fully combined Stribeck model for both counterclockwise and clockwise directions of the rotary actuator since these unknown parameters show differences when direction of motion is altered. For that purpose, an experimental setup is designed which includes pressure sensors for measuring the chamber pressures of actuator, analogue potentiometer for reading angular position as well as speed of vane and Arduino microcontroller card for data acquisition. A proper MATLAB Simulink block diagram is prepared for the simultaneous estimation of processed data from experimental data. Nonlinear curve fitting operation is applied and the unknown friction parameters are estimated on the fitted curve easily.