Title :
Adaptive cascade controller applied to a hydraulic actuator
Author :
Cunha, Mauro A b
Author_Institution :
Pelotas Fed. Center for Technol. Educ., Praca Vinte de Setembro, Pelotas, Brazil
Abstract :
This work proposes a cascade controller for the trajectory tracking control of a hydraulic actuator. The hydraulic actuator is modeled as a forth order nonlinear system including the valve dynamics as a first order linear system. This mathematical model is interpreted as a mechanical subsystem (load and friction) driven by a hydraulic one (actuator and valve). From this interpretation, one proposes a cascade controller by combining two different control laws with parameters adaptation for each subsystem. By adapting the inverse of the hydraulic constants and by using a suitable Lyapunov function, the adapted parameters are not used in the denominator of the control and adaptation laws. The closed loop system stability is analyzed by Lyapunov´s direct method. Simulation results illustrate the main characteristics of the proposed controller.
Keywords :
Lyapunov methods; adaptive control; cascade control; hydraulic actuators; nonlinear systems; Lyapunov direct method; Lyapunov function; adaptive cascade controller; closed loop system stability; hydraulic actuator; linear system; nonlinear system; trajectory tracking control; valve dynamics; Adaptive control; Friction; Hydraulic actuators; Linear systems; Mathematical model; Nonlinear dynamical systems; Nonlinear systems; Programmable control; Trajectory; Valves;
Conference_Titel :
Control and Automation, 2005. ICCA '05. International Conference on
Print_ISBN :
0-7803-9137-3
DOI :
10.1109/ICCA.2005.1528192