Output feedback control for the driving cylinder of hydraulic support with error constraint

The position control of the driving cylinder of hydraulic support affects the straightness of the underground coal mining face, so this paper focuses on improving tracking performance of the driving cylinder system. Since only position signal of the system is measurable, a Levant differentiator is designed to estimate the velocity and acceleration of the driving cylinder system, which can reduce the effect of the measurement noise. Besides, the parameter changes, modelling errors and external disturbances are treated as a lumped disturbance, an extended disturbance observer is constructed to estimate the lumped disturbance and compensate for the proposed controller. Moreover, barrier Lyapunov function is introduced to limit the tracking error into a small set around zero, and then the stability of the close-loop system is proved. Both the performance of differentiator and disturbance observer is verified in simulation experiments in MATLAB/Simulink. Finally, an experiment rig for the driving cylinder system of hydraulic support is established and comparative experiments are carried out. The experiment results show that the proposed extended disturbance observer-based output feedback controller with error constraint has a satisfied effectiveness in improving tracking performance.