Comparison of Motion Controllers for a Flexure-Based Precision Manipulator

For a flexure-based precision manipulator, four different feedback controllers (PID, H2, STSMC, and ADRC) are compared. Their performance in maintaining a non-equilibrium position for a system without friction is measured, for which H2 control is found to have the best standstill performance of 160 nm at the end-effector. These controllers are, furthermore, tested for their performance in tracking and disturbance rejection. For the tracking performance, different levels of feedforward based on the system’s dynamics are tested to give insight into the performance of the controllers. When all the system information is used H2 yields the best tracking results, otherwise PID outperforms the other controllers. For the disturbance rejection, PID or ADRC have the best performance.