Intelligent Proportional-Integral-Derivative Control-Based Modulating Functions for Laser Beam Pointing and Stabilization

This paper studies the problem of high-precision positioning of laser beams using an intelligent proportional-integral-derivative (i-PID) controller. The control problem addressed in laser beams aims at maintaining the position of the laser beam on a position sensing device under the effects of noise and active disturbances. The design of an i-PID control is based on the so-called ultralocal model. The i-PID controller has been implemented and validated on a real test bench. For the sake of enhancing the performance of the closed loop, it has been combined with a nonasymptotic and robust modulating function-based estimation method, which is used to estimate the unmodeled dynamics and disturbances. The proposed i-PID controller has shown good performance in handling the active disturbances and uncertainties present in the platform. A comparison to the classical PID and robust PID is also provided based on the experimental setup. Robustness tests are performed experimentally to show the effectiveness of the i-PID control.