Stable and Robust Alternating Current Power Source Control Technique Applied to Ultraprecision Machining of Aluminum Alloy Materials

Abstract

This paper develops a stable, robust control technique for AC power sources in ultraprecision machining of aluminum alloy materials that maintains low total harmonic distortion output-voltage and fast transient under uncertain interferences. The proposed control technique associates the properties of the finite-time variable structure controller (FTVSC) with the gray Bernoulli model (GBM). The FTVSC provides finite system state convergence time with non-singular advantages, which is different from the asymptotic convergence of the traditional variable structure controller in infinite time. However, once there is a highly uncertain disturbance, there will be chatter around FTVSC. The chatter produces high voltage harmonics in the AC power source output, which reduces the stability of ultraprecision machining of aluminum alloy materials. The GBM is used to eliminate the chatter and produce a high performance AC power source. Experimental results on a high-performance AC power source show that the proposed stable and robust control technique can result in high quality AC output voltage against system uncertainties. Since the proposed control technique is easier to implement than the existing control technique, and has high-precision tracking, fast convergence speed and efficient calculation, this paper will cause an interest in researchers of related aluminum alloy materials applications.