Showing papers by "Anindita Sengupta published in 2020"
05 Mar 2020
TL;DR: This paper presents a multiloop approach to compute High-Order Repetitive Controllers (HORC) that results in delivering a robust performance in terms of stability and model uncertainty along with internal uncertainty and unstructured model uncertainty.
Abstract: Conventional repetitive controller has a prominent capability for tracking any periodic reference signal or attenuating periodically distributed signal due to its infinite dimensional property and the condition for that is the period of the periodic signal should be equal to the amount of delay in RC loop. But due to this infinite dimensional property, the practical system remains unstable in higher frequency range. Small changes in the frequency and phase of input signals results in instability. This paper presents a multiloop approach to compute High-Order Repetitive Controllers (HORC) that results in delivering a robust performance in terms of stability and model uncertainty along with internal uncertainty and unstructured model uncertainty. Here, the LTI system deals with multiplicative parametric uncertainty. A novel multiple loop structure is proposed to make the system robust enough to reject disturbance signal and stable in the presence of internal uncertainty and model uncertainty. The ability of disturbance rejection of the proposed HORC is performed through MATLAB simulation. A comparative study has been carried out among RC, FDRC and HORC.
1 citations
TL;DR: A new cascade model using fractional-order PIDs is presented, which gives improved responses for the first-order and second-order systems with time delay and its superiority over normal cascade.
Abstract: Industrial process control systems suffer from the overshoot problem. Designing the controller plant models by conventional Proportional Integral Derivative (PID) may increase the rise time, settling time and overshoot. Cascade control is a remedial measure undertaken to overcome these problems. In this paper, we present a new cascade model using fractional-order PIDs. The fractional-order cascade controller can be expressed by fractional-order differential equations. Different laws proposed in the field of fractional calculus form the theoretical part in evaluating the equations and designing the controllers. The new structure gives improved responses for the first-order and second-order systems with time delay. Better simulation results are obtained by introducing Smith predictor in primary and secondary loops. Detailed analyses have been done on the stability, performance criteria and disturbance rejection. The usefulness of this proposed cascade structure and its superiority over normal cascade are illustrated with examples.