Designing Digital Controllers using a Lag-Lead Compensator and Implementation using FIR Filters

Writer/Researcher : Ferry Rippun Gideon Manalu

Area of Research : Elektronika

Journal : Jurnal Elektro

Volume : 2, No. 1

Year : 2009

Plant is a set of device with certain characteristics, working to execute an operation. Each plant has its own characteristics. Sometimes a plant must operate with certain desired characteristics, therefore a controller is needed to manage it. There are two kinds of controller, an analog controller or digital controller. This paper will discuss a plant (machine tools) which is controlled by a digital controller and is implemented using FIR (Finite Impulse Response) filter. Desired specifications are: a system that can work with maximum overshoot (OS) < 16%, time settling (ts) <12s with step function input, and error steady state (ess)=1 with ramp function input. A digital controller design using Lag-Lead compensator showed the results OS =11,8% and ts=11s with step function input and ess=1 with ramp function input. Implementation using FIR 16 filter didn’t give the same response due to a number of delay problems and rounding off in FIR system.

Keywords: digital filter, fir filter, lag-lead compensator