EEC 602 Automation and Control Exam 2022

About this paper

EEC 602: A 6-page Written Examination for Automation and Control (EEC602), University of Buea, Semester Two 2021/22, Course Leader Dr. Jules Simo, July 2022, 2 hours (answer 2 of 3 questions). Question 1: an antenna azimuth position control system (block diagram with preamplifier/power amplifier/motor-load/gear blocks, Table Q1 parameters) -- deriving the open-loop transfer function and its gain/phase as functions of frequency, computing error constants Kp/Kv, and a full frequency-response lag-compensator design (required Kv and pre-amplifier gain for five-fold steady-state error improvement, damping ratio and phase margin for 20% overshoot, the compensator design frequency and magnitude from a Bode plot, and the lag compensator's break frequencies and transfer function). Question 2: PD-controller design for a motor Gm=25/[s(s+1)] to meet 10% overshoot and 0.5s settling time -- damping ratio/natural frequency and desired pole locations, a root-locus block diagram and sketch, angle/magnitude criterion for the PD zero location and gain, the compensated closed-loop transfer function and pole verification, position/velocity error constants comparison, and an explanation of why a simulated step response does not meet the design specification (nearby closed-loop zero effect). Question 3: state-space control of an inverted pendulum and servo system (given A, B matrices) -- the Lagrangian method's advantages, stability/controllability from a pole-zero map and controllability-matrix rank, companion matrices, pole placement to meet a damping ratio/natural-frequency specification with two additional fixed poles, companion-form state-feedback gains, and an explanation of excessive control effort with proposed remedies. Appendices: rules for plotting root loci, miscellaneous control-system formulae, and a table of Laplace-transform pairs.