2026 ECE 4550 — Control System Design Lab #8- Control of a Rocket-Like Balancing System Georgia institute of technology GEORGIA INSTITUTE OF TECHNOLOGY
SCHOOL of ELECTRICAL and COMPUTER ENGINEERING
ECE 4550 — Control System Design — Fall 2026 Lab #8: Control of a Rocket-Like Balancing System
Contents 1 Background 1 1.1 Plant Modeling............................................................................................................................2 1.2 Position Controller Design..........................................................................................................2 1.2.1 Estimator Design.............................................................................................................2 1.2.2 Regulator Design.............................................................................................................3 2 Lab Assignment 4 2.1 Pre-Lab Preparation....................................................................................................................4 2.2 Tasks............................................................................................................................................4 2.2.1 Response of Rocket to a Zero Reference Command....................................................6 2.2.2 Response of Rocket to a Step Reference Command.....................................................6
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Background
The requirement of balancing arises in many human activities, such as standing on two legs or one leg, walking or running on smooth or rough surfaces, ascending or descending stairs, riding a bicycle or unicycle, or riding a self-balancing vehicle with two wheels or one wheel. The objective of this lab project is to explore the modeling and control of a nonlinear motion system, where the goal is to balance a pendulum by rotating an arm on which it pivots freely. This topic is closely related to steering a rocket by orienting the thrust vector generated at its base, either during ascent or descent, such that the rocket body remains upright under the influence of gravity. The simplest versions of rocket-like balancing systems have two interconnected moving objects, such that the motion of the first object is actuated by a motor whereas the motion of the second object is merely induced by the motion of the first object. This type of mechanical system is said to be under-actuated, because only one actuator is present, and yet two objects experience motion. Two masses (or inertias) connected by a spring and damper, and driven by just one external force (or torque), are under-actuated systems that do not involve balancing. The feature of balancing is introduced only if the un-actuated object is a pendulum experiencing the influence of gravity. Two classic balancing systems have the actuated object experiencing either: • linear motion in the horizontal plane (as considered in lecture notes, the so-called “cart-pole” system where the pole is a pendulum); or • rotary motion in the horizontal plane (as considered in this lab project, the Quanser Motion System (QMS) with pendulum load attachment). These balancing systems cannot be stabilized using classical control concepts that rely on singleloop feedback with PD, PI, or PID compensation. On the other hand, these same balancing systems are readily stabilized using state-space control concepts, due to the appropriate number of available